SKETCHY MICRO ALL

(Pico) Coxsackievirus -VIRUS

(Pico) Coxsackie virus -Positive sense RNA virus (all replicate in the cytoplasm) -Picornavirus -RNA virus -naked virus -infection common in summer months -treatment is just supportive Coxsackie A virus -Hand, foot and mouth disease causing red vesicular rash -asceptic (viral) meningitis called aseptic because viruses dont show bacteria on gram stain Coxsackie B virus -causes dilated cardiomyopathy -Devil's grip; Bornholm's disease/pleurodynia extreme sharp pain in the lower chest and unilateral

Bartonella henselae - Bacteria

-gram negative -warthin-starry silver stain -cat scratch fever transmitted by cat scratches >can also involve regional lymph nodes (painful) especially in the axilla >axillary lymphandenitis >occurs in immunoCOMPETENT patients TX: Self-limiting but can use azithrymycin (macrolides) for painful lymph nodes -bacillary angiomatosis also transmitted by cat scratches >fever, chills, HA >raised red vascular lesions in bacillary angiomatosis >affects immunocompromised patients TX: doxycycline treatment for bacillary angiomatosis; can also use macrolides

Cryptosporidium - parasite

- severe diarrhea in immunocompromised pts (HIV patients) -immunocompetent just have watery diarrhea -unicellular partially acid fast (look like amethyst crystals) organisms; -only parasites to stain acid fast oocysts transmit fecal orally -infectious cysts passed through stool -cysts composed of 4 motile sporozoites then attach to intestinal wall and cause diarrhea and small intestinal damage -campers, swim in dirty water, people who work with animals TREATMENT: NITAZOXANIDE (anti-protozoal used in immunocompetent hosts) -filtration can remove oocysts from infected water (highly resistant to cloronation) TREATMENT: SPIRAMYCIN (macrolide antibiotic) -mainly supportive (fluid status and electrolyte balance to monitor)

Naegleria fowleri - PARASITE

-AMOEBA -associated with fresh water -trophozoite enters CNS via cribiform plate -meningoencephalitis (primary amoeba meningoencephalitis) -rapidly fatal disease with poor prognosis -affects patients involved in water-sports -has been associated with nasal irrigation systems and contact lens solution -fever, neck stiffness and headache -diagnosis by lumbar puncture TX: amphoterecin

Aspergillus fumigatus - FUNGI

-CATALAST POSITIVE (exception since this is usually a bacterial quality - candida is an exception as well) -peanuts associated with aflatoxcin produced by Aspergillus flavus -aflatoxcin is associated with development of hepatocellular carcinoma -acute angle branching (<45 degrees) and septate -ASpergillus think A for acute angle branching and S for Septate -forms conidiosphores with fruiting bodies -transmitted by inhalation -3 types of infections: (1) allergic bronchopulmomary asperigillosis - type 1 hypersensitivity reaction with increased IgE, associated with asthma, wheezing,fever; (2) aspergillomas associated with TB cavities; fungus balls within cavities are gravity dependent; (3) Angioinvasive aspergillosis affects immunocompromised patients - invades blood vessels and disseminates through the body; kidney failure; endocarditis; ring enhancing brain lesions on CT; spread to paranasal sinuses may cause necrosis around the nose (this also occurs in mucor which has right angle branching) TX: less serious infections can use -azole specifically VORICONAZOLE TX: angioinvasive disease use amphoterecin B

Trypanosoma cruzi - PARASITE

-Chagas disease (predominantly South America or Central America) - "kissing bug" bites (PAINLESS) around victim's mouth, and deposits feces which can later be introduced by scratching area -transmitted by Reduviid, or "kissing bug" -megacolon (may present as constipation) -dilated cardiomyopathy (what many patients die from) -mega-esophagus (makes things dilated and massive) -diagnosed by blood smear only during ACTIVE infection can see motile trypanosomes -chronic (inactive) can be diagnosed with serology and clinical symptoms -trypanosomes may be seen within cardiac myocytes on heart biopsy -burrows into endocardium TX: Nifurtimox (active); no treatment for chronic chagas

Coccidioides immitis - FUNGI

-Coccidioidomycosis -distribution: Southwestern US (like California) -route of transmission: inhalation of spores in dust -earthquakes are a risk factor for spread of infection -dimorphic fungus; mold in the cold (soil and dirt) and SPHERULES OF ENDOSPORES in the heat (our bodies particularly the lungs) -cocci spherules > RBC size (cocci > blasto = RBC > histo in size) -clinical manifestation may look like an acute pneumonia: cough, fever, and arthralgia -radiographic images may show either nothing or cavities and/or nodules -cocci is associated with erythema nodosum (shows a robust immune response so only seen in healthy people) -in immunocompromised: skin and lungs are common sites of infection; may disseminated to the bone and meninges causing meningitis -diagnosis: KOH prep or culture and urine antigen test TX: -azoles for local lung infections like Ketoconazole TX: disseminated infections Amphotericin B

Epstein-Barr virus -VIRUS

-DNA virus - replicates in the nucleus -double stranded -member of the herpes virus family causes infectious mononucleosis -primarily transmitted through saliva -fever -tender lymphadenopathy (cervical and diffuse) -reactive cytotoxic CD8+ T cells (Downey, or atypical cells) seen on blood smear -T cells proliferate which is why splenomegaly happens -targets the B lymphocytes and EBV remains latent in B cells -EBV envelope glycoprotein binds CD21 to infect B cells -pharyngitis and tonsillar exudates -if mistakenly given amoxicillin or ampicillin can develop maculopapular rash risk factor for cancers: -Hodgkin's lymphoma - Reed sternberg cells that look like "owl's eyes" (mixed cellularity subtype) -Endemic or African Burkitt lymphoma large jaw lesion and swelling (t8;14) -nasopharyngeal carcinoma associated with Asian EBV patients oral hairy leukoplakia in HIV patients, non-cancerous lesion (you cant scrape this off the tongue) diagnose: monospot test -rapid diagnosis TX: mainly supportive, but must refrain from contact sports due to risk of splenic rupture

HSV 1 and 2 - VIRUS

-DNA virus - replicates in the nucleus -double stranded and linear -member of the herpes virus family -ENVELOPED -intranuclear inclusions bodies (Cowdry bodies) -sex and saliva, and vertical transmission TORCH infection HSV1 -gingivostomatitis is first sign of HSV1 -herpes labialis, or "cold sores" -keratoconjunctivitis -serpiginous corneal ulcers on Fluorescein slit lamp exam -causes with temporal lobe encephalitis (Hemorrhage and necrosis) -#1 cause of sporadic encephalitis in USA (change in personality etc) -HSV1 latent in trigeminal ganglia -herpes rash has "dew drops on rose petal" appearance -herpetic whitlow, more common in dentists (caused by HSV1&2) -erythema multiform may appear 1-2 weeks after infection HSV2 -herpes genitalis -painful and vesicular; painful inguinal lymphadenopathy -latent in the sacral ganglia -can cause asceptic meningitis in adolescents and adults diagnosis: Zank smear look for multinucleated giant cells, characteristic of herpes infections TX: can help prevent breakups: Acyclovir or Valcyclovir

Cytomegalovirus -VIRUS

-DNA virus - replicates in the nucleus -member of the herpes virus family -REMAIN latent in mononuclear cells (white blood cells with one nucleus; B and T cells and macrophages) -reactivated by immunosuppression -TORCHES infection -blueberry muffin rash (thrombocytopenia seen with petechial rash) -jaundice and hepatosplenomegaly -sensorineural deafness -intracranial calcifications (periventricular or parenchymal); ventriculomegaly -seizures caused by intracranial calcifications -congenital CMV is most likely to be asymptomatic 80-90% -2nd trimester has highest risk of transmission -hydrops fetalis -#1 cause of sensorineural hearing loss in children and #1 cause of congenial viral infection -organ transplant patients at risk of CMV pneumonia -AIDS patients particularly at risk with CD4 count <50 -CMV retinitis typically unilaterally -linear ulceration in esophagus (singular deep and linear) -CMV colitis with ulcerated walls -"OWLS EYE inclusions bodies" -mononucleosis but monospot test is negative tx: Ganciclovir; second line treatment is foscarnet when the virus has UL97 gene mutation against Ganciclovir

Varicella zoster virus - VIRUS

-DNA virus - replicates in the nucleus -member of the herpes virus family -ENVELOPED (all herpes viruses are enveloped) chicken pox -fever, headache -respiratory droplet transmission -"dew drop on a rose" rash vesicular (like herpes simplex virus) -lesions in different stages of healing (unlike smallpox where they are al the same stage) -Tzank smear shows multinucleated giant cells -adult presentation can get pneumonia -encephalitis especially in immunocompromised -live attenuated vaccine for children -remains latent in dorsal root ganglia -can reactivate under stress, aging or immunocompromised state -herpes zoster, or shingles is reactived form -herpes zoster or shingles, has "Dew drop on a rose" appearance with dermatomal distribution (sits on an erythematous base) -if the rash crosses the midline its a sign that the pt is immunocompromised -extremely painful rash -postherpetic neuralgia - pain after rash subsides -herpes zoster opthalmicus- vision loss possible if V1 affected -vertical transmission (TORCH) -congenital varicella syndrome; limb hypoplasia, cutaneous dermatomal scarring; blindness TX chickenpox: Acyclovir treatment for children ages 12+, adults and immunocompromised -vaccine: live attenuated zoster vaccine recommended for adults >60; can give it to HIV patients with CD4 count >200 may be given shingles vaccine TX shingles: FAMCICLOVIR treatment for shingles; also valacyclovir

Reovirus - VIRUS (ROTAVIRUS, Colorado Tick virus)

-DOUBLE STRANDED RNA* replicated in the cytoplasm (so its both positive and negative sense) -NAKED VIRUS -segmented ("BOAR" - bunyavirus, orthomyxo, arenavirus, reovirus) 11 segments ROTAVIRUS -watery diarrhea can be explosive -NSP4 viral enterotoxin that increases CHLORIDE permeability that promotes secretory diarrhea - SECRETORY DIARRHEA -seasonal virus (WINTER) where it occurs most often -children are at risk for rotavius infections -#1 leading cause of severe diarrhea in infants and children TX: ORAL rehydration Prevention: live attenuated oral vaccine (1st dose should be considered before 3 months of age to reduce risk of side effect; the vaccine increases risk of intussusception = telescoping of the bowel due to stimulation and enlargement of peyers patches which act as a lead point) Colorado Tick virus -myalgia, fevers, vomiting (BUT NO rash- so can determine form RMSF)

Clostridium difficile - BACTERIA

-SPORE former like all clostridium species -obligate anaerobe and gram positive -nosocomial diarrhea -spores are removed with soap and water and cant compete well with normal flora- but antibiotics kill normal flora -antibiotics like CLINDAMYCIN can kill normal flora and poor hand washing can cause c.diff infections -exotoxin A and B -exotoxin A binds to brush border enzymes causes inflammation, cell death and WATERY diarrhea -exotoxin B causes depolymerization of actin filaments causes pseudomembrane formation, enterocyte death and necrosis -assay (like PCR) to detect TOXIN in the stool, not the actual bacterial - to see if its the cause of diarrhea -nurses can detect this by smell alone -TREATMENT: ORAL VANCOMYCIN and METRONIDAZOLE

Papillomavirus - VIRUS 1-4, 6, 11, 16, 18, 31, 33

-DOUBLE stranded DNA virus -naked virus -HPV is the most common STD 1-4 -verruca vulgaris= cutaneous common wart 6, 11 -laryngeal papillomatosis = recurrent respiratory papillomatosis (MC seen in children & acquired at birth) -anogenital warts = condyloma acuminata (sexually transmission) -HPV shot - gardisal inactivated subunit vaccine 16, 18 -anogenital squamous cell cancers -HPV shot - gardisal inactivated subunit vaccine 31, 33 -anogenital squamous cell cancers E6 TARGETS P53 P53: cell cycle checkpoint at G1->S phase (stops transition from G1S phase) E7 TARGETS RB retinoblastoma protein = tumor suppressor post-coital bleeding (bleeding after sex) = think cervical cancer PAP smear: screening for cervical cancer from transformation zone KOILOCYTES* (look like blue sunny side up eggs) AIDS-defining illness: invasive cervical/anal/penile cancers immunosuppression increases risk of HPV related cancer

Borrelia burgdorferi - BACTERIA

-Northeastern US -wooden areas -transmitted by tick bite -Ixodes scapularis - tick -mouse reservoir: (host of the tick larvae) -deer obligatory host: (host of adult tick) -tick is the vector -humans are incidental host -dont gram stain -Giemsa stain and Wright stain -SPIROCHETE LYME disease -stage 1: erythema migrans (within 1 month of tick bite) "bull's eye rash" >flu like symptoms -stage 2: heart block caused by mycocarditis >Bilateral bells palsy -stage 3: arthritis of large joints (knee) - migratory polyarthritis >CNS: memory difficulty, encephalopathy TX: doxycycline in early stages ceftriaxone for more severe or lateral diseases

Picornavirus OVERVIEW - VIRUS

-Picornavirus family -RNA virus -positive sense (all replicate in the cytoplasm) -naked virus -large polyprotein product that is cleaved into smaller polyprotein subunits -fecal oral transmission (except rhinovirus) Hepatitis A -causes hepatosplenomegaly Enteroviruses -Polioviruses -Coxsackie A and B -Echovirus -#1 causes of aseptic meningitis -CSF glucose is normal -CSF shows no organisms (asceptic meanign without bacterium) -CSF has elevated protein -children most affected by meningitis Rhinoviruses -primary cause of the common cold -respiratory transmission -upper respiratory infection

Pneumocystis jiroveci- FUNGI

-Pneumocystis pneumonia or PCP -diffuse interstitial pneumonia, nonproductive, and wont see consolidation on xray (might not see anything at all) but if you do you will see ground glass* appearance in both lungs -AIDS defining illness CD4 count < 200 also the value when you want to start prophylaxis -transmitted through respiratory transmission -asymptomatic in healthy people -symptomatic in immunocompromised pts -diagnosis: can be confirmed with (BAL) bronchoalveolar lavage sample (obtains lung samples through fluid rinses) BAL sample is stained with methamine silver to identify PCP that will look like disc shaped* yeasts ground class appearance on PCP pneumonia X-ray can look like crushed ping pong balls prophylaxis AND TX: TMP-SMX (bactrim) can be used for both; pentamidine in case of sulfa allergy (both prophylaxis and Tx)

(Pico) Rhinovirus - VIRUS

-Positive sense RNA virus (all replicate in the cytoplasm) -Picornavirus -RNA virus -naked virus -ACID-labile can NOT go through GI tract (unlike rest of picornaviruses) -transmitted through fomites (hand) and inhalation -ICAM-1 is how it attaches to host cells -THE COMMON COLD -grows best in cooler temperatures around 33 degrees Celsius -affects the Upper Respiratory tract ->causing URI -113 different serotypes; thats why cant make a vaccine against common cold; no vaccines; no treatments

(Pico) Hepatitis A- VIRUS

-Positive sense RNA virus (all replicate in the cytoplasm) -Picornavirus -RNA virus -naked virus -causes HEPATITIS -ACID stable (transmitted fecal orally) like most of the picornaviruses -how to inactivate Hepatitis A: heat the water to 80 degrees Celsius for >1 minute (boiled), UV irradiated, bleach, chlorination -contaminated water is a common source in DEVELOPING countries -we can get it from water indirectly; like uncooked SHELLFISH- common source in DEVELOPED countries -commonly seen in travelers in endemic areas -commonly subclinical but can also cause acute hepatitis: jaundice, hepatomegaly, fever -common symptom: vomiting -anicteric hepatitis (no jaundice) in young children and infants -smokers with Hep A develop aversion to smoking products -one month duration of symptoms; self-limiting; no carrier state or chronic state -VACCINE -INACTIVATED VACCINE

Orthomyxovirus - VIRUS influenza virus (A,B,C)

-RNA VIRUS -NEGATIVE SENSE RNA -need to be transcribed into a positive strand so RNA negatives bring their own RNA polymerases -ENVELOPED influenza virus (A,B,C) -replicates in the nucleus -8 virus segments; it is one of 4 viruses that are segmented ("BOAR" - bunyavirus, orthomyxo, arenavirus, reovirus) -antigenic drift- point mutations (epidemics disease outbreak limited to one geographical areas) this is why we get a flu shot every year -antigenic shift - reassortment (pandemics diseases that occur over multiple continents or worldwide) -antigenic variation -influenza A shift and drift -influenza B is associated with drift only -hemagluttinin (HA) determines cell tropism (which cells can get infected by the virus) -sialic acid residues are bound by HA -HA antigens: H1, H2, H3 etc. -M2 protein is needed to create proper pH for proper uncoating (amantadine/Rimantadine inhibit M2 = no uncoating) -neuraminidase (NA) it cleaves sialic acid to release the newly formed virions from the host cell -Oseltamivir(Tamiflu)/Anamivir: NA inhibitors =>inhibit virion release -transmitted by respiratory droplets -December through Feb -October is the time for vaccination -Killed injectable vaccine -Live intranasal vaccine -pneumonia = major complication -staph aureus pneumonia -aspirin is contraindicated in children with viral illness (can get encephalitis, fatty liver, liver failure = Reyes syndrome) -associated with Guillain-Barre Syndrome (ascending paralysis); would see high protein with low WBC counts = albuminocytologic dissociation)

Togavirus Group - VIRUS Arbovirus Rubella (German measles)

-RNA virus (all RNA replicate in the cytoplasm) -POSITIVE SENSE RNA virus -ENVELOPED -long polyprotein precursor cleaved by proteases (like picornavirus) Arbovirus (arthropod vector) -arthropod born virus (mosquitos are the vector) -Western, Eastern and Venezuelan -Encephalitis (HA, fever, altered mental status) Rubella (German measles) -is a childhood exanthem >BUZZ word is immigrant -congenital Rubella >ToRCHS (toxo, rubella, CMV, HIV, HSV, Sphillis; VZV and parvovirus too) >can cross the placenta and affect the child in utero >mental retardation, microcephaly, deafness, blindness, cataracts, jaundice, PDA, pulmonic stenosis, purpuric blueberry muffin rash, radiolucent bone lesions >main triad: congenital cataracts, sensory-neural deafness, patent ductus arteriosus -childhood Rubella >causes postauricular and occipital lymphadenopathy >maculopapular rash that begins on the head and moves downward ~ typically present for 3 days >transmitted by respiratory droplets -adulthood Rubella >lymphadenopathy and fever >arthritis no treatment VACCINE: live attenuated vaccines MMR (not for pregnant and immunocompromised people) -HIV positive patients should receive vaccine only with CD4 count > 200

Leptospirosis - BACTERIA

-SPIROCHETE small thin and spiral shaped -commonly associated with water sports -found in water contaminated with animal urine -fever occurs in early disease -conjunctival suffusion, redness around the eyes (without pus) -Weils disease -travels through the blood stream and affects multiple organs -renal dysfunction and jaundice from liver infection

Treponema Pallidum - BACTERIA

-SYPHILIS -SPIROCHETE. May be described as spiral shaped -STD -DARKFIELD microscopy needed for direct visualization, taken from direct sample from a lesion of a pt -VDRL is screening test (checking for antibody) -RPR rapid plasma reagent -mono, Rheumatoid factor, SLE, leprosy , IV drug user = can cause false positives -FTA-Ab (ab directly against t. pallidum) is specific test to confirm positives screening result -early stages: (first year) primary, secondary and early latent primary: PAINLESS genital chancre (bacteria damages small vessels and nerves taken out with necrosis) heals within 3-6 weeks, if not treated progresses secondary: systemic disease; maculopapulary rash occurs on palms and soles weeks to months after infection; condyloma latum on mucous membranes; visualize spirochetes within condyloma latum on darkfield microscopy -late stages: tertiary and late latent tertiary: formation of gummas- soft growths within firm necrotic center that can occur anywhere; ascending thoracic aneurysm - tree barking appearance (destroys vasa vasorum that supplies aorta with blood- weakening of the aortic wall); tabes dorsalis (damage to posterior columns of spinal cord) loss of vibration sense, proprioception and descriptive touch; Argyll Robertson pupils reacts to accommodation but NO REACTION TO LIGHT (prostitutes pupil) -congenital syphilis: saber shins (anterior bowing of the tibia), saddle shaped nose, hutchinson's teeth and mulberry molars, deafness Treatment: PENICILLIN in every stage and in everyone, desensitize and use penicillin if they are allergic, even in pregnant pts -JARISCH-HERXHEIMER reaction may occur hours after treatment- dying spirochetes release LPS releasing cytokines, causing fever and chills

Malassezia furfur / Pityriasis Versicolor - FUNGI cutaneous mycoses

-causes Pityriasis Versicolor which is hypopigmented and/or hyperpigmented patches -M. furfur resembles "spaghetti and meatballs" on KOH prep of skin scrapings -Malassezia furfur is part of normal skin flora and thrives under hot and humid conditions -produces melanocyte damaging acids via lipid degradation -remains confined to the skin, the stratum corneum of the epithelium (top layer of the skin) -mainly just a dermatologic complication of immunocompetent people -NICU neonates receiving Total Parenteral Nutrition (with liquid infusions) are at risk of M. furfur fungemia due to lipophilicity of M. furfur TX: for cutaneous infection is "Selsun Blue" (selenium sulfide)

Mycobacterium tuberculosis - BACTERIA

-acid fast stain -Mycolic acids -carbol fushon stain -TB grows on Lowenstein-Jensen medium -obligate aerobe (like nocardia) -transmission by respiratory droplets primarily residing and living in macrophages -cord factor (serpentine shape) activates immune system to activate macrophages so it can be walled off by a granuloma - VIRULENCE FACTOR -sulfatides prevent phagolysosome fusion -primary infection infects the middle or lower lobes of the lungs; hilar lymph node involvement >GHON COMPLEX = hilar lymphadenopathy + peripheral granulomatous lesion in middle or lower lung lobe -necrotic macrophages -after primary infection: 1) healed latent infection -primary TB in children often resolves and becomes latent infection and fibrosis -positive PPD skin test -BCG vaccine can cause a false positive PPD skin test 2) systemic infection (miliary TB) -miliary means it can go to multiple organs; potentially lethal 3) reactivation TB -TNFa inhibitors (neutralized TNFa) ->uncontained infection >like inflixamab -when reactivated affects the UPPER LOBES -symptoms of reactivation: cough, night sweats and hemoptysis -TNFa promotes wasting -POTTS disease (vertebrae) demineralized bones -CNS: cavitary lesion or tubulerculoma TX: R- RIFAMPIN I- ISONIAZID P- PYRAZINAMIDE E- ETHAMBUTOL prophylaxis for latent TB for 9 months: R- RIFAMPIN I- ISONIAZID

Babesia - PARASITE protozoa

-causes babesioisis -blood related symptoms (like hemolytic anemia, hemoglobinuria and resulting jaundice) -carried by Ixodes tick (tick-borne illness), a deer tick; the longer the tick is attached the greater the chance of transmission -coinfection is common -fever, irregularly cycling fevers -higher risk of severe disease in sickle cell disease and asplenia pts (asplenic pts more likely to be symptomatic) -babesioisis diagnosed by thick blood smear -maltese cross appearance in red blood cells -predominantly in NE united states along with borellia also transferred by the Ixodes tick (co infection is common) -many healthy people with babesioisis are scarcely symptomatic and can spontaneously recover TX: atovaquone and azithroymycin (macrolide)

Bacillus anthracis and Bacillus cereus - BACTERIA

-black eschar -large gram positive rods in chains -encapsulated - made of proteins & poly-D -obligate aerobe- only survive in the presence of oxygen bacillus anthracis -spore forming -2 toxins = LF lethal factor and EF= edema factor -EF increases cAMP and causes edema -LF exotoxin acts as a protease and cleaves MAP kinase (signal transduction responsible for cell growth) causes tissue necrosis seen in the black eschar -wool sorter's disease causing pulmonary anthrax starting as a dry cough but can progress to pulmonary hemorrhage (hemorrhagic mediastinitis) which on xray appears as widened mediastinum -TREATMENT: Fluroquinolones and secondary doxycycline Bacillus cereus -aerobic and spore forming -food poisoning -vomiting and/or diarrhea from reheated fried rice

Pasteurella multocida - BACTERIA

-catalase positive -oxidase positive -capsule is important virulence factor -grows on 5% Sheep blood agar -demonstrates bipolar staining, described as "safety pin" staining (like yersenia) -found in the respiratory tract of small animals like cats and dogs -transmission by dog and cats bites -cellulitis may occur within first 24 hours of infection -infection may spread to bone and cause ostemyelitis TX: penicillin is empiric treatment + beta lactamase inhibitor to prevent resistance (so can use amoxicillin + clavulanic acid)

Mucormycosis- FUNGI caused by Mucor and Rhizopus

-caused by Mucor and Rhizopus -immunocompromised pts are highly susceptible to infection; diabetics are highly susceptible to infection -Rhizopus = bread mold -transmission via spore inhalation -> likes to proliferate in blood vessels in the blood where there is extra glucose and ketones -> after invading blood vessels, the fungi penetrates the cribiform plate (causes necrosis) -rhinocerebral mucormycosis -proliferation of this fungi causes necrosis of surrounding tissue -necrotic tissue presents as black escar on the nose and face -DKA is the most common predisposing factor to infection with this fungus -this fungi has hyphae that are nonseptate and branch at wide angles (90 degrees) TX: SURGICAL debridement of dead tissue amphoterecin B for medical treatment

Blastomycosis dermatitidis - FUNGI

-causes Blastomycosis -Geographic distribution BUZZ words: "Great Lakes" and Ohio River Valley and Southern US -dimorphic fungus; mold in the cold (soil and dirt) and yeast in the heat (our bodies) -transmission: inhalation of aerosolized spores -single Broad Based Budding -appear to be about the SAME size as a RBC -Chest X-ray has patchy alveolar infiltrate "haziness" -lesions or cavities in the lungs -systemic fungus only really see systemic infection in immunocompromised -> SKIN and BONE (osteomyelitis) -majority of infections are subclinical or asymptomatic -diagnosis: KOH prep or culture and urine antigen test TX: -azoles for local infections like Itraconazole TX: disseminated infections Amphotericin B

Histoplasma capsulatum - FUNGI

-causes Histoplasmosis -Geographic distribution: is endemic to midwestern and central US; along the Mississippi and Ohio river valley -transmission through respiratory tract, usually spores or bird/bat droppings are inhaled -bird/bat droppings seen in farmers or cave spelunkers -histology: macrophages with intracellular oval bodies -KOH prep and culture for diagnosis; serum and urine rapid antigen test would be faster -histoplasma is much smaller than a RBC -dimorphic: mold in the cold (soil) and yeast in the heat (in the body) -chronic histo can resemble TB in presentation; cavitary lesions in the upper lobes; granulomas; erythema nodosum -dissemination of the fungus (usually immunocompromised pts) will show up as hepatosplenomegaly and show up as calcifications TX: local infection -conazoles like fluconazoles and ketoconazole TX: disseminated infection is amphotericin B

Paracoccidioides brasiliensis - FUNGI

-causes Paracoccidioidomycosis -distributed in Brazil and other parts of South America* -dimorphic - mold in the cold, yeast in the heat -yeast form looks like "captain's wheel"* very large compared to RBC -Cocci and paracocci are roughly the same size -transmission: respiratory droplets -cervical lymphadenopathy* and can move downward to progress to lungs, causing granulomas in the lungs -mucosal ulcers in the mouth that can have small hemorrhages (mucocutaneous lesions*) TX: Itraconazole for mild infections and Amphotericin for systemic and more serious infections

Cryptococcus neoformans- FUNGI

-cryptococci are heavily ENCAPSULATED -capsule is made up of repeating polysaccharide capsular antigens -capsule is the main virulence factor making it anti-phagocytic -found in soil and in pigeon droppings -enters body via inhalation and sets up primary focus in the lungs -pulmonary symptoms: cough, dyspnea and other serious lung infections -UREASE positive -is an opportunistic infection that more commonly affects immunocompromised patients (e.g. HIV patient) -can spread to the CNS and cause meningitis -symptoms: fever, pneumonia, meningitis -tissue samples can be stained with mucicarmine (red) or methanamine silver stains -diagnose: INDIA ink outlines cryptococcal capsules as "halos" - uworld says "CSF shows round or oval budding yeast" -diagnose: LATEX agglutination test detects capsular antigen and causes agglutination -diagnose: gross pathology seen in cryptococcal meningitis: "soap bubble" lesions in gray matter of brain -diagnose: bronchopulmonary washings can be used TX: JOINT therapy with amphotericin B + flucytosine followed by maintenance therapy with fluconazole

Candida albicans- FUNGI

-cutaneous and systemic fungal infections -MC cause of opportunistic mycoses -DIMORPHIC (different though because = it is a yeast in the cold and mold in the heat) -candida forms germ tubes - true hyphae(mold) at 37 degrees C -candida forms yeast at 20 degrees C in cold temperature -pseudohyphae with budding yeast -CATALASE POSITIVE, making individuals with chronic granulomatous disease susceptible to infection -part of normal flora in about 40% of individuals -candida causes diaper rash in a characteristic distribution due to the heat and humidity within a baby's diaper -oral candidiasis is seen in immunocompromised pts or those using oral steroids -oral steroid use must be followed by oral rinsing to avoid development of oral candidiasis -oral candidiasis can be scraped off the oral mucosa. This feature directly contrasts to leukoplakia, which may present in a similar manner -KOH is used to prep oral scrapings when attempting to diagnose oral candidiasis -white pseudomembranes -candida esophagitis is an AIDS defining illness, seen when CD4 count <100 -diabetes predisposes people to candida infections; candidal vulvovaginitis is common in diabetes and in people who use antibiotics and birth control pills -candida does NOT change vaginal pH -IV drug users are at increased risk of developing candidal endocarditis which commonly affects the tricuspid valve TX: azoles for minor infections and amphoterecin B for more severe and disseminated infections TX: nystatin (liquid) is used for oral or esophageal candidiasis TX: capsofungin may be used for disseminated candidial infections resistant to amphotericin

Entamoeba histolytica - parasite

-cysts form infectious when ingested from contaminated waters -associated with men who have sex with men. found be to related to anal oral transmission -right lobe of liver is most common site involved with amoebic liver abscess -right upper quadrant pain and may have enlarged and tender livers -abscess described as having "anchovy paste" consistency -intestinal amebiasis: ulcerations in the colon and bloody diarrhea (invasive) -intestinal biopsy may show flask-shaped lesions -diagnosis with stool O&P to look for cysts or trophozoites -presence of trophozoites with endocytosed RBCs under microscope -Treatment: METRONIDAZOLE, elimination of cysts in the lumen of intestine (luminal agents) PARAMYCIN & IODOQUINOL very rarely need to drain this

Dermatophytes: - FUNGI Trichophtyon Epidermophyton Microsporum

-dermatophytes are fungi that cause TINEA infections -dermatophytes live on the skin -TINEA means ring worm -TINEA capitis is on the head and scalp -TINEA corporis is on the body -TINEA cruris is on the groin -TINEA pedis is on the feet (athletes foot) -athletes commonly get tinea infections, wrestlers and swimmers etc. -animals are a common source of dermatophytes -tinea lesions are pruritic -hyphae can be seen with KOH prep of skin scrapings -woods lamp can be used to diagnose Microsporum -Onychomycosis: dermatophyte infection of the nails TX: TOPICAL azoles used to treat infections TX: Terbinafine is used to treat Onychomycosis TX: oral Griseofulvin is used to treat more serious dermatophyte infections (note it has a lot of GI side effects- "like if you eat a lot of greasy foods")

Clostridium tetani - BACTERIA

-gram POSITIVE -obligate anaerobe (cant survive in presence of oxygen) -all SPORE formers -spores found in rusty nails and in soil -SPASTIC paralysis -RISUS SARDONICUS "evil grin" or Lock Jaw symptoms -opisthotonus-exaggerated arching of the back due to spastic exaggeration of back muscles -spores are embedded in the flesh where it produces and releases tetanus toxin (which causes the symptoms) travels RETROGRADE through motor neurons from periphery to the spinal cord -tetanus toxin acts as protease which cleaves SNARE protein inhibiting release of GABA and Glycine (inhibitors) so it inhibits inhibitors ->uncontrolled firing of the neurons and spasms -GABA and Glycine released from Renshaw cells is inhibited vaccine is TOXOID (toxin conjugated to protein)

Clostridium botulinum - BACTERIA

-gram POSITIVE -obligate anaerobe (cant survive in presence of oxygen) -all SPORE formers -transmitted by improper canning of food (when you hear multiple family members developing neuro symptoms) -DESCENDING FLACCID paralysis (absence of muscle contraction) - (opposite of guillain barre syndrome which is ascending paralysis) -early symptoms included ptosis and diplopia -adults get PREFORMED toxin only effects PNS (not able to cross BBB) -toxin targets nerves that release acetylcholine (excitatory) so inhibiting excitatory causing flaccid paralysis -toxin is a protease that cleaves SNARE proteins in babies = flaccid paryalsis "floppy baby syndrome" -SPORES germinate and produce toxin in the baby -infantile botulism transmitted through injections of honey -so thats why you dont give honey to infants (spores in the honey)

Brucella - BACTERIA

-gram negative -direct contact: cow, pig, and farm animals -ingestion of unpasteurized dairy products -facultative intracellular organism (can live in both) -symptoms: fever, chills and anorexia -undulant fever -liver and spleen involvement and enlargement -osteomyelitis in chronic brucella infection TX: doxycycline, rifampin as adjunct therapy

Proteus mirabilis- BACTERIA

-gram negative -facultative anaerobe -when plated demonstrates swarming motility -staghorn calculi kidney stones -urease positive whats responsible for forming staghorn calculi and creating alkaline environment -alkaline environment can cause struvite stones formation -may cause UTI -FISHY ODOR -TREATMENT: sulfonamides

Yersinia enterocolitica - BACTERIA Yersinia pestis

-gram negative -resistant to cold temperates -SAFETY PIN, bipolar staining -encapsulated Yersinia enterocolitica -transmitted through puppy feces -commonly infects toddles -also transmitted through contaminated milk products -bloody diarrhea- invasive -CAN MIMIC appendicitis symptoms: RLQ pain Yersinia pestis -the black bubonic plaque -characteristic buboes form on the skin -causes blackening and death of tissues -Yops secreted via type 3 secretion system (yersinia associated outer protein) -prairie dogs are main reservoir in US -transmitted by flea bites Treatment: aminoglycosides (streptomycin) used in combination with tetracycline killed vaccine used to prevent infection (not typically used)

Pseudomonas - BACTERIA

-gram negative ROD -encapsulated -#1 cause of gram neg nosocomial pneumonia -MCC of respiratory failure in CF patients -osteomyelitis in IVDU and diabetics -thrives in aquatic environments -OXIDASE positive AND MOTILE (according to UWORLD) -Catalase positive -blue/green pigment when plated (pyocyanin and pyoverdin) -fruity grape like odor -obligate aerobe -BURN patients infections -nosocomial UTI -undercloronated hot tubs - hot tub fasciculitis -ECTHYMA GANGRENOSUM- black necrotic lesions on skin -otitis externa (swimmers ear) -exotoxin A (diptheria toxin have identical toxins) inactivates by ribosylation target elongation factor 2 Treatment: piperacillin (With tazobactam) and aminoglycosides (in combo with beta lactam antibiotics) and FQ (UTI)

Haemophilus influenzae - BACTERIA

-gram negative bacteria -coccobacillary shape -chocolate agar needs factor 5 (Nicotinamide=NAD) and factor 10 (hematin) -aerosol transmission -main cause of epiglottitis (inflamed epiglottis, inspiratory stridor, drooling, "cherry red epiglottitis") -otitis media -strains with type B capsule cause meningitis -increased risk of infectino in sickle cell asplenic patients -VACCINE is for type B capsule; vaccine is polysacccharide conjugated to Diptheria toxoid; between 2-18 months should get vaccine TX: beta-lactam antibiotic use ceftriaxone for meningitis or systemic disease; rifampin is used for close contact prophylaxis

Legionella - BACTERIA

-gram negative but doesn't take up gram stain well but needs SILVER STAIN to be visualized -grows on charcoal yeast extract -oxidase positive -growth requires presence of iron and cysteine -Pontiac fever, fever and malaise and usually self limited -Legonnaires' disease more common in smokers -atypical pneumonia -Xray shows patchy infiltrate with consolidation of one lobe -Legonnaires' disease may present with hyponatremia (<130) -may present with headache and confusion (neurological symptoms) -pneumonia with diarrhea* and hyponatremia think Legonnaires' disease -Legonnaires' disease present with high fever (>104F) -culture respiratory sputum but can do RAPID URINE ANTIGEN test for diagnosis TX: macrolides and flouroquinolones

Shigella sonnei - BACTERIA Shigella dysenteriae

-gram negative enteric leading to bloody diarrhea -green colonies on hektoin agar -immotile -acid stable (acid doesnt effect it)few organism to cause infection -shigella induces M cells to take it up and escapes by use of actin filaments; fecal blood and leukocytes -bloody diarrhea and inflammatory diarrhea -facultative intracellular -binds 60s subunit of ribosomes and inhibits translation -type 3 secretion system to release cytokines Shigella sonnei -most common in the US Shigella dysenteriae -infection can cause HUS in children (<10 years old) -glomerular damage activates platelets ->leading to drop in platelet count ->lyse RBCs (RBC hemolysis) ->shistocytes

Staph Aureus- BACTERIA

-gram positive cocci -grape like clusters -golden colored when plated -beta hemolytic (looks like glowing when plated on red agar) -ferments mannitol turns agar bright yellow (if not it will stay pink) -protein A is the main virulence factor for staph aureus - component of cell wall combined FC portion of immunoglobulin prevents compliment from binding same region preventing phagocytosis -coagulase positive (parting the red sea in the picture) (converts fibrinogen to fibrin) -CATALSE POSITIVE (hydrogen peroxide to water conversion) -colonizes the nose -MCC of septic arthritis in adults -pneumonia which looks like patchy infiltrates on x-ray -post-viral bacterial pneumonia -abscesses -rapid onset acute bacterial endocarditic >IV drug users endocarditis >tricupsid most likely involved -MCC of Osteomyelitis -scalded skin syndrome where skin peals off (exfoliatin toxin) -toxic shock syndrome like leaving gause on or tampon in (foreign material in the body) which is a superantigen (TSST) -staph food poisoning from performed toxin - more associated with vomitting; from meats and mayonnaise -MRSA resistance by altering PBP which constructs cell walls -treat MRSA with VANCOMYCIN -Nafcillin if its methacillin sensitive

Nocardia species - BACTERIA

-gram positive filamentous branching rod (similar to actinomyces) -obligate aerobe (UNLIKE actinomyces which is obligate anaerobe) -found in soil but does NOT form spores -weakly stains acid fast - carbol fuchsin stain used -mycolic acids (long chain FA with long tails) -catalase positive, pts with chronic granulomatous disease are susceptible to infection -urease positive -primarily infects immunocompromised patients and men more -symptoms include pulmonary nocardiosis as pneumonia like symptoms with cavitary lesions in the lungs associated; brain abscess formation; cutaneous symptoms - indurated lesions and inflammatory reaction TX: sulfonamides (unlike actinomyces you treat with penicillin)

Helicobacter pylori - BACTERIA

-helical shaped -pylori near our pylorus in the antrum of our stomach -MOTILE -curved gram negative rods (but more helical) -UREASE POSITIVE (helps reduce acidity of the environment) -urea breath test -oxidase positive (all curved are) -95% of all DUODENAL ulcer are from H.pylori -ULCERS (reducing somatostatin or increasing gastrin production) -increased risk for gastric adenocarcinoma - MALT (maltoma) mucus associated lymphoid tissues TREATMENT: TRIPLE THERAPY - Proton pump inhibitor, amoxicillin, macrolide (clarithromycin specifically)

Clostridium perfringens - BACTERIA

-infection associated with motorcycle accidents and military combat wounds -SPORE FORMING can be found in soil and dirt -obligate ANAEROBE - need to plate it in anaerobe environment -soft tissue infection GAS GANGRENE (gas is produces gas under tissue as it eats carbohydrates- crepitus) -myonecrosis involves alpha toxin or lecithinase that cleaves lecithin that is a phospholipase and causes damaged to cell membranes by damaging phospholipids -lecithinase can cause RBC hemolysis -double zone of hemolysis when plated on blood agar -TX IS IV PENICILLIN G food poisoning diarrhea -large amount of spores which germinate in the gut that produce toxin so it is slow onset -> watery diarrhea -transient and self resolves

Salmonella typhi -BACTERIA Salmonella enteritidis

-motile -H2S positive black colonies on Hektoen Agar(all enteric bacteria that are motile are H2S positive) -encapsulated -acid labile (means easily degraded in the stomach so need large dose to infect) >taking omeprazole, or prenicious anemia where you lower stomach acid= more susceptible to infection -type 3 secretion system -facultative intracellular (specifically in macrophages) Salmonella enteritidis -the reservoir is chicken; get it from undercooked chicken -inflammatory diarrhea Salmonella typhi -in gallbladder of chronic carriers -Typhoid Mary -rose-colored macules on abdomen -#1 cause of osteomyelitis in sickle cell patients -constipation and sometimes pea soup diarrhea -TREATED with FQ (Cipro) -live attenuated vaccine

Mycoplasma pneumoniae - BACTERIA

-no cell wall so cant appear on gram stain -cell membrane contains cholesterol - UNIQUE for a bacteria -atypical pneumonia "walking pneumonia" -xray shows severe pneumonia appears much worse than the patient looks; shows reticulonodular or "patchy" infiltrate -increase incidence in young adults like military recruits living in close quarters -diagnosis: IgM cold agglutination test causes agglutination of red blood cells -culture it takes a long time - Eaton agar TX: macrolides because no cell wall

Rickettsia prowazekii- BACTERIA

-obligate intracellular -poor gram stain -unable to produce CoA, gets it from eukaryotic cells -NAD+ also important for bacterial growth and replication -Rash starts at trunk, and spreads outwards towards extremities -rash SPARES hands, feet and head -affects military camp recruits and prisoners of war -spread by LOUSE (scratching usually introduces poop into blood) -illness is called epidemic typhus (wide spread rapid outbreak) -causes myalgia and arthalgia -causes pneumonia -encephalitis with dizziness and confusion -serious infections can cause coma TX: Doxycycline

Rickettsia rickettsii- BACTERIA

-obligate intracellular -poor gram stain -use Giemsa stain -unable to produce CoA, gets it from eukaryotic cells -NAD+ also important for bacterial growth and replication -transmitted by direct contact with Dermacentor Tick -rash not immediate- has incubation period between 2-14 days -rash begins at extremities (WRIST and ANKLES) -rash spreads centrally from extremities INCLUDING face and feet -symptoms include, headache, fever* and myalgia TX: Doxycycline

Rickettsia species overview - BACTERIA

-obligate intracellular -unable to produce CoA, gets it from eukaryotic cells -NAD+ also important for bacterial growth and replication -poor gram stain -weakly gram negative -coccobacillary shape -weil-felix agglutination test for Rickettsial infections -headache and fever in early Rickettsia infections -vasculitis -infection and rupture -rash may be associated with vasculitis TX: Doxycycline DOC

Chlamydia trachomatis - BACTERIA Chlamydia pneumoniae Chlamydia psittaci

-obligate intracellular bacteria -lack of staining with gram staining -lack of muramic acid in cell wall -1st stage: elementary stage -2nd stage: reticular body active form that can multiply elementary body is the infectious form "elementary enters" reticular body is active dividing form "reticular body replicates" -inclusion bodies visible within cells under microscope (a bunch of reticular bodies) -Giemsa stain to be visualized -NAAT nucleic acid amplification test to diagnose (PCR) Chlamydia trachomatis A-C: blindness -leading cause of blindness worldwide -transmitted by hand to eye contact or fomites D-K: STI -characterized by WATERY discharge -infection if left untreated can lead to pelvic inflammatory disease (PID) -newborns born to infected mothers can develop neonatal conjunctivitis and pneumonia (these babies will present later 1-2 weeks later) L1-L3: LGV >lymphogranuloma venereum characterized by tender inguinal lymphadenopathy reactive arthritis or Reiters syndrome -uveitis, urethritis, arthritis -"cant see, cant pee, cant climb a tree" Chlamydia pneumoniae -causes atypical pneumonia "walking pneumonia" in elderly Chlamydia psittaci -also causes pneumonia transmitted by bird droppings TX: macrolides such as azithromycin oral macrolides effective against trachoma tetracyclines (doxycycline) also effective coinfection with gonorrhea (treat ceftriaxone for this coverage)

Strep agalactiae (Group B Strep)- BACTERIA

-polysaccharide capasule -CAMP test positive - separates GROUP B strep from ALL the other streps (WHEN its plated with s.aureus it has an increasing zone of hemolysis; "arrowhead" zone of hemolysis) -positive hippurate (hydrolyses Na hippurate) -beta hemolytic (like group A strep) -bacitracin resistant (unlike group A strep) -CAUSES really serous infections in newborns - #1 cause of meningitis in neonates - common cause of sepsis in neonates -causes pneumonia -culture mom at 35 weeks of pregnancy to see if colonized with group B strep -prophylaxis give mother intrapartum penicillin

Calicivirus (most common is Norovirus) - VIRUS

-positive sense RNA virus (all positives replicate in the cytoplasm) -NAKED virus -produces one long polyprotein that is cleaved by viral proteases into smaller active constituents Norovirus - is the most common calicivirus - common on cruises - diarrhea breakout viral gastroenteritis that can be explosive -EXPLOSIVE WATERY DIARRHEA - outbreaks common in day care centers and schools - consumption of shellfish is associated with norovirus (or handling of food like in a buffet)

Francisella tularensis - BACTERIA

-rabbits are main reservoir (eating, handling - direct) -transmitted by dermacentor tick -MC -aerosolized -gram negative, coccobacilli -facultative intracellular organism -painful ulcer at site of inflammation -goes into macrophages and travels in the lymph system -causes granulomas with caseating necrosis in reticuloendothelial organs (i.e. lymph nodes) -regional lymphadenopathy TX: Streptomycin (aminoglycosides)

Sporothrix schenckii - FUNGI

-sporothrix is found in rose thorns, tree bark, and other plants -is a dimorphic fungus -causes "rose gardener's disease" -looks like cigar shaped yeast under a microscope -infection spreads in an ascending pattern along the path of draining lymphatics -red bumps appear on the skin following infection -culture is gold standard for diagnosis; you can also biopsy where you see granulomas consisting of histeocytes, multi-nucleated giant cells and cigar shaped budding yeasts TX: itraconazole is the drug of choice to treat lymphocutaneous sporotrichosis TX: saturated solution of potassium iodide may also be used to treat lymphocutaneous sporotrichosis

Arenavirus - VIRUS

-ss RNA (replicates in the cytoplasm) -negative sense RNA viruses -ENVELOPED -AMBISENSE* (it can encode positively and negatively) -helical shape nucleocapsid -segmented virus - 2 segments* ("BOAR" - bunyavirus, orthomyxo, arenavirus, reovirus) -grainy appearance on electron microscopy -roden transmission Lymphocytic choriomeningitis virus (LCV) -meningoencephalitis -fever TX: inactivated by heating, low pH, irradiation and detergents

Rhabdovirus (Rabies)- VIRUS

-ss RNA (replicates in the cytoplasm) -negative sense RNA viruses -ENVELOPED -capsule "looks bullet shaped" -helical capsid -zoonotic virus (carried by animals and transferred to humans) -bats are #1 carriers in US -foxes, skunks and other rodents are also common carriers -binds to nicotinic ACh receptors -initially infects neurons at the post-synaptic motor endplate -virus travels in a retrograde transmission along peripheral nerves -replicates in motor neurons -travels to dorsal root ganglia before spreading to the brain -fever, rabies encephalitis, drooling and foaming of the mouth are symptoms -eosinophilic Negri bodies in neurons found on biopsy -Negri bodies in the hippocampus cytoplasm (hippocampal pyramidal cells) -Negri bodies in purkinje cells TX: passive immunization after exposure to rabies (preformed antibodies) and give killed vaccine to have active immunization -once symptoms appear prophylaxis is ineffective

Bunyavirus family- VIRUS Hantavirus California encephalitis Rift Valley Fever

-ss RNA (replicates in the cytoplasm) -negative sense RNA viruses -ENVELOPED -golgi in its envelope -segmented - 3 circular segmented ("BOAR" - bunyavirus, orthomyxo, arenavirus, reovirus) -ARBOVIRUS -reservoir: deer mouse -transmitted via rodent urine/feces Hantavirus -pulmonary edema via pulmonary capillary leak - pre-renal azotemia -hemorrhagic fever California encephalitis and Rift Valley Fever -seizures -encephalitis -transmitted by Aedes mosquito

Paramyxovirus -VIRUS Measles (Rubeola) Mumps RSV respiratory syncytial virus Croup

-ss RNA (replicates in the cytoplasm) -negative sense RNA viruses -ENVELOPED -transmitted by respiratory droplets -MMR: live attenuated vaccine (CI in pregnancy) Measles (Rubeola) -4 C's: Cough, Coryza (runny/stuffy nose), Conjunctivitis, Koplik spots) Koplik spots - pathognomonic = small, bluish white spots on a red background found on the buccal mucosa in the cheek near the second molars) -fever can be very high -rash starts on the face and moves downwards -pneumonia is a complication of measles infection -SSPE subacute sclerosing pan encephalitis is another complication -Hemagluttinin (HA) -fusion protein: multinucleated giant cells -vitamin A reduces measles morbidity and mortality Mumps -parotitis replicates there and in the testes (unilateral orchitis) -meningitis -Hemagluttinin (HA) -Neuraminidase (NA) -fusion protein: multinucleated giant cells RSV respiratory syncytial virus <6 months of age -attaches to G protein to infect respiratory epithelial cells -RSV is the #1 cause of pneumonia and bronchiolitis in infants -fusion protein: multinucleated giant cells -ribaviron can be used in adults to treat RSV -prevent fusion protein with Palivizumab Croup "laryngotracheobronchitis" -seal bark cough -has all 3 virulence factors: fusion protein, HA, NA -x-ray: "steeple sign" narrowing of the sub glottis region -mainly infects children -buzz word: inspiratory stridor

Filovirus - VIRUS Ebola Marburg

-ss RNA (replicates in the cytoplasm) -negative sense RNA viruses -helical capsid -ENVELOPED Marburg Ebola -fever -petechial rash (micro hemorrhages) -hemorrhagic fever -end organ failure -hemorrhagic (hypovolemic) shock -possibly transmitted via primates -monkeys or bats in endemic areas like Africa -health care works taking care of infected individuals -very dangerous infections

Gardnerella vaginalis- BACTERIA

-the cause of BACTERIAL VAGINOSIS -gram variable rod staining- can stain both -normal vaginal flora contains majority lactobacilli; bacterial overgrowth that disrupts the normal flora -grayish-white discharge -FISHY ODOR -KOH wiff test -infection occurs when pH >4.5 -CLUE CELLS - epithelial cells diffusely coated with bacteria - are characteristic* on wet mount -TREATMENT: metronidazole (also used to treat c.diff)

Mycobacterium leprae - BACTERIA

-thrives in cool temperatures explaining predilection for extremities -acid fast bacteria -Mycolic acids -carbol fushon stain -armadillo is main reservoir in US -leprosy also known as Hansen's disease Tuberculoid -Tuberculin response -TH1 response with cell mediated immunity -can contain bacteria within macrophages -symptom: include well demarcated hairless lesion on skin -positive Lepromin skin test demonstrates good cell mediated response -generally well controlled Lepromatous -Lepromatous response -TH2 response humoral response -bacteria unable to be contained by macrophages -human to human transmission -symptoms: symmetric glove and stocking neuropathy -poorly demarcated raised lesions on extensor surfaces of extremities -profound facial deformity described as "Leonine facies" tx: Tuberculoid needs Dapsone and Rifampin for 6 months Lepromatous needs Dapsone and Rifampin + Clofazimine FOR 2-5 YEARS

Bordatella pertussis - BACTERIA

-transmission: respiratory droplets -filamentous hemagglutinin -(1)pertussis toxin acts by ADP ribosylation and toxin inhibits Gi (toxin inhibits inhibitor and thus increases cAMP) and causes lymphocytosis -(2)adenylate cyclase toxin acts like the anthracis EF toxin and increase in cAMP -(3) tracheal toxin damages respiratory epithelium -catarrhal stage (nonspecific symptom stage) -paroxysmal stage: whooping cough -convalescent stage can last for months can have gradual reduction of symptoms -treatment: treat early with macrolides -prevention: killed vaccine no longer available; acellular vaccine = DTaP (aP is for acellular pertussis antigens)

Giardia Lamblia - parasite

-transmitted through unfiltered or poorly purified drinking water associated with campers -transmitted by fecal oral transmission of CYSTS -bloating, flatulance and foul smelling diarrhea -causes steatorrhea, or "fatty diarrhea" -distinct trophozoite shape, they attach but do not invade the intestinal wall (thus wont cause bloody diarrhea) -trophozoites in stool is diagnostic -Stool O&P is diagnostic test -ELISA stool antigen test can also make diagnosis -Treatment: Metronidazole

Klebsiella pneumoniae, Enterobacter cloacae, Serratia marcescens- BACTERIA

ALL -nosocomial infections -pneumonia and UTI -multi-drug resistant -ferment lactose (e.coli also does) form pink colonies on MacConkey agar Enterobacter cloacae -motile Serratia marcescens -motile -produces red pigment when cultured Klebsiella pneumoniae -immotile -Alcoholics, Abscesses and Aspiration -polysaccharide CAPSULE -BUZZ WORD "currant jelly sputum" -cavitary lesion originally makes people think its TB -UREASE POSITIVE

Strep. pneumoniae / Strep viridans- BACTERIA

BOTH: alpha hemolytic = partial hemolysis giving a green hue (group A and B are beta hemolytic) strep pneumoniae - polysaccharide capsule (main virulence factor) -optochin sensitive -lancet shaped diplococci -bile soluble (cant grow in bile) - #1 cause of CA pneumonia (lobular) -rust colored sputum -"MOPS", Meningitis, Otitis media, Pneumonia, Sinusitis (MC bacterial cause of all of these) -IgA protease -encapsulated -sickle cell disease (Asplenia) particularly susceptible - Treatment: macrolide (erythromycin), 3rd gen cephalosporin (ceftriaxone) -prophylaxis (adult) 23 valent IgM response; (child) is 7 conjugated to protein - IgG generates a more robust T cell response Strep viridans -optochin resistance -NO CAPSULE -bile insoluble (bile resistant) -strep mutans causes dental caries ->subacute endocarditis in damaged heart valves (mitral valve) -adheres to platelets -dextrans that makes them stick to platelets

vibro cholerae -BACTERIA vibro parahaemolyticus vibrio vulnificus

BUZZ WORD: "COMMA SHAPED" gram negative vibro cholerae -perfuse watery diarrhea - RICE WATER stools -fimbraie attachment then releases cholerae toxin but does NOT invade -grows on alkaline media - its ACID LABILE (hate acidic environment of the stomach) -oxidase positive -activates Gs pathway, increases cAMP secretion of water into intestinal lumen hence watery diarrhea -Treatment: oral rehydration with electrolytes vibro parahaemolyticus & vibrio vulnificus -they can contaminate sea food particularly oysters

HHV6 - Roseola -VIRUS exanthema subitem

Double stranded DNA virus is in the HERPES VIRUS FAMILY -6th disease -infects CD4+ cell helper T cell has the ability to cause immunosuppression -occurs primarily in children 6 m to 2 y.o and is usually self limiting -high grade temperature fever >104 degrees lasts 4 days -> can cause febrile seizures -AFTER fever, appears diffuse lacy body rash that spares the face -TREATMENT: SUPPORTIVE

HHV-8 Kaposi's Sarcoma - VIRUS

Double stranded DNA virus is in the HERPES VIRUS FAMILY -immunosuppression and AIDS associated with Kaposi Sarcoma -causes violacious lesions on the nose, extremities and mucous membranes -angiogenesis causes proliferation of vasculature and gives it its violet color -causes dysregulation of VEG-F -lesions can be found within the GI tract -kaposi's lesions most commonly occur on the hard palate -infection of B cells can cause Primary Effusion Lymphoma (B-cell lymphoma) -sexual active including kissing -higher incidence in elderly russian men and African populations -can be confused with bartonella henslea (cause of bacillary angiomatosis- which has a neutrophilic infiltrate & bacterial etiology); must be distinguished lesion by microscope; karposi is characterized by lymphocytic infiltrate & viral etiology -Treatment - antiretroviral therapy and the lesions should shrink

Tissue Nematodes- PARASITE Dracunculus medinensis, Onchocerca volvulus, Wuchereria bancrofti, Toxocara canis, Loa loa

Dracunculus medinensis -drinking contaminated water with copepods containing larvae (intermediate hosts) -adult females emerge from PAINFUL ulcers in the skin -eosinophilia Onchocerca volvulus -hyper and hypo-pigmented spots occur with onchodermatitis -microfilariae in eye causes blindness also called RIVER BLINDNESS -eosinophilia -microfilariae seen in skin biopsy under microscope TX: ivermectin Wuchereria bancrofti -causes elephantiasis: long standing lymphedema in the lower extremities -lymphadenopathy -cough from microfilariae in lungs causes hypersensitivity reaction making someone cough -transmitted by mosquitos (intermediate host) -diagnosis by organisms seen on thick blood smear -eosinophilia TX: diethylcarbamazine Toxocara canis -contamination from food by dog or cat feces -visceral larvae migrans name of disease -ocular larva migrans leads to blindness -eosinophilia TX: Albendazole Loa loa -causes transient angioedema -local subcutaneous swellings -adult worms can migrates across conjunctiva also called african eye worm -microfilariae seen on blood smear -transmitted by deer flies -eosinophilia TX: diethylcarbamazine and Albendazole

Enterococcus - BACTERIA

Enterococcus Faecalis (more common) Enterococcus Faecium (more dangerous) Both: -inhabits the INTESTINAL tract -gram + cocci -can grow in 6.5% NaCl -bile resistant -UTI, endocarditis, biliary tree infections (hence bile resistant) -VRE - vancomycin resistant TREATMENT: Linezolid (antibiotic); Tigecycline

Escherichia coli - BACTERIA (ETEC, EHEC)

Escherichia coli -lactose fermenter -Pink on MacConkey Agar -encapsulated -K antigen present on capsule -green on EMB agar -catalase postiive -fimbriae necessary for UTI -#1 cause of UTI -leading cause of gram negative sepsis -LPS endotoxin located in outer cell membrane (virulence factor for all gram negatives) -neonatal meningitis - only if it has the K antigen Enterohemorrhagic E.coli (EHEC) -transmitted by eating undercooked meat/hamburgers -bloody diarrhea -only e.coli that DOESNT ferment sorbitol -inhibits ribosomes at 60s subunit - like SHIGA LIKE TOXIN -hemolytic uremic syndrome in <10 y.o. patients (damages endothelial cells in glomerulus; platelet aggregation and decrease in platelet count; hemolysis of RBCs) -O157:H7 associated with outbreaks enterotoxigenic E.coli (ETEC) -"travelers diarrhea" -"montezuma's revenge" -transmitted via water -recent travel to Mexico -heat labile toxin increases cAMP -heat stable toxin increases cGMP (similar to cholera) -watery diarrhea

Corynebacterium diphtheriae- BACTERIA

GRAM POSITIVE -CLUB shaped -metachromatic granules -V or Y formation -exotoxin A (active) and B (binding) -toxin causes ADP ribosylation of elongation factor 2 (EF2) which inhibits ribosome function and inhibit protein synthesis ->cell death -pseudomembranes formation (throat and tonsils) -RESPIRATORY DROPLET spread -"bulls neck" due to lymphadenopathy -cardiotoxic effects (myocarditis, arrhythmia, heart block) -damages myelin of nerve fibers -plated on tellurite agar and Loeffler's medium to culture -Elek's test -often immigrants get this because can be vaccinated (toxoid- inactivated exotoxin bound to protein) -passive immunization by administrating anti-toxoid if pt presents with symptoms

Strep pyogenes (Group A Strep) - BACTERIA

GRAM POSITIVE COCCI -form long chains or pairs - encapsulated -hyaluronic acid what the capsule is made up (we produce this in our CT) -beta hemolytic -impetigo honey crusted! (skin rash also caused by s.aureus) - pharnygitis - MCC of cellulitis and erysipeias (inflammation of the skin) STREP PYOGENIC EXOTOXIN SPE causes the following 3: 1) scarlet fever (strawberry tongue, pharyngitis, diffuse rash that spares the face) 2) TSLS- toxic shock like syndrome by a superantigen 3) necrotizing fasciitis (surgical emergency) SpeA- superantigen (TSLS) SpeB- protease (Nec. fasc) SpeC- superantigen (TSLS) -Rheumatic fever >type 2 hypersensitivity reaction >M protein main virulence factor responsible for RF (antiphagocytic) >M protein mimics myosin in our heart causing antibodies to attack our mitral valve (damaged causing mitral stenosis in RF) >pharyngitis precipitates RF >jones criteria (joints (polyarthritis), o (heart problems), n (subcutaneous nodules), erythema marginatum, sydenham's chorea) > can occur only after pharyngitis >>TREATMENT: penicillin WILL help -post streptoccocal glomerularnephritis PSGN >type 3 hypersensitivity reaction > glomerulonephritis (cola colored urine, facial edema) >2 weeks post infection >can occur after pharyngitis or impetigo >TREATMENT: penicillin will not help VIRULENCE FACTORS: -streptolysin O - lyse red blood cells and be beta hemolytic (we generate ASO antibodies) -streptokinase (lyses clots) -DNase (depolymerize DNA) -BACATRACIN sensitive (group b strep is resistant) -antistreptolysin O titer tell us if we have a had a recent infection with group A strep

Retrovirus - HIV/AIDs - VIRUS

HIV -immunocompromised -RNA postive virus -ENVELOPED -diploid RNA positive virus -gag = p24, which is the capsule for RNA strands -Env = gp 41 and 120 -gp41 is transmembrane protein -gp120 is outer glyocprotein that eventually comes in contact with host receptors -pol = reverse transcriptase (creating DNA from RNA) -TORCHES infection -HIV initially infects macrophages and targets helper T cells progression of the disease -prodrome consists of flu or mono-like symptoms and cervical LAD, fever can last for several weeks but generally gets better on its own, CD4+ cells are infected -latent for up to 10 years where the virus is replicating in the lymph nodes -steep decline in CD4+ cells -AIDS diagnosed when CD4+ cells <200 or if AIDS defining illness with a higher count (diffuse large b cell lymphoma is an AIDS defining illness) gains entry via CCR5 receptor in early stages or gains entry via CXCR4 receptor in late stages diagnosis: screening done with ELISA looking for antibodies (tested early can be false negative) confirmation done with a Western Blot use PCR to check viral load and CD4 count once diagnosed with HIV HIV RNA and DNA amplification test in neonates to check for virus itself because they will have antibodies passed down from the mom TX: HAART -combination therapy is BETTER than monotherapy -NRTI are the backbone of antiretroviral therapy (nucleotide analog halting further elongation); inhibits reverse transcriptase -Zidovudine for pregnant patients -NNRTI (doesnt incorporate itself but still inhibits reverse transcriptase) -protease inhibitors to cleave proteins necessary for viral replication -CCR5 inhibitor (early stage) = Maraviroc EVERYONE GETS TREATMENT esp pregnant people, high viral load patients or those with low CD4 counts

Leishmaniasis donovani - PARASITE Leishmaniasis baziliensis

Leishmaniasis donovani -visceral leishmaniasis caused by Leishmaniasis donovani -black fever, or kala-azar -bone marrow affected causing pancytopenia -hepatosplenomegaly (so fevers, hepatosplenomegaly, pancytopenia) -100% fatal if left untreated TX: Amphoterecin B for visceral leishmaniasis Leishmaniasis baziliensis -mucocutaneous Leishmaniasis (cutaneous leishmaniasis) -consuming the flesh of the victim -vertebrates are the host -sandflies are the vector -AMASTIGOTE is intracellular form, seen within macrophages TX: stibugluconate treatment for cutaneous leishmaniasis

Polyomavirus- VIRUS JC BK

NAKED (non enveloped) circular double stranded DNA virus JC virus (john cunningham) -progressive multifocal leukoencephalopathy PML -immunocompromised people -HIV patients with CD4+ <200 -DEMYELINATING disease -non-enhancing multifocal brain lesions in the white matter (brain lesions that light up on brain imaging) -example: 40 y.o HIV patient complains of weakness, visual changes and difficulty with speech getting worse over the past couple of weeks, CD4+ count is 150, get brain scan CT or MRI which shows multiple non-enhancing lesions around the brain BK virus - nephropathy and other problems with the urinary tract including hemorrhagic cystitis in kidney and bone marrow transplant patients (adenovirus causes this in young patients who go swimming) -example: 50 y.o renal transplant patient taking immunosuppressions that presents with fever and gross hematuria

Neisseria - BACTERIA Neisseria meningitidis Neisseria gonorrheae

Neisseria -gram negative diploccoci -oxidase positive -heat blood agar = chocolate agar allows neisseria to grow because it inhibits enzymes that would prevent growth -VPN agar (vancomysin, polymixin and nystatin) -thayer martin agar another name for VPN agar -C5-C9 deficiency (complement deficiency) are unable to form MAC complex leading to increased infections -pili (fimbriae) demonstrate antigenic variation -IgA protease - cleaves IgA at hinge region Neisseria meningitidis -colonizes nasopharynx first and transmitted by respiratory secretions and then spreads hematogenously -LOS envelope proteins cause inflammatory response -inflammation leads to leaky capillaries -characterized by petechial rash (indicator of thrombocytopenia) -capillary leakage can lead to hypovolemia and shock -Waterhouse-Friderichsen syndrome, characterized by hemorrhage of adrenals -only meningitis ferments maltose but both ferment glucose -polysaccharide capsule inhibits phagocytosis -vaccine contains polysaccharide capsule - except type b not included in vaccine -sickle cell and asplenic pts at higher risk of infection because its encapsulated -TX: CEFTRIAXONE; close contacts prophylaxis RIFAMPIN Neisseria gonorrheae -STD -facultative intracellular likes to invade PMNs -NO capsule -in men -> urethritis and prostatitis -in women -> PID can cause scarring leading to infertility or ectopic pregnancies -PID can spread to peritoneum - Fitz Huge Curtis Syndrome; "violin string" adhesions form to capsule of liver -both men and women characteristic white purulent discharge (thick) -asymmetric arthritis commonly at knee -purulent synovial fluid that doesnt gram stain (because its intracellular) -early purulent neonatal conjunctivitis can happen within days TX: CEFTRIAXONE for gonorrheae (coinfection with chlamydia is with azithromycin or doxycycline)

ALL RNA virsuses replicate in the cytoplasm EXCEPT which one replicates in the nucleus?

Orthomyxovirus

(Pico) Poliovirus- VIRUS

Positive sense RNA virus (all replicate in the cytoplasm) -Picornavirus -RNA virus -naked virus -fecal oral transmission -acid stable virus -replication occurs in Peyer's patches (submucosal of the gut) takes 2-3 weeks -anterior horn of the spinal cord (lower motor cell bodies) -> paralysis -asymmetric paralysis concentrating in the lower legs, myalgias and decreased deep tendon reflexes, respiratory insufficiency from paralysis of the diaphragm, asceptic viral meningitis (remember enteroviruses are the #1 causes of aseptic meningitis) -no treatment -prevention with vaccines SALK vaccine = killed vaccine -injection (since it bypasses the GI tract) only forms IgG SABIN vaccine = live attenuated vaccine given orally -forms IgA* and IgG response

which is the only exception to RNA viruses that are all single stranded EXCEPT which one is DOUBLE STRANDED?

REOVIRUS

(Flavi) Hepatitis C - VIRUS

RNA virus -Positive sense virus -enveloped virus -antigenic variability of envelope proteins -tranmission through blood transfusions (esp before 1990) -transmission through needle sharing or sticks -no proofreading 3->5 exonuclease activity in virion encoded RNA polymerase, leads to antigenic variation -inflammation of the liver -acute: jaundice, RUQ pain, enlarged liver, increased liver enzymes -60-80% of acute infections will go on to become chronic (think hepatitis C for "Chronic") -cirrhosis -hep C is a primary cause of hepatocellular carcinoma -leading cause of liver transplants -acute infection: ALT will rise and fall by 6 months -associated with cryoglobulins (serum proteins that contain IgM that precipitate in cooler temperatures) -no vaccine TX: Ribavirin and Interferon-alpha and protease inhibitors

Flavivirus Group - VIRUS Hepatitis C Dengue fever Yellow fever West Nile virus

RNA virus -Positive sense virus -enveloped virus -non-segmented (single segment of RNA) Hepatitis C -hepatitis or liver inflammation Dengue fever -mosquitos = Aedes Egyptei (vector) -"break bone fever" (type 2 of dengue fever) -thrombocytopenia increase risk of bleeding -hemorrhagic fever -can lead to renal failure -can lead to septic shock and death TX: mainly supportive, hydration Yellow fever -mosquitos = Aedes Egyptei (vector) -jaundice -backache -bloody stool/diarrhea -bloody vomiting -live attenuated vaccine for travelers West Nile virus -birds are the reservoir -mosquitos are vector -encephalitis- major complication -meningitis -flaccid paralysis -seizures, coma TX: mainly supportive, hydration

Trematodes (FLUKES): Schistosoma mansoni, Schistosoma japonicum, Schistosoma haematobium, Clonorchis sinensis, and Paragonimus westermani = PARASITES

Schistosoma mansoni, Schistosoma japonicum, Schistosoma haematobium -Swimmers at risk of infection -getting into the blood stream and go to the liver and mature they like to go to different parts of the body -SNAILS are intermediate host -migrate AGAINST portal blood flow to reach venous destination Schistosoma mansoni and Schistosoma japonicum - like to reside in mesetenteric veins -Schistosoma manson has "large lateral spine" seen on stool O&P -Schistosoma japonicum has a "small spine" seen on stool O&P -both these cause portal hypertension which can eventually cause cirrhosis and liver failure; jaundice - all three cause swimmers itch where the larvae penetrate the skin TX: PRAZIQUANTEL Schistosoma haematobium -likes to reside in the veins of the bladder -"large terminal spine" seen on stool O&P -migrate against portal blood flow -PRIMARILY hematuria and risk of bladder cancer TX: PRAZIQUANTEL Clonorchis sinensis -Chinese liver fluke -SNAILS are intermediate host to the fish and we can eat these uncooked in like sushi -biliary fibrosis, cholangiocarcinoma risk, pigmented gallstones -"operculated eggs" on stool O&P TX: PRAZIQUANTEL Paragonimus westermani -LUNG fluke -chronic cough with bloody sputum -SNAILS are intermediate host -transmitted through consumption of raw or undercooked crab meat with larvae -"operculated eggs" on stool O&P TX: PRAZIQUANTEL

Staph epidermidis and Staph saprophyticus - BACTERIA

Staph epidermidis and Staph saprophyticus -gram positive take up crystal violet stain -staph grows in clusters -CATALSE positive -UREASE positive (urea ->ammonia conversion) - coagulase negative Staph epidermidis -part of normal skin flora -contamination of blood cultures -effects artificial joints and prosthetic joints -indwelling catheters is a common source of infection -MCC of endocarditis in artificial heart valves -produces biofilms coating valves etc. -Novobiocin sensitive -treat with VANCOMYCIN Staph saprophyticus -Novobiocin resistant -common cause of UTI in sexually active females

Cestodes (TAPE WORM) - PARASITE Taenia genus (Taenia solium,Taenia saginata) diphyllobothrium latum (fish tapeworm) echinococcus granulosus

Taenia solium -intermediate host for t. solium is pigs -hooks on proglottid heads of T.solium seen on O&P TX: Praziquantel Taenia saginata -intermediate host for T. saginata is cattle TX: Praziquantel neurocysticercosis - taenia EGGS transmitted by water contaminated with animal feces; lesions in the brain; looks like cheese cysts on head CT; seizures; immigrant or farmer and symptoms of hydrocephalus; TX: Albendazole diphyllobothrium latum (fish tapeworm) -resides in the small intestine and causes diarrhea -B12 DEFICIENCY (cobalamine deficiency) LEADING TO MEGALOBLASTIC ANEMIA -longest tapeworm -proglottid segments seen on stool O&P TX: Praziquantel or Niclosamide echinococcus granulosus -dogs are definitive host, sheep are intermediate host -humans are incidental host transmitted by dog feces -"egg shell calcifications" (buzz word) in cysts on liver CT -hydatid cysts in liver -cysts rupture causes an anaphylactic reaction and acute abdomen -eosinophilia

Toxoplasma gondii - PARASITE

Toxoplasmosis -intracellular parasitic protozoan -pregnant women and immunocompromised at risk -(1)pregnant women at risk of transplacental transfer ToRCHeS -(2)water or vegetables containing oocytes shed in animal feces -(3) raw or undercooked meat can transfer the cysts -can be transmitted by CAT FECES -OOCYTES in the feces ("toxo eggs") -causes MULTIPLE RING ENHANCING lesions on CT or MRI particularly in immunocompromised -encephalitis -brain biopsy to differentiate from CNS lymphoma -asymptompatic in immunocompetent people -congenital toxoplasmosis triad (1) intracranial calcifications (2) hydrocephalus (3) chorioretinitis -seizures and deafness also associated with congenital toxo -diagnosed made by serology or biopsy looking for intramuscular cysts TX: sulfadiazine and pyrimethamine prophylaxis when seropositive for IgG+ for toxo AND CD4 count <100 = TMP-SMX

Actinomyces israelii- BACTERIA

gram POSITIVE branching (filamentous) rod -obligate anaerobe -normal flora of the oral cavity -infection happens with jaw trauma (like dental procedure) -cervical facial actinomyces -formation of sinus tracts that drain pus of yellow sulfur granules TX: penicillin G and surgical drainage (for more complicated infections)

Listeria monocytonegenes - BACTERIA

is gram positive bacillis -infections in pregnant women (20x more likely) -pregnant women are discouraged from eating soft cheese may lead to early termination or disease in newborn -3rd MCC of meningitis in the newborns -in adults over 60 can cause meningitis -narrow zone of hemolysis when plated -beta hemolytic -facultative intracellular -TUMBLING motile extracellularly on LM -ACTIN ROCKETS intracellular and can jump from cell to cell -catalase positive -survives and multiplies in near freezing temperatures (can contaminate things even in the refrigerator) -contaminates UNPASTEURIZED milk and soft cheeses TREATMENT AMPICILLIN esp to cover elderly getting meningitis

Coxiella burnetii - BACTERIA

cause of Q fever -pneumonia, headache, cough and fever -MAY CAUSES HEPATITIS -gram negative -no rash -once classified as rickettsia species -obligated intracellular organism -forms a spore structure that can survive in the GI of animals -contained in spore like structure in animal poop -transmitted to humans in aerosol transmission -immunocompromised can cause endocarditis -vets can receive an acellular vaccine- may transmit by birthing a baby animal -pasteurized milk can kill most organisms treatment - self limiting and goes away in 2 weeks

Trichomoniasis vaginalis - PARASITE

causes vaginitis and cervicitis -cervicitis described as "strawberry cervix" -vaginitis cause symptoms of burning and itching and malodorous discharge -symptoms include yellow green discharge -wet mount KOH prep -distinct MOTILE TROPHOZOITES seen on wet mount -pH of vaginal fluid 4.5 and up with infection -sexually transmitted infection, STD treat both partners -Treatment: METRONIDAZOLE

campylobacter jejuni - BACTERIA

curved gram neg rod of the digestive tract (this is one of three curved) -oxidase positive (as are all the other two curved) -thermophilic - grows at 42 degrees celsius (intrinsically linked to heat) -poultry reservoir -bloody stool -invasive -reactive arthritis (Reiters syndrome) -Guillain-Barree syndrome- ascending paralysis (remember botulism is descending paralysis)

Intestinal nematodes - PARASITES enterobius vermicularis - pinworm Ancylostoma duodenale hookworm Necatar Americanus hookworm Ascaris lumbricoides Strongyloides stercoralis Trichinella spiralis

enterobius vermicularis PINWORM -female pin worms lay eggs at the anus -fecal oral route -scotch tape test shows eggs under the microscope TX: Pyrantel pamoate and ALBENDAZOLE Ancylostoma duodenale and Necatar Americanus hookworms -hookworm larvae penetrate skin of soles of feet -bloods stream -> lungs -> GI tract (matures in GI tract) -severe iron deficiency anemia because they suck on blood -eggs in stool -high eosinophil count (esophinophilia) TX: Pyrantel pamoate and ALBENDAZOLE Ascaris lumbricoides - giant roundworm -bloods stream -> lungs -> GI tract (matures in GI tract) -respiratory symptoms -intestinal obstruction occurring and ileo-cecal valve -eggs in stool -high eosinophil count (esophinophilia) TX: ALBENDAZOLE Strongyloides stercoralis -larvae penetrate skin of soles of feet -bloods stream -> lungs -> GI tract (matures in GI tract) -larvae hatch from eggs laid in intestinal wall, penetrate wall, enter blood stream -LARVAE in stool -high eosinophil count (esophinophilia) TX: ALBENDAZOLE and ivermectin Trichinella spiralis -undercooked meat like pork or bear -periorbital edema -vomiting and fever -larvae enter blood stream and travel to striated muscle where the larvae forms cysts within the striated muscle -severe myalgia and muscle inflammation -high eosinophil count (esophinophilia) TX: ALBENDAZOLE

Plasmodium (4) species - PARASITE Plasmodium malariae Plasmodium vivax, Plasmodium ovale, Plasmodium falciparum

malaria -fever, HA, pts often have splenomegaly and anemia -diagnosis by blood stain and Giemsa stain to see parasites in RBCs -anopheles mosquitos carry sporozoites in saliva -sporozoites mature to trophozoites in liver -schizont divides into merozoites which burst from hepatocytes and infects RBCs -lifecycle continues to RBC: trophozoite -> schizont -> merozoites ->infect RBC -ring form of immature schizont shape in it -merozoite can also form gametocyte (sexual form of plasmodium) Plasmodium malariae -Quartan fever cycle - occurs on day 1 and on 72 hours later occurs again (day 4) Plasmodium vivax and Plasmodium ovale -treat them the same -produce dormant formed in the liver called hynozoites -hypnozoites in hepatocytes -Tertian fever cycle - fever on day 1 and 48 hours later occurs again on day 3 Plasmodium falciparum -most severe illness -fever patterns are irregular -pts may present with neurological symptoms as cerebral malaria (occluding vessels to the brain) -parasitized RBCs occlude vessels to kidneys and lungs -banana shaped in the peripheral blood smear -sickle cell disease is protective against P. falciparum TX: -chloroquine- works by blocking plasmodium heme polymerase -primaquine- destroys hypnozoites in hepatocytes (check for G6PD deficiency before taking this can cause severe anemia) -mefloquine- good against resistance species; prophylaxis medication for travelers in chloroquine resistant areas -atovaquone/proguanil- prophylaxis or treatment drug better for resistant species; prophylaxis medication for travelers in chloroquine resistant areas -artemisins for severe Plasmodium falciparum infections (atovaquone/proguanil can also be used here) -IV artesunate for severe malaria infections -IV quinidine for severe malaria infections; side effects is cinchonism, including tinnitus and HA

Coronavirus- VIRUS

ss RNA virus -Positive sense virus -encapsulated virus -HELICAL SHAPED virus - unique to coronavirus -can cause common cold -acute bronchilits, can lead to acute respiratory distress syndome -SARS -replicates in the cytoplasm (like all POSITIVE sense RNA virus)

Trypanosoma brucei - PARASITE trypanosoma brucei gambiense trypanosoma brucei rhodesiense

trypanosoma brucei gambiense trypanosoma brucei rhodesiense -tsetse fly vector for these parasites - PAINFUL bite -sleeping sickness -endemic to western and southeastern Africa -AFTER biding the parasites move from the blood to the lymph nodes -cervical and axillary lymphadenopathy -recurrent or undulating fevers -coma - one of the only parasites to penetrate the CNS -trypomastigotes seen on blood smear -variable surface glycoproteins coats, undergoing constant antigenic variation (enabling chronic infection - hence the recurring fevers) -motile with a single flagella -TX melarsoprol treatment - CNS infection -TX suramin treatment - peripheral blood infection (think suramin for the serum)