total MMI 1

what strains of adenovirus are responsible for adenoviral pneumonia? What is the vaccine?

4,7,21. The vaccine is a live strain that is taken orally (very unique) and is only available to the military

prosthetic joints and cultures

5-7 cultures must be sent. If 3 are positive, the probability of infection is 95%, if only 2 are positive, it is 20%, 1 positive sample is 13%.

Bacteroides fragilis

a normal bacteria of the colon. Doesn't really cause infection, but if the colon is perforated, or the appendix ruptures, it can cause fluid to accumulate in the abdominal cavity.

bile solubility test

bacteria are placed in a solution with bile. A (+) test is if the bacteria is lysed by the bile. S pneumonia is soluble, while Strep viridans is (-), aka bile insoluble.

Q fever

caused by Coxiella burnetii, obligate intracellular, culture negative, spore former. Spores are released (usually from cattle or sheep) and can be inhaled. Q fever causes pneumonia, fever, cough. rare condition.

hand foot mouth disease

caused by Coxsackie A virus, a picornavirus (naked, ssRNA). Symptoms are fever, vesicular lesions/rash on the palms of the hand, soles of the feet, and inside the mouth. The mouth lesions are called herpangina.

Enterococcus (aka group D streptococci) faecalis, faecium

gram (+) cocci, not hemolytic, grow in bile and 6.5% NaCl. Normally present in the GI tract, can cause UTI, subacute endocarditis (following GI procedure.

Corynebacterium diphtheriae

gram (+) rod, aerobic.. Cause diphtheriae (pseudomembranous pharyngitis), which is a gray-white membrane near the tonsils. Like Pseudomonas, it uses exotoxin which inhibits protein synthesis via ADP ribosylation of EF-2 (elongation factor-2, causes elongation in protein synthesis). Acquires the toxin gene via bacteriophage. Grows on Tellurite agar. Toxoid vaccine prevents diphtheria.

S aureus

gram (+) rod, catalase (+), coagulase (+), capsule, causes skin infection and lung abscesses. Coagulase causes blood to clot. VF (virulence factor) is protein A, which binds to Fc region of IgG and prevents phagocytosis and complement activation. Can infect salivary gland (sialadenitis) if there is an obstructing stone.

Clostridium perfringens

gram (+) rod, obligate anaerobe, spore former, produces toxins. A cause of necrotizing fasciitis. Produces Alpha toxin, a lecithinase which breaks down tissues, RBC. Can also cause food poisoning/diarrhea.

Clostridium difficile

gram (+) rod, spore forming, obligate anaerobe. Causes pseudomembranous colitis in patients taking antibiotics. MC cause of nosocomial diarrhea. Produces Toxin A and Toxin B. Treat with metronidazole

Listeria monocytogenes

gram (+) rods, facultative anaerobes. Food borne illness that can be passed from mother to baby, doesn't occur in normal healthy folk. They have a unique motility; an end-over-end tumbling motion. They bind to/enter cell via internalins (thus evade phagocytosis), then moves from cell to cell via actin tails,without being outside of cells. Produces hemolysins such as Listeriolysin and phospholipase. The only gram (+) organism that produces endotoxin. Can cause meningitis, retardation or death in newborns.

exotoxins that increase intracellular cAMP levels

heat labile toxin of ETEC, Vibrio cholerae, Bacillus anthracis, Bordetella pertussis. The first three cause fluid secretion.

titers

indicate levels of a molecule or antigen that indicate an infection. Ex "elevated ASO titers are evidence of a group A beta-hemolytic streptococcal infection."

Chediak-Higashi syndrome

lysosomes in neutrophils can't bind with phagosomes, thus preventing elimination of phagocytized bacteria. This is due to microtubule dysfuction. Symptoms are recurrent pyogenic infections, giant granules in neutrophils, partial albinism,

pharyngitis

majority of causes are viral (same as rhinitis), some are bacterial. The MC bacterial is group A strep (S pyogenes). Symptoms are sore throat, difficulty swallowing, fever.

how many STDs can you have at once

many

neutrophil oxidative burst (DHR) assay

measures the ability of neutrophils to produce the H2O2 needed for killing phagocytized microbes. The cells are tested in vitro and must be alive

general purpose growth mediums

mediums that are designed to grow most organisms and do not contain growth inhibitors. ex. blood agar

differential growth mediums

mediums that distinguish a microorganism with a certain metabolic pathway. An observable change is made when that reaction takes place. ex, simmons citrate agar, which turns a pH indicator from green to blue when citrate is used as the sole carbon source

selective growth mediums

mediums that favor the growth of distinct groups of microorganisms while inhibiting others. ex. PEA agar, which contains phenylethyl alcohol which inhibits gram-negative microorganism

transformation and bacterial genes

taking up naked DNA from the environment, such as if other bacterial cells had been lysed.

taeniasis (cysticercosis)

tapeworms caused b y Taenia solium (pigs) or Taenia saginata (cows). They are proglottids (segmented, with each segment containing male and female organs) with a sucker and hooklets to attach to the intestine and form long (meters) worms. Diagnose by finding eggs/proglottids in poop, or serology.

Transduction

transfer of chromosomal DNA via phages (bacteria viruses). The excisions (DNA segments) from the bacteria that are added to the phage and given to other bacteria are transposons (also transferred via plasmids).

Protozoa CNS infections

Toxoplasma gondii, Naegleria fowleria, Trypanosoma brucei

causes of meningitis/encephalitis/abscesses in AIDS patients

#1 is Cryptococcus (meningitis), #2 is toxoplasmosis (abscesses, classically shows a ring enhance lesion). #3 JC virus (PML), #4 CMV

Normal CD4 counts, normal ration of CD4 to CD8 cells.

1000 is normal CD4 count, normal ration is 2:1. A decreased ration can indicate AIDS.

Rubella virus.

+ss RNA virus, enveloped, from Togavirus, requires . When the virus replicates they take the host membrane as their envelope, except the host membrane now has viral proteins in it; thus the virus doesn't lyse the cell because it needs the host cell membrane. Infected mothers can cause teratogenic effects (congenital defects) in babies such as cataracts, deafness, mental retardation, "blueberry muffin" rash. The defects are due to the the virus inserting itself into host cell DNA, not just using host machinery. No treatment, only vaccination.

polio virus

+ss RNA virus, picornavirus. A type of enterovirus. It destroys the lower motor neurons in the anterior horn of the spinal cord. Causes asymmetrical muscle weakness and atrophy, sensation is undisturbed.

RSV (respiratory syncytial virus)

- SS RNA virus, belong to paramyxovirus, non-segmented. Envelope contains two glycoproteins: G/glycosylated are important for viral attachment to host cells. F/fusion proteins are important for fusing infected cell together to form syncytia, This virus is most common in children and infants, and is most common in the winter. Also causes bronchiolitis (different than pneumonia), pneumonia in babies.

Parainfluenza virus

- SS RNA, non-segmented, belong to paramyxovirus group. Is an envelope which contains HA and NA (like influenza) which are viral attachment proteins. Type 1 causes Croup. There is no method of control or drug therapy for this virus

rabies

-ss RNA, Rhabdovirus. From animal bites, especially bats. Progresses from fever to paralysis to coma. Virus travels up nerve to brain. Long incubation allows vaccines and antibodies to be given after animal bite. Histology shows negri bodies (cytoplasmic inclusions). Treat someone who is bit by giving immunoglobulins. Killed vaccine available.

HIV (human immunodeficiency virus) and the cells it infects

-ss RNA, retrioviridae, enveloped. carries reverse transcriptase. It is single stranded but has two copies. It only infects cells that have CD4 proteins like CD4+ T cells, macrophages, other APC.

stages of lyme disease

1 erythema migrans (only applies to lyme disease), a target shaped skin rash. 2, effects the heart and nervous system, facial hemiparalysis. 3, arthritis, further CNS dysfunction.

the three stages of whooping cough (B pertussis)

1, Catarrhal stage, 1-2 weeks characterized by runny nose, fever, sneezing. Pertussis is most communicable at this stage. 2, Paroxysmal stage, 2-4 weeks or "whoop" cough. 3, Convalescent stage, the frequency of cough and other symptoms decrease

and what 3 toxins does B pertussis use?

1, Pertussis toxin, the major virulence factor of pertussis. An A-B toxin that increases cAMP levels via ADP ribosylates. 2, adenylate toxin, increases cAMP levels via conversion of ATP to cAMP. 3, Tracheal cytotoxin, a toxin that is a fragment of cell wall peptidoglycan, which produces NO and kills ciliated cell. After the death of the ciliated cells, the lungs rely on coughing up stuff to protect it, which is why they cough so much.

the 3 mechanisms of Pseudomonas aeruginosa that make it resistant to antibiotics

1, a mutated porin protein that does not allow entry of antibiotics into the cell (porin proteins controls transport of stuff into the cell). 2, It has b-lactamase (via plasmids). 3, has acetylating enzymes (also via plasmids)

3 stages of lyme disease and when it needs to be diagnosed

1, acute illness; lasts a few weeks and classically causes a red bulls-eye shaped rash. 2, dissemination; lasting months, causing cranial nerve issues (facial hemiparalysis) and meningoencephalitis (inflammation of the meninges and brain. 3, late chronic form that causes destructive arthritis, neuropathy. This disease should be diagnosed in the early stage before it leads to strange and severe symptoms.

3 evidences that the immune system fights cancer

1, lymphocytic infiltrate around tumors and enlargement of draining lymph nodes. 2, in experimental models, a transplanted tumor is rejected by the host that was previously exposed to that tumor. 3, immunodeficient hosts are more susceptible to developing certain types of tumors.

3 mechanisns of P aeruginosa that all it to resist antibiotics

1, mutated porin protein (doesn't allow entry of antibiotics). 2, beta lactamase. 3, acetylating enzymes

2.5 pathogenic aspects of tuberculosis

1, they possess sulfatides which inhibit phagosome-lysosome fusion and allow TB to survive. 2, they possess Cord Factor (mycolic acids wrapped like a cord, a virulence factor) which weakens the cell by disrupting mitochondrial activity. 1/2, They possess the surface protein tuberculin which is responsible for the DTH immune response. Only the DTH reacts because antibodies cannot access the intracellular TB cells

what infects the URT and what are the symptoms and treatment

80% of the time it is a virus which presents with cough. runny nose, body ache, head ache, fever (constitutional symptoms, meaning that it affects many parts of the body). Bacteria is limited to Streptococcus group A (pyogenous), Corynebacterium diphtheriae, Neisseria gonorrheae, which presents with difficulty swallowing, throat pain, cough, swollen lymph nodes. Treat strep with penicillin, Neisseria gonorrheae with antibiotics, and Corynebacterium diphtheria with antitoxin and antibiotics

leading causes of bacterial meningitis by age group

<1 month: group B strep (GBS, S agalactia), E coli, Listeria. 1-23 months: S pneumonia, Neisseria. 2-18 years: Neisseria, S pneumonia. 19-59 years: S pneumonia, Neisseria. >60 years: S pneumonia, Listeria.

infections of AIDS patients when CD4 counts are <500, <200, <100, <50

<500: Candida (oral thrush). <200: Pneumocystis jirovecii, Cryptosporidium, JC virus. <100: Toxoplasma gondii, Candida esophagitis, Histoplasma capsulatum (pulmonary symptoms) <50: Cryptococcus neoformans, CMV, MAC

Trypanosoma Brucei (of Trypanosomiosis)

A parasite that occurs in the forms of kinetoplastids. Causes CNS problems. Relapses of this infection occur due to antigenic variation of the different life cycles/morphologies of the Trypanosoma cells..

what are the known obligate anaerobes

ABCs, Actinomyces, Bacteroides, Clostridium

AFB (Acid Fast Bacilli) test and auramine-rhodamine fluorescent stain

AFB is a test to determine whether a cell is acid fast or not. First the cell is stained with carbolfuchsin, which is red. Then it is washed with an acid alcohol. At this stage acid fast bacilli (AFB) will remain remain red and non AFB will be colorless. Then methylene blue is added which colors non AFB cells blue. Red means positive, blue is negative. This help identify tuberculosis (TB). Mycobacteria like TB also can be identified using auramine-rhodamine fluorescent stain, which turns the cells a bright flourescent green/yellow.

Diagnosing AIDS/HIV

AIDS is diagnosed by having CD4 count <200. HIV is diagnosed using ELISA (detects antibodies specific for p24) and western blot tests (detects viral proteins), but these tests are not reliable within the first 4 weeks of infection. The best test for someone who may have been infected recently is detectiong of HIV RNA using PCR.

acute otitis media (AOM), AOM with effusion

AOM MC from S pneumonia or H influenzaa non infectious condition of the middle ear. usually the eustachian tube drains fluid. If it gets blocked then fluid can accumulate, which would be a clear effusion with mild or minimal symptoms

ABCs of obligate anaerobes

Actinomyces, Bacteroides, Clostridium. Obligate anaerobes are not the same as obligate intracellular organisms.

phases of HIV

Acute phase is 2-4 weeks after infection and has symptoms like the flu or mononucleosis. After symptoms subside there is an asymptomatic period.

where do B and T cells mature? Negative selection

B cells in the bone marrow and T cells in the thymus. Negative selection is when cells are selected (allowed to live) if they do not react/bind to the presented antigen. This prevents autoimmune antibodies.

normal WBC count

Adult: 4,500-10,500 cells/mL. Anything over that range suggests an acute infection

Ataxia-Telangectasia

Ataxia = involuntary muscle movements, Telangiectasia = dilation in small blood vessels of the skin. Gene defects in DNA repair enzymes cause the symptoms: cerebellar atrophy, ataxia, telangectasia (especially in the eyes), low IgA IgG and IgE, high AFP (alpha fetoprotein) levels

treatment of toxoplasmosis

Atovaquone is the only drug that attacks both the tachyzoites and the tissue cyst form

Prophylaxis against Mycobacterium avium complex (MAC)

Azythromycin. Prophylactic treatment should start when CD4 <50. MAC cause TB like symptoms in AIDS patients.

what pathogen classically causes a tetrad formation in infected cells?

Babesiosis

STDs

Bacterial: Neisseria gonorrhoeae, Chlamydia trachomatis, Treponema pallidum, Haemophilus ducreyi, Calymmatobacterium granulomatis. Viral: HSV, HPV, HIV. Protozoal: Trichomoniasis

HSV and meningitis/encephalitis

HSV-1 causes encephalitis. Treated with acyclovir. HSV-2 usually causes causes meningitis (especially babies born of infected mothers).

viral causes of eye infections

HSV-1 causes keratoconjuctivitis, aka ulcers on the cornea in a dendritic pattern. Adenovirus causes pink eye (conjunctivitis). CMV causes retinitis in AIDS peeps or congenital infections.

difference between hereditary angioedema caused by C1 esterase inhibitor deficiency and anaphylaxis.

Both can present as swelling. in the former there would be low levels of complement proteins C2, C3, C4 (because they have been used up). In anaphylaxis there would be high levels of eosinophils and IgE. If epinephrine injection resolves the issue, it is anaphylaxis. Angioedema mainly affects the face, anaphylaxis affects multiple organs.

The 3 strains of chlamydia.the difference between C. pneumoniae and C. psittaci

C. trachomatis (#1 bacterial STD), C psittaci and C pneumoniae both cause pneumonia, however C. psittaci can be differentiated because it is acquired via association with birds and infects the liver and spleen

C1 esterase inhibitor deficiency

C1 esterase inhibitor normally prevent complement activation on self cells. A deficiency causes hereditary angioedema (swelling of the face). Blood tests would show low levels of complement proteins C2, C3, C4, because they have been used up. The entire MAC isn't dysfunctional because there are multiple pathways of activating it, including starting at C3. ACE inhibitors are CI

complement system

C3b causes opsonization of bacteria (for elimination). C3b also splits C5 into C5a and C5b. C3a and C5a cause inflammation by causing mast cells to release histamine which increases the permeability of capillaries. C5a also is a neutrophil chemoattractant. C5b activates C6-9 and they all form the MAC (membrane attack complex) which creates pores in cell membranes which causes lysis of the cell.

gram (-), oxidase (+), comma shaped

Campylobacter jejuni, Vibrio, Helicobacter pylori. Campylobacter grows at 42 degC. Vibrio grows in alkaline media. Helicobacter produces urease.

Vaginitis

Can be caused by Trichomonas vaginalis, Candida albicans (thrush), Gardnerella vaginalis (bacterial vaginosis).

MC causes of osteomyelitis in intravenous drug users?

Candida and P aeruginosa, (the same bugs that cause endocarditis in drug users), and someitmes S aureus.

rhinitis

Caused by rhinovirus (MC), adenovirus, coronavirus, influenza

laryngitis

Causes are same as rhinitis and pharyngitis with viruses being the most common. S pyogenes is MC bacterial. Symptoms are hoarseness or loss of voice. Associated with symptoms of pharyngitis and rhinitis.

fungal OM

Causes in immunocompetent individuals: Blastomycosis, coccidioidomycosis, sporothrix. In immuno compromised: cryptococcus, candida, aspergillus

bacteria with exotoxins that lyse cell membranes

Clostridium perfringens (alpha toxin) and Steptococcus pyogenes (streptolysin O)

gram (+) rods

Clostridium, Corynebacterium, Bacillus, Listeria, mycobacterium (kinda).

Cryptosporidium gastroenteritis

Cryptosporidium, a protozoa parasite, obligate intracellular. Infects the GI, acquired via contaminated water. Only causes severe infection in immunocompetent individuals (AIDS patients , <200 CD4). Can be stained with AFB (acid fast) stain. Causes diarrhea that won't go away.

bacteria with exotoxins that inhibit protein synthesis

Corynebacterium diphtheriae (diphtheria toxin), Pseudomonas aeruginosa (exotoxin A), Shigella (shiga toxin), Enterohemorrhagic E coli (EHEC) (Shiga-like toxin)

culture negative osteomyelitis

Cultures negative for a bacterial pathogen but clinical, pathologic, and radiologic evidence suggests OM. often due to prior antimicrobial use. Stop antibiotics and try again. If you still can't grow it, use broad spectrum antibiotics

capsid symmetry/shape of viruses

DNA viruses (except pox, which is complex) and +ssRNA are icosahedral (except HIV, complex and conical). Reovirus which is dsRNA has a double icosahedral capsi. -ssRNA viruses have helical symmetry.

what vaccine is available for diphtheriae and pertussis?

DTP, aka DTaP. The aP stands for acellular Pertussis

ways that bacteria can change their genes?

Transformation, conjugation, transposition, transduction

C3 deficiency

a deficiency of the complement system that causes increased risk of (encapsulated infections) severe, recurrent, pyogenic and respiratory infections.

types of E coli

EPEC, EIEC (EnteroInvasive E Coli), ETEC (EnteroToxic), EHEC,

bacteria with exotoxins that increase fluid secretion

ETEC (enterotoxigenic E coli) (heat-labile toxin and heat stable toxin), Bacillus anthracis (edema factor), Vibrio cholerae (cholera toxin)

enteroviruses

Echovirus, Coxsackie virus A and B, Polio virus. They are +ss RNA viruses, in the Picornavirus family. Can cause meningitis (except HAV)

HIV treatment: fusion inhibitors

Enfuvirtide. Prevent the virus from entering the host cell by binding gp41.

GI tract protozoa infections

Entamoeba histolytica, Giardia, and Cryptosporidium (in immunocompromised). They are transferred fecally contaminated foot or water, with no animal reservoir.

types of HSV and treatment

HSV-2 causes the STD and HSV-1 causes everything else. HSV-1 aquired via respiratory secretions. Treat with Acyclovir and Penciclovir which are nucleoside analogues that cause the virus to produce DNA that is defective.

middle respiratory tract infections

Epiglottitis is almost always a bacterial infection (usually due to Haemophilus influenza) . Laryngitis and croup (more severe form), tracheitis, bronchitis, and bronchiolitis are usually viral

pathogenicity of S pyogenes

Exotoxin A which causes TSS (toxic shock syndrome. Streptolysin which lyses RBCs by degrading the cell membranes. Antibodies that form against the M proteins of S pyogenes cause rheumatic fever.

conjugation and bacterial genes

F+ bacteria have plasmids, those plasmids are replicated and transferred via a sex pilus to F- bacterial cell (no plasmid). Chromosomal genes are not transferred. Hfr (high frequency recombination) cells replicate the plasmid and add segments of chromosomal DNA (transposons) to the plasmid, which is also transferred to F- bacteria.

stains for malaria

Giemsa (stains for malaria and other parasites) and Wright's stain (differentiates blood cell types). With Plasmodium falciparum, Wright's stain will show intraerythrocytic (inside RBC) inclusions.

Ghon complex/focus, locations of TB infection in lung, secondary TB

Ghon focus is a fibrotic/calcified focus in the lower region of the middle lobe. If there is also a calcified hilar lymph node then it is called a Ghon complex. They can calcify and appear on xray. Primary TB causes ghon complexes. Secondary TB (latent infection) causes cavitary lesions in the apex of the lung, because TB is an obligate aerobe and the apex is where higher O2 levels are found.

prosthetic joint infections

Gram (-) bacilli is 25%, coagulase negative staphylococcus (22%), S aureus (coagulase positive) 22%, and many others. S viridans is low virulence and has a tendency to infect prosthesis. Patient will complain of joint pain, fever, joint swelling. It is treated by antibiotics and removing the prosthesis

disorders of hyperthyroidism and symptoms

Graves disease, Toxic multinodular goiter, Thyroid storm. Symptoms: heat intolerance (increased heat production), weight loss and increased appetite, hyperactivity, diarrhea, increased reflexes, pretibial and periorbital myxedema, warm moist skin, fine hair, tachycardia.

HIV types

HIV-1 is MC in US and most of the world, has a faster progression to AIDS. HIV-2 is more prevalent in west africa and has a slower progression to AIDS

HLA types

HLA- types A, B, and C are MHC l. HLA- types D, Q. They are MHC encodes by HLA genes, they present antigen fragments to T cells and bind TCRs.

HLA types that are associated with autoimmune diseases

HLA: A3 (hemochromatosis), B27 (reactive arthritis, other arthritis), DR2 (multiple sclerosis, SLE, Goodpasture), DR3 (diabetes type l, SLE, graves disease), DR4 (Rheumatoid arthritis, diabetes type l), DR5 (Hashimoto thyroiditis) DQ2/DQ8 (celiac disease).

rheumatic fever

HSR type ll, a condition that follows an upper respiratory infection with S pyogenes. Due to antibodies that formed against M protein. Symptoms are Jones criteria: Joints, carditis, Nodules, Erythema marginatum (round skin spots), Sydenham chorea (uncontrolled movements). The cardiac effect (rheumatic fever) affects heart valves (usually mitral valve, causing mitral stenosis).

HSV vs HPV

HSV has only two subtypes, HSV-1 causes all infections (except STDs), thus infects many different tissues. HPV has many subtypes, and each subtype can only infect a specific type of tissue

SCID: X linked

Have problems with production of T cells and B cells. IL-7 is impeded because IL-2R (IL-2 receptor) has a defective gamma chain. IL-2R shares the same gamma chain with IL-7R, which is why IL-7 function is impeded. IL-2 stimulates T cell development (which helps B cell development), so both T and B cells are defective and will be absent in the blood. If they require bone marrow transplants they do not need immunosuppressive therapy.

HBV (hepatitis B virus)

Hepadnavirus, incomplete (partially ds) dsDNA virus, acquired parenterally (any way besides digestive tract), needles, sexually, mother to fetus; unlikely via blood transfusions due to screening of blood viruses (same for HCV). Chronic disease only occurs in 20% of peeps. Can cause liver cancer by inserting DNA into host genoma which acts as oncogene; the viral genome encodes a reverse transcriptase which allows production of viral DNA. 30% of peeps with Polyarteritis nodosa have HBsAg, but <1% of peeps with chronic HBV have Polyarteritis Nodosa.

HEV (hepatitis E virus)

Hepevirus, +ssRNA virus, similar to HAV. Can cause acute hepatitis. Transmitted fecal oral route via contaminated water or undercooked seafood. In pregnant women it can cause liver failure and liver necrosis and be fatal.

What do vesicles in the palate indicate

Herpes viral infection. aka gingivostomatitis.

drugs that cause drug induced lupus

Hydralazine, INH (Isoniazid), procainamide

IFN (interferon)

IFN is released by virally infected host cells, which prevents neighboring cells from becoming infected. It also activated macrophages and NK cells. Possess antiviral and antitumor properties.

activators of specific antibodies

IFN-gamma and IL-2 act via TH1. IL-4 and IL-5 act via Th2. IFN-gamma induces IgG production, IL-4 induces igE, IL-5 induces IgA antibodies. Children are more skewed towards Th2 types of antibodies, but complete protection requires Th1 as well.

cytokines released by macrophages

IL-1 and IL-6 induce inflammation, fever and cause the liver to produce acute phase proteins. TNF induces inflammation and chemotaxis of neutrophils.

cytokines released by Th1 cells

IL-2 stimulates growth of both Th (CD4) and cytotoxic (CD8) T cells.

cytokine released by Th2 cells

IL-4 which causes development of more Th2 cells, stimulates B cell growth and class switching to IgE. IL-5 increases number of eosinophils and causes class switching to IgA. IL-10 is an anti inflammatory cytokine which inhibits development of Th1 cells.

the difference between elbow flexion between olecranon bursitis and septic arthritis

If pain increases with flexion, it is olecranon bursitis. If pain increases with extension, it is septic arthritis.

role of IgA, IgM, IgG

IgA's job is to prevent pathogens from crossing mucus membranes, does not fix complement. IgM fixes complement. IgG fixes complement, opsonizes bacteria, and neutralizes bacterial toxins and viruses.

Type ll hypersensitivity

IgG and IgM Abs bind to cell surface self Ags. This Ag-Ab binding activates the cytotoxic immune response which kills via complement-mediated lysis, cell injury by inflammatory cells, or phagocytosis. Response time is minutes-hours, appearance is lysis and necrosis. ex, organ transplant rejections, autoimmune disease (myasthenia gravis), drugs that trigger a reaction (may bind to RBCs and cause lysis and anemia)

IgM class switching

IgM antibodies are first produced, then class switch to IgA, IgG, IgE, but not IgD (a product of different gene splicing). CD40 on B cells interacts with the CD40 ligand on T helper cells, along with release of cytokines (IL-4 or IL-13 for IgE) from the T helper cell, to cause class switching

cold agglutinins

IgM autoantibodies against RBC that can cause hemolytic anemia. Cause clumping when blood is chilled (hence the name). Produced due to infections with Mycoplasma pneumonia.

Antibody types : IgM, IgG, IgA, IgE

IgM: the first antibody type formed when a new antigen is introduced, a pentamer. IgG: the second antibody formed (after IgM) after an antigen is introduced. It causes long term immunity, crosses placenta. IgA: found in the mucosal tissues such as the respiratory tract and the gut; also found in breast milk. IgE: causes allergic response, it binds to mast cells and causes histamine release.

how to test for whooping cough and when to treat.

In the first stage (catarrhal), use culture. During the less communicable Paroxysmal stage (2nd), aka the coughing stage, it is less communicable, so serology tests are necessary. Treatment with erythromycin or clarithromycin are effective if given in the early stage of infection (catarrhal)

Nematodes (roundworms)

Intestinal: Enterobius vermicularis, Ascaris lumbricoides, Strongyloides stercoralis, Ancylostoma duodenale, Necator americanus. Tissue: Onchocerca volvulus, Loa loa, Wuchereria bancrofti, Toxocara canis

how does pertussis bind to the respiratory epithelium of the trachea and what makes these patients cough so much.

It binds via filamentous heme agglutinin (FHA). After tracheal toxin kills the ciliated epithelial cells, the body coughs up sputum to expel bad stuff, making patients cough. Also, the pertussis toxin makes them more sensitive to histamine, which causes brochoconstriction and also makes them cough.

a way that the bubonic plague was spread, other than fleas.

It can also be spread person to person by respiratory droplet (coughing) in people whose infection spread to the lungs. It causes bloody mucoid sputums, with death by cyanosis on the 2nd or 3rd day. Terminal cyanosis is the reason it is called the "Black Plague." No bubo present with primary pneumonic plague.

mannitol salt agar

It is selective at 7.5% salt by inhibiting all but staphylococci (gram +) organism. It is differential when it Staphylococcus aureus ferments mannitol and turns a pH indicator from red to yellow

the difference between Kingella kingae and Eikenella corrodens

Kingella can ferment glucose, Eikenella doesn't. Kingella is beta hemolytic, Eikenella is not.. Eikenella is ornithine decarboxylase (+) and Lysine decarboxylase (+), Kingella isn't.

can cause septic arthritis or OM due to bite wounds from a human. How would you treat those?

Kingella kingae and Eikenella corrodens. A 3rd generation cephalosporin. Even tho either bacteria can be killed by a lower grade antibiotic, culturing the bacteria to identify them takes a long time, so a 3rd gen cephalosporin is given that will kill all options.

Normal flora of the female genital tract

Lactobacillus, which produces an acid which prevents infection of other bacteria.

Leprous and Tuberculoid forms of Leprosy

Leprous is more severe; spreads over skin, leonine (lion-like) facies. Th2 response, no granuloma formation, can cause loss of digits. Highly infectious. Tuberculoid; only causes hairless skin plaques that are hypoesthetic (less feeling) and become anesthetic when bacterial invade peripheral nerves, Th1 response. Has noncaseating epitherlioid granuloma. Less infectious.

Phagocyte dysfunction syndromes

Leukocyte adhesion deficiency, Chronic Granulomatous disease, Chediak-Higashi syndrome

bacterial Septic arthritis

MC cause is S aureus, others are coagulase negative Staphylococcus, Streptococcus. All age groups have S aureus as the MC cause except 16-40 yo, which has Neisseria gonorrhoeae. Existing illnesses/conditions are important predisposing factors to arterial arthritis. Symptoms is swelling, redness, pain in the joint, but also fever and chills

causes of osteomyelitis in children. What is the only category of osteomyelitis where S aureus isn't the MC cause?

MC cause is S aureus, then S pneumoniae (group B strep is 2nd most common in adults)..Infections that occur after puncture wound of foot are MC due to Pseudomonas aeruginosa, S aureus is second.

causes of wound infections

MC cause is S aureus, which is pyogenic, also Pseudomonas (especially burns). Anaerobic bacteria cause necrotizing fasciitis.

Guillain-Barre syndrome

MC cause of acute paralysis. Causes rapidly progressing muscle weakness that starts in legs and ascends. Can occur as a complication from viral illnesses (upper respiratory tract infections, HIV, mononucleosis), infection with Campylobacter jejuni (whether symptomatic or asymptomatic). Symptoms are caused by destroying schwann cells and causing demyelination. A type lV HSR. High CSF with normal WBC count (aka albuminocytologic dissociation).

Graves disease

MC cause of hyperthyroidism. An autoimmune disease when antibodies (IgG) bind to and activate TSH receptor, causing hyperthyroidism and a goiter. Autoantibody binding also causes exopthalmos (aka proptosis, eye bulging), and pretibial myxedema (redness, swelling on shins). Other typical symptoms of hyperthyroidism is high T3/T4, excess heat production, weight loss, increased appetite, etc. Associated with HLA-DR3.

Hashimoto thyroiditis

MC cause of hypothyroidism in iodine sufficient areas. An autoimmune disorder of autoantibodies against thyroid peroxidase and thyroglobulin, both are found in the thyroid, causing destruction of the thyroid. Symptoms are enlarged, nontender thyroid, hypothyroid symtpms. Classically shows Hurthle cells. Associated with HLA -DR5.

symptoms of CMV

MC cause of retinitis in AIDS patients. Also causes pneumonia in AIDS and bone marrow transplant patients. In immunocompetent peeps it causes mono like symptoms (fever, lethargy). In congenital cases it causes birth defects (blueberry muffin syndrome, due to combo of yellow skin and red subcutaneous hemorrhages).

S pneumoniae

MC cause of the following: meningitis, Otitis media in children, pneumonia.

UTI (urinary tract infections) pathogens

MC is E coli. 2nd MC is S. saprophyticus, especially common in sexually active women. 3rd MC is Klebsiella pneumonia. Others: Enterobacter cloacae, Proteus mirabilis, enterococcus. Pseudomonas and Serratia Marcescens can cause UTI in peeps with catheter (because unlike the others, they are not normal GI flora) tho they are still far less common

specific types of osteomyelitis and their MC causes

MC is S aureus for all of these, but the 2nd MC varies: Osteitis pubis (OM of symphysis pubis) Enterococcus (GI and urinary tract proximity), OM of the clavicle: M. tuberculosis. OM in neonates (<1 month old) is group B Streptococcus.

most common causes of acute sinusitis,

MC is S pneumoniae, 2nd is H influenza (same as AOM). Same for children and adults.

MC causes of otitis media in children

MC is S pneumoniae. 2nd is Haemophilus influenza.

AL (Amyloid Lightchain) amyloidosis (aka primary amyloidosis)

MC type of amyloidosis, caused by deposition of Ig light chains (bence jones protein). Can occur in plasma cell disorders or multiple myeloma (cancer of plasma cells). Often affects multiple organs: kidney (nephrotic syndrome), heart, hematologic (easy bruising), GI, neurologic.

gram (-) bugs that cause bloody diarrhea (dysentery= intestinal inflammation with bloody diarrhea)

MC: Salmonella, Shigella, Campylobacter. Less common: E coli, Yersinia

HIV treatment: CCR5 antagonist

Maraviroc. It binds to CCR5 which inhibits the binding of gp120 (which normally is the first step of the virus binding to a host cell).

live attenuated vaccines (viral)

Measles, mumps, rubella, polio (Sabin), influenza, varicella, yellow fever.

what is the cell wall of gram (+) bacteria made of?

N-acetylmuramic acid and N-acetylglucosamine.

treatments for influenza

Neuraminidase inhibitors (preferred) like Zanamivir (inhaled) and oseltamivir (oral) work against type A and B. Amantadine and rimantide treat only influenza A and are 70%-90% effective. All medications should be given within 48 hours of onset of symptoms.

What abnormally high values on the WBC differentials indicate (high neutrophils, lymphocytes, macrophages, etc).

Neutrophils indicate : bacterial infection, usually recent (depending on monocytes). Lymphocytes indicate viral infection. Monocytes (macrophages) indicate persistant infection. Eosinophils:indicate allergic reaction, maybe parasite. Basophils indicate parasite.

PCR test vs RTPCR (real time PCR) test

PCR is a qualitative test, detects whether a pathogen is present or not. RTPCR is a quantitative test which detects how much of a pathogen is present

reverse transcriptase PCR (RTPCR)

PCR that uses reverse transcriptase first to produce DNA from RNA, then proceeds with a normal PCR.

general management of bacterial arthritis

if there is pus it must be drained, a sequestrum (bone fragment) must be removed

Treatments for Pseudomonas aeruginosa

Piperacillin and ticracillin (anti-pseudomonal penicillins) are effective, as well as combos that include these drugs. Vaccines is not available yet.

Protozoa hematologic infections

Plasmodium, Babesia

reverse transcriptase (RT)

RNA dependent DNA polymerase (using the formula: template dependant product polymerase).

HIV treatment: Protease inhibitors

Proteases are necessary to the virus because they cleave the polypeptide products of translation into their functional parts. Protease inhibitors stops this process. All protease inhibitors end in "navir".

types of pathogenic conditions caused by S pyogenes

Pyogenic: Pharyngitis, cellulitis, impetigo. Toxigenic (exotoxin A/superantigen): scarlet fever, toxic shock like syndrome, necrotizing fasciitis. Immunologic (M protein): rheumatic fever, acute glomerulonephritis (PSGN, a HSR type lll). Streptolysic O is a protein that degrades cell membranes, including lysis of RBC that causes beta hemolysis.

why doesn't the body eliminate the virus

RT has a high rate of mutation which causes different strains of the virus. The body can kill older strains but it can't catch up to the mutating virus.

killed viral vaccines (Rest In Peace Always) (viral), other killed or viral vaccines

Rabies, Influenza, Polio (Salk), hepatitis A, they are all viral vaccines. A killed Cholera vaccine is available. Recombinant HBV and HPV vaccines also available

HIV treatment: Integrase inhibitors

Raltegravir. prevents HIV DNA from being integrated into host cell DNA by inhibiting integrase.

viruses that are segmented

Reovirus (10-12 segments), Orthomyxovirus (8), Arenavirus (2), Bunyavirus (3).

Papillomavirus/Human papilloma virus/HPV

STD, non-enveloped, ds DNA virus, many subtypes. MC STD. Cause genital warts (condyloma acuminatum), cervical cancer, vaginal, anal, penile cancer, throat cancer. Warts are removed like normal warts, lasered or frozen. HPV is present in 99.7% of cervical cancers. Thus a HPV that causes a wart on your hand will not cause a genital wart. Newborns can be infected at birth. Warts are caused by HPV 6, 11, and cancer by HPV 16, 18.

superantigens (type of exotoxin) of S aureus and S pyogenes

S aureus produces TSST (toxic shock syndrome toxin) and S pyogenes produces exotoxin A. The antigen links the TCR to MHC LL on APC and cause massive release of IFN-gamma and IL-2, which is TSS (toxic shock syndrome). Symptoms of TSS are fever, rash, and shock.

Post partum infections

S aureus, S pyogenes, Bacteroides, Clostridium, E coli

bacteria with capsules

S pneumoniae, E coli, Haemophilus influenza type B, Neissera meningitidis, Klebsiella, Shigella, Salmonella, S agalactiae. They opsonized and then removed by macrophages in the spleen, thus people without a spleen will have problems with encapsulated bacteria.

glomerulonephritis, Impetigo cause by S pyogenes

S pyogenes caused impetigo can precede glomerulonephritis, which is also caused by antibodies formed against S pyogenes that are deposited in glomeruli and cause a type lll HSR (like rheumatic fever causes type ll). The inflammation causes tissue damage.

the only two bacteria that cause upper respiratory infection

S. pyogenes and C. diphtheria. N. gonorrhoeae may in a rare case. However, most upper respiratory infections are viruses. Viral infections will present with constitutional symptoms; body aches, fever, runny nose, fatiguge, etc. In bacterial infections there may be pseudomembranes (diphtheria) and sore throat.

B and T cell disorders

SCID, Ataxia-telangiectasia, Wiskott-Aldrich syndrome

HSV (herpes simplex virus)

STD (HSV-2), enveloped, ds DNA virus, uses DNA polymerase that is a target for antiviral drugs. Has immune escape proteins: gC binds to C3 of complement system, inhibiting the complement system, gE and gI are bound to Fc portion of antibodies, allowing the virus and virally infected cells to remain undetected. Virus infects nerve cells, allowing reactivation (latent infection), so your never really cured. Causing red bumps that turn into blisters, itching, burning, severe pain in women.

Chancroid

STD due to Haemophilus ducreyi, gram (-). Produces a painful, soft chancre (ulcer). Can cause a buboes (swollen lymph nodes in the groin). Males are usually symptomatic with inguinal tenderness, but females are usually asymptomatic for a while and then have vaginal discharge, pain when pooping/peeing, and rectal bleeding. A major cofactor in the transmission of HIV

Syphilis

STD due to Treponema pallidum, a spirochete. Transmission can also be from rashes (hands/feet) that contact broken skin or mucus membranes. Does not gram stain because it is a spirochete but can be viewed with dark field microscopy. Non-specific serological tests are RPR (rapid plasma reagin) and VDRL (venereal disease research laboratory) which detect tissue damage, not the pathogen, resulting in false positives. Confirm diagnosis FTA-Abs (fluorescent treponemal antibody absorption).

Granuloma inguinale (Klebsiella granulomatis, aka Calymmatobacterium granulomatis)

STD, Gram (-), capsulated, intracellular. Normally present in the gut flora, so it can also be transferred by accidental contamination. Found in tropics, more common in blacks than whites. Classicly shows Donovan bodies (intracellular inclusions). Raised nodules turn into nasty ulcers.

HIV (human immunodeficiency virus)

STD, enveloped, 2 copies of + strand, RNA virus. Capsid carries reverse transcriptase, which is targeted by antiviral drugs. Causes aids, affects CD4 helper T cells making patients susceptible to opportunistic infections (including Candida, Kaposi sarcoma). Also transmitted in blood, found in all body fluids except urine. It has a long asymptomatic period, thus allowing spread of the disease. Can spread perinatally to newborns.

Trichomoniasis

STD, from protozoa Trichomonas vaginalis. Symptoms for women: itching of vulva and vagina, inflammation, yellow-green frothy vaginal discharge, burning when peeing, "strawberry" red cervix. It is very motile, motility will be seen on wet mount. pH will be high, >4.5 (4.0-4.5 is normal). Found in vaginal secretions and urine.

Neisseria gonorrhoeae

STD, gram (-) diplococcus, facultative intracellular. Attaches to host cells via pili (fimbriae). Antigenic variation is due to difference in type of pili, which also allows gonorrhea to attach to different types of cells. Produces an enzyme that break down IgA antibodies. Opa proteins are on the outer membrane and increase adherence to host cells, and also attach to CD4 T cells, thus preventing activation and proliferation of T cells. In men it can cause pain, pus discharge, scarring and sterility, in women painful urination, vaginal discharge, can spread and cause PID (pelvic inflammatory disease) resulting in sterility or ectopic pregnancy.

Chlamydia trachomatis

STD, spherical, obligate intracellular (because it can't produce its own ATP). Mimics gonorrhea, causing penile and vaginal discharge, pain vaginal bleeding, sterility. It can attach to sperm which allows it to spread, causing PID. Some subtypes can cause trachoma (an eye infection) and blindness. It cannot be gram stained because it is intracellular, so diagnosis is done via immunofluorescence.

stain and agar for fungus

Sabourad agar grows some types of fungus. Silver stain can identify some types. India is stain is specific for Cryptococcus (shows thick capsule on black background)..

enterobacteria and what infections they commonly cause

Salmonella, Shigella, E coli cause GI infections. Yersinia and Klebsiella causes respiratory infections. Proteus and E coli cause UTI.

Enterobacteria (enterobacteriaceae) of note

Salmonella, Shigella, Klebsiella, Yersinia, E. coli, Proteus. They are all gram (-) rods, facultative anaerobes, oxidase (-), catalase producers. E coli and Klebsiella are the only lactose fermenters. Salmonella and Proteus produce H2S and are motile. Shigella and Yersinia (SHY because the don't produce anything) do not produce lactose or H2S and are not motile.

MC cause of osteomyelitis among sickle cell disease patients

Salmonella. If they are HLA DQB1 they are susceptible, and HLA DRB1 is protected.

Trematodes (flukes)

Schistosoma haematobium, Clonorchis sinensis.

What bacteria is the most common cause of bacterial endocarditis? what other bacteria cause it?

Streptococcus Viridans (alpha hemolytic) which is low-virulence, (doesn't do much damage). It could also be S aureus, S pneumonia, others.

similarities of RSV and influenza

Similarities are typical flu-like symptoms like cough, fever, dyspnea (shortness of breath), runny nose, sore throat. Both infect the epithelial cells of the respiratory tract and have high risk of secondary bacterial infection.

cause of dental caries and gingivitis

Strep mutans (part of viridans) causes caries. Porphyromonas gingivalis causes gingivitis in old peeps. Gingivitis is inflammatory response in gums to plaque bacteria. Gingivitis causes plaque, inflammation, bleeding, and receding gums.

chronic mucocutaneous candidiasis

T cell deficiency specifically for Candida albicans. Peeps will have skin and mucous membrane infections (but not invasive or systemic).

production of T cells

T cell precursors travel from the bone marrow to the cortex of the thymus where there undergo positive selection where the cells capable of binding self MHC molecules survive. Then negative selection pccurs in the medulla of the thymus where the self antigens are presented and any T cells with high affinity are destroyed.

markers for lymphocytes

T cells are CD3 + (CD4 or CD8). B cells are CD19, CD21. NK cell are CD16, dendritic cells are CD123

HSR type lV

T-cell mediated. Th1 cells recognize antigens, then activate other T cells and macrophages, thus initiating an immune response. Symptoms peak in 2-3 days (slowest of HSR). ex, contact dermatitis (red rash appearance).

Prophylaxis against Pneumocystic jirovecii and Toxoplasmosis

TMP-SMX (Trimethoprim sulfamethoxazole) which inhibits folate synthesis by inhibiting dihydrofolate reductase and tetrahydrofolate reductase. Prophylactic treatment should start when CD4 <200 for pneumocystis and <100 for toxo.

Cestodes (tapeworms)

Taenia solium, Diphyllobothrium latum, Echinococcus granulosus. These types of worms have a scolex which allows them to attach to the intestinal wall. They body is divided into segments called proglottids

Azole antifungal drugs

inhibit an enzyme involved in synthesis of ergosterol, a necessary part of fungal membranes.

what is the differences between the common cold and the flu (influenza)? Symptoms

The commons cold is an upper respiratory infection, while the flu is a lower respiratory infection. Same symptoms, but influenza is more severe

Allylamines

inhibit ergosterol production, thus inhibiting fungal cell membrane synthesis.

vaccine and treatment for Haemophilus influenze

The vaccine is HIB (Haemophilus influenza type B, which has a capsule). Treat with 3rd generation cephalosporin (ceftriaxone, cefotaxime)

how HIV replicates

The virus enters the cell, in the cytoplasm reverse transcriptase produces viral DNA from viral RNA. Viral DNA enters the nucleus and integrase integrates the viral DNA into the host genome. NFkB initially causes the the first viral proteins to be produced, including tat and rev. Then tat (the transcription activator) binds to TAR (transcriptional activation region) which is a sequence in the LTR, thus causing continuous transcription. Rev protein transports the transcribed RNA to the cytoplasm.

life cycles of Taeniasis (cysticercosis) and intermediate and definitive hosts

The worm are tissue cysts in pigs or cows, which peeps eat. They worm mature in the stomach and release eggs which are pooped out. When we are definitive host (when we poop out the larva) the symptoms aren't a big deal, but when we are the intermediate host (we infect ourselves) and the reproduced eggs enter the blood and then to tissues like muscle and the brain and cause cysts (cysticercosis), thats a problem.

anthrax toxin

There are 3 toxins: protective factor, lethal factor, and edema factor. Edema toxin raises cAMP levels by acting as an adenylate cyclase by converting ATP to cAMP. This which causes loss of chloride ions and water, which causes edema to the borders of the infected area. Similar acting toxins are Cholera and E coli which stimulate adenylate cyclase to increase cAMP levels, which causes release of ions and fluid which causes diarrhea.

T cell disorders

Thymic aplasia, IL-12 receptor deficiency, Hyper IgE syndrome, Hyper IgM syndrome, Chronic mucocutaneous candidiasis,

treating bacterial arthritis

Treat according to the gram stain. if it is gram (+) and there are no risk factors of MRSA (past history of MRSA, long hospital stay), give Nafcillin or Oxacillin. If there are risk factors for MRSA and it is gram (+), use vancomycin. If it is gram (-), use 3rd gen cephalosporin. If you can't isolate it with gram staining, give both.

congenital syphilis

Treponema pallidum infeciton that crosses the placenta and infects the fetus. Can cause early death in babies, also causes nicked teeth (Hutchinson's teeth).

C5-9 deficiency

a deficiency of the complement system that causes an increased risk for Neisseria infections, both gonorrhea and meningitidis.

Hyper IgM syndrome

X linked recessive excess IgM due to lack of class switching. CD40 ligand on T helper cells which helps in class switching is defective. CD40 is also present on macrophages, so macrophages are dysfunctional, and cannot release GC-CSF. Peeps suffer from pyogenic and opportunistic (pneumocystis, cryptosporidium, CMV). Blood tests show high IgM and low IgG, IgA, and IgE levels.

B cell disorders

XLA, selective IgA deficiency, CVID

HIV treatment: NRTI

Zidovudine (AZT), and many others. They are nucleoside analogs that inhibit reverse transcriptase bec

Echinocandins

inhibit fungal cell wall synthesis

leukocyte, lymphocyte

leukocytes are all WBCs: neutrophils, eosinophils, basophils, monocytes, T cells, B cells. Lymphocytes are only T and B cells.

X-linked agammaglobulinemia (XLA)

a B cell deficiency caused by a defect in BTK, which is responsible for B cell maturation. More common in males (because X linked). Causes low antibody count of all types, low B cell count but normal levels of B cell precursors (which have CD19 markers). Results in recurrent bacterial and enteroviral infections after 6 months (earlier than 6 months babies still have the mother's antibodies). Peeps are more susceptible to pneumoniae infections (S pneumoniae, H influenza, etc), enteroviruses, and Giardia. Treatment is periodic infusion gamma globulins (a group that includes immunoglobulins). Prognosis is good, the person will likely live a normal life.

Burkitt lymphoma

a B cell lymphoma caused by EBV

Adenovirus

a DS (double stranded) DNA virus, non enveloped. No seasonal predisposition. Cause "smudgelike" inclusion bodies. Causes upper respiratory infection, pneumonia, "pink eye" (conjunctivitis), and hemorragic cystitis (blood in urine due to ruptured bladder blood vessel).

Thymic aplasia (DiGeorge syndrome)

a T cell deficiency caused by failure of the 3rd and 4th pharyngeal pouches to develop (gene deletion on chromosome 22), causing the thymus and parathyroid glands to not develop. Likely has cleft palate and heart defect. Patients will frequently have viral, fungal, protozoal infections, which T cells normally prevent (B cells and antibodies usually prevent bacterial infections). Patient will also have tetanus due to low calcium levels due to lack of parathyroid. Blood will show low T cells, low parathyroid hormone, low calcium. There will not be a thymic shadow on chest xray.

Coccidioidomycosis (valley fever), ex, C. immitis

a arthrospore forming, dimorphic fungus that forms spherules (containing endospores) instead of yeast in host tissue. Causes respiratory infection that is acquired in the southwest. Causes typical fever, and also cavity formation in the lungs. Also causes meningitis. Can spread to bone and skin, causing skin rashes. Treat with Fluconazole (less severe) and Amphotericin B (more severe).

mycoplasma pneumonia

a bacteria lacking a cell wall and MC cause of atypical pneumonia (10% of all pneumonia cases). It must be grown in an agar that has sterols/cholesterol (Eaton agar), which it needs because it doesnt have a cell wall. Common in groups of people, like school aged children, military recruits, etc. Can cause anemia due to cold agglutinins (IgM formed against the bug but sometimes bind to and lyse RBCs).

Optochin Test/ P disc

a biochemical test for Streptococcus pneumoniae using an optochin disc. The disc is placed on an agar plate with growth around it. A positive test is a zone on inhibition around the plate, because Steptococcus pneumoniae is optochin sensitive

Bacitracin susceptibility test/ A disc

a biochemical test for group A Streptococci. A disc containing bacitracin is put on a plate. If there is a zone of inhibition, the colony is Streptococcus group A, which is sensitive to bacitracin.. An example of group A Streptococci is S. pyogenes

Indole biochemical test

a biochemical test for indole, an aromatic compound. E. coli tests positive

oxidase test (biochemical test)

a biochemical test for oxidase. Positive tests results from the production of indophenol, a purple product. Neisseria will test positive

Thayer-Martin agar

a blood agar that is selective for Neisseria gonorrhoeae and Neisseria meningitidis (gram -). Other contaminants are killed by the antibiotics Colistin, nystatin, vancomycin, trimethoprim and lincomycin.

Streptococcus agalactiae and camp test

a camp test is where a blood agar plate is streaked with a line of S aureus and an intersecting line of S agalactia. Results in an arrowhead appearance where the lines intersect due to synergistic effect of CAMP factor (from S agalactia) and springomyelinase C (from S aureus).

Ryes syndrome

a complication of influenza, it occurs in children with recent history of aspirin intake. Characterized by fatty liver, CNS dysfunction, and cerebral edema.

safranin

a counterstain that stain gram negative bacteria a pink/red color while leaving the gram negative cells purple

sequestrum

a dead piece of bone that has broken off. Indicates an established bone infection.

Common variable immunodeficiency (CVID)

a defect in B cell differentiation with many causes, not hereditary. Occurs in the 20s and 30s, and results in a decrease in plasma cells and immunoglobulins. B cells don't receive the help they need from T cells.

Chronic granulomatous disease (CGD)

a deficiency of NADPH oxidase, which is utilized by phagosomes to kill phagocytized bacteria. These patients will be more susceptible to infections by catalase (+) organisms (S aureus, Pseudomonas). Granulomas (the body's method of walling off an infection) are common. Nitroblue tetrazolium dye reduction test for NADPH oxidase; if the dye turns blue (a positive test) then NADPH is present. Will show abnormal dihydrorhodamine (flow cytometry) test, which normal would show superoxide radicals.

Selective IgA deficiency

a deficiency where a person does not produces IgA, unknown cause. Most peeps are asymptomatic. If that person is given a blood transfusion they can have an anaphylactic response due to antibodies against IgA in the transfused blood. Blood levels will show low IgA which normal count of everything else.

Hektoen Enteric Agar

a differential medium that selectively prevents growth of all bacteria except Enterobacteriaceae (gram -), especially Salmonella and Shigella. Also contains lactose and distinguishes lactose fermenters from nonfermentors (Salmonella, Shigella). It also contains thiosulfate which differentiates Salmonella from Shigella. Salmonella reduces thiosulfate to hydrogen sulfide, a black precipitate.

RhoGAM

a drug that suppress the immune response to Rh+ blood. It acts by killing all the Rh+ blood before the body is able to form antibodies against it. It is injected once between 26-28 weeks of pregnancy and once withint 72 hours after delivery

Klebsiella pneumoniae

a enterobacteria (gram -). oxidase negative, and lactose forming. Causes pneumoniae. Their sputum is a thick, red, gelatinous sputum. It has a thick capsule which it allows it to escape the immune system. MacConkey agar is good for it because it is gram (-) and can ferment lactose.

Kingella kingae

a facultative anaerobe bacteria normally found in the oral cavity, can cause OM from human bite wounds. Can ferment glucose, is beta hemolytic

Eikenella corrodens

a facultative anarobe bacteria normally found in the oral cavity, can cause OM from human bite wounds. Is both ornithine decarboxylase and lysine decarboxylase positive. They smell like bleach when grown on agar

Legionella

a facultative intracellular bacteria named because of a group of people who attended an american legion meeting and who died from it, and the ella part is because it requires cysteine for growth. Symptoms are body ache, fever, chills, flu like symptoms. It is only contracted by people with immunocompromised states (or old folk). It is a water-born illness so people who contract it may be pool cleaners, work around water, etc. Can cause atypical pneumonia. People who have renal transplants may also acquire it. Causes Legionnaire disease which is typical pneumoniae symptom along with GI symptoms (nausea, vomiting, watery diarrhea). Also causes pontiac fever, which is just mild flu like symptoms. Detected by presence of antigen in the urine. Labs show hyponatremia.

bacterial spore

a form that can be induced due to lack of nutrients. Sproes are resistant to heat (due to dipicolinic acid in their core) and chemicals, have no metabolic activity. Kill via autoclave (121 degC for 15 mins). Spore formers in soil: Bacillus anthracis, C perfringins, C tetani. Other spore formers: B cereus, C botulinum, Coxiella burnetti

mucormycosis: Mucor and Rhizopus (MC)

a fungal infection that grows in and around blood vessel walls, including those of the face and brain. They block the blood vessels and cause necrosis of tissues that are distal to the blocked vessel. Classically presents as black eschar on the face. Usually found in peeps with diabetic ketoacidosis or leukemia (where there is excess ketones and glucose in the blood), and the fungus proliferates in the blood vessels where there is excess ketone and glucose. Microscopically shows non septate hyphae.

Tinea versicolor

a fungal skin infection caused by Malassezia furfur. Occurs in hot, humid weather. The fungus degrades lipids in the skin which damages melanocyts and caused hypopigmented or hyperpigmented patches of skin. "Spaghetti and meatball" appearance is seen histologically.

Giemsa stain

a fungal tissue stain that detects Histoplasma capsulatum

Aspergillus

a fungi that causes opportunistic infections. It is killed by neutrophils, so neutropenic peeps and chronic granulomatous peeps are high risk. Infects the lungs and can form aspergillomas. Produces aflatoxins that can hepatocellular carcinoma.

Cryptococcus neoformans

a fungus that causes acquired from pigeon poop. Only found in immunocompromised, AIDS peeps with CD4 <50. Initially infects the lungs, then spreads to the brain and causes meningitis. Symptoms will be fever, loss of consciousness. Can be view on india ink staining, which shows white budding yeast on black backgroud. It does not stain because of its thick polysaccharide capsule, which is also a virulence factor (VF).

aspergillus

a fungus that causes nosocomial respiratory infections. Branched (acute/45 deg anlges), septate (have septum which divide cells) hyphae. Invasive aspergillus that invades the lungs and can cause hemoptysis is only found in immunocompromised. They can form aspergillomas (growths) in the lung in cavities left by TB (aka colonizing). ABPA found in peeps with asthma or cystic fibrosis.

Pneumocystis jiroveci

a fungus that causes respiratory infections/pneumonia. It does not have ergosterol in its cell wall so it will nor respond to traditional antifungal drugs. The only people who get infected are immunocompromised (like HIV).

HIV: nef gene

a gene that downregulates CD4 and MHC ll expression. MHC ll is found on APC (antigen presenting cells) and help identify pathogens. So when MHC ll is downregulated, the body can't fight infections as well. Thus this gene plays a large role in the progression to AIDS.

BTK (Bruton's Tyrosine Kinase)

a gene that encodes a tyrosine kinase that is essential for B cell differentation. If there is a dysfunction in that gene then B cells can't mature. Those B cells die in the periphery, and there is a low blood B cell count, but there is a normal blood count of B cell precursor cells which have CD19 marker.

Tinea

a general term for a skin condition caused by 3 specific fungi. Skin conditions that are caused includes ringworm, athletes foot, etc. Generally cause pruritic leasions in a ring shape. The 3 species are known as dermatophytes: Microsporum, Trichophyton, and Epidermophyton.

CBC (complete blood count) and normacl values:

a general test for RBC count, WBC count and diferential, hemoglobin, hematocrit, and others. It can detect anemias and infections. Normal values: RBC count: 4.8x10^6 /mL. WBC: 4,500-10,000 /mL, platelent counts 150,000-400,000/mcL WBC differential: Neutrophils 40-60%, Lymphocytes 20-40%, monocytes 2-8%, eosinophils 1-4%, Bands(immature WBCs) 0-3%, Basophils 0.5-1.0%.

Wiskott-Aldrich syndrome

a genetic defect that causes a triad of conditions: thrombocytopenic purpura, thrombocytopenia, eczema, and recurrent infections. T cells are unable to recognize actin cytoskeleton (found in encapsulated bacteria), so they don't stimulate production of IgM. Peeps have low IgM and platelets, normal IgG, high IgE and IgA. Platelets are also smaller.

Atopy

a genetic predisposition to have high IgE and a Th2 bias. Kids with 1 allergic parent have a 30% chance of allergy and kids with both allergic parents have 50%

Rickettsia

a genus of gram (-), pleomorphic, obligate intracellular. Causes Disease like Typhus and Rocky mountain spotted fever.

Nocardia

a gram (+) bacteria that forms branched rods. Can cause pneumonia and lung abscess. Unique because it can stain gram (-) with gram (+) intracellular beads. Also AFB (+) (unlike actinomyces). Treat with sulfonamide antibiotics

enterococcus

a gram (+) bacteria that is part of the normal intestinal flora. Ex, Enterococcus faecalis and Enterococcus faecium. They usually infect the urinary tract or soft tissues adjacent to the intestine. They are able to grow in the presence of high concentrations of bile salts and sodium chloride. They are identifiable because they are the only bacteria that is able to grow in bile esculin agar (which has a high bile and salt content), which is evident by changing the agar to a black color.

Streptococcus pneumoniae

a gram (+) diplococcus, the most common cause of pneumonia, specifically lobar pneumonia. Lancet-shaped. A flora common to the URT that can become pathogenic if a person is immunocompromised. People with pneumonia due to this will have runny nose, cough, fever, chest pain, puruluent and "rusty" (bloody) sputum. The lung may become consolidated (filled lung) which will be apparent during auscultation. Because it is gram (+) treat with a penicillin. Bile soluble (lysed by bile, unlike S viridans). No virulence without capsule

Rhodococcus

a gram (+) facultative intracellular bacteria that can be coccus or rods. AFB (+). Can cause pneumonia. Treat with with a combo of vancomycin and ciprofloxacin (a quinolone)

Clostridium tetani

a gram (+) rod, spore forming, obligate anaerobe, that produces the exotoxin tetanospasmin which causes paralysis by cleaving inhibitory neurotransmitters in spinal cord.

Haemophilus influenza

a gram (-), oxidase (+) bacteria that grows on chocolate agar (broken down RBC) and not blood agar, unless another bacteria like Staphylococcus breaks down the RBCs in normal blood agar which will allow satellite colonies. It can cause respiratory infections in older children and adults, and meningitis in young children. Type B has a capsule (made of polyribitol phosphate (PRP)), other types do not have a capsule.

Pseudomonas aeruginosa

a gram negative bacteria, B-hemolytic, catalase (+), oxidase (+), doesn't ferment lactose, and is unique because it produces a bluish green color. Produces Exotoxin A which inhibits protein synthesis by causing ADP ribosylation which inactivates elongation factor-2 (EF2). It also produces elastin which breaks stuff down. It is resistant to many antibiotics.

Escherichia coli (E. coli)

a gram negative, lactose fermenter, has fimbriae.

Bacillus anthracis

a gram positive bacteria that is unique because it has a poly-D-glutamyl (D glutamate) capsule that has antiphagocytic properties. It can be identified in agar by adding a specific phage that only breaks down B. anthracis

Lowenstein-Jensen agar/Middlebrook agar

a growth medium selective for Mycobacterium. It is an egg-based medium containing malachite green, which kills contaminants. Middlebrook agar more chemically defined

TCBS (thiosulfate citrate-bile salts) agar medium

a growth medium selective for the Vibrio (gram -) bacterial family (cholera, diarrhea, food poisoning)

Cefsulodin-Irgasan-Novobiocin (CIN) agar

a growth medium selective for the Yersinia (gram -) bacterial family. Yersinia pestis is the plague

Eosin Methylene Blue (EMB) agar

a growth medium that allows gram negative growth, but the eosin and methylene blue inhibit gram positive growth. It also contains lactose which allows differentiation between lactose fermenters and non fermenters. Lactose fermenters grow as purple/black colonies, except E coli which has a green sheen.

selective/differential media

a growth medium that contains characteristics of both selective and differential media. ex, mannitol salt agar.

Tinsdale (tellurite) medium

a growth medium that identifies Corynebacterium diphtheriae (gram +), which converts the metal tellurite into tellurium, which is the indicator. Tellurite inhibits gram negative and other gram positives

BG (Bordet-Gengou) agar

a growth medium that is selective for Bordetella pertussis (gram -), aka whooping cough

BCYE (buffered charcoal yeast extract) agar medium

a growth medium that is selective for the Legionella (gram -) bacterial family, contains cysteine.

Colombia CNA (colistin naladixic acid) blood agar

a growth medium that provides rapid growth of gram positive organisms and inhibits gram negative organisms via colistin naladixic acid

MacConkey agar medium (Mac)

a growth medium that selects for gram negative bacteria due to bile salts which inhibit gram positive bacteria. Bacteria which ferment lactose (E. coli) change the neutral red indicator in the medium to a dark pink/red, which causes the colonies of bacteria to appear dark pink (a differential affect)

MES (2-N-morpholinoethanesulfonic acid), AKA ureaplasma agar

a growth medium used to isolate Ureaplasma urealyticum, a mycoplasma (lacks cell wall). Contains horse serum which supplies the cholesterol needed for stabilizing organisms that lack a cell wall

XLD (Xylose Lysine deoxycholate) agar

a growth medium which isolates Salmonella and Shigella (gram -) and differentiates between the two. Salmonella produces H2S in the form of a black precipitate, Shigella doesn't.

egg yoke agar

a growth medium with phospholipids. Organisms with lecithinase like Clostridium (gram +) are differentiated from those without. Lecithinase degrades phospholipids into insoluble diglycerides which is the indicator.

cholesteatoma

a growth of squamous epithelium in the inner ear that can cause bone erosion. Symptoms are ear discharge and hearing loss. Can be congenital or acquired. Physical examination reveals epitympanic retraction pocket, or perforation that exudes keratin debris.

Taq polymerase

a heat stable DNA polymerase used in PCR. It is from Thermus aquaticus

antiphospholipid syndrome

a hypercoagulable state. Can occur with or without lupus. Lupus anticoagulant antibody (+),

Clostridium perfringens exotoxin (alpha toxin)

a lecithinase (a phospholipase) that degrades tissue and cell membranes (cell membranes contain phospholipids). Causes myonecresis ("gas gangrene" because it produces gas in infected tissues). Also causes hemolysis which causes a double zone of hemolysis on blood agar.

disaccharidase deficiency

a malabsorption deficiency caused by a lack of enzyme that break down disaccharide sugars, usually the deficiency is lactase. The villi appear normal. Causes osmotic (watery) diarrhea. Since lactase is located at the tip of intestinal villi, the enzymes can get washed out by something like viral diarrhea and cause a temporary lactase deficiency. Diagnosis is if giving lactose produces symptomes and glucose levels rise <20 mg/dL.

Tropical sprue

a malabsorption disorder the happens to peeps who recently visited the tropics. Responds to antibiotics.

abetalipoproteinemia

a malabsorption syndrome caused by decreased synthesis of apolipoprotein B, which results in inability to generate chylomicrons, which causes decreased cholesterol secretion and VLDL in the blood, which causes accumulation of fat in enterocytes. This syndrome is evident in young kids due to failure to thrive, ataxia, night blindness

pancreatic insufficiency

a malabsorption syndrome due to cystic fibrosis, obstructing cancer, or chronic pancreatitis. Causes malabsorption of fat and fat soluble vitamins (A,D,E,K). Diagnose with D-xylose absorption test.

Whipple disease

a malabsorption syndrome usually seen in older men. Caused by Tropheryma whipplei; gram (+), periodic acid-schiff (PAS) (+). Symptoms are typical of a malabsorption syndrome: diarrhea, steatorrhea, weight loss, weakness, vitamin and mineral deficiency. This disease also causes arthralgias, cardiac symptoms, neurologic symptoms. shows foamy macrophages in intestinal lamina propria.

Babesiosis

a malaria like disease of genus Babesia, a microscopic parasite that invades RBCs and causes hemolytic anemia, hemoblobinuria, high fever. Parasites transmitted by ticks, found in northeastern US. Humans are accidental "dead end" hosts, because they do not transfer it to other humans.

Histoplasmosis (ohio valley fever), ex, H. capsulatum

a micro and macro conidia forming, dimorphic fungus that can cause respiratory disease. Acquired in the midwest due to contact with bat poo (found in caves). It grows within macrophages. In immunocompentent it is usually asymptomatic, but can cause lung infection (pneumonia) in immunocompromised.

Trypanosomiasis (Chaga's disease and african sleeping sickness)

a microscopic parasite transmitted by triatomine "kissing" bugs or by fecal contamination. Affects the nervous system (african sleeping sickness) and the heart (Chaga's). Found in central and S america.

hapten

a molecule that can elicit an immune response when bound to another molecule (which is not bound to a cell). When the molecule that the hapten binds to is an antibody, the immune reaction is a type lll HSR. When the other molecule is not an antibody, the immune reaction will be a type lV HSR mediated by T cells.

gram's iodine

a mordant (it "sets" or "fixes" dyes into the material) that fixes crystal violet into the cell wall

MAC (Mycobacterium avium intracellular complex)

a mycobacterium (stains with AFB), found in AIDS peeps withCD4 <50. Acquired from tobacco, soil, or water. Causes TB like symptoms, starts with respiratory infection that disseminates

Rhinovirus

a non-enveloped, + SS (single stranded) virus, member of picorna virus, that grows well in lower temps and lower pH. Binds to respiratory epithelium via specific ICAM-1 receptors.

Measles (aka rubeola)

a paramyxovirus that affects children. Symptoms are fever, cough, conjunctivitis, coryza (cold like symptoms, rhinitis), and a rash that starts on face/head and moves down the body (like rubella). Classically has Koplik spots (red spots with a white center, in the mouth). Can be followed by encephalitis, or Subacute Sclerosing Encephalitis (SSE) many years later. Prevented with MMR vaccine.

Chagas disease (American Trypanosomiasis)

a parasite caused by infection of Trypanosoma cruzi due to a bite from the "kissing bug", found in central and south america (or immigrants). It has a few forms in the body, the trypomastigote form is in the blood and is detected for diagnosis.

Malaria

a parasite transferred by the Anopheles mosquitos. Sporozoites enter the blood and travel to the liver and enter hepatocytes where they replicate, morph into merozoites, and rupture/kill the liver cells. Those leave the liver and start invading/lysing RBCs, and also produce gametocytes, which are taken up by the mosquito when it bites.

Leishmania donovani

a parasite transmitted by sandflies, outside US. Causes leishmaniasis, aka Kala- azar. They are intracellular parasites whose intubation period is a couple months of typical fever. Causes pancytopenia (low white/red blood cells and low platelets) protrusion of abdomen due to spleen and liver enlargement (massive hepatosplenomegaly). Amastigotes seen in macrophages. Also causes edema of the face and bleeding mucus membranes

Gardnerella vaginalis

a pleomorphic, gram variable rod that causes vaginosis.

Spore formers and Clam

a pneumonic for gram (+) rods. If you know these and the 5 cocci, then the rest are gram (-) rods.

Urease biochemical test

a positive test is the production of ammonia. Proteus (gram -) species will test positive

calcineurin

a protein phosphatase in T helper cells that becomes activated and causes the cell to produce IL-2. Calcineurin acts on NFAT (nuclear factor of activated T cell) which moves into the nucleus and causes transcription of IL-2 proteins. It is inhibited by Cyclosporine and Tacrolimus.

Toxoplasma gondii symptoms

a protozoa CNS infection. Acquired by eatingn undercooked meat, or cats (common reservoir). Is asymptomatic in immunocompentent peeps (about 50% of peeps are serologically (+)). 2nd MC cause of encephalitis in AIDS patients , it causes a ring enhanced lesion. A fetus can be infected only if the mother in infected while pregnant; it can cause triad of chorioretinitis (inflammation of choroid), intracranial calcifications, retardation, etc.

Giardia

a protozoa that exists as a cyst and trophozoite form. Transfer occurs by fecal-oral route, ingestion of cysts in fecally contaminated water. The trophozoite attaches to the gut wall but does not invade the mucosa or enter the bloodstream. It causes malabsorption of protein and fat. Symptoms are watery, foul-smelling diarrhea, bloating, flatulence, nausea, abdominal cramps, fat in the stool (not bloody). Trophozoite is pear shaped with two nuclei.Treat with metronidazole.

opthalmis neonatorum

a purulent ocular infection of neonates at birth due to gonorrhea.

HIV: gag (group antigen) gene

a retroviral (HIV) gene that codes for matrix protein p17 (MA) and capsid protein p24 (CA). p24 elicits the first antibody response in patients and that antibody is detected by ELISA as a means of screening.

what does a high ESR (erythrocyte sedimentation rate) indicate?

a rough indication of inflammation somewhere in the body. It is not that helpful because there is a good chance that inflammation is happening somewhere.

Phenylethyl alcohol agar with blood (PEAB)

a selective medium that supports gram positive organisms and inhibits gram negative organisms via phenylethyl alcohol. Gram negative will still grow, but not as much

Reactive arthritis (Reiters syndrome)

a seronegative spondyloarthropy (HLA-B27 (+), RF (-), arthritis), an autoimmune condition. Manifests as arthritis, urethritis, and conjunctivitis, and occurs days after a GI or Chlamydia trachomatis infection. Arthritis is asymmetric and usually affects the knee, ankle, or sacroiliac joint.

mTOR (mechanistic target of rapamycin)

a signaling protein in T helper cells that plays a role in the production of IL-2 transcription. When IL-2R (IL-2 receptors) are activaed, they activate mTOR which causes IL-2 transcription. Sirolimus (rapamycin) binds it to prevent IL-2 transciption, which causes immunosuppression.

Borellia burgdorferi

a spirochete bacteria that causes lyme disease that is most MC in northeastern US. Lyme disease is transferred by nymph form of Ixodes (ticks, same vector as Babesia) that are active summer and fall only. Human are dead end hosts. Can't be gram stained because the cell wall is so thin that the gram stain isn't picked up. Diagnose with Elisa, then confirm with western blot. Treat with antibiotics. The vaccine contains recombinant OspA (a virulent surface protein)

anergy

a state of nonreactive T cells that cannot act because they need stimulatory signal/molecule. When an T cell doesn't receive the costimulatory signal from the APC (B7 binding to CD28), the T cell isn't activated, which is anergy.

Streptococcus bovis

a strep species that lives in the gut. Unique because it is gamma hemolytic (no hemolysis).

atypical mycobacteria

all mycobacteria except tuberculosis and leprae (leprosy). They are acquired via soil and water (TB is aqcuired by human transmission via respiratory droplet). Stain with AFB (Ziehl-Neelsen) same as TB.

vaccine adjuvants

a substance that aids another substance in its action to help a vaccine induce an earlier, more potent, and longer lasting immune response. It concentrate the Ag at the site of injection (depot effect), helps deliver the Ag to the APCs (antigen presenting cells), directs effects of APCs and lymphocytes via inflammation, and targets innate immune components like TLR (toll like receptors). Ex, inorganic salts, bacterial products, cytokines, etc

urea breath test

a test for H pylori. A person ingests urea with radiolabeled (C13 or C14) carbon. If the bacteria is present it will break it down into ammonia and CO2, and the person will breath out the radiolabeled CO2, which is a positive test.

TB/Tuberculin/Mantoeux skin test/PPD (purified protein derivative test

a test for TB where an injection is given. If the person has TB or has been exposed to it, the area will become red and swollen. The injected is analyzed 48 hours after it is given because the immune response that mediates it is the delayed type hypersensitivity (DTH), aka cell-mediated immunity

CAMP test

a test for group B streptococcus (agalactiae). It is done by streaking a line of S aureus on a blood agar plate, with a line of agalactiae that intersects it. An arrowhead appearance where the two lines meet is a positive test, and indicates a broad area of hemolysis caused by a synergistic effect of both pathogens.

transillumination test

a test for maxillary sinusitis. shine light below infraorbital rim. Normally light will illuminate the upper part of the mouth on that side. A positive test is an absence of light, which is blocked by the inflammation.

allogeneic stimulation

a test that determines compatibility between donor and recipients. APC from the donor are mixed with T cells from the recipient.

sequencing

a test that recognizes specific sequences of nucleic acids (DNA)

biochemical tests utilizing coagulase

a tests for coagulase which allows the ability to bind fibrinogen, causing agglutination of organisms. Staphylococcus aureus tests positive

Grocott-Gomori methenamine-silver nitrate stain

a tissue stain that stains fungal elements black

Masson-Fontanta stain

a tissue stain that stains melanin in the cell wall brown

Periodic acid-schill stain

a tissue stain that will detect the presence of fungus. It stains fungal walls pink

rubella virus (acquired after birth)

a togavirus that affects kids. Symptoms are fever, arthralgia, postauricular lymphadenopathy (swollen lymph nodes), rash (starts at head and moves down). Similar to measles.

HAART (Highly Active Anti Retroviral Therapy)

a treatment for HIV that is given when the patient is symptomatic or has CD4 <500. At least 3 drugs are given simultaneously to prevent resistance: NRTI (Nucleoside Reverse Transcriptase Inhibitor) are nucleoside analogues that stop DNA synthesis. They lack the 3' hydroxyl group needed to bind the next incoming nucleotise, thus ending DNA synthesis. NNRTI (Non Nucleoside Reverse Transcriptase Inhibitors) bind to RT, thus inactivating it.

Schistosoma haematobium

a trematode (fluke) found in the middle east. Snails are the reservoir. Infects the bladder and can cause squamous cell carcinoma of the bladder, which manifests as painless hematuria. Treat with praziquantel

Kaposi's Sarcoma

a tumor caused by HHV-8 that can occur with or without association of AIDS. Causes skin lesions.

contact dermatitis caused by small molecule sensitization

a type lV hypersensitivity where molecules that are too small to be antigens bind to self proteins and create an antigen. These creations are known as haptens and are taken up by the langerhan's cells and presented to Th cells; this is the first phase. The second phase is subsequent exposure to the same Ag which elicits rapid secretion of inflammatory cytokines like TNF and IL-1. Then T cells, monocytes, and macrophages are recruited to the site of inflammation. The release of lytic enzymes by the phagocytes causes tissue damage. Eventually prostaglandin E helps down regulate the inflammation.

arthus reaction

a type lll HSR caused by an intradermal injection (such as a tetanus shot) of antigen induces antibodies, which form antigen-antibody complexes in the skin. Characterized by edema, necrosis, activation of complement. Immunoflourescent staining will detect the IC (immune complexes). This reaction is a local version of serum sickness.

serum sickness

a type lll HSR reaction that occurs 5-10 days after exposure to a drug (or other antigen). Antibodies are formed against the drug bind to the drug to cause the reaction.

What is croup and what is the number one cause in infants

a type of laryngitis characterized by labored noisy breathing and a metallic/brassy cough. A "steeple sign" is seen on an xray, which represents the swelling of the glottis. It is almost always due to a virus, especially Parainfluenza, which is the number one cause in infants.

Plasmodium falciparum and its effect on RBCs

a type of malaria that is sever because it targets all erythrocytes, as opposed to other forms of malaria that only target some. It causes erythrocytes to stiffen (later lysed) which makes it difficult to pass thru tiny capillaries.

Influenza

a virus belonging to the orthomyxovirus family. The genome has 8 segments. It binds to ciliated epithelial cells via hemagglutinin (surface binding protein) and neuraminidase (releases progeny virus from infected cell), hence H1N2. There are 3 strains, A is the most severe and crosses species barrier. B is purely human and less important. C is unimportant. Symptoms are headache, body ache, fever, shaking chills, dry cough, sore throat. Intubation period is short (2 days) with symptoms lasting 3-5 days.

Yellow fever

a virus spread by mosquitos that causes jaundice (yellow) and hemorrhaging of the intestine that causes "black vomit." Nonexistant in N America, occasionally S America.

amyloidosis

abnormal aggregation of misfolded proteins that cause damage or apoptosis in cells. there are many types

Toxoplasma in AIDS patients

about 50% of the general population is sero (+) for Toxo. They form a latent infection which can become active in AIDS patients when CD4 <100. This can cause a "ring enhancing" abscess in the brain. Causes CNS effects (all brain functions) that progress quickly over a period of days.

HIV prevention

abstinence, condoms

diagnosing aspergillus

accomplished by isolating and growing the fungus and identifying the branching, septate hyphae with typical conidium. serology does not help because anti-aspergillus antibody is present in healthy people.

treatments for all types of herpes viruses, except CMV

aciclovir. CMV is treated with gancyclovir. They are prodrugs that first must be phosphorylated by the viral kinase, which converts them into nucleoside analogues that stop DNA polymerase when the polymerase tries to incorporate them into DNA. Viral resistance occurs when the kinase which phosphorylates the prodrug (like thymidine kinase) is mutated so that it doesn't phosphorylate the prodrug.

HIV: tat (trans-activator of transcription) gene

activates transcription of viral genoma

Acute and chronic phase of Chagas disease

acute follows right after infection, and classically causes Romana's sign (swollen eye on one side). Chronic symptoms are more common and are usually cardiomyopathy.

labyrinthitis

acute onset of continuous, usually severe vertigo lasting several days to weeks, along with hearing loss and tinnitis. Often follows upper respiratory tract infection that causes the labyrinth to become inflamed. Peeps with multiple sclerosis can have similar symptoms without the inflammation.

What is the most common causes of acute pneumonia? Chronic pneumonia?

acute: S. pneumonia, S. aureus, H. influenza. Chronic: M tuberculosis, Nocardia

Pseudomonas

aeruginosa is the most important species, and other species only cause opportunistic infections.

Dengue

aka "breakbone fever," a + SS RNA Flavi viral disease transmitted by mosquitos

Ziehl-Neelsen stain

aka AFB stain. Stains mycobacteria, Nocardia.

cat scratch disease

aka bacillary angiomatosis. caused by Bartonella hensalae, gram (-) rod. Transferred via cat scratch. In HIV peeps it causes bacillary angiomatosis which is angiogenesis that causes knots of capillaries, which forms a red papule on the skin that bleeds easily, can be mistaken for kaposi sarcoma.

Sporotrichosis

aka rose gardener's disease. Opportunistic fungal infection caused by Sporothrix schenckii, dimorphic, cigar shaped. Infections occur when spores are traumatically put into the skin, like a thorn. A pustule or ulcer will appear at the site of injury and ascending lymphangitis (draining lymph nodes are inflamed/infected).

acute otitis externa (AOE), malignant AOE, fungal causes (otomycosis)

aka swimmer's ear. Pseudomonas is MC. Can be painful, itchy and have a purulent discharge. Malignant is also MC from Pseudomonas, usually occurs in diabetics, elderly, or immune compromised, can spread to soft tissue, cranial bone, and brain. If fungal it is usually aspergillus, and is also called "tropical ear". Will have good typanic membrane motion, as opposed to limited or absent motion in AOM.

ETEC (EnteroToxigenic E Coli)

aka travelers' diarrhea. Causes watery diarrhea via heat-labile or heat-stable enterotoxins. Doesn't cause inflammation and doesn't invade.

Atypical pneumonia

aka walking pneumonia, unproductive hacking cough, chest x ray with patchy infiltrates. It symptoms are less severe. Causes are legionella (waterborne), mycoplasma (more common in young people), chlamydia. Erythromycin (a macrolide) will resolve all three.

vulvovaginal candidiasis

aka yeast infection. vaginal infection by Candida albicans or Candida galabrata. Induced by a disruption of the normal flora, such as antibiotics or pregnancy. Symptoms: itching, burning, whitish vaginal discharge. pH will be normal (4.0-4.5) Diagnose by viewing the examining scrapings microscopically.

causes of pneumonia in unique situations

alcoholic/IV drug user: S pneumonia, Klebsiella, S aureus. Aspiration: anaerobes. Cystic fibrosis: Pseudomonas. Nosocomial: S aureus, Pseudomonas, other gram (-). Postviral: S pneumonia, S aureus

bind of T cell types

all T cells have CD3 and TCR, Th cells also have CD4, their TCR binds to MHC ll on B cells. Cytotoxix T cells have CD8, their TCR binds to MHC l.

Cell surface markers of lymphocytes

all cells except RBC have MHC l. All T cell have CD3, TCR, CD28, Th also have CD4 and CD40Ligand, cytotoxic T cells also have CD8. B cells have CD19, CD20, CD21, CD40, MHC ll, B7. NK cells have CD16, CD56. Macrophages have CD14, CD40, MHC ll, B7, Fc, C3b receptors

examples of the 3 types of type lll hypersensitivity

all examples demonstate Ab-Ag binding where the Ab is not bound to a cell. When dead parasitic worms remain lodged in the body, Ab bind and constant inflammation occurs. Rheumatoid arthritis and glomerulonephritis are an example of autoimmune reaction, where Ab bind to self antigens. Mold or plant (hay fever) is an example of an inhaled antigen.

MacConkey (MAC) agar and enterobacteria

allows growth of only gram (-). contains bile salts which prevents growth of non gram (-). it has lactose, which allows pathogens to ferment lactose to differentiate, they will grow pink colonies (E coli, Klebsiella). Non fermenters will grow white colonies.

4 toxin types of S aureus

alpha-toxins: cytolysins (break down cell membrane). Exfoliatin: cause skin infections. PTSAgs (pyrogenic toxin superantigens): cause toxic shock syndrome and includes TSST (toxic shock syndrome toxin). Staphylococcal enterotoxins: cause GI infections

treating histoplasmosis

amphotericin B and itraconazole

AA (Amyloid Associated) amyloidosis (aka secondary amyloidosis)

amyloidosis that is seen in chronic conditions: rheumatoid arthritis, inflammatory bowel disease, spondyloarthropathy. Deposited proteins are Amyloid A serum protein.

how T cells (Th1) are activated (costimulation)

an APC displays an antigen (presented via MHC ll) which is recognized by the TCR. CD4 on the T cell also binds to MHC ll. The second (costimulatory) signal is when the B7 protein on the APC interacts with CD28 on the T cell. Now the T cell is activated and can will produce IL-2 which produces more naive T cells and activates cytotoxic (CD8) t cells.

hydrops fetalis

an accumulation of fluid in the fetus caused by fetal anemia. The anemia could be caused by parvovirus B19, syphilis, or alpha thalassemia.

Hektoen enteric agar

an agar that helps differentiate enterobacteria because it shows lactose formenters and H2S producers

Regan-lowe

an agar that will grow Bordatella pertussis (whooping cough)

amyloid-beta (A-beta) protein

an amyloid protein found in alzheimer's disease. it is cleaved from amyloid precursor protein (APP)

structure of an antibody

an antibody is shaped like a "Y", the arms contain the antigenic epitopes, and the base contains the Fc region (which normally binds to the Fc receptor on phacocytes)

goodpasture syndrome

an autoimmune disease and type ll hypersensitivity, caused by antibody binding to type lV collagen in lungs and kidneys, which initiates the immune response against those organs. Characterized by hemoptysis and hematuria

sjogren syndrome

an autoimmune disorder where exocrine glands are attacked and don't work, causing xeropthalmia (lack of tears), xerostomia (saliva, dry mouth), etc. (+) for anti-SSA, SSB (sjogren's syndrome A and B, aka anti-Ro anti-La) antibodies. Causes bilateral parotid gland enlargement It is often found in people who have another disease, like lupus or RA, and will have the antibodies for those also. Increases risk for MALT (mucosa associated lymphoid tissue) lymphoma.

Celiac sprue

an autoimmune intolerance to gliadin, a gluten protein found in wheat. Causes a malabsorption syndrome. Associated with HLA-DQ2 and HLA-DQ8. Anti-endomysial, anti-tissue transglutaminase and anti-gliadin antibodies are found. Villi are blunted and lymphocytes are found in the lamina propria. Causes decreased mucosal absorption in the distal duodenum and proximal jejunum. Diagnosis is via serum levels of transglutaminase antibodies. It is a risk factor for malignancy such as T cell lymphoma. Treatment is a gluten free diet.

Proteus

an enterobacteria that causes UTI and can produce urease (urease (+)). Can cause renal stone formation. They are highly motile, which is why they forms wavy growth on agar plates.

"shift to the left"

an increase in the proportion and number of immature neutrophils (bands/stab) in a blood count compared to mature neutrophils (segmented/segs/polys). Indicates an acute bacterial infection

Roseola

an infection by HHV-6,7 that causes high fevers for several days followed by a diffuse rash. The high fever can cause seizures. Usually affects infants

osteomyelitis (OM)

an infection of the bone. Can be blood borne, a secondary infection due to local trauma, inoculation of microbe during surgery, from an adjacent soft tissue infection. Staphylococcus aureus (coagulase positive) is 50% of cases, coagulase negative Staphylococcus is 25%. Mycobacterium tuberculosis (TB) and salmonella are rare, but noteworthy.

Trichinosis

an infection of tiny nematodes (roundworms) caused by the genus Trichinella. T spiralis is the MC type, has a length of 1-2 mm, and is transferred by eating undercooked pork or bear. Diagnose via high eosinophils and high IgE levels. When treating (mebendazole), drugs are given to kill the parasite, and steroids must be given to prevent a hypersensitivity reaction that will result, which is worse than the initial infection.

zoonosis

an infectious disease that is transferred between species. Ex, Malaria transferred from mosquitos to humans.

tumor necrosis factor (TNF) alpha

an inflammatory cytokine released primarily by macrophages as part of the acute phase response. It caused chemotaxis by increasing synthesis of adhesion molecules to allow neutrophils to pass thru the endothelium at the site of infection. Also causes fever.

Mycobacterium tuberculosis

an obligate intracellular bacteria that can cause pneumonia. It enters macrophages and chills in a phagosome while preventing the fusion of the phagosome with lysosomes (via sulfatides). It produces niacin and has a catalase that is active at body temp but not at high heats (68 deg). It is acid-fast like all mycobacterium, meaning that after it is colored by a stain (like carbolfuchsin) it will not decolorize with an acid wash.

Toxoplasmosis

an obligate intracellular parasite caused by Toxoplasma gondii. Symptoms are similar to mononucleosis; fever, sore throat, etc. Animals (especially cats) are a reservoir, and people can acquire it by eating infected animals (pork) or by contact with animal feces. It can be passed from pregnant mothers to the fetus, causing many symptoms, including abortion or stillbirth. People who are immunosuppressant can have a reactivation of a latent infection. 50% of AIDS patients (or patients receiving immunosuppressive therapy) develop toxoplasmic encephalitis (2nd MC cause). Diagnose via serology (even tho 50% of US population is sero (+))

epiglottitis

an upper respiratory infection that is usually from Haemophilus influenza infection, (not viral like other upper respiratory infections). Can be seen with "thumb" sign on xray which is an inflamed epiglottis. Symptoms are fever, sore throat, hoarseness, muffled cough, inflamed "cherry red" epiglottis. The surrounding tissue can also be inflamed and obstruct the airway.

interferon (IFN) alpha and beta

anti tumor signaling molecules that are released by infected cells. They act on uninfected cells and prime them for viral defense. When those primed cells are infected by a virus, protein synthesis stops in the cell which prevents viral amplification and eventually causes apoptosis.

what makes SLE patients test (+) for on VDRL (syphilis) tests

antibodies that bind to cardiolipin cause the false (+). Called antiphospholipid syndrome, which can occur along with SLE

HSR (hypersensitivity reaction) type ll

antibody mediated, cytotoxic response. IgM and IgG bind to antigens on pathogen cell and trigger an immune response. Antibodies can mistakenly target host cells, such as RBCs (which would cause a (+) Coombs test) and cause hemolytic anemia. ex, Rheumatic fever

HSR type lll

antibody mediated. IgG attach to antigens not attached to a cell and form an immune complex that can deposit in tissues and cause inflammation. ex, Rheumatoid arthitis, serum sickness

Flucytosine

antifungal drug that inhibits synthesis of DNA, RNA, and proteins.

Staphylococci

appear in clusters and are catalase (+). S aureus is coagulase (+), the S epidermidis and S saprophyticus are (-). Saprophyticus is resistant to novobiocin but epidermidis is not, and they can be distinguished this way. They are common nosocomial (hospital acquired) infections. They are resistant to drying out and thus reinfection can occur from clothing contaminated with pus from previous infection

allergic bronchopulmonary aspergillosis (ABPA)

aspergillus infection found in peeps with asthma or cystic fibrosis. Can cause bronchiectasis and eosinophilia.

how to determine if a joint that is painful has septic arthritis or septic bursitis

aspiration biopsy of the bursa and joint

cytolytic activity assay,

assays that measure the ability of a population of cells to kill another population (like infected cells or tumor cells).

systemic mycoses: dimorphic fungus

at room temp (20 degC) it grows as a mold. As body temp (37 degC) it grows as a yeast. Systemic mycoses (which cause pneumonia) like histoplasma, coccidioides, blastomyces, and paracoccioides fall in this category except coccidioides which exists as a spherule at body temp. Sporothrix schenckii is also dimorphic. No person to person transmission.

multiple sclerosis

autoimmune destruction of CNS myelin and oligodendrocytes, a type lV HSR. MC found in women in their 20s and 30s. Symptoms are neuropathy: optic neuritis (causing loss of vision), internuclear opthalmoplegia (difficulty adducting eye), hemiparesis (one sided body weakness), hemisensory, incontinence, others. Oligoclonal bands (IgG in CSF) are diagnostic. MRI is used for diagnosis which reveals damage, periventricular plaques. HLA-DR2. Treat with interferon beta

scleroderma

autoimmune disease characterized by fibrosis and collagen deposition, causing puffy and taught skin. There are two types: diffuse scleroderma (more severe), and limited scleroderma (aka crest syndrome). Often anti-ANA (+) (many autoimmune disease are anti-ANA (+)).

myasthenia gravis

autoimmune disease where autoantibodies bind to postsynaptic ACh receptors, causing muscle weakness. Droopy eyelids and double vision classically presents. Treat with acetylcholine esterase inhibitors.

Celiac sprue (disease)

autoimmune disease, intolerance of gliadin (protein found in gluten/wheat), due to malabsorption. HLA-DQ2,8, antiendomysial (+), anti-tissue transglutaminase (+), anti-gliadin (+). Causes blunting of intestinal villi. Associated with dermatitis herpetiformis. Increases risk for T cell lymphoma. Treat with gluten-free diet.

Rheumatoid arthritis

autoimmune disease. RF (+)(rheumatoid factor) are immunoglobulins (IgM, IgG, etc) that bind to the Fc region of IgG. Cause inflammation in joints, type lll and lV HSR. Inflammation and joint destruction caused by release of IL-1 and TNF (inflammatory cytokines). Inflamed synovium leads to pannus formation, which is inflamed granulation tissue. Rheumatoid nodules are often seen. Morning stiffness improves with activity. Also anti-CCP (+) (anti cyclic citrullinated peptide)

systemic lupus erythematosus (SLE)

autoimmune disorder, caused by IgG autoantibodies that cause type lll HSR. Symptoms: rash (malar), joint pain, fever, photosensitivity. Lab values: ANA (+) is sensitive but not specific , Anti-dsDNA antibodies (+), anti-Smith (+) both are specific but not as sensitive. Antihistone antibodies indicate drug induced lupus. HLA-DR2 and DR3. Can cause false positives to syphilis screening tests VDRL and RPR. There will be low levels of early complement proteins (C2, C3, C4) due to immune complex formation. Symptoms can be treated by suppressing immune system: NSAIDs, steroids, etc.

difference between manifestations of babies with B cell versus T cell deficiency

babies with a B cell deficiency will be fine for about 6 months because they still have IgG from the mom that compensates for their lack of production. Babies with a T cell deficiency will have problems from infections from birth.

difference between bacterial infections, viral infections, and allergies of the eye

bacterial may cause a purulent discharge, redness, gritty feeling, can infect one eye and spread to the other. Viral can cause a watery discharge, redness, irritation, can affect one eye and spread to the other. allergic affects both eyes and itching, tearing, swollen eyelids.

immunodeficiency induced by HIV

because HIV infects our own cells, those cells are killed by other cells in our immune system such as NK cells and

why influenza is so dangerous/can lead to death, and what are the secondary bacterial pathogens.

because influenza targets and kills the ciliated epithelial cells of the respiratory tract, bacterial infections are can more easily enter. the secondary bacterial pathogens are: S. pneumoniae, S, aureus, S. pyogenes, H. influenza.

staining techniques for fungus

before using the stains crystal violet or lactophenol cotton blue, first treat with 10-20% KOH solution, which dissolves the keratin of skin, hair, and nails, but leaves fungal elements intact. Calcofluor white is added to the KOH solution. India ink gives negative staining (black backdrop of fungus), also stained with Mucicarmine.

Onset of symptoms in HIV

begins when the CD4 T cell count is <450/uL. Full blown AIDS and more significant disease occur when CD4 count is <200. CD4 cells normally activate macrophages and CD8 T cells.

characteristics of S aureus

beta hemolytic, ferments mannitol, catalase positive (S pyogenes is negative), coagulase positive. The cell wall contains ribitol-teichoic acid, which is unique to S aureus. A virulent factor of S aureus is protein A, that prevents phagocytosis by binding to the Fc region of IgG. Can cause pneumonia after influenza infection (but S pneumonia more likely).

alpha/beta/gamma hemolytics

beta hemolytics completely break down RBCs so the agar will be clear around those colonies on a plate, ex , Streptococcus group A. Alpha hemolytics only partially bread down RBCs, and those colonies will turn the agar green (from red), ex, S. pneumoniae. Gamma hemolytic means that it does not break down RBCs.

characteristics of mucor and rhizopus

broad, non septate hyphae, branch at wide angles (aspergillus is septate and branches at acute angles). Rhizopus is more common than mucor.

protein A (S aureus)

binds the Fc region of IgG, preventing opsonization and phagocytosis.

bile esculin test

biochemical test for group D streptococci, AKA Enterococcus, which can hydrolyze esculin. A vial with esculin in inoculated. If Streptococcus group D (aka Enterococcus) is present, it will hydrolize esculin and the vial will change color

difference between RMSF and typhus

both are caused by Rickettsia, RMSF by ricketsii and typhus by prowazekii. RMSF vector is a tick, typhus is fleas. RMSF causes a fever, Typhus doesn't. RMSF spreads inward (Rickettsia on the wRists, Typhus on the Trunk) and affects palms and soles, typhus spreads outward and does not affect palms and soles.

Salmonella and Shigella

both are gram (-), enterobacter, lactose (-), cause bloody diarrhea, also watery diarrhea. Salmonella is motile, has flagella (thus motility), and produces H2S (hydrogen sulfide. Shigella (is shy) is not motile, no flagella, does not produce H2S. Salmonella enterica is the GI pathogen, S typhi causes typhoid fever.

similarities and differences between exotoxins of Clostridium tetani (tetanospasmin) and Clostridium botulinum (botulinum toxin)

both are proteases that cleave SNARE proteins that are required for neurotransmitter release. Tetanospasmin causes a paralysis of muscle contraction (like lockjaw), while botulinum toxin causes a flaccid paralysis. Tetanospasmin prevents release of GABA and glycine (inhibitory neurotransmitters) from Renshaw cells (gray matter) in spinal cord. Botulinum toxin prevents release of ACh (stimulatory) at neuromuscular junction.

similarities between chlamydia and mycoplasma

both cause atypical pneumonia and cannot be stained (chlamydia can't be stained because it is intracellular, mycoplasma cannot because it has no cell wall). Chlamydia can be distinguished because it has inclusion bodies

Chlamydia pneumoniae, psittaci

both cause atypical pneumonia, aka walking pneumonia, less severe than typical, xray show patchy infiltrates rather than lobar, and unproductive cough. The reservoir of psittaci is birds.

ETEC exotoxin (heat labile toxin and heat stable_)

both cause watery diarrhea. Heat labile toxin overactivates adenylate cyclase which increase cAMP, which increases Cl- secretion and water efflux (water follows ions, causes diarrhea) in the gut. Heat stable toxin overactivates guanylate cyclase which increases cGMP, which decreases absorption of NaCl and H2O in the gut.

exotoxins of Shigella (Shiga toxin) and EHEC (enterohemorrhagic E coli O157:H7) (Shiga like toxin)

both exotoxins inactivate 60S ribosome by removing adenine from rRNA. Shiga toxin causes GI mucosal damage that causes dysentery (bloody diarrhea). Also increases cytokine release, which causes hemolytic-uremic syndrome (anemia, thrombocytopenia, acute renal failure).

Are groups A and B of Streptococcus alpha or beta hemolytic

both group A and B are beta hemolytic. an example of group A is S pyogenes. Example of group B is S. agalactia

exotoxins of Corynebacterium diphtheriae (diphtheria toxin) and Pseudomonas aeruginosa (exotoxin A)

both inactivate EF-2 (elongation factor 2). Diphtheria causes pharyngitis with pseudomembranes in throat (white crap) and severe lymphadenopathy. Exotoxin A causes host cell death.

How EBV causes a latent infection

by infecting B cells and incorporating its genome into the host DNA, which can be expressed later.

furuncolosis in ear canal (class only)

can appear as AOE, but is just an infected hair follicle (from S aureus like all hair follicle infections).

E coli

can cause GI infections, UTI (urinary tract infections) and OM, based on which subtype of E coli it is. Subtypes are based on the presence of 3 different antigens: O antigen is on Outer membrane LPS, K antigen is on the capsule/Kapsule, H antigen is on the flagella. Pili (not flagella) are an important VF (virulent factor) because they mediate attachment to epithelial cells. There are entero subtypes are cause GI infections, and there are uro subtypes which cause UTI and OM E coli ferments lactose (pink colony on MAC agar) and produce indole/are indole (+).

Mycobacterium tuberculosis and OM

can cause OM of the vertebrae (Pott's disease). Culturing the pathogen takes 3 weeks because it is slow growing. Mycolic acids are significant part of the cell wall. It causes a mass to form in the spine that can cause curving of the spine and pain when bending

what test will discern between Staphylococcus and Streptococcus?

catalase test. Staphylococcus is positive (produces catalase), and Streptococcus is negative

TSS (toxic shock syndrome)

cause by S aureus and S pyogenes. Causes fever, chills, vomiting, rash. Can lead to severe hypotension, organ failure. Desquamation on palms and soles can occur 1-2 weeks after onset of illness. Causes decreased liver function, decreased renal function (causes increased creatinine and urea levels). Causes red eyes mouth and vagina due to increased blood flow in those areas. Risk groups are women who are menstruating or use tampons (due to S aureus), people who have nasal surgery (because of plugging the nose to absorb blood), postoperative staph wound infections.

S aureus and and S pyogenes and skin infections

cause impetigo and cellulitis. Impetigo is a superficial skin infection that causes lesions with honey colored crusting. Cellulitis an infection of the dermis or subcutaneous tissue, often due to a break in the skin.

TSS superantigens

cause massive activation of T cells, (normal antigens activate a few T cells), and massive release of cytokines. That cytokines trigger increased vascular permeability which causes hypotension, which causes decreased blood flow to organs, which causes liver and kidney malfunction.

anthrax

caused by Bacillus anthracis, a gram (+) rod, facultative anaerobe, spore former. The only bacteria that has a polypeptide capsule (normally polysaccharide) made of D-glutamate. Produces anthrax toxin. Can infect cutaneously, causing an ulcer with black eschar. Can also be inhaled, causing pulmonary anthrax, flu like symptoms that progress rapidly.

lyme disease

caused by Borrelia bergdorferi, spirochetes. Acquired in the northeast US via ticks.

Infectious Mononucleosis aka "kissing disease"

caused by EBV (Epstein-Barr virus), aka HHV-4 (Human Herpes Virus-4), of the Herpes family. A DS DNA, enveloped. Spread by oral contact. It affects B cells. It causes increase of lymphocytes on a differential, not monocytes (as the name would suggest). Lymphocytes would be reactive (atypical) as expected from a viral infection. Symptoms: fever, hepatosplenomegaly, pharyngitis (often exudative), lymphadenopathy. Monospot (+) (antibodies that agglutinate sheep or horse RBCs). Atypical lymphocytes seen on blood smear are atypical T cells (not B cells).

bacterial vaginosis

caused by Gardnerella vaginalis, Gardnerella mobiluncus due to use of broad spectrum antibiotics, douching, overused tampons, etc. Symptoms: clue cells (sloughed off epithelial cells of the vagina that are covered in bacteria), strong fish odor, itchiness, vaginal discharge (usually thin and white). pH will be high, >4.5 (4.0-4.5 is normal). Diagnose via observation and foul smell. Confirmed cases should have a full STD screening. Complications are aquiring other STDs.

gingivostomatitis, herpetic stomatitis

caused by HSV-1

progressive multifocal leukoencephalopathy (PML)

caused by JC virus, a ds DNA virus, naked, polyoma virus (similar to papilloma/papova family). Affects AIDS peeps when CD4 <200. Infects oligodendrocytes in the brain and causes demyelinative lesions; causing problems behavior, speech, cognition, motor function etc. The symptoms progress over several weeks, (toxo CNS symptoms progress over days). There is no direct treatment, so HIV is treated to that CD4 count rises so it can fight the JC infection.

neonatal conjunctivitis, Chlamydia serotypes. enophthalmitis

caused by Neisseria gonorrhea, Chlamydia trachomatis (serotypes D-K), Haemophilus influenza. Chlamydia serotype A,B,C (not STD) also causes trachoma, conjunctivitis and blindness in adults, but mainly in africa. Infection of other part of the eye is probably S aureus. Endophthalmitis (intraocular infection) is usually caused by Staphylococcus epidermidis

Rocky mountain spotted fever (RMSF)

caused by Rickettsia ricketsii. Vector is a tick. Rickettsia destroys endothelium, and in this disease the blood vessel destruction causes headaches and a rash that starts at the wrists and ankles, then spreads to trunk, palms, and soles. Also causes a fever.

necrotizing fasciitis

caused by S pyogenes or anaerobic bacteria.

Typhoid fever

caused by Salmonella typhi (aka Salmonella enterica serotype typhi). A GI infection that can cause diarrhea (sometimes bloody, usually watery). When the infection spreads to the blood it is typhoid fever (an enteric fever). It infects macrophages which go to the reticuloendothelial system (spleen and liver) and causes hepatosplenomegaly. Symptoms are fever, diarrhea, abdominal pain, "rose spots" (faint pink spots) on abdomen. Infection can reside in gallbladder and cause carrier state.

toxoplasmosis

caused by Toxoplasma gondii, an obligate intracellular parasite, anaerobe, MC acquired by eating pork, also commonly found in felines. The oocyte is the infective form, trophozoite (tachyzoite) is the invasive form which, there is a tissue cyst form. Can cross the placenta and infect fetus. If fetus is infected early in pregnancy there can be cerebral calcifications, microcephaly, hydrocephaly, retardation, stillbirth. If fetus is infected in the 3rd trimester the symptoms may not manifest until later in life, such as mononucleosis symptoms, granulomatous uveitis. Diagnose with serology, treat with Atovaquone (kills tachyzoite and tissue cyst forms).

type lll hypersensitivity

caused by buildup of Ab-Ag that cannot be cleared quick enough. Ab-Ag immune complexes deposit on tissues (the antigen is not bound to a cell like it is in type ll) instead of being cleared by the immune system, and then cause inflammation, platelet aggregation and complement activation. This can be caused by a persistent infection, autoimmunity, or an inhaled antigen. It has a response time of 3-8 hours. The antibodies causing it are IgG and IgM. Diagnosis is via tissue biopsies for deposits of Ab and complement

Mumps

caused by the Paramyxovirus, - SS RNA, enveloped. There is only one serotype and it only infects humans. It is acquired by exposure to infective respiratory droplet or direct human to human contact. Not deadly but can cause other complications. Vaccine is available but no medication. Symptoms: parotitis (swollen parotid glands and other salivary glands), aseptic meningitis, orchitis (enlarged testicles) that can cause sterility.

Hantavirus pulmonary syndrome

caused by the Sin nombre virus, - SS RNA, 3 segmented genome, enveloped viruses of the hantavirus genus, bunyavirus family. Virus is from deer mice (inhaled, feces). Causes flu like symptoms rapid deterioration and most importantly, pulmonary edema (which will kill).

HUS (hemolytic-uremic syndrome)

caused by the shiga toxin and shiga like toxin. Damages endothelium of blood vessels which causes platelet microthrombi formation. Causes anemia, thrombocytopenia, and acute renal failure.

chickenpox (Varicella), shingles (zoster)

caused by varicella zoster virus, herpesviridae. Chickenpox causes rash of vesicles all over the body, the vesicles eventually rupture. Vesicles contain the virus, which is spread by inhalation. The virus lays dorment in the nerves and can become activated, causing a similar rash with smaller vesicles. The rash roughly follows the course of the infected nerve. Prevented with live vaccine.

Diagnosis of pneumocystis, treatment

causes "ground glass" appearance on xray. CD4 count is <200. Stain with silver stain. Sample must be from alveolar lavage, not sputum, because the infection is in the alveoli and not the airways. Prophylaxis/treatment is TMP-SMX when CD4 <200.

what is TSS (toxic shock syndrome) and what pathogens cause it?

causes a mass release of cytokines that causes vasodilation, and thus hypotension. Also, causes DIC (disseminated intravascular coagulation) which is when coagulation factors are activated and consumed, which then causes a deficit of coagulation factors, causing bleeding. It is caused by S aureus and S pyogenes.

transforming growth factor (TGF) beta

causes angiogenesis, fibrosis, cell cycle arrest. Part of wound healing. It also is anti inflammatory by preventing release of inflammatory cytokines. Released by many cells: macrophages, B cells, T cells, etc.

Chlamydia

causes atypical pneumonia, obligate intracellular bacteria responsible for 10% of pneumonia. It cannot be stained because it is intracellular. It has three strains. It has two cell forms; the Elementary body (E for extracellular) is the infectious extracellular form. The Reticulate body (R for reproductive) resides inside a cell and is responsible for reproduction. It has also been linked to atherosclerosis. Treat with erythromycin (like other atypical pneumonias)

EIEC (EnteroInvasive E Coli)

causes bloody diarrhea, dysentery. Invades intestinal mucosa and causes necrosis and inflammation. The only diarrhea causing e coli that also causes leukocytes in the blood (because it is invasive).

Typhus

causes by Rickettsia typhi (endemic(unique to a region)) and prowazekii (epidemic (antigenic drift)). Causes a rash that starts on the trunk and spreads outward, spares palms and soles. Vector is fleas for typhi and louse for prowazekii.

EHEC (enterohemorrhagic E coli O157:H7)

causes dysentery/bloody diarrhea. The MC serotype of E coli. Produces Shiga-like toxins that can cause HUS (triad of anemia, thrombocytopenia, acute renal failure). Hemorrhage of small vessels causes anemia and microthrombi which consumes platelets (and causes thrombocytopenia) and causes acute renal failure. The toxin causes necrosis and inflammation. Unlike other E coli, it doesn't ferment sorbitol.

bacterial endocarditis

causes fever, roth spots (white spots on retina surrounded by hemorrhages), Osler nodes (raised lesion on finger pads), Janeway lesions (small painless red lesions on palms or soles), splinter hemorrhages (in fingernails), heart murmur, anemia, emboli. MC cause is strep viridans (low virulence). S aureus is very virulent. Staph epidermidis occurs with prosthetic valves, Strep bovis in colon cancer peeps.

group B (Streptococcus agalactiae) congenital disease

causes pneumonia, sepsis, and MC cause of meningitis in newborns. The baby can be infected in utero, during birth, or right after birth.

EPEC (enteropathogenic, aka entero Pediatric)

causes watery diarrhea in children. Doesn't produce toxin, it adheres to intestine wall and flattens villi and prevents absorption.

what type of immunity fights fungal infections, and what is the exception?

cell mediated immunity fights intracellular infections such as fungal infections, except aspergillus and candida which rely on innate immunity like neutrophils and marcophages. This is why neutropenic patients are more likely to get aspergillus and systemic candida infections.

with what type of immune response does the body respond to a Chlamydia infection

cell mediated, because it is intracellular.

phospholipid ester-linked fatty acid analysis (PLFA)

cell membrane lipids can be used to identify groups of organism. Because phospholipid degrade after death, cell membrane lipids can also determine whether the organisms are alive or dead. Can determine live versus dead biomass percentages

type lV hypersensitivity, aka delayed type hypersensitivity, is equal to?

cell-mediated immune response. This is different from the first 3 hypersensitivities, which are Ab, (humoral) immune mediated

Clonorchis sinensis

cestode, acquired by eating undercooked or raw fish in asia. They infect the biliary tract and cause inflammation. Associated with cholangiocarcinoma (bile duct cancer).

Diphyllobothrium latum

cestode, acquired via eating raw freshwater fish. Usually asymptomatic, but can cause megaloblastic anemia due to vit B12 deficiency because the worm eats it.

Echinococcus granulosus

cestode, fecal oral route by ingesting eggs in dog feces. Form hydatid cysts (unique to echinococcus) which are large cysts in the liver. Rupture of the cyst can cause anaphylactic shock due to massive release of antigens, so during surgical removal the cyst must be injected with something (like ethanol) to kill everything inside just in case it ruptures.

how to diagnose/test for TB

chest x ray and TB skin test are the cornerstone. QuantiFERON TB Gold (QFT-G) test is best. It takes a person's blood and adds TB antigens. Positive test results from the increase of cytokine like IFN, which indicates that the body recognized the antigen and is mounting an immune response

Enterococcus (group D streptococcus)

cocci, chains (like most streptococci). Include species Enterococcus faecalis and faecium. Normal colonic flora that can cause UTI. Grows on bile esculin agar, which contains salt and bile.

HIV: env (envelope) gene

codes for surface proteins gp41 (TM) and gp120 (SU). gp120 (SU for surface protein) is the first molecule on the virus that attaches to CD4 protein. gp41 (TM for transmembrane protein) is important for viral entry.

HIV: pol (polymerase) gene

codes for the enzymes RT (reverse transcriptase), integrase, and protease.

cold agglutinins, warm agglutinins, autoimmune hemolytic anemia

cold are IgM, warm are IgG, They are antibodies that bind to/lyse RBCs in the body and can cause anemia. Cold agglutinins are seen in mycoplasma pneumonia. Warm are due to SLE and other conditions.

e coli that causes neonatal meningitis

comes from the maternal fecal flora. The major virulence factor is the capsule (serotype K)

H influenza vaccine

conjugated to diphtheria toxoid. This causes a better immune response (increases immunogenicity), including T cells that induce class switching from IgM to IgG and memory B cells, which gives longer protection from the bug.

vaccines for encapsulated bacteria

contain polysaccharide capsule antigens that are conjugated to a carrier protein. This causes T-cell activation and class switching. Type of bacteria with these vaccines are Haemophilus influenza, Neisseria meningitis, strep pneumonia.

causes of rash on palms and soles

coxsackie A, syphilis, rocky mountain spotted fever (ricketsii). Also bacterial endocarditis (S aureus in sever cases, S viridans in mild cases, S epidermidis in prosthetic valves, etc).

causes viral (aseptic) encephalitis.

coxsackie, HSV-1, VZV, Mumps, West Nile, Echovirus

messenger molecules that cause fever

cytokines like IL-1, IL-6, TNF-alpha and others act on the hypothalamus, which releases PGE2, which causes the effects of fever.

hematological changes of hantavirus

thrombocytopenia (low blood platelets) and bandemia (increased immature WBC count)

Leukocyte adhesion deficiency

defectin LFA-1 integrin, aka CD18, which is an adhesion molecule that allows phagocytes to pass the endothelium and enter the site of infection. Symptoms are recurrent pyogenic infections with absence of pus, and omphalitis (inflamed umbilical cord stump). There will be high blood levels of neutrophils, but they will be absent at site of infection.

HDV (hepatitis D virus)

deltavirus, -ssRNA virus, transferred parenterally and requires the help of HBV to infect. Someone infected with HBV and later infected with HDV will have a superinfection. If they both infect at the same time it not so severe.

dendritic cells, langerhans cells, epithelioid cells

dendritic cells are APC (antigen presenting cells) in the immune system. They phagocytize pathogens and present antigens to T and B cells. Langerhans cells are dendritic cells that are found in the skin. They have S-100 markers (because they are from the neural crest), and have "tennis racquet shaped" cytoplasmic granules known as Birbeck granules. Epithelioid cells are macrophages that resemble epithelial cells, and are an essential characteristic of granulomas.

Coombs test, indirect coombs test.

detects antibodies that are bound to RBCs. a test that detects autoimmune hemolytic anemia. (+) peeps will have antigens on RBC that are targeted by the person's own antibodies. It can detect hemolytic disease of the newborn (such as Rh disease). Indirect tests for the antibodies that would cause agglutiniation, but are not bound to anything; this is useful for things like prevent Rho disease of the newborn by detecting the mothers antibodies before she gets pregnant.

OM and diabetes

diabetes peeps have a high risk for OM (and everything else). Often their infections will be polymicrobial

diagnosing, preventing and treating RSV

diagnose via DFA (direct flourescent antibody) of respiratory secretions. There is no vaccine, but the prophylactic (preventive) drug palivizumab can be given before the start of the season to people with underlying illnesses. No drug is given for actual treatment of the illness, unless they have existing lung/heart disease, they are given Ribavirin.

disorders of hypothyroidism and symptoms

disorders: Hashimoto thyroiditis, Congenital hypothyroidism (Cretinism), Subacute thyroiditis (de Quervain), Riedel thyroiditis. Symptoms: cold intolerance (decreased heat production), weight gain and decreased appetite, hypoactivity (lethargy, fatigue, weakness), constipation, diminished reflexes, facial/periorbital myxedema, dry cool skin, course brittle hair, bradycardia. Increased levels of TSH, decreased T3 and T4

dysentery

diarrhea that contains blood and pus. Caused by Shigella, EHEC, EIEC, and Entamoeba histolytica. The infection is usually in the colon (which absorbs less water than the small intestine, most of the water has already been absorbed), so the diarrhea is not as voluminous. Dysentery usually lasts longer than watery diarrheas, but still usually resolve in 2 to 7 days.

differences of RSV and influenza

different viral protein (F and G vs HA and NA). RSV is usually found in infants and young children, influenza in all peeps.

blastomycosis

dimorphic fungus infection found in the midwest (similar as histoplasma). Causes inflammatory lung disease, can spread to skin and bone. Forms granulomatous nodules. Biopsy shows broad-based budding (Blasto buds).

when you have a patient with a genital ulcer, what do you do to discern between syphilis and chancroid?

do a RPR or VDLR test

how to treat Klebsiella and what not to do

do not give penicillins or B-lactams because it has a R factor which breaks down B-lactams. The R factor is found on a plasmid which is transferred by transposition. Treat with 3rd generation cephalosporin

CMV (cytomegalovirus)

ds DNA virus, enveloped, herpesvirus. Can be transferred congenitally, via saliva, sexually, blood transfusions. Can caused latent infection that become reactivated upon immunosuppression. Infected cells become large (cyto=cell, mega=large, virus) with intranuclear inclusion body (not intracellular/cytoplasmic). CMV inhibits the expression of MHC molecules on infected cells (MHC molecules display infective antigens) so the cells escape detection. Treat with gancyclovir

Hansen's disease (leprosy)

due to Mycobacterium leprae, identical to TB in morphology, structure, and staining; AFB. Affects skin and superficial nerves, causing"glove and stocking" effect, which is a loss of sensation. Cannot be grown in vitrio, only live cells. Reservoir in US is armadillos.

Hyper IgE syndrome (Job's syndrome)

dysfunctional Th1 cells don't produce the needed IFN-gamma required to activate macrophages to kill bacteria. Th2 cells proliferate as a compensation and caused production of IgE. Patients will have "cold" (noninflamed) staphylococcal abscesses, course facies (facial features), high IgE levels, and eczema, retained primary teeth.

Bacillus anthracis toxin (edema factor)

edema factor mimics adenylate cyclase which increases cAMP. This increases fluid secretion and is the reason why the black eschar (scab) caused by anthrax has a edematous border.

symptoms and lab values of malaria

elevated temperature, sweating, weakness, enlarged liver and spleen. Lab values will show low hematocrit, low RBC count,thrombocytopenia (low blood platelets), high liver enzymes like aminotransferases (ALT, AST) which indicates liver damage,

asplenic (without a spleen) peeps are more susceptible to what?

encapsulated bacteria, and they should get vaccinated against them. Capsule are made from polysaccharides. Encapsulated bacteria includ: Haemophilus influenza, Neisseria meningitidis, E coli, Klebsiella, Streptococcus pneumoniae, Streptococcus agalactiae (group B strep), Salmonella.

Libman-Sacks endocarditis

endocarditis caused by SLE. Causes wart-like vegetations on both sides of valve.

lipid A, O antigen for gram negative LPS (lipopolysaccharide)

endotoxins (aka LPS) in the outer membrane of gram (-) bacteria have lipid A which causes release of TNF and IL-1, and also O polysaccharide which is the antigen. Lipid A induces inflammation and O polysaccharide is what the body recognizes (i thought they were the same thing, still think they are).

types of exotoxins

enterotoxins (causes intestinal cells to secretel electrolytes and water, aka diarrhea). Cytotoxins (inhibit protein synthesis). Neutotoxins (inhibit neurons)

coronavirus

enveloped, + SS RNA virus. SARS (severe acute respiratory syndrome) is part of this family and is the most important strain. Travel history is important for diagnosis of SARS

leukocyte esterase

enzyme released by the presence of WBC, which may indicate an infection. It is likely elevated a person's urine who has a UTI.

IgA protease

enzymes that cleave IgA and allow certain bacteria to colonize mucosa. Haemophilus influenza, S pneumonia, Neisseria (both types).

What is responsible for seasonal epidemics (new disease) in influenza (the flu). Pandemic (widespread disease)

epidemic (new disease) is from antigenic drift, which are caused by point mutations of hemagglutinin (HA) and neuraminidase (NA) which form NEW variations. Pandemic (widespread) is from antigenic shift, such as crossing species.

extracellular vs intracellular infection

extracellular cause pyogenic infections. Intracellular cause granulomatous infection.

Haemophilus influenza growth requirement.

fastidious (require special diet). They cannot lyse RBC so they are grown on chocolate agar which has factos V (NAD+) and X (hematin) for growth. Has IgA protease. Many subtypes, H inluenza type b is most invasive.

HCV (hepatitis C virus)

flavivirus, +ssRNA virus, transferred parenterally. Can cause chronic hepatitis. Chronic disease occurs in most cases. Can cause liver cancer due to repeated inflammation.

Streptococcus pyogenes

gram (+) cocci, chains, M protein allows it to escape phagocytosis. M protein also causes rheumatic fever. Can cause TSS via exotoxin. Produces C5a peptidase which breaks downs C5a of the complement system. Skin infection like impetigo can cause PSGN (HSR type lll), but not rheumatic fever (requires strep throat infection).

Schistosoma

flukes (trematodes) from middle east, snails are host, infect by penetrating the skin. They mature in liver and reproduce in GI tract, and release eggs that appear in stool and urine. They induce eosinophilia, cause hepatosplenomegaly, liver and spleen granulomas. Cause portal hypertension. Chronic infection can cause squamos cell carcinoma, which presents as painless hematuria. Treat with Praziquantel.

Lower respiratory tract infections (LRTI)

found in the alveoli and lung parenchyma, there are acute and chronic types. Acute can be caused by viruses, tho bacteria are more common. All other LRTI like Chronic pneumonia, lung abscess, empyema (pus collection in a natural occurring cavity) are bacterial or fungi, not virus.

Schistosomiasis (blood flukes)

found in the middle east, parasitic worms that are released from snails (a must) in water, they infect by penetrating the skin. They mature in the liver and reproduce in the GI tract, and release eggs that appear in the stool and urine. They induce eosinophilia (IMPORTANT), hepatosplenomegaly, very itchy. They lay eggs in the veins of the bladder, then the eggs penetrate the endothelium and enter the bladder. Can cause bladder cancer.

Coxsackie virus

from Enterovirus genus, Picornaviridae family. + SS RNA, naked (nonenveloped), but has capsid. Has two different types. Group A causes vesicular lesions, "Hand-Foot-Mouth" disease. Group B causes Pleurodynia (Bornholm disease) which is sudden fever and chest pain "devil's grip," which is painful but not fatal. Group B also can cause myocardial and pericardial infections which can be fatal.

Molluscum contagiosum

from poxvirus. It is a skin infection that causes small blisters and lesions anywhere on the body, including genitalia.

pathogens that cause food poisoning

from reheated rice: Bacillus cereus. Improperly canned foods (can might bulge): Clostridium botulinum. Reheated meat dishes: Clostridium perfringens. Undercooked meat: E coli. Eggs, poultry, meat: Salmonella. Meats, mayonnaise, custard: S aureus (preformed toxin). Contaminated seafood: Vibrio species. Bacillus and S aureus cause nausea and vomiting quickly (1-8 hours) after eating. Other things take longer for symptoms to develop, are usually less severe.

Cytomegalovirus (CMV)

from the Herpes virus family, it is a DS DNA, enveloped. Most people are asymptomatic, but newborns (especiallyP and immunodeficient peeps like AIDS can have complications. It is found in body secretions like saliva, mucus, milk, etc, and can be spread sexually.

the definition of upper respiratory tract (URT)

from the epiglottis and up

Paracoccidioides

fungus found in south america. Dimorphic fungi that causes pneumonia. Has a unique "captains wheel" formation of budding.

candida

fungus that can cause vaginitis. Catalase (+), dimorphic. Causes thick, white, "cottage cheese" discharge. pH will be normal (4.0-4.5,). In order to become pathologic, it must switch from yeast form (budding) at 20 degC, to germ tube form which occurs at 37 degC (body temp), and can also be pseudohyphae in tissues (37 degC). The change in temperature causes the change.

Pneumocystis jirovecii

fungus that infects immunocompromised peeps especially AIDS (<200 CD4). It is a fungus but cell wall does not have ergosterol in the cell wall, so typical antifungals that target ergosterol do not work. Treat with TSX. It forms trophozoites and cysts inside cells (used to be classified as a protozoa). It causes pneumonia, peeps can die from respiratory failure. Causes "ground glass" appearance on xray.

terminology: gangrene, myonecrosis

gangrene is necrosis of a large chunk of tissue, whether by infection, ischemia, other. Myonecrosis is "gas gangrene", necrosis of tissue due to Clostridium perfringens which produces methane and CO2 gas (Clostridium is obligate anaerobe).

Severe combined immunodeficiency (SCID)

genetic defects that prevent development of T cells and B cells. It is so severe that some peeps live inside a plastic bubble (Bubble boy disease) to prevent infection. Bone marrow transplants can help, and the patient won't need immunosuppressives for the operation. There are two major types: X linked and autosomal. Autosomal lacks enzymes such as adenosine deaminase (ADA) and others, and are generally less severe.

treatment for Yersinia pestis

gentimicin

Ascaris lumbricoides

giant roundworm (nematode), fecal-oral route. Ingested eggs hatch and become larva in the intestine, pass the gut wall and enter the blood stream, travel to the alveoli where they mature a bit, then are coughed up and swallowed, then enter the intestine and form large worms. They stay in the intestine but don't attach to the wall. Often asymptomatic, but can cause malnutrition (because the worms need nourishment too) in developing countries. can also cause symptoms of pneumonia due to alveolar affect (if its a parasite with pneumonia symptoms, Ascaris is MC).

Corynebacterium diphtheria

gram (+) bacteria that grows on cysteine-tellurite blood agar and grows in colonies that looks like chinese letters. Symptoms are sore throat and grayish-white membrane on the tonsils and pharynx. This are may become very inflamed. This bacteria produces an exotoxin (which has an A (acting) and B (binding) portion) which inhibits protein synthesis via ADP ribosilation. Diagnosis is clinical. Treatment is with an antitoxin and antibiotic (erythromycin)

Staphylococcus saprophyticus

gram (+) cocci in clusters, novobiocin resistant, urease (+), 2nd MC cause of UTI in sexually active women. Will have a negative nitrite test (only gram (-) bugs are nitrite test(+)). Can cause struvite stones but is less likely than Proteus to be the cause, even in women.

Staphylococcus aureus

gram (+) cocci in clusters. has protein A which prevents phagocytosis by binding to Fc region of antibody. Has coagulase, which allows it to clump blood around itself which hides it. Can cause TSS.

Streptococcus bovis

gram (+) cocci, not hemolytic, a group D streptococcus (aka non enterococcal group D). Grows in bile but not 6.5% NaCl (unlike enterococcus). In colon cancer patients it can cause bacteremia and endocarditis.

Clostridium

gram (+) rods, obligate anaerobic, spore forming. Cause post partum infections. Produce alpha toxin, a lecithinase (breaks down tissues). Diagnose by growing on egg yolk agar, which will show lecithinase activity, while half of the culture possessing antitoxin won't have lecithinase activity.

Bacillus cereus

gram (+) spore former, causes food posoning. Spores survive cooking. Found in reheated rice (fried rice from chinese food leftovers)

Bacillus anthracis

gram (+) spore former, the only bacteria that has polypeptide capsule (others are polysaccharide capsule) which contains D-glutamate. Produces an anthrax toxin

Nocardia

gram (+), aerobe, found in soil, AFB stain. Histologically shows long branching filaments that look like fungi (like Actinomyces). Causes cutaneous infections after trauma in immunocompetent and pulmonary infections in immunocompromised. Treat with sulfonamides.

Staphylococcus epidermidis

gram (+), cocci, novobiocin sensitive, normal skin flora. Normally isn't dangerous but can infect prosthetic devices (including heart valves), and catheters by producing biofims.

listeria

gram (+), intracellular, catalase (+), tumbling motility, beta hemolytic. Internalins (surface protein) on the bug allow the bug to enter the cell (causes granulomas). Doesn't cause symptoms in normal peeps, usually just babies. Acquired at in utero or at birth (fecal exposure) from mother or via contaminated dairy products (milk or cheese). Can cause CNS symptoms (meningitis) in babies. The only gram (+) that produces endotoxin.

Clostridium botulinum

gram (+), obligate anaerobe, spore (exotoxin) forming. Causes food poising in improperly canned foods (look for bulging can). Also causes floppy baby syndrome due to eating honey. Spore/toxin/exotoxin/botulinum toxin inhibits ACh release at neuromuscular junction. Toxin is a protease that cleaves SNARE protein that is required for the neurotransmitter release.

Actinomyces

gram (+), obligate anerobe. Shows long branching filaments histologically that look like fungus (like Nocardia). Causes oral/facial abscesses that drain thru sinus tracts, forms yellow (sulphur granules)

species that form cocci

gram (+): Staphylococcus, streptococcus, enterococcus. Gram (-): Neisseria, Moraxella

coccoid/coccobacillus

gram (-) bacteria that are technically rods, but are a combination of coccus and bacillus shapes. Haemophilus influenza, Bordetella pertussis, Pasteurella

Yersinia enterocolitica

gram (-) bacteria that causes a GI infection. Caused by milk or pork contaminated with pet poop. Causes bloody diarrhea and mesenteric adenitis (inflammation of mesenteric lymph nodes in the abdomen) that can mimic crohn's disease or appendicitis.

Klebsiella pneumoniae

gram (-) cocci, enterobacter family, oxidase (-), lactose fermenting, encapsulated. Intestinal flora that can cause nosocomial UTI. Mucoid capsule causes mucoid (mucous like) colonies. Also causes lobar pneumonia in alcoholics and diabetics when aspirated, and causes red "currant jelly" sputum.

Proteus

gram (-) rod, 2nd MC UTI, Very motile, causes "swarming" on agar. Nitrite (+) (like all gram (-) UTI), produces hydrogen sulfide (H2S). Produces urease which converts urea to ammonia, which can raise the pH of the urine, also can cause struvite stones

Brucella, brucellosis (undulant fever)

gram (-) rod, acquired from proximity to farm animals or by eating unpasteurized dairy. Causes fever than comes and goes (aka undulant).

Helicobacter pylori

gram (-) rod, catalase (+), oxidase (+), urease (+) (can use urea breath test or fecal antigen test for diagnosis). Creates alkaline environment with urease (which produces ammonia). Also has proteinases that damages the mucosa. Treat with triple therapy: one proton pump inhibitor and two antibiotics.

E coli

gram (-) rod, lactose fermenter, encapsulated. Virulence factors: fibriae (cystitis and pyelonephritis), K capsule (pneumonia), LPS endotoxin (septic shock). On EMB agar it grows colonies with a green sheen

Serratia marcescens

gram (-) rod. Can cause UTI and OM (osteomyelitis), usually nosocomial. Produces a red pigment when cultured.

Pasteurella multocida

gram (-) rods, causes zoonotic infection from cat or dog bite such as cellulitis and osteomyelitis.

P aeruginosa

gram (-), aerobic, beta hemolytic, oxidase (+), the 2nd MC nosocomial pathogen (after S aureus), has a flagellum (making it motile). Love to grow in water (on veggies, flowers, faucet). Causes OM in IV drug users (along with candida). Produces Alginate, which creates a slime layer outside the cell wall. Its toxins are exotoxin A (which inhibits protein synthesis by inhibiting EF2, Elongation Factor 2), and elastase (which breaks down elastin and other stuff)

Pseudomonas aeruginosa skin infection

gram (-), aerobic, water borne, produces blue-green pigments, sweet smelling odor. Can cause hot tub folliculitis (acquired in hot tubs). Produces exotoxin A which inhibits protein synthesis by ribosylation of ADP and inactivates EF-2 (same as exotoxin of C diphtheria). Common infection of wounds and burns. Causes External otitis (swimmer's ear), chronic pneumonia in peeps with cystic fibrosis.

Vibrio cholerae

gram (-), comma shaped, oxidase (+), grows in alkaline media. Causes GI infection by contamination by contamination of water/food by human feces, thus poor sanitation and developing countries are risk factor (endemic to developing countries). Treatment is by prompt oral rehydration (not antibiotics).

Vibrio vulnificus, parahaemolyticus, cholerae

gram (-), comma shaped. Cause food poising from contaminated seafood. V cholera is also a waterborne pathogen in developing countries without proper sanitation. Cholera produces cholera toxin, an exotoxin/enterotoxin that permanently activates Gs recepting, causing adenylate cyclase to increase cAMP levels, causing Cl- secretion with water efflux, which produces the watery ("rice water") diarrhea

Enterobacter (cloacae, aerogenes)

gram (-), enterobacter family, not normal GI flora. Rarely cause UTI infection (E cloacae). Relatively unimportant.

Campylobacter jejuni

gram (-), oxidase (+), comma or S shaped, grows at 42 degC (Camp likes the hot campfire). Common cause of bloody diarrhea, especially in kids. Fecal-oral transmission thru foods such as poultry (MC), meat, unpasteurized milk. Can lead to Guillain-Barre syndrome.

Serratia marcescens

gram (-), rod, catalase (+), urease (-). Causes UTI in peeps with catheters and osteomyelitis in IV drug users (both also occur with Pseudomonas) . Produces a red pigment

Francisella tularensis

gram (-), zoonotic, causes tularemia (tularensis = tularemia). Acquired by being bit by ticks or handling wild animals like rabbits or deer. Causes a fever, an ulcer where the bug entered, and granulomas (in the reticuloendothelial cells, like lymph nodes)

rickettsia

gram (-),obligate intracellular. It does not stain well because it is intracellular, but can be stained by Giemsa. It is obligate intracellular because it can't make its own ATP. Species are rickettsii, prowazekii, typhi. They eventually destroy the cells they infect. They tend to infect blood vessels in the skin

Streptococcus agalactiae

group B streptococcus, gram +. The most common cause of pneumonia, sepsis and meningitis in neonates (0-28 days old)

Streptococcus viridans

group of alpha hemolytic streptococcus; S mutans, S sanguinis. Unlike S pneumoniae, they are resistant to optochin and are bile insoluble (not lysed by bile). They are normal flora of the oropharynx, thus cause dental caries/cavities. Sanguinis can cause low virulence endocarditis (MC cause of bacterial endocarditis), especially after dental procedures.; the type of endocarditis is not severe..

Streptococcus species

grow either in chains or in pairs (diplococci, S pneumoniae only). There are beta (pyogenes and agalactiae) and alpha (S pneumomniae and viridans) hemolytic types. Alpha hemolytic S pneumoniae is optochin test (+), due to sensitivity to optochin. Of the beta hemolytics, there is group A (pyogenes, bacitracin susceptible) and group B (agalactiae, CAMP test positive). The virulent factor of S pyogenes is M protein.

what WBC population suggests a parasitic infection? fungal infection?

high eosinophils indicate a parasitic infection. No populating is a clear indicate of a fungal infection.

dendritic cells

highly phagocytic APC. Functions as a link between innate and adaptive immune system. Expresses MHC ll and Fc receptors on surface. They present antigens on their MHC ll molecules to TCR on naive T cells, which activates them. They are located in the periphery, mucosa, and on the skin (known as Langerhans cells on the skin.

RIA (Radio Immuno Assay)

highly sensitive assay, unlikely to have false negatives or false positives. Not frequently used because it is very difficult.

Ancylostoma duodenale (errwhere but america), Necatur americanus (america)

hookworms (nematodes), larva penetrate skin, mature in the intestine. They attach to the gut wall and feed on blood, causing anemia.

types of transplant rejection

hyperacute, acute, chronic, graft vs host disease

Enterococcus and OM

if a procedure is done on part of the GI tract that allows enterococcus to get into the blood, it can cause OM.

implications of food poisoning and chronology of symptoms

if symptoms like nausea, vomiting, or diarrhea occur within a few hours of eating the food, it is form a preformed toxin (S aureus, Bacillus cereus). If it takes a day or more it is from the bacteria itself.

Antibody tests for infectious mononucleosis (IM) and CMV mononucleosis (CMV-M)

if you test positive for the Heterophile (other species loving) antibody test (monospot test, agglutinates other species RBCs like sheep or horse), EBV-IgM (aka EBV-VCA (viral capsid antigen) then you have IM. If you test positive for CMV-IgM then you have CMV-M (CMV mononucleosis).

PMN (polymorphonuclear) cells

immature granulocytes (neutrophils, eosinophils, basophils, mast cells) that usually refer to immature neutrophils. High levels indicate an infection.

hypersensitivity reaction

immune reactions that cause disease and tissue damage. Are manifested on second/subsequent exposure to an antigen. The first three are Ab mediated and the last is T Cell mediated. Type l, immediate/anaphylactic hypersensitivity. An allergen triggers the IgE response. Type ll, Cytotoxic sensitivity, caused when IgG/IgM binds to cell surface self Ag. Type lll, Immune complex hypersensitivity, involves non-clearance of immune complex. Type lV, T Cell mediated hypersensitivity, aka delayed type hypersensitivity (DTH).

the difference between XLA and CVID

in CVID there are B cells present in the peripheral blood, but they can't differentiate into antibody secreting plasma cells.

B cell lymphoma due to HIV

in an attempt to kill the virus, the body induces production of antibodies via polyclonal activation of B cells, which results in B cell lymphoma. AIDS patients are 60x more likely to have a B cell lymphoma than T cell lymphoma for this reason.

causes of viral diarrhea

in babies and little kids 5 and under it is rotavirus (reovirus, dsRNA virus, segmented). In adults it is Norovirus (Calicivirus, +ssRNA virus, linear). Both cause watery diarrhea. Viruses probably cause bloody diarrhea, but it will also have other major identifying symptoms.

neutrophil vs lymphocyte proportion in different infections

in bacterial infections the neutrophil count is high. In viral/fungal infections the lymphocyte count is high.

difference between type ll and lll HSR

in type ll antibodies bind to antigens on cells, so they will attach at specific location on the body (such as Goodpasture syndrome where the basement membrane of alveoli and glomeruli are attacked). In type lll the antigen is free flowing, so anywhere on the body can be affected (like serum sickness, SLE).

inactivated toxins or toxoids

inactivated toxins that are used as vaccines that protect against the toxins of diphtheria, tetanus, Cholerae, etc. They only induce short term immunity due to inadequate memory cell generation, and thus require booster shots.

parvovirus B19/Slap cheek fever/Fifth disease/Erythema infectiosum

infection by parvovirus, a(-) ss DNA virus. Infects the bone marrow. Causes and a red rash on the cheeks that spreads to the body, and cause fever and malaise. Can cause hydrops fetalis in pregnant women. Can cause aplastic anemia in peep with preexisting problems. Can also cause arthritis like symptoms in adults

scarlet fever

infection of S pyogenes that causes scarlet rash, strawberry (bumpy like a strawberry) tongue, no renal effect. Symptoms caused by release of toxin (aquired via bacteriophage) by S pyogenes. Usually affects children.

Filariasis

infection of nematodes (roundworms). They exist as filariform (large adults) in humans which produce microfilariae, which are spread in the blood and taken up by mosquitos. They transform into larva in the mosquitos, and the larva are passed on to people where they develop into filariform. Can cause elephantiasis (many other ways). Eosinophilia is prominent.

acute or chronic sinus infections

infection of the frontal, sphenoid, ethmoid, or maxillary sinuses. Maxillary is MC because it is the largest and it's ostia (opening into the nasal cavity) is above the sinus, so its easier for bacteria to enter. RF for sinusitis are obstruction of the sinus ostia, mucociliary impairment, or thickening of secretions.

bacteremia

infections in the blood (emia = blood)

mononuclear cell infiltratrion

infiltration of lymphocytes and monocytes.

Septic bursitis

inflammation of the bursa, usually caused by S aureus, Streptococcus species are possible. The patient will have painful swelling, redness, limited range of motion, fever, chills. Treat the same as with septic arthritis, do a gram stain and treat with appropriate antibiotics.

2 phases of leptospirosis

initial phase (occur after a 1-2 week incubation period): flu like symptoms like fever, muscle pain, headache, conjunctival suffusion (erythema without exudate). After the initial phase the patient can recover or progress to the second phase. Second phase: liver damage, kidney damage. Jaundice (from liver damage) due to leptospirosis is know as Weil's disease.

immunotherapy treatment for Type l hypersensitivity

injections of the allergen extract with the goal of declining IgE levels, rise in allergen specific IgG, T cell tolerance, changing the predominant phenotype from Th2 to Th1

what do intracellular and extracellular pathogens create in the body

intracellular pathogens usually create granulomas, like tuberculosis. Extracellular pathogens usually cause pyogenic lesions.

Shigella causes damage via..

invades intestinal mucosa (similar clinical manifestation as EIEC). Also produces shiga toxin. Because it invades the mucosa it causes a leukocytic infiltration, mainly neutrophils.

intrinsic pathway of apoptosis

involved in tissue remodeling in embryogenesis. BAX and BAK are prop-apoptotic factors and Bcl-2 is anti-apoptotic factors. Results in apoptosis via caspase activation.

diagnosing/testing for legionella, and treatment

is accomplished via DFA (direct fluorescent antibody) smears, plus culture in BCYE (buffered charcoal yeast extract) agar. treat with erythromycin (same for other atypical pneumonias)

how to grow potential M. tuberculosis and how long does it take?

it can be grown using Lowenstein-Jensen agar, and takes at least 3 weeks for growth to be evident. If a question says that no growth was evident within a week, it means nothing because it takes at least 3 weeks

Pathogenesis of legionella

it is a facultative intracellular pathogen, and it want to be phagocytized. Its porin proteins bind to C3b (which opsonize cells) which initiates phagocytosis. Another surface protein called macrophage invasion potentiator (Mip) also helps in phagocytosis.

95% ethanol decolorizer (3rd step)

it removes the crystal violet stain from gram negative bacteria. It also dehydrates and locks in the crystal violet stain with gram positive

killed vs live attenuated (weakened) vaccines

killed viruses ellicit a weaker immune response, and may require adjuvants which help cause a better response. Both stimulate IgG production, but living vaccine also stimulates IgA production (better because it the antibody type found in mucosal tissues like the nose), and also cell-mediated response.

diagnostic markers for UTI

leukocyte esterase test (in urine) which indicates bacterial infestion. (+) nitrite test indicates gram (-) bacteria (reduce nitrate to nitrite). Urease (+) indicates urease producing bugs such as proteus, klebsiella, and saprophyticus (proteus causes struvite stones). (E coli is urease (-).

DAF (decay accelerating factor), aka CD55. DAF deficiency

like C1 esterase inhibitor, it prevents complement activation on host cells. A deficiency causes complement mediated lysis of RBC and paroxysmal nocturnal hemoglobinuria.

type of immunity produced by live attenuated vs killed vaccine

live attenuated vaccines produce cell mediated immunity (more powerful), while killed only produces humoral immunity. Cell mediated immunity involves T cell activation and class switching.

lobar, bronchial, and interstitial pneumonia

lobar and bronchial pneumonia are most likely bacterial infections. Interstitial pneumonia is most likely viral. if a person with interstitial pneumonia is immunocompetent then is it is pneumocystis, in a bone marrow patient it is cytomegalovirus (CMV)

Lymphoma in AIDS peeps

lymphoma from EBV (epstein-barr virus) is 1000x more common in AIDS patients than normal peeps.

Meningococcus/Meningococcemia/Neisseria meningitidis

meningitis due to Neisseria meningitidis, a gram (-) diplococci. Transferred via respiratory secretions. Also causes petechial rash. Can cause adrenal insufficiency due to hemorrage of adrenal vessels (Waterhouse-Friderichsen syndrome)

what to use against penicillin resistant bacteria like MRSA

microbes like MRSA that have penicillinase (beta lactamase), use vancomycin

TORCH disease

pneumonic for intrauterine infections that cause congenital defects: Toxoplasma, others, Rubella, CMV, Herpes. Others are syphilis, listeria, parvovirus B19.

preventing transmission of HIV from mother to baby

mother should take antiviral drugs before giving birth, birth by C section instead of normal vaginal delivery decreases risk because the secretions of the vaginal canal contain HIV, and the mother should not breast feed the baby.

how to draw blood for blood cultures to detect bacteremia

multiple sites are drawn and are drawn about 15 minutes apart to rule out contamination. If patient is on antibiotics, they must use an antimicrobial device: ARD (antimicrobial removal device), FAN (fastidious antimicrobial neutralization)

3 irregular gram staining bacterias that can't be stained

mycoplasma (no cell wall, so can't be stained), Chlamydia (obligate intracellular that can't produce ATP, so it can't stay alive on it own, like a virus). Rickettsia.

treating S aureus

nafcillin, oxacillin, or methicillin. If it is MRSA (methicillin resistant) then vancomycin. If it is MRSA and vancomycin resisitent, give Streptogramin or Daptomycin

Trench mouth

name due to WWII soldiers who didn't brush and had this infection. Due to a combo of Treponema (spirochetes, not syphilis type) and fusobacterium.

nasal vestibulitis, complications

nasal folliculitis by S aureus. Complication is retrograde spread of infection to the cavernous sinus and intracranial structures.

Toxocara canis

nematode, fecal-oral route. Dogs are reservoir (Canis for canine), humans are dead end hosts. Larva form cysts and just die in the body without doing anything (hence dead end), but the cysts can cause hypersensitivity reactions. Cysts can be found in liver and eyes, possibly causing hepatomegaly and blindness. The disease it causes is visceral larva migrans.

Wuchereria bancrofti

nematode, found errwhere but america, transferred via mosquito bite which deposits larva. Larva takes one year to mature into microfilariae. Microfilariae can be ingested by mosquitos, then produce larva in the mosquito. worms can cause elephantiasis which is swelling limbs due to worms blocking lymph vessels.

Loa loa

nematode, found in africa, acquired from bite by deer fly horse fly, mango fly. Can cause swelling of the skin, and worms in the conjunctiva of the eye but won't cause blindness, not very dangerous.

Onchocerca volvulus

nematode, found in africa, acquired via female blackfly bite which deposits larva. Can cause dark skin nodules (black fly, black nodules), and infect the eyes and cause blindness.

Strongyloides stercoralis

nematode, larva in soil penetrate the skin. Cause intestinal infection with symptoms of vomiting, diarrhea, nausea. Can also cause pulmonary symptoms because worms pass from the blood to the alveoli, then are coughed up and enter the esophagus and into the GI. Only symptomatic in immunocompetent peeps.

causes of bacterial meningitis

newborns: S agalactia. Everyone else: S pneumonia, H influenza (MC among teens).

Yersinia pestis/Black Plague/Bubonic Plague

nonmotile, nonspore forming, gram - rods. Rodents are the reservoir, and are spread by fleas. Fleas acquire it via rodent blood. Then the flea's gut is clogged by the bacteria, making them feel hungry and eat. They bite humans and regurgitate into the open wound. Found in southwest US. Can also be spread person to person. Cause enlargement and tenderness of the lymph nodes, especially in the groin (bubo).

BCG (Bacillus Calmette-Guerin)

nonspecific stimulation of the immune system, given like a vaccination. BCG activates macrophages and acts as an adjucant to stimulate T cells against TB and some tumor antigens.

differences in CSF composition in different types of infections

normal CSF will have few (0-5) leukocytes and no PMN. Viral, bacterial, and TB/fungal infections will all have increased leukocytes and PMN. Viral and TB/mycosal will have <50% PMN, while bacterial infections will have >60%. CSF normally has >60% of the glucose that normal blood has, and viral infection has the same. Bacterial and TB/fungal infections have <45% of the glucose in the CSF compared to normal blood. The protein count is <30 in normal CSF, is normal or high (30-80) for viral infections, and is high (>60) for bacterial and TB/fungal infections. CSF opening pressure is increased in bacterial, TB/fungal, and normal/increased in viral.

Candida

normal flora of the mouth, dimorphic, can be grown on sabourad agar. Catalase (+). Its phenotype switch (dimorphic) from hyphae, pseudohyphae, yeast etc, is pathologic

Cryptosporidium treatment

nothing can treat the pathogen directly. Treat HIV which will raise the CD4 count and allow the body to handle it (same as JC virus).

dialysis related amyloidosis

occur in people that have end stage renal disease or that are on long term dialysis. Causes depositions of beta2 microglobulin. May present as carpal tunnel syndrome

Chronic transplant rejection

occurs in months to years. Host T cells react against donor antigens, and includes both cellular and humoral components (similar to type lV HSR). Causes fibrosis that is irreversible and is organ specific: heart (atherosclerosis), lungs (bronchiolitis obliterans), liver (vanishing bile ducts), kidney (vascular fibrosis, glomerulopathy).

drug-induced type ll reactions to blood components

occurs when a drug binds to a RBC cell membrane. Abs to the drug bind to it, resulting in complement-mediated lysis. If this occurs, the patient will see blood in the urine and stool

acute transplant rejection

occurs within weeks to months. Causes by cellular immunity (T cell mediated), cytotoxic T cells are activated against donor MHCs. Some antibodies will develop after transplant. Results in vasculitis of graft vessels with dense interstitial lymphocytic (aka mononuclear) infiltrate. Can be prevented/reversed with immunosuppressants.

septic shock

often caused by endotoxins (gram -, lipopolysaccharides) which causes BP to drop due to capillary leakage (via complement activation). Also causes disseminated iintravascular coagulation which activates/depletes clotting factors, leaving the person susceptible to bleeds.

Anti-IgE monoclonal antibody (Omalizumab) treatment for type l hypersensitivity

omalizumab binds to IgE and blocks the binding of IgE to FcR on mast cell, which prevents mast cell degranulation (cromolyn also inhibits mast cell degranulation). IgE levels are also reduced

GVHD (graft vs host disease)

onset varies (usually 21 days but can be more). Caused by donor T cells that attack host cells and can cause severe organ dysfunction. Causes rash, jaundice, diarrhea, hepatosplenomegaly. Usually occurs in bone marrow and liver transplants (which contain a lot of lymphocytes). Potentially beneficial in bone marrow transplants for leukemia.

hyperacute transplant rejection

onset within minutes. Due to preexisting recipient antibodies against donor antigen (type ll HSR), which activates complement. Causes widespread thrombosis of graft vessels and ischemia/necrosis. The graft must be removed.

3 life forms of toxoplasmosis

oocyte (infective form), which are pooped out and consumed by another animal. Tachyziote (trophozoite) are the invasive form which are mature from the oocytes. They can travel to distant tissue and form tissue cysts (the 3rd form) which can also initiate infection if eaten. People can get infected by ingesting the oocysts (handling a cat litterbox) or consumption of tissue cysts (eating contaminated pork is MC cause), or by congenital transfer..

biochemical tests utilizing catalase

organisms that contain catalase will test positive because the catalase breaks down hydrogen peroxide into water and oxygen. Staphylococcus will test positive, streptococcus will test negative.

Vibrio cholerae exotoxin (cholera toxin)

overactivates adenylate cyclase and increase cAMP by permanently activating Gs receptor (hard core diarrhea due to permanent activation). This increases Cl- sectretion and water efflux in the gut (same effect as ETEC heat labile toxin). This causes the "rice water" diarrhea.

pathology of hepatitis

panlobular infiltration with mononuclear cells, hepatic necrosis, hyperplasia of Kupffer cells (liver macrophages).

active vs passive immunization

passive is when the antibody was created somewhere else (like a sheep or horse) and given to a patient. Giving antitoxin is also considered passive. Active is when the infection is given to a person so that they develop antibodies.

how to tell the difference between otitis media and otitis externa

pneumatic otoscopy should show good tympanic membrane motion in externa, and absent or limited motion in media.

toll-like receptors (TLR)

pattern recognition receptors that recognize PAMP (pathogen associated molecular pattern). They recognize pathogens

genetic immunity from AIDS

peeps with a homozygous CCR5 mutation have immunity from AIDS even tho they have HIV. Heterozygous mutations in CCR5 slow the progression towards AIDS.

another term for transpeptidase

penicillin binding protein (PBP). This is the enzyme that crosslinks the peptidoglycans in the cell walls of gram (+) bacteria, and is the enzyme that penicillin binds to and inactivates.

safety issues and vaccines

people may have allergic reactions to chicken egg proteins, or antibiotics (like neomycin) or other parts of a vaccine

window period of HBV infection

period of infection during which the person tests negative for both HBsAg and anti-HBs. Both are present in the blood but are present in similar quantities and are bound to each other, so they test negative. There would be anti-HBc IgM and anti-HBe in the blood and would test positive.

HAV (hepatitis A virus)

picornavirus, +ssRNA virus, asymptomatic but can cause acute hepatitis. Transferred via fecal oral route, acquired by travellers. Anti-HAV (IgM) indicates an active infection, anti-HAV (IgG) indicates prior infection and is protective.

Enterobius vermicularis

pinworms (type of nematode), fecal-oral route. Eggs are ingested and cause intestinal infection causing anal pruritis. The pinworms leave the anus at night and lay eggs around the anus, diagnose by scotch tape test.

the least effective type of vaccine and why

polysaccharide are the least protective because they only induce T independent Ag. No response of cytokine, memory B cells (plasma cells), or antibody class switchover.

smallpox

practically eliminated with live vaccine.

preformed and newly synthesized mediators released by mast cells during hypersensitivity type l

preformed mediators are stored in granules and are released immediately after the mast cell is activated: histamine, neutrophil and eosinophil chemotactic factors (NCF, ECF-A), platelet activating factor (PAF, which does the same thing as histamine). Newly synthesized mediators are leukotrienes, PgD2

primary tuberculosis and reactivation (secondary) TB

primary is when a person is infection with TB and the TB grows and becomes active instead of being latent (occurs in very few people). It will create Ghon's complexes, which become caseous granulomas. These granulomas can become calcified and will show up on an x ray. The lung infection can spread to blood, causing miliary TB (bacteremia of TB). Secondary is when a person is infected with TB, it goes latent in their body, and then become active later in life, usually when the immune system becomes compromised. The patient will present with fever, fatigue, chest paints, cavitary lesions.

3 stages of syphilis

primary syphilis (3 weeks): : painless chancre/red ulcer with a hard rim. Secondary syphilis (2-10 weeks): condylomata lata (smooth warts) rash on palms and soles of feet, runny nose water eyes. Tertiary syphilis: infarct, stroke, mental illness, blindness, gumma (necrotizing mass), tabes dorsalis (nerve demyelination), Argyll Robertson pupil.

EMT (epithelial to mesenchymal transition)

process that occurs in normal cells during development; epithelial cells transition to mesenchymal stem cells. Also a mechanism by which cancer cells metastasize during cancer progression. In the transition cells lose anterior-posterior polarity and cell to cell adhesions

How does the body fight viral infection?

production of IFN which limits viral replication, NK cells, virus specific CD8 CTL. Antibodies help contain the virus by binding to and inactivating the virus

coreceptors CCR5 and CXCR4

proteins on cells that HIV will bind to in order to infect that cell. they are coreceptors because they also need CD4 receptors on the host cell in order to infect. HIV binds to CCR5 (and CD4) on macrophages and unactivated CD4 T cells. HIV binds to CXCR4 (and CD4) on activated CD4 T cells.

proto-oncogenes, oncogenes, tumor suppressor genes

proto-oncogenes are genes that normally contribute to or cause cell division, including growth factors and receptors, gene transcription and signal transduction. Oncogenes are mutant forms of proto-oncogenes that contribute to malignancy. Tumor suppressor genes encode proteins that inhibit unwanted proliferation, such as p53; both copies of these genes must be mutated to cause malignancy.

Naegleria fowleri

protozoa that causes CNS infections. Causes rapidly fatal meningoencephalitis. Acquired by swimming in warm, freshwater lakes. Enters the nose, goes up cribriform plate to enter the brain. Diagnosed via Amoebas in spinal fluid.

Entamoeba histolytica

protozoa that causes bloody diarrhea (amoebic dysentery). Fecal-oral route, Ingested cysts travel to the intestine and become trophozoites (amebas). Trophozoites cause liver abscesses with "anchovy paste" exudate. Causes flask-shaped ulcer in the colon. Histologically shows trophozoites with RBCs in the cytoplasm. Cysts may up to 4 nuclei. Diagnose by serology, trophozoites in blood, or cysts in stool. Treat with metronidazole

Trypanosomiasis cruzi (Chaga's)

protozoa, acquired in south america by triatomine/Reduviid "kissing" bugs. Classic sign is when one eye swells (Romana's sign). Causes dilated cardiomyopathy, megacolon, megaesophagus.

Trypanosoma brucei

protozoa, cause CNS infections, African sleeping sickness. Transferred via bite from Tsetse fly. Causes recurring fever due to antigenic variation, and somnolence (sleepiness) which can progress to coma. Antigenic variation is caused by the many different cell cycles and morphologies (kinetoplastids), and is the reason why the fever is recurring.

Plasmodium malariae, vivax/ovale, falciparum

protozoa, infection acquired outside US by bite from anopheles mosquito. Symptoms are fever, headache, anemia, splenomegaly. Once entering the body from the mosquito they travel to the liver to develop. Once developed they rupture the hepatocyte they are in, then travel to the blood and begin lysing RBC. Histology: may show trophozoite form within RBCs, and schizont containing merozoites (immature malaria cells in a hepatocyte). Malariae species is generic and can be treated with normal Chloroquine. Vivax/ovale causes fever that comes and goes in 48 hr cycles, also has dormant form in hepatocytes which is treated by adding Primaquine as well as Chloroquine. Falciparum is a more severe form and can be drug resistant, so mefloquine is used.

Babesia

protozoa, similar infection as malaria. found in northeast US, ixodes tick is vector (same as lyme disease). Invades and lyses RBC, causes hemolytic anemia and high fever. Histologically shows "Maltese cross", aka tetrad formation in infected RBC. Humans are dead end hosts.

Ecthyma gangrenosum

rapidly progressing cutaneous necrotic lesions caused by P aeruginosa.

fulminant liver disease

rapidly progressing liver disease

type lV hypersensitivity

rather than being activated by antibodies, this hypersensitivity recognized antigens via CD4 helper T cells, which release factors that activate other T cells, macrophages, etc. Symptoms peak at 48-72 hours after exposure. The three different types are contact, tuberculin (soluble), and granulomatous form.

petechia

red or purple spots on the skin caused by bleeding (broken capillaries) under the skin. They do not blanch. They are less than 3 mm, anything greater is purpura.

HIV: rev gene

regulates transport of viral transcripts (spliced and unspliced) from nucleus to the cytoplasm

IL-8

released by macrophages, it is a major factor for chemotaxis of neutrophils (TNF and C5a are also a chematactic factor for neutrophils).

most common viral causes of the common cold

rhinovirus, corona virus, adenovirus (may cause epidemic). Less common viruses are Respiratory syncytial, influenza, parainfluenza, Coxsackie A and B, Epstein-Barr, and Herpes simplex.

Symptomatic progression of HIV

roughly a month after infection a person may feel flu like symptoms or malaise, which corresponds to a temporary decline in CD4 T cells. The flu like symptoms end (and CD4 cells increase). Then a long asymptomatic period occurs, an anverage of 10 years, during which the CD4 T cell count slowly decreases. Symptoms (opportunistic infections) return when the CD4 count is <500, sever illnesses occur when it is <200.

fungal septic arthritis

same as OM: Causes in immunocompetent individuals: Blastomycosis, coccidioidomycosis, sporothrix. In immuno compromised: cryptococcus, candida, aspergillus

what 2 parasites causes eosinophilia?

schistosoma (blood flukes), and Filiaresis (nematodes, aka roundworms)

limited scleroderma (CREST syndrome)

scleroderma that mainly affects the skin of the hands and face. CREST: Calcinosis, Raynauds phenomenon, Esophageal dysmotility, Sclerodactyly (skin thickening on fingers), Telangectasia (dilated capillaries). Anti-centromere (+).

IL-3

secreted by all cells, it stimulates bone marrow to synthesize production of all cells that bone marrow produces.

role of IL-12. IL-12 receptor deficiency

secreted by macrophages and causes development of Th1 cells from T cells. Th1 cells secrete IFN-gamma which activates macrophages and cytotoxic T cells. Peeps with IL-12 receptor deficiency will have low Th1 cells, and will easily acquire fungal and mycobacterial infections. Peeps will have low IFN-gamma levels.

fusobacterium

similar to Bacteroides: gram (-), anaerobic. Pathogenesis is via LPS. Fusobacterium, peptostreptococcus, or bacteroides are usually responsible for abscesses/fluid levels in the body (according to Dr Duus)

rhinitis medicamentosa

sinus congestion due to overuse of nasal sprays like oxymetazoline or phenylephrine.

bacterial reactive arthritis

some infections such as GI infections (from campylobacter, salmonella, shigella) can cause immune complex deposition that cause arthritis

the difference between true sputum (from the lungs) and saliva

sputum has no squamous epithelial cells and most/all of the bacteria will be from the same organism. In saliva there are squamous epithelial cells and a variety of bacteria

diagnosing Pneumocystis jiroveci

sputum will not yield anything because the virus affects the alveoli and not bronchioles. So bronchoalveolar lavage is used. Confirm with silver (methenamine) stain

how to stain, culture and treat TB

stain on Ziehl-Neelson or AFB (acid fast bacteria) stain. Culture on Lowenstein-Jensen agar. Use 2 or all 4 drugs: RIPE Rifampin, Isoniazid (INH), Pyrazinamide, Ethambutol.

silver stain

stains fungus, pneumocystis, Legionella, Helicobacter Pylori

Giemsa stain

stains funky things that can't normally be stained. Chlamydia, Borrelia, Rickettsiae, Trypanosome, Plasmodium. Pneumonic: CBRTP: Certain Bugs Really Try my Patience.

treatment of mucormycosis

surgical debridement and amphotericin B.

symptoms of Pneumocystis jiroveci

symptoms are fever, dry cough,shortness of breath, dusky skin color (indicating poor oxygenation). Patient can be treated with antifungals, but the inflammatory reponse damages the alveolar walls and prevents gas exchange

Mycobacterium kansasii

symptoms are similar to TB (cavitary lesions of the lung). PPD (purified protein derivative, a test for TB) is positive.

strep throat (S. pyogenes)

symptoms: absence of cough, sore throat, difficulty swallowing, fever, red throat with white patches of pus with hemorrhagic cracks/yellow exudates, enlarged and tender cervical lymph nodes. The virulent factors are M protein, which degrades C3b and evades phagocytosis. Other virulent factors are G and G protein

Fungemia

systemic fungal infections, usually Candida albicans, often caused by infected needle use, and bone marrow transplants.

life cycles of chlamydia

the Elementary body is infectious and non replicating. It induces its endocytosis within a cell and enters the cell inside an endocytic vacuole, then changes into a Reticulate body which is the reproductive form. After reproducing they revert back to elementary bodies and the cell lyses, releases the elementary bodies.

Salmonella

the MC cause of OM in sickle cell disease patient. There are only two species of Salmonella; enterica and typhi. Enterica causes GI infections/everything except typhoid fever, which is the only thing typhi causes. Enterica acts by invading the intestinal mucosa and causes monocytic response. Typhoid fever is a GI disease that back in the day became systemic and killed peeps

How do you know if a baby born to an HIV infected mother is also infected?

the baby will test positive on ELISA and western blot tests because the antibodies from the mother get passed to the baby, but that doesn't mean the baby is infected. PCR detection of HIV RNA will give an accurate diagnosis.

Yersinia pestis

the bacteria responsible for the pneumonic/bubonic plague. it is a gram (-) bacteria that is transferred by rat fleas. Mainly located in the four corner area of Arizona, New Mexico, Colorado, and Utah. Symptoms are CDEF, Cyanosis, Diaphoresis (sweating profusely), Edema of the Face.

unique capsule staining characteristic

the capsules will not stain, leaving a halo around the bacteria cells

Rheumatic heart disease

the cardiac manifestations of rheumatic fever. an autoimmune disorder. Antibodies that normally bind to the M protein of S pyogenes also bind to myocardial fibers, especial mitral valve (causing mitral stenosis).

blood markers of HBV: HBsAg (HBV surface antigen), Anti-HBs (antibody to HBsAg), HBeAg (HBV envelope antigen), Anti-HBe, anti-HBc (antibody to HbcAg, "core"),

the first evidence of infection of HBV is surface antigen (HBsAg), present in the acute and chronic stage. Surface antibody (Anti-HBs) is IgG and is protective (the body won), only present in resolved and immunized stages (only antibody present in immunized stage). Envelope antigen (HBeAg) is present only when HBV is infectious, which is the acute and chronic stages, absent during window, resolved, and immunized. Core antibody (Anti-HBc) is IgM during acute and window stages, IgG in resolved and chronic stages. Chronic carrier state is low infectivity state with the persistence of HBsAg, anti-HBe, and anti-HBc.

Hypersensitivity type l

the first expose to an allergen causes B cells to secrete IgE. Allergen specific IgE bind to mast cells and basophils via Fc receptors. On the second exposure the allergen bind to the IgEs that are attached to mast cells/basophils and activates them. The release vasoactive amines. The response time is 15-30 mins, and the appearance is wheal and flare (redness)

chronic discoid lupus erythematosus, subacute cutaneous lupus erythematosus

the first is a disorder of skin manifestations of lupus, but not systemic. Subacute is the skin manifestations with mild systemic symptoms.

2 phases of Trichinosis

the first phage is when the larva that was eaten in pork/bear meat hatch from the tissue cyst, causing GI problems like stomach pain, diarrhea, nausea, fever, sweating, caused by the parasites in the gut. The second phase is when the mature parasites release larvae of their own that go throughout the body, mainly striated muscle.

renal transplant patients with pneumonia/meningitis

the former will have contracted legionella, the latter has contracted listeria

what happens when you have a household reptile (like a turtle) and a kid with sickle cell disease?

the kid gets OM from a Salmonella infection from the turtle

Leptospirosis

the pathogen strain is Leptospirosis interrogans. gram (-), obligate anaerobe, spirochete, can be transferred sexually person to person or via contact with urine from infected animals. Common in Hawaii. The infection occurs thru breaks in mucous membranes or skin, then spreads in the blood

crystal violet

the primary stain that stains all cells purple

HIV: LTR (Long Terminal Repeats) region

the promoter region of the viral RNA genome

what is the purpose of the vaccine for Bacillus anthracis, and what drug is used to treat it.

the purpose of the vaccine is to initiate antibody response to factor ll, which is the protective factor. The drug of choice is Doxycycline or Ciprofloxacin

Blotting techniques (northern, southern, western)

the sample (DNA, RNA, protein) are separated based on size/charge, put on a gel, then a detecting agent can be added.

Bordetella pertussis exotoxin (pertussis toxin)

this exotoxin prevents the microbe from being phagocytized. It does this by disabling Gi receptor which overactivates adenylate cyclase, increases cAMP, which evidently impairs phagocytosis. Toxin not actually the cause of cough

polyoma virus

there are two viruses in this family and they both affect AIDS/immunocompromised patients. JC virus causes PML, BK virus infects the kidney

Types of influenza vaccine and who must take it

there is a killed vaccine made up of a few strains, and there is a live vaccine. The live vaccine should not be given to children less than 5yo. People who must get vaccinated are people who would have serious flu complications, like young children, pregnant women, old people, people with chronic conditions like asthma/diabetes/lung disease.

the appearance of type ll HSR, compared to others

there will not likely be any inflammation/exterior signs like the other HSR. Type l reactions can cause swelling. Type lll often causes redness or swelling with autoimmune diseases like rheumatoid arthritis, and also swelling seein in persistent infection like elephantitis. Type lV can cause redness due to contact dermatitis like poison ivy, and also granulomatous skin lesions.

the appearance of type ll hypersensitivity, compared to others

there will not likely be any inflammation/exterior signs like the other hypersensitivities. Type l reactions can cause swelling. Type lll often causes redness or swelling with autoimmune diseases like rheumatoid arthritis, and also swelling seein in persistent infection like elephantitis. Type lV can cause redness due to contact dermatitis like poison ivy, and also granulomatous skin lesions.

characteristics of bacteria that abscesses/fluid levels in body cavities ( says Dr Duus)

they are facultative or obligate anaerobe.

what do superantigens cause and what makes them super?

they cause TSS (toxic shock syndrome). They are super antigens because they induce a polyclonal T cell response, which means they activate many T cells instead of just ones that are specific for that bacteria (which normally occurs). This causes mass activation of T cells, and mass cytokine release. Superantigens accomplish this because they bind to the V-beta region of a TCR (T cell receptor).

how penicillin in inactivated by penicillin resistant bacteria

they have beta-lactamase (penicillinase), which opens up the beta-lactam ring of penicillin, which inactivates it.

why can't aids patients fight infection

they have low CD4 T lymphocytes. which is part of cell mediated immunity

generic pathogenesis of viruses

they initiate the inflammatory response and proliferation of lymphocytes (neutrophils in bacterial infections)

vaccination of HIV peeps

they should not be given live attenuated vaccines because they are immunocompromised. Some vaccines should be given if the possible infection would result in severe symptoms. Vaccines that should be given: Rest In Peace Always, Rabies, Influenca, Polio, hepatitis A. Polio has two types, Sabin (alive), Salk (killed)

how vaccines protect for so long

they trigger long term response via memory T and B cells (cell mediated immunity). The best/longest lasting response is when Th and B cells interact to form a response. Ab-secreting plasma cells in bone marrow (or other survival niches) in children and aduls provide long lasting protection. Short-term antibody response is due to non-survival of formed plasma cells/blasts. Long term immunization occurs when B cells bind to Ag, which activates/causes clonal expansion of those B cell and they start creating Ag specific Ab. Those B cells present Ags to Th cells, which release cytokines which induce a class switch of B cells to better memory B cells.

transudate vs exudate

transudate is lighter, has less protein and cells than exudate. Exudate refers to inflammation, and is what collects in the lungs in pneumonia.

treating Pneumocystis jiroveci

treat with TSX (trimethoprim-sulphamethoxazole)

treatment for aspergillus

treat with amphotericin B and itraconazole, and possible surgical excision. But mortality of invasive aspergillus is almost 100%.

Pott's disease

tuberculosis that infects the spine

Ehrlichiosis (Erhlichia), Anaplasmosis (Anaplasma)

two infection by bacteria that are part of the Rickettsia family. They are acquired via tick bite, cause a fever and headache (the same symptoms of rocky mountain spotted fever without the rash).

extrinsic pathway of apoptotic factors

two methods: via killer T cells which release granzyme B and perforin, or Fal-FasL interactions. Fas-FasL (Fas ligand, which is on T cells in the thymus that help the maturation process) interactions is the process utilized in medullary negative selection for T cells, and results in activation of caspases (like the intrinsic apoptosis pathway)

kidney problems caused by lupus (lupus nephritis)

type lll HSR. Causes diffuse proliferative glomerulonephritis, which is nephritic. Also causes membranous glomerulonephritis/nephropathy

symptoms of histoplasmosis

typical fever symptoms. It also cause hepatosplenomegaly (liver and spleen get big) because of the infected macrophages that travel there

H influenza

uncommon cause of meningitis.

Mycobacteria

unique group of bacteria who have mycolic acid in their cell wall.

How to diagnose/treat osteomyelitis

use blood culture to determine type of infection. If the blood culture is negative, use scans (xray, MRI, etc). Scans may appear normal for the first week, but after a week bone thinning, deposition, new bone formation will be evident. Use antibiotics according to type of infection. Acute osteomyelitis may only require short term antibiotics, but chronic osteomyelitis may require long term antibiotics and surgery.

diagnosing bacterial arthritis, synovial fluid

use blood cultures and examine synovial fluid. Normal synovial fluid will be clear, high viscosity, <200 WBC, <25% PMN (polymorphonuclear) cells, and similar glucose levels as blood. Trauma/degenerative joint disease will have clear or yellow color, high viscosity, 200-2,000 WBC, 25-50% PMN, similar glucose levels as blood. Rheumatoid arthritis/Gout will have translucent yellow, or opalescent color, low viscosity, 2,000-20,000 WBC, >=50% PMN, 50-80% glucose level. Septic arthritis will be opaque, yellow to green color, variable viscosity, 25,000-100,000 WBC, >75% PMN, <25% glucose.

ELISA (enzyme linked immunosorbent assay)

uses an antibody specific for the target of interest: bacterial antigen, hormone level, cytokine level. It can be used to detect and measure the amount of almost anything: illicit drugs, etc. Negative results are not definitive, should be confirmed by other methods.

NADPH oxidase (oxidative burst, respiratory burst)

uses oxygen to produce superoxide anion (O2-, a reactive oxygen species) which is used by phagosomes to produce H2O2/hydrogen peroxide. H2O2 can kill bacteria, as well as its derivative OCl/hypochlorite/bleach. Catalase is an enzyme that breaks down hydrogen peroxide into water and oxygen.

congenital genital herpes

usually acquired when the baby passes thru the vaginal canal. Often fatal because the babies' cell mediated immune system is immature. Can cause vesicular lesion, CNS defects, retardation, etc. Tzanck test is a smear from open vesicles which shows multinucleated giant cells (multinucleated giant cells are found in other diseases also), also have Cowdry type A inclusions. Can be confirmed with a culture.

why influenza can cross species

usually the HA binds to specific sialic acids on the epithelial cells of only one species. However some sialic acids like swine flu, can bind to the HA of other species. If the same cell in pigs is infected with multiple influenzas of different species, it mixing of the HA binding protein with the influenza virus of other species.

Vaccination and TB treatment

vaccination is possible, but since it is a live strain it is contraindicated in immunocompromised patients who may contract the disease. Treatment is by administering a couple drugs (to prevent resistance development) for 6-9 months.

DTaP vaccine

vaccine for diphtheria, tetanus, and pertussis.

recombinant vaccines

vaccines that are created by inducing a bacteria like E coli to produce fragments from other pathagones, like HPY (human papilloma virus)

subcellular fragments and surface antigen vaccines

vaccines that contain a fragment of a microorganism, like a surface antigen polysaccharides. It has no virulence because it does not replicate, thus induces a weak immune response/requires boosters. However these polysaccharides can be conjugated to other proteins, which allows the immune system to better recognize them and induce a Th cell response. usually safe for immuno compromised patients

how MRSA becomes resistant to vancomycin

vancomycin normally binds to the amino acid side chain of peptidoglyans. MRSA that is vancomycin resistant has altered side chains that vancomycin does not bind to.

HSR (hypersensitivity reaction) type l

very fast, antibody mediated, typical allergic reaction. IgE (allergy) bind to antigen and triggers an immune response

Staphylococcal scalded skin syndrome (SSSS)

when S aureus releases exfoliatins (exotoxins) that destroy the stratum granulosum, which causes blistering and causes the skin to peel off. Affects newborns and children

endocarditis

when bacteria in the blood (bacteremia) infects the endocardium. Platelets and clotting proteins surround the bacteria, forming vegetations, making it worse because now antibmicrobials can't get to them. Can cause disrupt blood flow and cause murmurs.

chronic granuloma

when the body's immune system fails to kill and clear a pathogen, the body attempts to "wall off" the pathogen, during which there is constant antigenic stimulation. The cell-mediated (aka type lV hypersensitivity) immune response is what causes these.

plasma cell (antibody) dysfunction will prevent the body from eliminating what types of pathogens? T cell dysfunction? NK cells?

while many types of pathogens/bacteria would be difficult to kill, macrophages and neutrophils can often kill them without antibodies. Encapsulated bacteria require antibodies for opsonization and elimination, so plasma cell dysfunction will make peeps susceptible. T cells dysfunction would make one susceptible to intracellular infections, such as viruses and fungus.

diffuse scleroderma

widespread skin involvement, rapid progression, affects visceral organs. Anti-Scl-70 (+) (anti DNA topoisomerase).

imaging of sinuses

x rays and CT scans can show fluid levels in sinuses.

diagnosing a lung abscess requires

xray or CT scans that show air fluid levels

What are the virulence factors for Yersinia pestis

yops and F1 capsular protein, which are outer membrane proteins which inhibit phagocytosis