Microbiology

____________________is an Hepadnavirus. Enveloped virion contains a small, partially double-stranded DNA genome and a DNA polymerase activity

"Serum hepatitis" HBV

Define Zoonosis

(e.g., by Chlamydophila psittaci) is an infection that is transmissible under natural circumstances from vertebrate (non-human) animals to humans. From Greek zoon meaning animal, and nosos, meaning disease. The pleural is zoonoses.

Describe the oxygen requirement for an Microaerophiles, how does it acquire ATP? and what enzymes are involved?

- Require a low concentration of oxygen for growth - The normal amount of O2 in the atmosphere, approximately 21%, may cause toxicity

What are Toxoid Protein vaccines?

- inactivated bacterial toxin ( a protein) -toxin would normally bind to receptor, and toxin would get inside cell and kill it -antibodies can bind toxoid and keep it from binding to receptors... - neutralizing antibodies (and Th)

DNA vaccination

- inexpensive and stable - plasmid mixtures: plasmid gets translated to protein, gets processed by proteasome, loaded on MHC class I and stimulates CD8 T cells -good for intracellular proteins (viruses --> in theory)

Patients at risk for harboring pathogens requiring droplet isolation:

- influenza (compatible illness in flu season, particularly if person was not vaccinated) - meningococcus (fever and petechial rash) - pertussis (child or adult with URI followed by persistent severe dry barking/whooping cough)

what are Subunit?

- isolated protein components, thus limited breadth - very safe - must be mixed with adjuvant for effectiveness these modify or alter a vaccine by mimicking PAMPs (Quil A, QS21, MF59) focus on antibody response Hepatitis B pertussis S. pneumonia

Patients at risk for harboring pathogens requiring respiratory isolation (place suspected cases in respiratory isolation, then determine if they have the pathogen):

- measles (rash in child with koplick spots) - chicken pox (characteristic rash (dew drop on rose petal), + Tzanck smear) - Tuberculosis (risk factors: homeless, alcoholism, poor nutrition, immune compromise, immigrant, HIV, imprisonment)

Patients at risk for harboring resistant organisms which may require contact isolation:

- nursing home residents - dialysis patients - patients with recent hospitalization, recent antibiotic treatment, or who have been in the ICUs Use active surveillance of high-risk patients to identify patients colonized with resistant organisms. Start immediate contact isolation if known to be colonized with resistant organisms.

What is C Diff? Where is it normally found, when does it become a disease? What happens? How is it treated?

-Clostridium difficile -Not antibiotic resistant, but this infection occurs as a complication of antibiotic use (antibiotics kill off normal bowel flora; then this organism can overgrow). Carried in colon. Disease: colitis with severe diarrhea and ulcers with pseudomembranes. Ulcers are breaks in bowel mucosal barrier: can allow other GI pathogens into bloodstream. Increasingly difficult to get rid of this infection once established, particularly in elderly or people with weak immune systems. Can be fatal Fecal transplants from healthy donors are promising.

Understand the difference between colonization and infection. What are some examples of organisms transmitted by carriers who don't have disease?

-Colonization: the patient harbors/carries the organism but is not currently suffering a disease from it. Can transmit it to others. -Infection: has a disease (infection) from the organism (generally fever and compatible illness). Some organisms are transmitted by carriers who don't have disease (MRSA, VRE, meningococcus); these people are colonized. For other organisms, essentially all infectious people have disease (influenza, pertussis).

what are collagenase and hyaluronidase?

-Enzymes secreted by some bacteria -degrade components of the extracellular matrix -allows bacteria to penetrate mucosal surfaces and provides easier access to deep tissues in the body

List methods of microbial identification leading to diagnosis

-History and Physical Exam -Laboratory Identification ---direct microscopic visualization ---cultivation ---microbial antigens/DNA or RNA ---Specific immune response to an organism -Note: interpretation of results includes consideration of sensitivity and specificity Identification of the organism is usually essential for effective antimicrobial and supportive therapy

Describe the spectrum of mutualism and its relationship to microbiota

-Mutualism is the coexistance of 2 species in an environment -symbionts: species that benefit the host and benefit from the host, Symbionts: species that benefit the host and gain benefit from the host Commensals: neutral relationship (indigenous microbes) Pathogens: cause disease

What is the composition of the cell wall?

-amino acids (some D amino acids) -2 amino sugars: N-acetylglucosamine (abbreviated NAG) and N-acetylmuramic acid (abbreviated NAM)

What is the Glycocalyx? What is composed of? What does it enable certain bacteria to do? What are examples of these bacteria?

-capsule -all bacteria secrete some kind of glycocalyx (outer viscous covering of fibers extending from the bacterium) -composed of polysaccharides or polypeptides -protects bacteria from drying, traps nutrients -enables bacteria Streptococcus pneumoniae, Haemophilus influenzae, Neisseria meningitidis to resist phagocytic engulfment by WBC is their body

What are some examples of virulence factors in bacteria structure?

-the pilus -the capacity to produce a capsule -Secretion of enzymes that facilitate invasion

What is a Live attenuated vaccine?

-virus is isolated and grown -cultured virus is used to infect monkey cells -the virus acquired many mutations that allow it to grow well -the virus no longer grows well in human cells an dbe used as a vaccine -stimualtes Ab and cellular response -example: MMR, yellow fever, varicella, MTB -Risks: disease in young, pregnant or immunocompromised persons; reversion to virulence

What factors lead to recent increases in TB morbidity

. HIV epidemic b. Increased immigration from high-prevalence countries c. Transmission of TB in congregate settings d. Deterioration of healthcare infrastructure

what is the size of a bacteria? what can this be compared to?

1 micrometer, a mitochondria

The chromosome is generally around 1)_____________ to 2)___________kilobase pairs (kbp) encoding as many as genes3)_____________, and physically 4)_______________μm long

1) 3,500 2) 7,500 3)3,500 4)1000

The peptidoglycan monomer contains what kind of backbone? What kind of linkage?How are the sheets formed?

1) A backbone that is made of the two amino sugars in which they alternate; 2)They are linked via -1,4 bonds; Peptides of 3 to 5 amino acid residues that alternate between L- and D- amino acids; 3)These are bound to the N-acetymuramic acid. The specific amino acids vary from species to species. In addition to the typical amino acids, these may include diaminopimelic acid, unique to peptidoglycans of Gram-negative bacteria. These monomers are cross-linked. This crosslinking forms a two-dimensional sheet. These sheets are then cross-linked to one another and become a large and strong covalently linked molecule.

Algorithm for evaluating asymptomatic persons for latent TB infection:

1) CDC recommends serial screening (every 6-12 months) with PPD skin test or QuantiFERON Gold test individuals with increased risks of TB infection/disease 2)Follow algorithm in syllabus for determining what induration size (5, 10 or 15 mm) of PPD response should be considered positive for latent TB infection All persons determined to have negative TB tests need no further work-up. 3rd) Proceed to obtain history asking about TB symptoms, complete physical exam, and do chest radiograph (posterior to anterior and lateral views) in any patient determined to have a positive PPD test or QuantiFERON Gold test. If TB symptoms elicited, abnormalities on exam suggestive of TB present or abnormality on chest radiograph seen, proceed to algorithm for working up TB disease. 4th) If no symptoms elicited, exam completely normal and chest radiograph normal, consider treatment of latent TB with 9 months of isoniazid chemoprophylaxis assuming no contraindication (eg-severe liver disease/history of isoniazid allergy). If patient has had known close contact with a drug-resistant strain of TB, rifampin for 4 months is an alternative if the strain is known to be susceptible to rifampin. If patient has an abnormal chest radiograph consistent with old, scarred down TB, make sure to rule out active disease before considering TB chemoprophylaxis with a single TB drug.

Discuss how the six stages of a viral replication cycle provide a framework for understanding the diverse molecular mechanisms employed by viruses

1) Entry (attatchment and penetration) 2) Uncoating 3) Gene expression (transcription/translation) 4)Genomic replication 5) assembly 6) release

A 1)__________________ is a long whip-like structure that provides the bacterial cell with motility (the ability to move). It ______________ (is or is not) present in many bacterial species. 1)_________________ rotate at high speeds to act as a fan or propeller that allows a bacterium to be motile.

1) Flagella 2) Is not

Each tRNA is also attached to a specific amino acid. The ribosome has three tRNA binding sites 1)_____ (because it is occupied by peptidyl-tRNA attached to the growing polypeptide chain), 2)_____ (because it binds the amino-acyl tRNA) and 3)_____ (for empty because it binds the free tRNA before it exits the ribosome). The amino acid on the tRNA occupying the A site, if it has the anti-codon

1) P 2)A 3)E

_____________________ is the enzyme that catalyzes the cutting and resealing of the DNA during transposition, or movement of DNA from one location to another. What do they contribute to?

1) Transposase 2)Thus they contribute in the transmission of antibiotic resistance among a population of bacteria.

To enable a macromolecule this large to fit within the bacterium, 1)____________________bind to the DNA, compacting it into ~2)_________ chromosomal domains.

1) histone-like proteins 2) 50

What are the stages of a symptomatic infectious disease

1) incubation period: the time between infection with the organism and beginning of symptoms 2) prodrome period: time during which non-specific symptoms such as fever, malaise and loss of appetite (inappetence) occur 3) specific illness period: time during which overt and characteristic signs and symptoms of the disease occur 4) recovery or convalescence period: time during which the illness abates and the patient returns to health

Algorithm for working up a patient with symptoms suggestive of TB (e.g.-chronic symptoms lasting longer than 2 weeks of fever, sweats, weight loss, productive cough):

1) take history (focus on risk of exposure) 2)Complete physical exam (any organ system COULD be involved) 3) Chest radiograph 4)Routine screening labs 5)Collect 3 sputum (every morning for 3 days) for acid fast bacilli smears and cultures. 6)Place PPD and control skin tests. 7) If AFB seen on microscopic exams of sputum, bronchoalveolar lavage fluid or other clinical specimen, begin multi-drug TB therapy with INH/RIF/PZA/ETH. If all specimens are negative microscopically for AFB, clinical judgement must be used to determine the likelihood that despite the negative smears, the patient is still likely to have TB and needs empiric treatment pending culture results. 8)Continue respiratory isolation until 3 sputum smears are negative for AFB or a bronchoalveolar lavage sample is negative for AFB (if MDR-TB suspected based on history of contact with MDR patient or patient had only partial treatment for TB disease previously then do not stop respiratory isolation until cultures negative).

The human microbiome in Western cultures contains approximately 1)___________ different bacterial species. For individuals who live in rain forests, the number of species is approximately 2)______________

1)700 2)1100

Peptidoglycan monomer: includes the backbone and the pentapeptide. Describe the backbone (what is it composed of and what kind of linkage) and describe the peptides.

1)Alternating amino sugars MurNAc and GlcNAc (in the figure, NAM and NAG) in a -1,4 linkage. Note that -1,4 linkages result in a very strong polysaccharide. This is the type of linkage that is found in chitin 2) Three to five alternating L- and D- amino acid residues (except for the final D-Ala as shown to the right), typically on all of the MurNAc (NAM) residues. The specific amino acids in the peptide vary from species to species.

1)______________________ are transposons that can carry multiple gene clusters called 2)_____________________ that move as a unit from one piece of DNA to another. An enzyme called 3)___________________ enables these 2)_________________ to integrate and accumulate within the integron. In this way, a number of different antibiotic resistance genes can be transferred together from one bacterium to another.

1)Integrons 2)gene cassettes 3)integrase

Describe the ways in which resistance is acquired in general and specifically in a hospital setting

1)Mutations & misuse of antibiotics 2) non-compliance with antibiotics 3) Horizontal gene transfer occurs as a result of transformation, transduction, and conjugation 4)Some bacteria have low-permeability membrane barriers and are thereby intrinsically resistant to certain antibiotics.

1)______________________species naturally lack a cell wall. As a result, they will not be visible when they are examined after undergoing a Gram's stain. 1)__________________ maintain a nearly even pressure between the outside environment and the cytoplasm by actively pumping out 2)_______________ions. The cytoplasmic membranes of 1)__________________ species contain 3)___________________

1)Mycoplasma 2)sodium 3) sterols

1) What type of media typically grow a wide range of bacteria (or fungi). Some of these are enriched with additional growth factors in order to permit the recovery of fastidious (difficult to grow under typical conditions) organisms or of organisms that have an obligate requirement for specific factors? 2)What is an example? 3)what does it require? What does it grow on?

1)Non-selective media 2)Haemophilus influenzae, a short, pleomorphic (a variety of morphologies) Gram-negative bacillus 3)requires X-factor (hemin) and V-factor (NAD) for growth 4)It does not grow on sheep blood agar, which is a very common non-selective growth medium. It does grow on chocolate agar, which is a medium that is made from heat-lysed blood and contains the two growth factors.

1)______________ perform protein synthesis, using genetic instructions for the formation of specific proteins. During protein synthesis, 2)_____________ attaches to the 30S subunit and an 3)______________attaches to the 50S subunit.

1)Ribosomes 2)mRNA 3)amino acid- carrying transfer RNA (tRNA)

1)_______________________ is the most common cause of skin and soft tissue infections in the United States, commonly causes life threatening infections such as infective endocarditis, septic shock, and abscesses. Strains that have the 2)________ gene produce the altered penicillin-binding protein 2a (known as PBP 2a) and are known as methicillin-resistant 1)__________________________ and are resistant to ALL 3)_____________________(with one recent exception).

1)Staphylococcus aureus 2)mecA 3)beta-lactams

The death phase occurs in cultures of 1_____________, which is the most common cause of community-acquired pneumonia and a common cause of bacterial meningitis. What can happen in a lab setting as a result?

1)Streptococcus pneumoniae 2). As a result, if a culture of blood is positive for the growth of Streptococcus pneumoniae, if the laboratory staff do not remove the bottle in which the organisms are growing in a timely way, the organisms will autolyze and die. In this setting, without viable bacteria, both the ability to identify the infectious cause of a patient's illness and those antibiotics to which the patient is likely to respond are greatly compromised

1)_________________are small pieces of DNA that contain at least one gene, but can contain up to twelve genes coding for antibiotic resistance or other traits, flanked at both ends by sequences coding for an enzyme called 2)_______________

1)Transposons (transposable elements or "jumping genes") 2) transposase

When looking at fermentation by bacteria what which each of the tubes be? 1)Uninoculated tube 2) Glucose fermenter with gas production 3) Glucose fermenter without gas production 4) Glucose non fermenter

1)Uninoculated tube (a negative control for fermentation 2)Glucose fermenter with gas production (visible air bubble in the Durham tube) (e.g., Escherichia coli 3)Glucose fermenter without gas production (no visible bubble in the inverted Durham tube) (e.g., Shigella sonnei), a cause of bacillary dysentery. 4)Glucose non-fermenter (e.g., Pseudomonas aeruginosa)

Most clinically relevant bacteria can be grown on artificial media, either on 1)______________________ or in 2)_______________, but numerous important causes of human infections cannot be grown on 1)________. For example, the 3)______________and 4)_________________ require growth in cells, though they are bacteria and are not viruses.

1)agar (as in Petri dishes) 2)broth media 3)Chlamydiae 4)Rickettsiaceae

The peptidoglycan monomers are synthesized in the 1) WHERE? and are then transported and assembled into a polymer 2)______________ and further (interlocking) crosslinks between the pentapeptides are formed between chains

1)cytosol 2)outside the cytoplasmic membrane PBPs are penicillin binding proteins, which include the transpeptidase

The acid-fast bacteria also have a third outer layer: in addition to peptidoglycan, the outer membrane or envelope of the acid-fast cell wall contains large amounts of 1)____________________ especially 2)_________________. Porins are embedded within the 1)___________________.

1)glycolipids 2)mycolic acids

Most viral genomes are 1)___________.Retroviruses are 2)____________

1)haploid 2)diploid

Bacterial growth in vitro follows a rather typical curve (see the figure). In the setting of what are initially optimal growth conditions, including the necessary nutrients, the bacteria will typically have a "1)_________phase" prior to an "2)_______________ phase." During exponential growth, bacteria may have a 3)___________________ (doubling) time of 30 minutes or even less (e.g., 4)____________________, the anaerobe causing gas gangrene and other infections).

1)lag 2)exponential growth 3)generation 4)Clostridium perfringens

All gram-negative bacteria have 1)_____________________, which has tremendous biological activity (it is also known as _______).

1)lipopolysaccharide 2)endotoxin

For the peptide bridge, From the terminal -COOH of one peptide to an available group that is usually the free -NH2 of 1)__________ or 2)______________________ which is unique to peptidoglycans and found in Gram-3)_________________ bacteria and not Gram-4)________________ bacteria. This crosslinking forms a two-dimensional sheet. In addition, bridges form between the sheets so that all of the peptidoglycan constitutes a very large - and very strong - 5)_______________linked molecule.

1)lysine 2)diaminopimelic acid, 3)negative 4)positive 5)covalently

Gram-1)__________ bacteria have two layers that surround the plasma membrane. A single layer of 2)__________________ that is surrounded by an outer membrane.

1)negative 2)peptidoglycan

Unlike the eukaryotic nucleus, the bacterial nucleoid has no 1)___________________or nucleoli. Since bacteria are 2_____________, that is they have only one chromosome and only reproduce asexually, there is also no 3_________________ in bacteria

1)nuclear membrane 2) haploid 3)meiosis

Describe resistance to β-lactams. What are examples of β-lactams?

1)penicillins, carbapenems, and cephalosporins 2)the production of various beta-lactamases. These enzymes are able to inactivate some forms of these drugs. β-lactamases break the β-lactam ring of the antibiotic, thus inactivating the drug

As a result of having an outer membrane, which is not present in Gram-positive bacteria, there is a 1________________, which lies between the inner and the outer membranes. It is not actually a "space" and contains a variety of 2)__________ that are transported across the cell membrane of the Gram-negative organism including, for example, -3)_________________ that can confer antibiotic resistance and exotoxins

1)periplasmic space 2)proteins 3)lactamases

Gram-1)____________ bacteria contain a thicker wall than do Gram-2)_________________bacteria. The wall contains peptidoglycan, which surrounds the plasma membrane. In 3)____________________, the peptidoglycan wall has 40 layers. By contrast, in 4)_________________ the wall has a single layer of peptidoglycan.

1)positive 2)negative 3)Bacillus subtilis 4)Escherichia coli,

Balance of high mutation rates and selective pressures produces a 1)____________________. A cluster of very closely related sequences

1)quasispecies

There is typically a 1)___________________, the host species (or multiple species) in which the zoonotic agent is typically found prior to its transmission to a human. There may be a 2)________________, an insect (e.g., flea for ____________) or a tick (e.g., Borellia burgdorferi for 4)__________________, and 5)________________ for Rocky Mountain Spotted fever.

1)reservoir 2) vector 3)plague 4)Lyme disease 5) Rickettsia rickettsia

Some strains of Clostridium difficile produce far greater amounts of toxin and are associated with correspondingly worse outcomes. In addition, these bacteria produce 1)________________ that are metabolically inactive. As a result, they may persist after treatment and result in 2)_______________________; even multiple 2)____________________, which are yet more likely to cause major clinical problems.

1)spores 2)relapses

Note that the cell wall of most Gram-positive bacteria also contains 1)__________________and 2)________________. 2)_________________, contains long chains of ribitol or glycerol phosphate. LTA is anchored to the cell membrane.

1)teichoic acid 2)lipoteichoic acid (from Greek, "teikhos", for wall)

A group of enzymes called DNA 1)______________ supercoil each domain around itself, forming a compacted mass of DNA approximately 0.2 μm in diameter. Supercoils are both inserted (for packaging into a daughter cell) and removed (for transcription and replication) by ___________________

1)topoisomerases

Penicillin binds to 1)_______________________very tightly thereby inhibiting it [from binding] to the polypeptide (pink balls). If 1)____________________ cannot bind to the polypeptide then it cannot catalyze the reaction. When this reaction can not occur, the structural integrity of the cell wall is greatly compromised, causing 2)__________________________"

1)transpeptidase 2) increased osmotic pressure within the cell, eventually causing cell death.

General microbiologic characteristics of mycobacteria

1. Acid fast (Ziehl-Neelsen/auramine-rhodamine stains) 2. Aerobic, non-spore-forming, non-motile bacilli 3. Unusual cell wall with large amount of high molecular weight lipids

Describe the ways in which bacteria resist control by antibiotics

1. Producing an enzyme capable of inactivating the antibiotic (e.g., β-lactamases) 2. Altering the target site receptor for the antibiotic to reduce or block its binding 3. Preventing entry of the antibiotic into the bacterium and/or using an efflux pump to transport the antibiotic out of the bacterium. 4. Modulating gene expression to produce more of the bacterial enzyme that is being targeted (viz. tied up or altered) by t1. Skin testing 2. QuantiFERON Gold test (newly FDA approved, CDC-recommended alternative) 3. AFB smear 4. Culture and identification 5. Histology and special stains 6. DNA probes 7. PCR he antibiotic. 5. Biofilms and bacterial communities.

How big are viruses?

100 nanometers, could be 500 times smaller than a bacteria

Phase I clinical trials

20-100 ppl principle rationale: Safety 1 year Vaccine-related side effects are assessed by comparing the vaccine with a control or placebo. A Phase I trial can also provide initial data on the dose and administration schedule to achieve optimum immune responses

What is the R0 of TB?

3-10

Ribosomes are composed of two subunits with densities of 50S and 30S. ("S" refers to a unit of density called the Svedberg.) The two subunits combine during protein synthesis to form a complete 1)_______S ribosome. A typical bacterium may have as many as 15,000 ribosomes.

50S=large subunit 30S=smal 1) 70S

Clinical features of HAV?

80% of adult infections are asymptomatic Almost always asymptomatic in children Causes mild hepatitis: self-limiting and acute No chronic infection Elicits life-long protective antibodies Symptoms usually appear 10-50 days post-infection; they usually resolve in 2-4 weeks. * Symptoms include dark urine, pale feces, elevated transaminase levels, and jaundice.

Define Heterothallic

: require a mate for sexual reproduction

What are the 3 parts of a flagellum?

A bacterial flagellum has three basic parts: a filament, a hook, and a basal body. Bacteria with multiple flagella operate each one independently to move in a precise path then undergo a tumbling mode to get their bearings. Approximately half of all known bacteria are motile.

What are the clinical manifestations of Pulmonary tuberculosis? (medical hx, pulm symptoms and systemic symptoms)

A) Medical history 1) History of TB exposure 2) Risk factors for TB Symptoms of pulmonary TB 1) Productive, prolonged cough 2) Chest pain 3) Hemoptysis . Systemic symptoms of TB Fever Chills Night sweats Easy fatigability Loss of appetite Weight loss

Describe the oxygen requirement for an Facultative anaerobe, how does it acquire ATP? and what enzymes are involved?

Able to live and to grow in the presence or the absence of O2 Typically prefers O2 ATP is obtained both anaerobically and aerobically depending upon conditions

1)___________________________________include Mycobacterium tuberculosis, which causes the vast majority of cases of tuberculosis and Mycobacterium leprae, the major cause of leprosy. What kinds of stains can be used to look at this?

Acid-fast bacteria (often called "AFB")

Describe the clinical aspects of an HBV infection (acute & chronic) how soon symptoms appears

Acute infection Symptoms appear 50-150 days post-infection Recovery is ~2-3 months later Infection becomes chronic in ~5% of adults but ~95% of neonates Chronic infection causes chronic hepatitis, fibrosis, cirrhosis, liver failure, and hepatocellular carcinoma

What is Active Immunization

Administering an infectious organism or parts thereof in a manner that stimulates long-term protective immunity Active immunity is generated It has memory and specificity Natural infection also stimulates active immunity

What are some methods of dissemination?

Aerosol- e.g. sneezing and coughing Fecal-oral- poor sanitation, lack of hand washing Sexual- unprotected oral, anal or genital contact Vector-borne-via mosquitoes and other biting insects Direct injection - sharing syringes, blood transfusions Unclean wounds - cuts, bites or surgical incisions Mother to child -at childbirth or during breast-feeding Also illustrates how entry is an important part of a pathogen establishing infection, and how public health measures can interrupt dissemination.

What is is bacterial DNA

All of the DNA in the cell, including both chromosomal bacterial DNAmosomal and plasmid DNA

What are some important endoparasites?

Ameobas: Entamoeba histolytica (has a Trophozoite form & cystic form) Flagellates: Giardia duodenalis (Giardia lamblia) iii. Ciliates:Balantidium coli Sporozoa Plasmodium falciparum (the major cause of life-threatening malaria) "Banana-shaped" macrogametocyte of P. falciparum in a thin blood smear. Also seen in this image are ring-form trophozoites.

What is a A bacteriocidal antibiotic

An antibiotic that is able to kill bacteria at appropriate concentrations

What is a A bacteriostatic antibiotic?

An antibiotic that is not able to kill bacteria but prevents their multiplication at appropriate concentrations. Their use is usually perfectly fine in treating infections since the body's defenses (such as white blood cells) can invade the area of infection and kill the non-reproducing bacteria

How do bacteria alter the target site receptor for the antibiotic in the bacterium to reduce or block its binding?

Antibiotics work by binding to some bacterial target site, such as a 50S ribosomal subunit, a 30S ribosomal subunit, or a particular bacterial enzyme such as a transpeptidase or a DNA topoisomerase. Bacteria may acquire genes that alter the molecular shape of the portion of the ribosomal subunit or the enzyme to which the drug normally binds.

Understand why the biosynthesis of peptidoglycan matters: penicillin and peptidoglycan synthesis

As a result of their structural similarity, the transpeptidase misrecognizes penicillin for the transpeptidase catalytic reaction

Whar is Multi-drug resistant TB (MDR-TB)

At least isoniazid (INH) and rifampin (RIF) resistant

What is anthrax due to?

Bacillus anthracis

Small, single-celled prokaryotic organisms that reproduce by division.

Bacteria

1)__________________ is the complete hemolysis of the red blood cells in the area of the culture medium surrounding a β-hemolyic

Beta hemolysis you can read a newspaper through it no longer any RBCs in this area

Special Populations at high risk for ALL infections

Bone marrow transplant (BMT) Solid organ transplant HIV infection Chemotherapy recipients People on immunosuppressive medications (steroids, TNFα blockers, azathioprine, etc.)

Describe some of the ways to limit acquisition of antibiotic resistance

By providing direct patient care using practices which minimize infection By following appropriate practice of hygiene (e.g., hand washing, appropriate patient isolation) By following procedures that limit transfer of bacteria from other infected patients and from hospital staff who may be infected

Steatosis and insulin resistance are more common with H____V than H____V

C, B

QuantiFERON Gold Blood Test

CDC-recommended alternative to PPD skin test IFN-γ release assay (IGRA) using whole blood ESAT-6/CFP-10/TB10.4 Ag-specific responses Ags encoded by RD1 genomic segment deleted from BCG Ags also not expressed by most atypical mycobacteria QuantiFERON more specific than PPD skin testing Sensitivities equal when screening close contacts Sensitivity may be less when TB infection not recent

What is CRE? Where is it normally found? What is it resistant to? when does it become a disease?

Carbapenem-resistant Enterobacteriaceae Enterobacter is a bacterial family that includes multiple species: Klebsiella, E. coli, Enterobacter, etc. These are normal GI organisms which have acquired genes that mediate resistance to the carbapenems, a very potent class of antibiotics used for severe gram negative infections. Disease: blood stream infections, urinary tract infections, abdominal abscesses, etc. Some of these organisms are now resistant to ALL antibiotics Increasing global health problem, very persistent in the environment once present.

What is MRSA? Where is it normally carried?How is it diagnosed? What classes of drugs is it resistant to? What could be used to treat it?

Carried in nose/on skin. People can be chronically colonized (carrier) without disease. Disease: abscesses, blood stream infections, etc. Diagnose disease based on growth of organism where it shouldn't be: blood or tissue cultures. Diagnose colonization from nares swab PCR. Resistant to many antibiotics including all penicillins and cephalosporins. Must use vancomycin or similar drugs. Increasing public health problem

what is Aspergillosis

Caused by several species of the filamentous fungus, Aspergillus. Most common species is A. fumigatus Found in soil, dust, decomposing organic matter normally in air.... determine if infection or not what is immune status of patient? Hyaline septate hyphae dichotomously branched (branches approximately the width of the parent hyphae) branching at 45 degree angles Tend to appear in radial fashion with hyphae nearly parallel to one another In cavitary lesions, conidial heads may be observed. Rarely manifest disease in healthy individuals Immunosuppressed, chemotherapy, diabetes

what is Pneumocystis jirovecii (formerly known as P. carinii)

Causes pneumonia in immunosuppressed individuals particularly in HIV Diagnosis by direct microscopy Organism cannot be cultured in vitro

What is a helminth? Is it a cell? Does it have Nucleic acids? What is its surface? What is its reproduction strategy?

Cell: multi cell Nucleic Acid: Both DNA and RNA Surface: Flexible membrane Reproduction Strategy: mitosis

What is a virus? Is it a cell? Does it have Nucleic acids? What is its surface? What is its reproduction strategy?

Cell: no Nucleic Acid: Either DNA or RNA (could have a little of both( Surface: protein capsid +Lipid envelope Reproduction strategy: replication

What is a fungi? Is it a cell? Does it have Nucleic acids? What is its surface? What is its reproduction strategy?

Cell: yes Nucleic Acid: Both DNA and RNA Surface: Rigid Cell wall chitin Reproduction Strategy: Budding or mitosis

What is a protozoa? Is it a cell? Does it have Nucleic acids? What is its surface? What is its reproduction strategy?

Cell: yes (eukaryote) Nucleic Acid: Both DNA and RNA Surface: flexible-membrane Reproduction Strategy: Mitosis

What is a bacteria? Is it a cell? Does it have Nucleic acids? What is its surface? What is its reproduction strategy?

Cell: yes, single celled Nucleic Acid: DNA and RNA Surface: Rigid Cell wall with proteoglycan Reproduction Strategy: Binary Fission *no nuclear membrane *circular chromosome

-Long, flat, segmented, ribbon-like bodies - Single anterior scolex ("mouth") - No gut; all nutrients are taken up through the tegument - All are hermaphroditic; each segment has both male and female organs

Cestodes (tapeworms)

Mycetoma

Clinical syndrome of abscesses, draining sinuses containing pus and colored granules following traumatic implantation

Mycobacterium avium-intracellulare complex (MAC) who is it seen in? How is it treated?

Commonly seen in advanced AIDS patients (disseminated reticuloendothelial involvement, positive bacillemia, resistant to chemotherapy) Chronic pulmonary disease in elderly with COPD (esp. if on steroids) Combination treatment with 3-5 drugs including clarithromycin, ethambutol, clofazimine, streptoptomycin, amikacin, rifabutin, ciprofloxacin Primary prophylaxis in AIDS patients with CD4<50-100 (azithromycin 1200 mg/wk)

What is contact isolation?

Contact: you must gown and glove before going into the room everything in the room, the patietns cell phone, gown, surfaces are all colonized with a resistant organism TOUCH NOTHING with bare hands -use a patient specific stethoscope -use alcohol foam hand scrub after leaving the room -organism is on/in patients body or objects in the room -mainly for antibiotic resistant bacteria or C Diff (MRSA, VRE, CRE)

What is Dermatophytosis

Cutaneous Infections of skin, hair or nails caused by: dermatophytes Microsporum, Trichophyton, Epidermophyton use keratin to live off, hair nails,

a topoisomerase called ___________________________catalyzes the negative supercoiling of the circular DNA found in bacteria

DNA gyrase

_______________________________ are, therefore, essential in the unwinding, replication, and rewinding of the circular, supercoiled bacterial DNA

DNA topoisomerases

What is transduction?

DNA transfer from one bacterium to another via bacteriophage -lytic cycle: cell lyses -lysogenic cycle: fusion of nucleic acid within the host

What is conjugation?

DNA transfer of genetic material between 2 bacterial cells via direct cell to cell contact (male to female) via pilus, and cant transfer plasmids

toxoids vaccines

DTaP Tdap

infection that looks like Dermatophytosis but caused by a different fungus than the dermatophytes is called what?

Dermatomycosis : Similar infections caused by other fungi

How is HBV transmitted?

Developed world: Primarily blood contact and sex Developing world: Primarily vertical transmission from infected mothers

HCV Diagnosis and prevention

Diagnosis: Primary test is an ELISA to detect anti-HCV IgGs RT-PCR is used to measure HCV levels during therapy Prevention: Avoid blood contact Using safer-sex practices may help No vaccine is available

what are the functions of gut microbiota?

Digestion and nutrient uptake - plant polysaccharides - nutrient and calorie uptake 2) Immune system development - regulate bacterial species - commensal v. pathogen recognition (self:non-self) - normal immune development 3) Occupy a biological niche - exclusion of pathogens - "dysbiosis"

What is Blastomyces dermatitidis

Dimorphic Lives in soil and decaying wood Highest incidence in Mississippi, Ohio and Missouri valleys Blastomycosis: cutaneous and systemic infections. Acquired by inhalation or direct inoculation. Can disseminate to most organs, particularly in immunocompromised. Characteristic broad based budding with thick wall that appears double contoured. broad based budding yeast

What are the following vaccines when are they given DTaP DT Tdap Td

Diphtheria+tetanus toxoids, acellular pertussis DTaP - full series for children <7 yrs (begin at 2mo) DT - for kids who don't tolerate first pertussis dose Tdap - lower dose for previously unvaccinated adolescents and as a first boost for adults Td - booster in adolescents and adults after Tdap; also wound management

What is direct selection vs indirect selection of antibiotic resistance?

Direct selection refers to the selection of antibiotic resistant pathogens at the site of infection. Indirect selection is the selection of antibiotic-resistant normal flora within an individual anytime an antibiotic is given. At a later date, this resistant normal flora may transfer resistance genes to pathogens that enter the body. In addition, this resistant normal flora may be transmitted from person to person through such means as the fecal-oral route or through respiratory secretions.

What is droplet isolation?Examples of diseases?

Droplets are small particles of respiratory secretions which contain infectious particles. Use for organisms which are infectious only over short distances (transmission by face to face contact in same room) - Pertussis (Bordatella pertussis) - Influenza (Influenza virus) - Meningococcus (Neisseria meningitidis) Wear a droplet isolation mask, no need for negative pressure room/air filters Droplet is from microbes that aren't as infectious, they don't hang out in the air as long, don't need rigid isolation procedures

Common lactose-fermenting Gram-negative bacilli include

E. coli (about 95% of these), and Enterobacter species.

__________________________ are lipopolysaccharide (LPS) components of the outer membranes of Gram- negative bacteria. They can be released into the circulation following bacterial lysis, for example by neutrophils

Endotoxins

Explain the basis for variation in disease between individuals (Microbial Factors)

Entry Adhesion Colonization Invasion Immune evasion Toxins Biofilms:

Common Features of Dimorphic moulds

Entry into host by inhalation of airborne spores Spores germinate in lung Asymptomatic primary pulmonary infection is common Acute pulmonary disease less common Chronic pulmonary or disseminated infection is rare

If there is Evidence of exposure or suspicion of false negative TB what do you do?

Evidence of exposure or suspicion of false negative, you need to look for TB and ppl with immunosuppression will have false neg, look @ chest x ray, abnormality, get sputum and 3 smears for AFB, If its extrapulmonary you need to be aggressive and get tissue

What are exotoxins?Describe its components

Exotoxins are proteins secreted by bacteria that poison host cells after uptake. One component of the toxin facilitates binding to cells, while the other is responsible for the toxic effect. They are extremely potent: as little as 1 μg of tetanus toxin can kill an adult. Anthrax, diphtheria, and pertussis toxins are other examples.

Where can exotoxins be carried?

Exotoxins in many cases are carried on plasmids.

____________-are those bacteria that will not grow in the laboratory unless quite specific conditions are present. Examples?

Fastidious Bacteria These include specific nutritional requirements, the amount of CO2, or the amount of O2 in the gas in which the organism is incubated. For example, Neisseria gonorrhoeae will not grow unless it is incubated in an atmosphere that contains a certain percentage of CO2. Similarly, the microaerophilic bacteria that are described above are fastidious (e.g., Campylobacter species, which are a common cause of bacterial diarrhea).

Transmission of HAV?

Fecal-oral Frequently found in focal, common source outbreaks (

what is Schistosoma japonicum?

Flatworms: Playthelminths a. Flukes (Trematodes) has small spine invade body, can go to spinal cord, can go to urine tract

what is Schistosoma haematobium?

Flatworms: Playthelminths a. Flukes (Trematodes) has terminal spine

What is Respiratory isolation?

For pathogens which spread through the air and maintain infectivity in air over time (do not need to be in same room with infected person to be infected) - tuberculosis (Mycobacterium tuberculosis) - measles (measles virus) - chicken pox (herpes zoster virus) Place patient in a negative pressure room with air filters, if you go in wear special N95 filter mask

what is Histoplasma capsulatum

Found in soil contaminated with bird droppings or guano Endemic in Ohio and Mississippi river basins Histoplasmosis can be acute and benign pulmonary disease to chronic (otherwise healthy), progressive and fatal (immunocompromised and elderly). Localized or disseminated. intracellular yeast

how do yeast reproduce?

Fungi with single-celled vegetative form that reproduces by budding

3 Types Sexual Reproduction in Fungi

Gametangial Meiosis Diploid vegetative body Haploid gametes produced by meiosis Gametes fuse to form diploid zygote Zygote divides by mitosis to form new diploid generation 2. Zygotic Meiosis Haploid vegetative body Haploid gametes produced by mitosis Gametes fuse to form diploid zygote Zygote divides by meiosis to form new haploid generation 3. Sporic Meiosis Haploid vegetative body Haploid gametes produced by mitosis Gametes fuse to form diploid zygote Zygote divides by mitosis to form new diploid generation Some cells undergo meiosis to become haploid spores Haploid spores divide by mitosis to become a new haploid generation

Identify the basic components of a virus and their function

Genome: The RNA or DNA that carries the genetic information . Capsid: A protein shell surrounding and protecting the genome. Envelope: A lipid bilayer surrounding and protecting the capsid. Viral surface glycoproteins are imbedded in the envelope. Not all viruses have envelopes.

Many ____________________ bacteria possess R (Resistance) plasmids that have genes coding for multiple antibiotic resistance , as well as transfer genes coding for a conjugation (sex) pilus

Gram-negative

Strains of a number of bacteria produce a variety of different pigments that may have a role in such things as bacterial resistance to injury. What color will the sputum of someone with pneumonia due to Pseudomonas aeruginosa be?

Green

Does Mycobacterium bovis reduce nitrate? What is its reservoir? How quickly does it grow?

Grows slowly (3-6 weeks) b. Nitrate reduction c. Bovine reservoir d. Resistant to pyrazinamide

_________________is a picornavirus. The small, non-enveloped virion contains a single stranded + polarity RNA genome,

HAV, Also called Enterovirus 72 "Infectious hepatitis"

What virus is found world-wide, especially Asia, Sub-Saharan Africa, and the Amazon?

HBV

vaccines given 11-13 y/o

HPV Meningococcal Tdap

What is Strongyloides stercoralis

Has a complex life cycle and can complete the entire life cycle in the human host (can have for many decades) Kept in check by immune system Immunocompromised patients may have hyperinfection syndrome larvae in soil, person may walk barefoot and be bitten, go to lungs (pulmonary phase)

- Multicellular, eukaryotic, invertebrate, large - Free-living or parasitic - Do not multiply in humans in their adult form (exception: Strongyloides stercoralis); usually exist as separate males and females in adult form - May cause eosinophilia (particularly if there is a tissue migration phase) - Adapted to survive in various environments with cuticle or tegument - Life cycle generally goes from egg to larval stage(s) to adult form - Usually requires soil/water to complete the life cycle

Helminth

What does Helminth elimination rely on?

Helminth elimination relies on TH2 cells and IgE production and eosinophil activation (which are stimulated by IL-4 and IL-5, respectively).

Hepatitis A vaccine

Hepatitis A vaccine (e.g. HAVRIX or VAQTA) is an inactivated vaccine. When given to children, it helps reduce transmission of hepatitis A to adults due to the high asymptomatic rate of infection in children <5 yrs. Hepatitis A vaccine is also given to children at risk for infection due to a household contact or travel to areas of high incidence.

What is the pathogenesis of Hep B?

Hepatitis B is an immune-mediated disease Primarily caused by cytotoxic T-cells attacking infected hepatocytes

subunit vaccine

Hepatitis B, HPV

__________________________ is a Flavivirus. It has an enveloped virion containing a single-stranded (+)polarity RNA genome.

Hepatitis C Virus

conjugate vaccines

Hib Pneumococcal Meningococcal

Explain the basis for variation in disease between individuals (host factors)

Immune system vitality maintains a "detent" with commensals responds to infection by pathogens and parasites Vaccination-induced immune responses Host characteristics age nutritional status genetics The immune system and genetics of the host are, in part, responsible for the host variance.

how is Cryptococcus neoformans diagnosed?

India ink: demonstrates capsule Cryptococcal antigen: Test for capsular polycaccharide, performed on CSF or blood. Culture-gold standard

what is Mucormycosis?**

Infection with zygomycete, Rhizopus most common Rhinocerebral mucormycosis: infection begins in the nasal mucosa or sinuses progresses to the orbits, palate and brain Very aggressive Rapidly fatal Surgical debridement must be performed Risk factors: leukopenia, diabetes, iron overload Cutaneous mucormycosis-trauma assoc. 90 degree angle hyphae

Define viruses and be able to contrast viruses from bacteria

Infectious obligate intracellular parasites Particles with a DNA or RNA genome Agents that direct synthesis of viral components using cellular systems Reproduced by de novo assembly Agents that create progeny particles for self transmission

vaccines given at 6 mo

Influenza

Describe the oxygen requirement for an Aerotolerant anaerobe, how does it acquire ATP? and what enzymes are involved?

Is able to grow in the presence of O2 ("tolerates it) but is unable to use it for a source of energy - Degree of aerotolerance varies from species to species - Has catalase or superoxide dismutase or peroxidase

What two chemotherapeutic agents inhibit synthesis of the acid-fast cell wall of the genus Mycobacterium?

Isoniazid (INH) appears to block the synthesis of mycolic acid, a key component of the acid-fast cell wall of mycobacteria. Ethambutol interferes with synthesis of the outer membrane of acid-fast cell walls.

What are some inadequacies with the germ theory?

It does not explain inter-individual variation It does not account for dose effects (clearance v. disease outcome) It does not consider protection by vaccination and natural host response to infection. Germ Theory must be combined with host concepts of immunology and population genetics to explain inter-individual variance Lots of microbes are unculturable, so Koch's postulates are inadequate to identify all pathogens as such

what is MacConkey Agar ?

It is both a differential medium and a selective media. The selective property of MacConkey Agar results from the incorporation of bile salts and crystal violet, which inhibit the growth of Gram-positive bacteria (Gram-negative cocci do not grow on the medium either). The inclusion of lactose in the medium provides a source of a fermentable carbohydrate. In addition, the medium contains the pH indicator neutral red. This pH indicator is red at a pH below 6.8 and is colorless at pH > 6.8. This is a differential medium because those colonies of Gram-negative bacilli that ferment lactose to acidic products will have pink colonies as a result of the pH indicator. Colorless colonies are bacteria that cannot ferment lactose.

what are Ectoparasites? Types?

Live in skin, These are arthropod parasites that include insects, arachnids, crustaceans and others. Haematophagous : ingest blood, Histophagous L eats dead tisseu

vaccines given at 1 year

MMR Varicella Hepatitis A

List the 3 most common antibiotic-resistant bacteria, know how they are acquired, how to determine whether people carry them, and how to properly isolate carriers.

MRSA, VRE, CRE are types of bacteria which have evolved to resist many common antibiotics.

Describe the types of reproduction in fungi

Many reproduce both sexually (meiosis) and asexually (mitosis) Asexual: Can occur by hyphae breaking into cells Cells may develop thick walls - Chlamydospores Can reproduce by binary fission or by budding Produces genetically identical offspring

What is Selective Media? What is an example of a bacteria that you would want to use selective media for?

Media that inhibit the growth of organisms that are not being sought are used for Neisseria gonorrhoeae

How is Active TB treated?

Multiple drugs necessary INH plus RIF most effective Long term compliance (DOT) Follow up susceptibility results Never add only 1 new drug to a failing TB treatment regimen! INH RIF PZA ETB 2 months INH RIF 4 months INH RIF PZA STM 2 INH RIF 4 INH RIF 9

What are some examples of bacteria that do not grow in or on culture media?

Mycobacterium leprae, one of two of the etiologic agents of leprosy, Treponema pallidum, the etiologic agent of syphilis, and obligate intracellular bacteria in the genera Chlamydia, Chlamydophila, Rickettsia, and Coxiella burnetii, the etiologic agent of Q fever. Others grow much more slowly due to a prolonged generation time compared with more typical bacteria, such as the bacterial causes of tuberculosis and other members of the genus Mycobacterium

Can you tell what type of tapeworm from looking at egg?

No

List the characteristics of fungi that differentiate them from plants and bacteria

Non-motile Heterotrophs: can't fix carbon, must obtain from organic material Cell wall containing chitin, glucan and mannan Membranes contain ergosterol rather than cholesterol Grow in dark places Grow in any orientation

What is Candida albicans

Normal flora of skin, mucous membranes, GI tract, GU tract Almost all infections are endogenous Mucutaneous: thrush, vulvovaginitis, esophagitis, diaper rash Systemic candidiasis occurs in immunosuppressed, cancer patients, patients on antibiotic therapy Can involve any organ system

What is Level of infection or basic reproduction rate (R0)

Number of contacts (c) in the host population a property of the host population Average probability (p) of transmission per contact a property of the pathogen Duration of time (d) when the host is infectious a property of the pathogen R(o)= CXPXD

What is Clostridium difficile? What does it usually follow or concurrent with?

Often is present in the human colon. It produces two toxins that act upon colonic cells and can cause colitis (inflammation of the colon) with diarrhea as well as severe disease. In nearly all cases, it follows or is concurrent with the use of an antibiotic.

Where are microbiota found?

Our microbiota occupy each mucosal and epithelial anatomical site. These communities are important/required to maintain health.

Pneumococcal vaccine

PCV13 (Prevnar 13) is given in 4 doses to children starting at 2 mo., or one dose in previously unvaccinated older children with certain risk factors. It consists of purified capsular polysaccharide of 13 serotypes of S. pneumoniae conjugated to diphtheria toxoid. S. pneumoniae is a common cause of otitis media and meningitis in children.

What is Paracoccidiodomycosis

Paracoccidiodes brasilensis South American blastomycosis Major endemic dimorphic fungus in Latin America Pilot or Mariner's wheel Morphology clinical specimens and in culture at 37oC

how is HCV transmitted?

Parenteral, primarily by direct blood contact Sexual transmission is possible but very infrequent

Why are pathogenic acid-fast bacteria so difficult to treat?

Pathogenic acid-fast bacteria are intracellular pathogens, and so are difficult to treat because an antibiotic has to cross the host cell membrane as well as the three layers of the bacterium's cell wall.

Know the special patient populations that are at particular risk of contracting these infections and how we try to protect them.

People frequently in health care (hospitals, nursing homes, rehab centers, dialysis) (e.g. sick people with chronic conditions). People who have had these organisms in the past. People who have received multiple or prolonged courses of antibiotics. People known or suspected to be at risk for these organisms can be placed in isolation and tested proactively (surveillance).

_________________________ are not essential for normal bacterial growth and bacteria may lose or gain them without harm.

Plasmids

___________________may contain genes that encode resistance to one or multiple antibiotics and/or to disinfectants and are one way in which genes that code for bacterial resistance to antibiotics spread from one species of bacteria to others.

Plasmids

Pneumococcal vaccine PPSV23 for 65+

Pneumococcal vaccine PPSV23 (Pneumovax), consists of capsular polysaccharides from 23 serotypes of S. pneumoniae. It is also administered after PCV13 doses in younger persons with serious health problems such as chronic lung and heart disease, diabetes, lymphoma, leukemia, asthma or a history of alcoholism or smoking. Healthy adults working with chronically ill people should also be vaccinated. Together, influenza and pneumonia are the 8th most common cause of death in the U.S., and the most common cause of death due to infectious disease. New recommendations: If adults are not previously vaccinated, administer PCV13 first, then PPSV23 6-12 mo. later. If previously vaccinated with PPSV23, administer PCV13 > 12 mo. later.

The goal of vaccination is

Prevent symptoms Develop herd immunity

how is HAV prevented and what therapy is out there?

Prevention and therapy: Good sanitation is most effective Immune seroglobin pre- or post-exposure is effective No antiviral therapy Inactivated whole-virus vaccine is available

what is Cryptococcus gattii?

Primarily infects HIV-negative people, previously in tropical and subtropical climates Over past decade has emerged as pathogen in North America: British Columbia, Oregon, Washington Appears more resistant to antifungal agents looks like Cryptococcus neoformans

Infectious protein particles. They are normal cellular proteins with an abnormal, self-duplicating pathogenic conformation. They do NOT contain a nucleic acid genome.

Prions

Describe HBV: Prevention and therapy

Protection from blood contact Use safer-sex practices Vaccination (recombinant HBsAg) is highly effective and safe Post-exposure prophylaxis is by concurrent HBIG (HBV immune globulin), and vaccination Pegylated interferon α leads to long-term clinical improvement for < 30% of chronic carriers but it has serious side-effects Lamivudine, Adefovir, Entecavir, Telbivudine, and Tenofovir (nucleoside analog DNA chain terminators) are approved They effectively suppress viral replication in most patients Viral replication rebounds after drug withdrawal Therapy cures HBV infections in only 3-6% of patients even after many years of treatment

how is HAV Replicated?

Proteins are made by cleavage of a large polyprotein HAV replicates with the standard cytoplasmic RNA-to-RNA mechanism used by most single-stranded (+) polarity RNA viruses Released from cells primarily by cytolysis

Compare and contrast protozoal and helminthic pathogens

Protozoa - Single-celled, eukaryotic organisms; microscopic - Free-living or parasitic - Able to multiply in humans, various routes of transmission -Protozoa exist in different forms during the life cycle.

What does Protozoa elimination rely on?

Protozoa elimination relies on TH1 cells and their cytokines.

Describe the HBV replication cycle

Replication is by error-prone reverse transcription Overlap of the S and P open reading framess slows development of drug resistance and vaccine escape Viral replication and release is non-cytopathic

Describe the oxygen requirement for an Obligate aerobe, how does it acquire ATP? and what enzymes are involved?

Requires O2 for growth - Generates ATP from the electron transport system - Uses O2 as the terminal electron acceptor - Catalase breaks down H2O2 -Superoxide dismutase detoxifies superoxide

What do biofilms enable bacteria to do?

Resist attack by antibiotics; Trap nutrients for bacterial growth and remain in a favorable niche; Adhere to environmental surfaces and resist flushing; Live in close association and communicate with other bacteria in the biofilm; Resist phagocytosis and attack by the body's complement pathways.

all vaccines given at 2 mo

Rotavirus Poliovirus DTaP Hib Pneumococcal

live-attenuated vaccines

Rotavirus, Influenza MMR Varicella

What are Nematodes?

Round worms long thin unsegmented bodies anterior mouth move side to side male and female forms

_____________________is the basis of chemotherapeutic control of bacteria. ____________________means that the chemical being used should inhibit or kill the intended pathogen but have little or no adverse effect on the host

Selective toxicity

define Serial interval

Serial interval - time between the onset of symptoms in the primary and secondary cases also affects the rate of transmission

treatment of HCV

Sofosbuvir plus ledipasvir (an NS5A inhibitor) was the first FDA-approved interferon-free regimen 1-pill combination called Harvoni Cures >90% of patients after 3 months Sofosbuvir plus simeprevir are also being used in combination Cures >90% of patients after 3 months Many other new drugs are approved or late in the pipeline The highly active interferon-free regimens just received a "black-box" warning due to ability to activate cryptic HBV infections

what causes Sporotrichosis: "rose-handlers disease"?

Sporothrix schenckii (dimorphic-yeast and mold) Infection of cutaneous or subcutaneous tissue and adjacent lymphatics with nodular lesions that may supparate and ulcerate.

What is the most common cause of α-hemolysis?

Streptococcus pneumoniae and the species that comprise the "viridans streptococci", which are often found in the oral cavity and are common causes of infectious endocarditis.

The anti-phagocytic carbohydrate capsule occurs in most strains of what?

Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis.

What is Taenia saginata?

Taenia saginata, the beef tapeworm. This does NOT disseminate in humans. Scolex of T. saginata. Note the four large suckers and lack of rostellum and rostellar hooks.

what are 2 ways to tell of you have a fungus in patient samples?

Take pt sample and use KOH prep: dissolves host cells, allows fungi to be visualized or Calcofluor: fluorochrome that binds to cellulose and chitin in fungal cell wall can tell for sure if its fungus it will light up! problem: tells nothing about host tissue

What are the steps of grams stain?

The Gram's stain, which greatly helps determine the type of bacteria involved in infections, involves a number of steps as shown in Table 1, below. Fix bacteria to the glass slide as the first step. This is often done with heat fixation, though methanol fixation is actually superior. Excessive heat may alter the morphology of the bacteria. Adding primary stain, crystal violet, stains both Gram-positive and Gram-negative bacteria. Add Gram's iodine. Rinse the slide with the decolorizing agent (typically alcohol or alcohol/acetone). Add counterstain (either safranin or basic fuchsin), which is a different color from the crystal violet. It is taken up by what are now decolorized Gram-negative organisms.

What kind of vaccine is Poliovirus?

The Salk inactivated poliovirus vaccine (IPV) is used in the U.S. because of its safety. The Sabin live-attenuated, oral polio vaccine (OPV) is used in countries where poliovirus is endemic because of its efficacy (mucosal immunity to it interrupts person-to-person transmission). begin at 2 months (2,4,6-18, then 6y/o)

What are the Cytosolic Components in Bacteria?

The bacterial cell wall and cytoplasmic membrane enclose a fluid cytoplasm that contains the genome (both chromosomal and extra-chromosomal DNA) as well as protein enzymes and machinery needed to convert food to energy (catabolic metabolism), replicate the genome, transcribe the genome, convert RNA to proteins on ribosomes, and produce the building blocks (anabolic metabolism) needed to reproduce the organism.

Relate how the Gram stain depends upon the characteristics of the bacterial cell wall.

The basis of the difference following the Gram stain is that the decolorization step selectively removes the primary stain from Gram-negative bacteria due to the thin layer of peptidoglycans in Gram-negative bacteria. Decolorization is a critical step

How are organisms named?

The first word is capitalized and denotes the genus. The second word is the species within that genus, or the species epithet. Typically, the genus and species are italicized or, in the absence of italics, underlined as in Escherichia coli or Escherichia coli.

What is Grocott's methenamine silver (GMS) stain?

The mucopolysaccharide components of the fungal cell wall are oxidized to release aldehyde groups, which react with the silver nitrate, reducing it to a visible metallic silver. you can still see surrounding host tissue

What is the Germ Theory: Koch's Postulates

The standard way to rigorously establish that a microbe causes a disease: The microbe must be found in abundance in all diseased people, but not in healthy people. The microbe must be isolated from a diseased person and grown in pure culture. The cultured microbe should cause disease when introduced into a healthy organism. The microorganism must be re-isolated from the inoculated, diseased experimental host and identified as being identical to the original microbe.

how is HCV replicated?

The viral RNA is translated independently of cap to make polyprotein The RNA is replicated in cytoplasm by a viral RNA-directed RNA polymerase Replicate as a very diverse quasispecies New viruses are released without killing the cell

What is Coccidiodomycosis?

Thermally dimorphic: grow as filamentous fungi at 25-30°C, and as yeast in tissue or cultured at 35-37°C Caused by Coccidiodes immitis Most cases occur in the arid areas of SW USA, central and SA Can disseminate to bones and CNS San Joaquin Valley Fever

What happens when Clostridium difficile begins to produce toxins after the use of antibiotics?

This may result in the need to surgically remove a part of the involved colon. It can be fatal, particularly in older patients. It is resistant to many antibiotics. Even a month or more after use of an antibiotic, many of the bacteria in the colon are killed by the antibiotic. This permits C. difficile to multiply as it has less competition for its ecological niche.

When can toxins be useful?

Though extremely poisonous in their native state, inactivated toxins (called toxoids) are useful as vaccines to prevent toxin-induced disease.

______________________, helps relax the supercoiled circular DNA, enabling the separation of the interlinked daughter chromosomes at the end of bacterial DNA replication.

Topoisomerase IV

- Small, flat bodies, oral and ventral suckers and a bland gut - Move in a gliding or creeping motion - Blood flukes and Intestinal or tissue (lung/liver) flukes - Intestinal and tissue flukes are hermaphroditic - Blood flukes have separate sexes - Intermediate host, where asexual reproduction occurs, is usually a snail

Trematodes (flukes)

T/F: Our microbiota include symbionts and commensals in health, and pathogens in disease states

True

T/F: Most microbes are not pathogens.

True: Some non-pathogenic bacteria are symbionts, others are commensals

What are Conjugate vaccines?

Two different portions of a microorganism; one polysaccharide isolated from the bacterial capsule to which antibodies are generated, linked to a protein (toxoid) that stimulates a Th response. more memory and antibody response Conjugate vaccines are particularly useful for vaccination of children under the age of 2, who don't mount significant antibody responses to the capsular polysaccharides without the Th response. Hib S. pneumoniae

Describe the oxygen requirement for an Obligate anaerobe, how does it acquire ATP? and what enzymes are involved?

Unable to use O2 as a source of energy - ATP is from fermentation, not the electron transport system - Unable to tolerate O2 as a result of the toxicity products (e.g., superoxide and catalase) - Anaerobic respiration uses something other than O2 as a terminal electron acceptor, such as nitrates

What is VRE? Where is it normally carried? When does it become a disease? What is it sensitive to? What is it resistant to?

Vancomycin-resistant Enterococcus Carried in GI tract. People can be chronically colonized. Disease: In the GI tract, it doesn't cause a problem. Disease comes from when the organism enters other body sites: blood stream infections, urinary tract infections, abdominal abscesses. VRE can still be sensitive to ampicillin in some cases. In other cases, can be resistant to almost all known antibiotics

how are glycolipids anchored to the peptidoglycan layer in AF B?

Via arabinogalactan that is linked to high molecular weight mycolic acids. The arabinogalactan/mycolic acid layer is overlaid with a layer of polypeptides and mycolic acids consisting of free lipids, glycolipids, and peptidoglycolipids. Other glycolipids include lipoarabinomannan and phosphatidyinositol mannosides

Naked infectious RNAs that do not contain or encode any proteins.

Viroids

What are Sub-cellular particles made of nucleic acid, protein, and sometimes lipid that reproduce by de novo assembly.

Viruses

Critically discuss how the unique aspects of viral genetics affect pathogenesis, diagnosis, and therapy

Viruses have adapted to overcome the primary barriers they typically face,Example: viruses that infect the GI tract are resistant to low pH and bile detergents The more serious viral diseases are usually associated with replication in secondary sites

___________________________is synthesized by some bacteria in the colon, which is absorbed and used by us to activate a number of inactive proteins that are involved in blood coagulation. What are common dietary sources? Who is this important for?

Vitamin K Common dietary sources include green, leafy vegetables. This is important for patients who receive broad-spectrum antibiotics for a period of time, especially if they do not eat sources of vitamin K.

Discuss the difference between colonization and clinically important infection

When a patient has a swab or other sample obtained from an uninfected site, whether skin or a mucous membrane, bacteria will be recovered. This is an example of colonization rather than infection. There should be a specific reason to obtain this culture (e.g., is the patient colonized with a resistant organism such as methicillin-resistant Staphylococcus aureus?). Similarly, sputum obtained from someone without a respiratory infection will grow bacteria - likely including those from the mouth. If bacteria are recovered from a normally sterile site, such as cerebrospinal fluid it must be considered to be infecting the patient unless the isolated organism is contaminating the culture (e.g., in the collection, transport, or laboratory evaluation of the specimen or the culture).

What is plague due to?

Yersinia pestis

anti-HBsAg antibodies plus anti-HBeAg or anti-HBcAg indicates?

a cleared infection HBsAg = the viral surface antigens; HBcAg = viral capsid protein; HBeAg = modified form of the HBcAg that is secreted into the blood.

Haemophilus influenzae B (Hib)

a conjugate vaccine given starting at 2 mo. Its intro-duction in 1987 dramatically reduced Hib meningitis and deafness. The vaccines are capsular polysaccharide linked to tetanus or diphtheria toxoid. Hib also causes pneumonia and epiglottitis

what is Klebsiella pneumoniae ?

a lactose-fermenting Gram-negative bacillus Gram's stain of any colonies that are growing should be performed in order to confirm the bacteria are Gram-negative bacilli. often are resistant to multiple antibiotics

Define Colonization

a long-term relationship in which the microbe lives in or on a person. The microbe may or may not cause disease (e.g. symbiont or dysbiosis). Can include chronic carrier (continuously replicating) and latent (dormant) states.

Helminth Life Cycles

a. Fecal-oral (Ascaris lumbricoides) b. Transdermal (Necator americanus) c. Vector-borne (Onchocerca, Schistosoma) d. Predator-prey (Taenia)

Does Mycobacterium tuberculosis reduce nitrate? What is its reservoir? How quickly does it grow?

a. Grows slowly (3-6 weeks) b. Nitrate reduction + c. Humans only reservoir

Define Specificity

ability of the test to correctly identify those without the disease (true negative rate).

The end products of fermentation are ___________.

acidic

What happens if the gram stain is Over decolorized?

all cells appear to be very pink. This is a sputum sample with Streptococcus pneumoniae, which appears to be Gram-negative (and is NOT)

What is α-hemolysis?

alpha hemolysis is a partial, or incomplete, hemolysis. it is the consequence of the production by bacteria of hydrogen peroxide (H2O2) that oxidize the hemoglobin in the culture medium to methemoglobin, in which the iron in hemoglobin is Fe3+ (ferric) rather than the normal Fe2+. In the area of the culture medium surrounding an α-hemolyic colony the red blood cells are green in appearance.

Define sensitivity

always be there in presence and not there in absence the ability of a test to correctly identify those with the disease (true positive rate)

Asexual state of fungo called ____________

anamorph

Shedding usually terminates when ___________________________________________to neutralize the virus at the shedding site or when the viral infection has been cleared

antibody titers have risen high enough - Knowing the pathogen's replication dynamics are needed to know when it becomes non-transmissible

Define Thermally Dimorphic Fungi

appear as a yeast at body temperature and a mould at room temperature.

What is Isoniazid (INH)

appears to block the synthesis of mycolic acid, a key component of the acid-fast cell wall of mycobacteria.

Define Conidia:

asexual spores that form from hyphae

Define Dematiacious

brown or black pigmented hyphae due to melanin production (phaeo-)

Define pathogen

cause disease

What is a prion? Is it a cell? Does it have Nucleic acids? What is its surface? What is its reproduction strategy?

cell: no Nucleic acid: none Surface: protein Reproduction strategy: conversion

What is agar derived from?

certain species of seaweed in the genera Gelidium and Gracilaria

Define Hyaline

clear, no melanin production

Cause the "tinea"s, which refer to

diseases, not fungal names, of dermatophytes

anti-HBeAg with no anti-HBsAg antibodies correlate with

effective immune control of the virus (but not clearance in the absence of anti-HBsAg antibodies)

what is Ascaris lumbricoides?

endoparasite (human intestinal roundworm)

What happens if the grams stain is Under decolorized?

eukaryotic cells, normally pink, are a good control. All bacteria appear to be Gram-positive

what are Platyhelminths?

flatworms, 2 types Trematodes(flukes) and Cestodes (tapeworms)

Describe the Ziehl-Neeson stain. What is it used for?>

for acid fast bacteria

What is a granuloma?

formation of avascular aggregates of activated macrophages, with macrophages, and lymphocytes), depending on the bacterium involved.

how does entry of a virus occur?

fusion or endocytosis

Who should be treated? PPD size considered + depends on risk of infection/progression to disease

greater than or equal to 5mm for HIV+ or equiv. immunosupp., HH contacts, x-ray c/w old TB greater than or equal to 10mm for Recent converters, IVDU, other greater than or equal to 15mm for No exposure or progression risks

What are Biofilms?

groups of bacteria attached to a surface and enclosed in a common secreted adhesive matrix, typically polysaccharide in nature. In biofilms, bacteria are often able to communicate with one another and interact with and adapt to their environment as a population rather than as individual bacteria.

When bacteria are grown on sheep blood agar, _______________ of different types may be observed surrounding a bacterial colony. This may help in the process of identifying the species that is growing this colony.

hemolysis

Define Asymptomatic infection

inapparent or subclinical (no noticeable disease). Often can be detected by directly detecting the microbe or by finding antibody against the organism in an individual's serum

Define Symptomatic infection

infection with a pathogen that causes discomfort or disease in a person. Severity (virulence) is determined by host factors, virulence factors possessed by the organism, and infectious dose.

What can happen when LPS producing bacteria are eliminated by antibiotics?

initially symptoms may be exacerbated due to the sudden bolus of endotoxin released into the circulation that causes a systemic inflammatory response damaging host tissues and disabling the immune system

Plasmids can acquire a number of different antibiotic resistance genes by means of ___________.

integrons.

What is Ethambutol?

interferes with synthesis of the outer membrane of acid-fast cell walls.

Meningococcal vaccine

is a 2 dose conjugate vaccine recommended starting at age 11-12 to prevent severe meningitis caused by Neisseria meningitidis infection, which can occur in dense housing situations such as dormitories. Most frequently used in high risk kids >2 years old is a quadrivalent conjugate vaccine (MCV4), protective against serogroups A/C/W/Y. In infants at high risk, a quadrivalent polysaccharide vaccine (MPSV4) may be used, but it elicits poor long-term immunity. A vaccine for group B has also been recently licensed.

Zoster vaccine (Zostavax)

is a higher dose of live-attenuated Varivax vaccine recommended at age 60 except in the immunocompromised as a therapeutic vaccine to protect against shingles. A new subunit vaccine in adjuvant with greater efficacy is also approved. Those who have never had chicken pox should receive the varicella (Varivax) vaccine as a prophylactic vaccine.

Varicella vaccine (Varivax)

is a live-attenuated virus given to children in two doses beginning at 12 mo. of age to prevent chickenpox.

What is Ascaris lumbricoides ? what is special about treatment of this parasite?

is the largest nematode (roundworm) parasitizing the human intestine. has a pulmonary form A female may produce approximately 200,000 eggs per day, which are passed with the feces If there is more than one parasite present in a patient, treat Ascaris before treating other parasites, Ascaris migrates when they are stressed

What is the minimum inhibitory concentration (MIC)?

is the lowest concentration of an antibiotic that prevents visible growth of a bacterium

What kind of vaccine is the Rotavirus vaccines? When is it given?

live-attenuated viruses Two orally administered vaccines are licensed in the U.S.: Rotateq and Rotarix. Both reduce the incidence of the most common cause of severe diarrheal disease in infants and children <5 years of age, and hospitalizations that may accompany it. (Nearly 100% experience rotavirus gastroenteritis by age 5.) In developing countries rotavirus gastroenteritis is a major cause of death vaccine goals: reduce symptoms, then transmission Starts at 2 months.

How does the micro lab identify fungi?

must grow it on a culture.. Sab-Dex plate: appearance of colony on fungal media. Examine color and texture of forward and reverse. Tape prep: lactophenol cotton blue staining from colony growth to identify structures

Define Commensal

neutral relationship (indigenous microbes)

The ________________is the region containing the bacterial genome, which is composed of a single molecule of chromosomal DNA.

nucleoid (as opposed to having 23 pairs of chromosomes)

Beta hemolysis is a characteristic of __________________which is also known as "group A beta-hemolytic Streptococcus" because it is both β-hemolyic and contains the Lancefield group A streptococcal antigen (streptococci are commonly grouped according to their Lancefield antigen). What does it cause?

of Streptococcus pyogenes It causes "strep throat", infections of skin and soft tissues (occasionally described in the news as "flesh eating bacteria"), bacteremia, and scarlet fever. After a throat infection with this organism, one of the post-infectious sequelae that is now far less common than it was in the past is rheumatic fever.

Define opportunistic infection

often normal flora that "take the opportunity" to infect an immunocompromised host or host with a barrier defect. This often can lead normally benign microbes to cause disease.

What are Fimbriae?Where are they found?

on bacteria facilitate attachment bacterial binding to cells. This may either result in colonization or infection on both invasive pathogens (e.g., Neisseria meningitidis, a major cause of bacterial meningitis that can also cause life-threatening bacteremia) and bacteria that multiply locally. Some multiply locally and produce a toxin that acts far from the site of the bacterium with potentially deadly results (e.g., tetanus, due to the toxin produced by Clostridium tetani, which can multiply locally following a breach in the integrity of the skin due to a contaminated wound).

What is a pilus?

one means for the exchange of DNA between bacteria, and is discussed in the lecture on bacterial genetics. It is not present in all bacterial species. Because plasmids that may carry antibiotic resistance genes that are exchanged via the pilus, its presence can be considered a virulence factor.

Define Nosocomial

organisms acquired in the health care setting. These are more likely to have antibiotic resistance (MRSA*, VRE, CRE) or are due to antibiotic use (Clostridia difficile).

What are peyers patches?

organized lymphoid follicles, named after the 17th-century Swiss anatomist Johann Conrad Peyer. They are an important part of gut associated lymphoid tissue usually found in humans in the lowest portion of the small intestine, mainly in the distal jejunum and the ileum, but also could be detected

Bacteria may also have extrachromosomal DNA known as a ___________________. They are reproduced and can be transferred to other bacteria. Bacteria may also lose one or more of their __________________.

plasmid

In some cases, antibiotic resistance is the result of a mutation that results in a change in the ___________ protein, resulting in the exclusion of an antibiotic to enter the cell when it did so via the ______________prior to the mutation.

porin

Gram-negative bacteria contain proteins known as _____________ These form channels that permit the entry of some molecules from entering the bacterial cell while they exclude other molecules.

porins

only ______________ polarity RNAs are translated

positive

define pyogenic?

pus inducing Pus contains primarily neutrophils, microorganisms, and may contain dead human tissue or blood cells.

Infections with encapsulated bacteria occur at higher rates to which patients?

rate in patients that have either undergone a splenectomy (such as following abdominal trauma or for medical reasons) or lack splenic function, such as in many sickle cell anemia patients following multiple splenic infarcts.

Influenza vaccine

recommended yearly for everyone >6 months of age. Two forms: Inactivated trivalent vaccine contains two A strains and one B strain, licensed for everyone. Live-attenuated, nasally administered vaccine (flu mist) is licensed for healthy people 2-49 yrs old. The live vaccine contains the same influenza strains as the inactivated, but the viruses have accumulated mutations during growth at low temp. (cold adaptation).

Define Metagenomics

refers to genetic sequencing of the microbiome

what is Uncoating

release of viral genome into the cytoplasm by membrane fusion, disassembly of capsid, or extrusion. Not all viruses uncoat (e.g., Rotavirus).

What are Ancylostoma duodenale and Necator americanus ?

roundworms

RNA viruses often have ______________genomes

segmented Often only 1 gene per segment Genetically equivalent to multiple cellular chromosomes

Define Homothallic

self-fertile, do not require a mate for sexual reproduction

Define Symbionts

species that benefit the host and gain benefit from the host

Schistosoma mansoni?

spine kind of "off" Flatworms: Playthelminths a. Flukes (Trematodes)

what is Periodic acid-Schiff (PAS) ?

stains glycogen in fungal cell walls

what is Mucicarmine

stains mucopolysaccharides, including capsules. (PInk)

what kind of vaccine is the Hepatitis B virus vaccine? when is it given?

subunit vaccine composed of a recombinant surface protein of the virus (HBsAg). Vaccination of infants starting within 24 hr of birth has dramatically reduced the rate hepatitis B among children. HBV infection is the leading cause of chronic hepatitis and hepatocellular carcinoma world-wide, and thus the HBV vaccine is the first anti-cancer vaccine.

What is Tinea versicolor?

superficial condition caused by Malassezia furfur causes skin discoloration caused by Colonization of stratum corneum microscopically looks like spagetti and meatballs requires lipids to grow pts at risk are ppl recieving IV lipids

Sexual state of fungi called _________________

telomorph

what reveals the level of viremia?

the amount of HBV DNA in serum

Define Microbiome

the collection of microbial genomes Our bodies contain more bacterial cells than human cells and our resident bacteria form our microbiome

Define Microbiota

the collection of microbial species associated with the human body

What are Trophozoites?

the motile, feeding and growing form of protozoans that multiple asexually. They generally require a host to survive and have adapted to live in harsh environments such as the gut. A trophozoite can undergo asexual division (called schizogony) to create a schizont. The schizont will release merozoites which can invade other host cells.

What is toxoplasmosis due to?

the parasite Toxoplasma gondii and why pregnant women should wear gloves if changing used cat litter

what is Taenia solium,

the pork tapeworm. This can cause severe disease by involvement of, for example, the brain and/or eye. Note the four large suckers and armed rostellum containing two rows of hooks. T. solium Causing Cysticercosis This infection is caused by ingestion of eggs shed in the feces of a human tapeworm carrier. Pigs and humans become infected by ingesting eggs or gravid proglottids, and it can harm brain etc

Define incubation period:

the time between infection with the organism and beginning of symptoms

What is the most common site of nosocomial infection ?

the urinary tract (about 40% of all nosocomial infections). Nearly 80% of nosocomial urinary tract infections are associated with the use of an indwelling bladder catheter.

Define prodrome period

time during which non-specific symptoms such as fever, malaise and loss of appetite (inappetence) occur

Define specific illness period

time during which overt and characteristic signs and symptoms of the disease occur

Define recovery or convalescence period

time during which the illness abates and the patient returns to health

Phase III trials

trials are used to determine whether a vaccine is effective in preventing infection and/or disease. Volunteers are vaccinated, and their rate of developing disease after potential natural exposure is monitored. Volunteers are not intentionally exposed to the pathogen. Phase III data indicating a vaccine's safety and efficacy in large numbers of people is required to support an application for licensure to the Food and Drug Adminstration (FDA). 3-5 yrs 1000's of ppl

Phase II clinical trials

trials still focus on safety, and also provide more detailed data on immune responses and the most effective dose and administration schedule to elicit a strong immune response. 100s of people 2-3 yrs

T/F If only colonization is occurring, treatment with antibiotics is rarely indicated.

true

What is transformation?

uptake of naked DNA

anti-HBsAg antibodies without any other markers indicates?

vaccination HBsAg = the viral surface antigens; HBcAg = viral capsid protein; HBeAg = modified form of the HBcAg that is secreted into the blood.

MMR

vaccine is composed of live-attenuated measles, mumps and rubella viruses given beginning at 12 mo. of age. It has largely interrupted their transmission in the U.S. Declining immunization rates (<95%) have led to sporadic outbreaks. Pregnancy is a contraindication

HBsAg in serum correlates with _____________?

viremia (presence in blood) HBsAg = the viral surface antigens; HBcAg = viral capsid protein; HBeAg = modified form of the HBcAg that is secreted into the blood.

Chromoblastomycosis

warty nodules and crusty abscesses along lymphatics following implantation of dematiacious fungi Brown-pigmented sclerotic bodies with septations (Medlar bodies or "copper pennies") and dark hyphae may be seen in tissue stepped on something that let mold get into tissue

whats an Inactivated (killed) vaccine?

whole organisms rendered non-infectious - stable, safer than live vaccines - Ab+Th > CTL so not optimal for many viruses dont get inside cells no cytolytic t cell response may not be as inactivated as you thought....

HBeAg correlates with?

with viremia

What is Cryptococcus neoformans **

yeast Sites of infection: lung, CSF, blood, skin, mucous membranes, systemic Usually 2-4 µm, narrow based budding, capsules stain with mucicarmine Mucicarmine see in pts with HIV Rarely manifest disease in healthy individuals Immunosuppressed, chemotherapy, diabetes

What is Gamma Hemolysis?

γ-hemolysis: gamma hemolysis is a lack of hemolysis around a bacterial colony.