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Immunity and Infection 1
Review for Immunity and Infection Exam 1
1081
Medical
Professional
10/21/2015

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Term
What is the difference between pathogenicity and virulence?
Definition
Pathogenicity is the ability to cause disease (qualitative term). Virulence is quantification of the ability to cause disease.
Term
What are the four requirements for an organism to be pathogenic?
Definition
1. Gain entry into the host.
2. Adhere to tissues within the host.
3. Evade host defenses.
4. Elicit some sort of damage to the host.
Term
List the four ways that a pathogen can be transmitted.
Definition
1. Autoinoculation (opportunistic infection).
2. Person-to-person (communicable infection).
3. Animal-to-person (zoonotic infection).
4. Environmental (opportunistic infection).
Term
What is the term for microbes that inhabit healthy humans?
Definition
Commensal species.
Term
List the four types of pathogen.
Definition
Bacteria, viruses, fungi, and parasites.
Term
What disease is caused by Salmonella enteritidis?
Definition
Food poisoning.
Term
What disease is caused by Mycobacterium tuberculosis?
Definition
Tuberculosis.
Term
What disease is caused by Variola?
Definition
Smallpox.
Term
What must happen to complement proteins in order for them to be activated?
Definition
They must be cleaved.
Term
What are two main functions of complement?
Definition
Complement facilitates bacterial destruction and induces inflammation.
Term
What is the precursor to a macrophage?
Definition
Monocyte.
Term
What are the 3 jobs of macrophages?
Definition
1. Recognize pathogens.
2. Eat pathogens.
3. Communicate with other cells.
Term
What do cytokines do?
Definition
Cytokines tell cells what to do.
Term
What do chemokines do?
Definition
Chemokines tell cells where to go.
Term
What are the second responders in innate immunity?
Definition
Neutrophils.
Term
What precursor gives rise to neutrophils?
Definition
Granulocyte.
Term
What precursor gives rise to eosinophils?
Definition
Granulocyte.
Term
What precursor gives rise to basophils?
Definition
Granulocyte.
Term
What are two functions of neutrophils?
Definition
Phagocytosis and release of cytokines.
Term
What are three locations where neutrophils are found?
Definition
Bone marrow, blood, and sites of inflammation.
Term
Do neutrophils have a short life span or a long life span?
Definition
Short.
Term
What is the purpose of vasodilation and increased vascular permeability in inflammation?
Definition
It allows fluid, protein, and inflammatory cells to leave the bloodstream and enter the tissue.
Term
What immune response is activated if pathogen spreads to lymphoid?
Definition
Adaptive.
Term
Which is faster, innate immunity or adaptive immunity?
Definition
Innate.
Term
Are the recognition mechanisms of innate immunity fixed or variable?
Definition
Fixed.
Term
Are the recognition mechanisms of adaptive immunity fixed or variable?
Definition
Variable.
Term
Do the recognition mechanisms of innate immunity or adaptive immunity have a greater number of specificities?
Definition
Adaptive.
Term
Do the recognition mechanisms of innate immunity or adaptive immunity improve during the response?
Definition
Adaptive immunity. The recognition mechanisms of innate immunity are constant during the response.
Term
What is the common precursor of all immune cells?
Definition
Hematopoietic stem cell.
Term
What is the precursor for B cells?
Definition
Common lymphoid progenitor.
Term
What is the precursor for plasma cells?
Definition
B cells.
Term
What is the precursor for the NK/T cell precursor?
Definition
Common lymphoid progenitor.
Term
What is the precursor for T cells?
Definition
NK/T cell precursor.
Term
What is the precursor for NK cells?
Definition
NK/T cell precursor.
Term
What is the precursor for dendritic cells?
Definition
Monocytes.
Term
What is the most abundant type of leukocyte in human peripheral blood?
Definition
Neutrophil.
Term
What cells are the mediators of adaptive immunity?
Definition
Lymphocytes.
Term
What are the two types of lymphocyte?
Definition
B cells and T cells.
Term
What do plasma cells do?
Definition
Secrete antibodies.
Term
What is the function of dendritic cells?
Definition
Dendritic cells are myeloid cells that interact with and help activate lymphocytes. They process and present antigen to naive T cells.
Term
Where does positive selection of T cells occur, and what cells participate in this positive selection?
Definition
Positive selection of T cells occurs in the cortex of the thymus, and T cells are positively selected by epithelial cells.
Term
Where does negative selection of thymocytes occur?
Definition
The thymic medulla.
Term
What are CD8 T cells?
Definition
Cytotoxic T cells.
Term
What are CD4 T cells?
Definition
Helper or regulatory T cells.
Term
Are most lymphocytes in the blood or the lymphoid tissue?
Definition
Lymphoid tissue.
Term
List two primary lymphoid tissues.
Definition
Thymus and bone marrow.
Term
What occurs in primary lymphoid tissues?
Definition
Lymphocyte development.
Term
List three secondary lymphoid tissues.
Definition
Lymph nodes, spleen, and Peyer's patches.
Term
What occurs in secondary lymphoid tissues?
Definition
Lymphocyte activation.
Term
Do pathogens and pathogen-infected dendritic cells travel to the lymph nodes via the blood or the lymphatics?
Definition
Lymphatics.
Term
Do naive lymphocytes arrive at lymph nodes via blood or lymphatics?
Definition
Blood.
Term
What cell is predominant in lymphoid follicles?
Definition
B cells.
Term
Where do germinal centers form?
Definition
Lymphoid follicles.
Term
What is the function of the spleen?
Definition
Blood filter (no lymphatics).
Term
Do MALT/GALT have afferent lymphatics, efferent lymphatics, both, or neither?
Definition
Efferent, but not afferent.
Term
Where is the majority of secondary lymphoid tissue?
Definition
In the gut.
Term
What are the two ways that antibodies combat infection?
Definition
Neutralization and opsonization.
Term
What is the first antibody made against an infecting pathogen?
Definition
IgM.
Term
What process selects for antibodies that bind more tightly to pathogen?
Definition
Somatic hypermutation.
Term
Switching IgM to which Ig isotype allows delivery of the pathogen to phagocytes?
Definition
IgG.
Term
What describes the movement of a T cell into and out of a lymph node?
Definition
Enters via the bloodstream and exits via the efferent lymphatics.
Term
What is the purpose of the flagella?
Definition
Locomotion.
Term
What motion results from a counterclockwise motion of the flagella?
Definition
Forward run.
Term
What motion results from a clockwise motion of the flagella?
Definition
Tumble.
Term
List two functions of pili.
Definition
Attachment and conjugation/mating.
Term
Does Bacillus anthracis have a capsule?
Definition
Yes.
Term
Does Streptococcus pneumoniae have a capsule?
Definition
Yes.
Term
What substance usually makes up the capsule?
Definition
Polysaccharide.
Term
What makes up the capsule of B. anthracis?
Definition
Poly-glutamic acid.
Term
List 3 ways that capsules are an important virulence factor.
Definition
Adherence, protection from desiccation, anti-phagocytic.
Term
What do Quellung and India ink detect?
Definition
Capsules.
Term
Describe the difference between Gram-positive and Gram-negative bacteria.
Definition
Gram-positive bacteria have one cell membrane, which is surrounded by a thick peptidoglycan cell wall. Gram-negative bacteria have two cell membranes and a thin layer of peptidoglycan.
Term
Where is lipopolysaccharide located?
Definition
In the outer membrane of Gram-negative bacteria.
Term
What is the mechanism of action of penicillin?
Definition
It blocks the cross-linking of peptide side chains in the peptidoglycan cell wall.
Term
What is the mechanism of action of vancomycin?
Definition
It inhibits bacterial cell wall synthesis.
Term
What is the mechanism of action of bacitracin?
Definition
It inhibits bacterial cell wall synthesis.
Term
What is the mechanism of action of cycloserine?
Definition
It inhibits bacterial cell wall synthesis.
Term
Teichoic acid and lipoteichoic acid are located on which bacterial cells?
Definition
Gram-positive.
Term
What are the 3 components of LPS?
Definition
Lipid A, core polysaccharide, and O side chain.
Term
Does C. difficile form spores?
Definition
Yes.
Term
What molecule is in the cortex of spores?
Definition
Calcium dipicolinate.
Term
What is the formula for the number of bacterial cells at time t?
Definition
Nt = N0 * 2^n
Term
What is the formula for number of generations?
Definition
n = (logNt - logN0)/log2
Term
What is the formula for generation time?
Definition
g = t/n.
Term
During which phase of growth can generation time be calculated?
Definition
Log phase.
Term
What toxin is associated with potatoes and can cause dizziness, dysphagia, blurred vision, and difficulty breathing?
Definition
Botulinum toxin.
Term
How does endotoxin cause damage?
Definition
It causes collateral damage through inflammation.
Term
Distinguish toxinosis from infection.
Definition
In a toxinosis, symptoms are due solely to the presence of a toxin. In an infection, the bacteria produces toxin after infection.
Term
Is staphylococcal food poisoning a toxinosis or an infection?
Definition
Toxinosis.
Term
Which has a faster onset, a toxinosis or infection?
Definition
Toxinosis.
Term
Does Campylobacter jejuni cause toxinosis or infection?
Definition
Food infection.
Term
What type of toxin is perfringolysin?
Definition
Cytotoxin.
Term
What type of toxin is C. difficile toxin B (and A)?
Definition
Cytotoxin.
Term
What type of toxin is S. aureus leukocidin?
Definition
Cytotoxin.
Term
What type of toxin is botulinum toxin?
Definition
Neurotoxin.
Term
What type of toxin is tetanus toxin?
Definition
Neurotoxin.
Term
What type of toxin is C. difficile toxin A (and B)?
Definition
Enterotoxin.
Term
What type of toxin is cholera toxin?
Definition
Enterotoxin.
Term
What type of toxin is E. coli heat labile toxin?
Definition
Enterotoxin.
Term
What type of toxin is Shiga toxin?
Definition
Enterotoxin.
Term
Give two examples of pore-forming toxins.
Definition
Perfringolysin and S. aureus leukocidins.
Term
Give an example of a toxin that disrupts the actin cytoskeleton.
Definition
C. difficile toxins A and B disrupt the actin cytoskeleton by inactivating Rho GTPases.
Term
Give three examples of toxins that work by ADP-ribosylating.
Definition
Cholera toxin, E. coli heat labile toxin, and pertussis toxin.
Term
Briefly, what is the mechanism of action of tetanus toxin and botulinum toxin?
Definition
Degrade synaptobrevins.
Term
What is the mechanism of action of C. perfringens alpha toxin?
Definition
Degrades lecithin.
Term
Is botulinum toxin a simple or compound A-B toxin?
Definition
Simple.
Term
Is cholera toxin a simple or compound A-B toxin?
Definition
Compound.
Term
What does the B subunit of cholera toxin do?
Definition
Binds to GM1.
Term
What does the A subunit of cholera toxin do?
Definition
ADP-ribosylates Gs.
Term
What bacterium produces diphtheria toxin?
Definition
Corynebacterium diphtheriae.
Term
What is the mechanism of action of diphtheria toxin?
Definition
It ADP-ribosylates EF2 and shuts down protein synthesis.
Term
How is the diphtheria toxin carried?
Definition
On a phage.
Term
Is Clostridium botulinum Gram-positive or Gram-negative?
Definition
Gram-positive.
Term
Is Clostridium botulinum aerobic or anaerobic?
Definition
anaerobic.
Term
Does Clostridium botulinum form spores?
Definition
Yes.
Term
What is the source of Clostridium botulinum?
Definition
Environmental: soil and water.
Term
List the three forms of botulism and state whether each is a toxinosis or an infection.
Definition
Foodborne - toxinosis.
Infant (consumption of spores) - infection.
Wound - infection.
Term
What type of paralysis is observed in botulism?
Definition
Flaccid.
Term
What is the treatment for botulism?
Definition
Passive immunotherapy using antiserum.
Mechanical ventilator.
Term
Is Clostridium tetani Gram-positive or Gram-negative?
Definition
Gram-positive.
Term
Is clostridium tetani aerobic or anaerobic?
Definition
Anaerobic.
Term
How does Clostridium tetani usually enter the body?
Definition
It can colonize deep wounds.
Term
What is the mechanism of action of tetanus toxin?
Definition
It migrates to the neuron cell body in the CNS and blocks the release of inhibitory neurotransmitters.
Term
What type of paralysis results from tetanus toxin?
Definition
Spastic.
Term
What is the mechanism of action of shiga toxin?
Definition
It cleaves host ribosomal RNA, blocking protein synthesis.
Term
What is the difference between a normal antigen and a superantigen?
Definition
Normal antigens are taken up and processed by APCs and displayed to T cells in the binding groove of a class II MHC. Superantigens are not processed and bind directly to the class II MHC outside the normal groove nondiscriminately, leading to activation of many T cells.
Term
Give two examples of superantigens.
Definition
Staphylococcus aureus and Streptococcus pyogenes make toxins that cause toxic shock syndrome.
Term
What is the effect of toxic shock syndrome on the sensitivity to LPS?
Definition
Increased 50000 times.
Term
What is the toxic portion of LPS?
Definition
Lipid A.
Term
What is the variable portion of LPS?
Definition
O polysaccharide.
Term
How does the potency of endotoxin compare with the potency of exotoxins?
Definition
Endotoxin is weaker than exotoxins, but large numbers of endotoxins are often involved.
Term
List the three important cytokines that cause an inflammatory response to endotoxin.
Definition
IL-1, IL-6, TNF-alpha.
Term
List three effects of endotoxin on the endothelial cells lining blood vessels.
Definition
Coagulation, vasodilation, hypotension.
Term
List 4 criteria for SIRS.
Definition
Hyper- or hypothermia.
Tachypnea.
High or low WBC count.
Tachycardia.
Term
List the criteria for sepsis.
Definition
2 SIRS criteria + infection.
Term
List the criteria for severe sepsis.
Definition
Sepsis + organ failure.
Term
List the criteria for septic shock.
Definition
Severe sepsis + hypotension.
Term
List the criteria for toxic shock.
Definition
Septic shock caused by Group A Streptococcus or Staphylococcus aureus.
Term
What are the three main functions of the complement system?
Definition
Enhance immune cell function.
Induce inflammation.
Induce lysis of bacterial cells.
Term
Define complement fixation.
Definition
Attachment of C3b to a bacterium.
Term
List the three pathways that activate C3.
Definition
Alternative, lectin, classical.
Term
Which pathway of C3 activation is first to act?
Definition
Alternative.
Term
Which pathway of C3 activation is second to act?
Definition
Lectin.
Term
Which pathway of C3 activation is third to act?
Definition
Classical.
Term
In which pathway of C3 activation does the pathogen surface create a local environment conducive to complement activation?
Definition
Alternative.
Term
In which pathway of complement activation does mannose-binding lectin bind to the pathogen surface?
Definition
Lectin.
Term
In which pathway of complement activation does a C-reactive protein or antibody bind to a specific antigen on the pathogen surface?
Definition
Classical.
Term
What does properdin do?
Definition
Properdin stabilizes C3bBb on the pathogen surfaces.
Term
What does Factor H do?
Definition
Factor H counters properdin by making C3b susceptible to cleavage by Factor I.
Term
What does Factor I do?
Definition
It cleaves C3b into iC3b and inhibits C3 convertase.
Term
What do DAF and MCP do?
Definition
They destabilize C3bBb on host cell surfaces.
Term
What is the function of CR1 on macrophages?
Definition
It binds to C3b on bacteria.
Term
What are the components of the alternative C5 convertase?
Definition
C3bBb + Bb.
Term
What is the function of C5b?
Definition
It initiates formation of the membrane attack complex.
Term
What bacteria does the MAC primarily work on?
Definition
Neisseria species.
Term
What does CD59 do?
Definition
It binds to C5b678 and blocks the binding of C9 to the forming MAC.
Term
What is the cause of nocturnal paroxysmal hemoglobinurea?
Definition
The GPI anchor that attaches DAF and CD59 is missing, which causes inappropriate formation of the MAC on erythrocytes and spontaneous complement-mediated hemolysis.
Term
What do C3a and C5a do?
Definition
They are anaphylatoxins that bind to cell receptors and induce degranulation of mast cells and basophils.
Term
What do serpins and alpha-macroglobulins do?
Definition
They block the action of microbial proteases.
Term
What are defensins?
Definition
35-40 amino acid peptides with antimicrobial activity.
Term
What cells make alpha-defensins?
Definition
Panneth cells (intestinal crypt cells) and neutrophils.
Term
What cells make beta-defensins?
Definition
Epithelial cells.
Term
List the three types of macrophage receptors that recognize pathogens.
Definition
Complement receptors, pattern recognition receptors, and toll-like receptors.
Term
What is the result of TLR signaling (especially TLR4)?
Definition
Production of inflammatory cytokines.
Term
What is the location of TLR4 and TLR1:TLR2?
Definition
Outer cell membrane.
Term
What is the location of TLR3, and what does it recognize?
Definition
TLR3 is on intracellular membranes and recognizes pathogenic nucleic acids (ds RNA).
Term
What protein does LPS bind to on macrophages?
Definition
CD14.
Term
What three parts form the complex that recognizes LPS on macrophages?
Definition
TLR4, CD14, and MD2.
Term
What adaptor protein bridges the signaling components in TLR4 signaling?
Definition
MyD88.
Term
What is the function of IRAK4?
Definition
It is a kinase that phosphorylates TRAF6 in the TLR4 signaling cascade.
Term
What is the function if IKK?
Definition
IKK phosphorylates IKB, leading to the formation of NFKB.
Term
What is NFKB?
Definition
A transcription factor that induces expression of multiple pro-inflammatory cytokines.
Term
What adaptor proteins are involved in the TLR4 signaling in response to viruses?
Definition
TRIF and TRAM.
Term
What transcription factor is involved in the TLR4 signaling in response to viruses?
Definition
IRF3.
Term
What is secreted as a result of TLR4 signaling in response to viruses?
Definition
Type 1 interferons: IFN-alpha and IFN-beta.
Term
List two functions of IL-6.
Definition
Fever and induction of acute phase protein production by hepatocytes.
Term
List 5 functions of TNF-alpha.
Definition
Activate vascular endothelium.
Increase vascular permeability.
Fever.
Mobilization of metabolites.
Shock.
Term
List 5 effects of IL-1-beta.
Definition
Activates vascular endothelium.
Activates lymphocytes.
Local tissue destruction.
Fever.
Production of IL-6.
Term
What is the function of CXCL8?
Definition
Chemotactic factor that recruits neutrophils and basophils to the site of infection.
Term
What is the function of IL-12?
Definition
Activates NK cells.
Term
What are selectins?
Definition
Carbohydrate-binding molecules on leukocytes that are used to attach to other cells.
Term
What are addressins?
Definition
Cell-specific oligosaccharides.
Term
What is CD34?
Definition
A vascular addressin.
Term
What are integrins?
Definition
Alpha, beta heterodimers that bind to immunoglobulin-like molecules and play a role in leukocyte circulation.
Term
What is LFA-1?
Definition
An integrin.
Term
What is ICAM-1?
Definition
An adhesion molecules that is recognized by LFA-1.
Term
What molecule on the endothelial surface binds tightly with LFA-1 on neutrophils?
Definition
ICAM-1.
Term
What cytokine increases expression of ICAM-1?
Definition
TNF-alpha.
Term
What do neutrophils use to kill?
Definition
Granules.
Term
What granules contain lysozyme, defensins, myeloperoxidase, and proteases?
Definition
Azurophilic (primary).
Term
What granules contain lactoferrin (which competes for iron) and NADPH oxidase, which is essential for neutrophil function and respiratory burst?
Definition
Specific (secondary).
Term
What is the effect of the respiratory burst on pH?
Definition
Increase.
Term
What is the cause of chronic granulomatous disease?
Definition
Lack of NADPH oxidase causes infections to be contained in localized nodules or granules.
Term
What is the main function of acute-phase proteins?
Definition
Activation of complement and opsonization.
Term
List the three benefits of fever.
Definition
Decreased rate of pathogen replication.
Human cells become resistant to TNF-alpha.
Antigen processing and presentation is increased.
Term
List the three proteins of the acute phase response.
Definition
C-reactive protein, fibrinogen, and mannose-binding protein.
Term
What does C-reactive protein bind to on bacteria and fungi?
Definition
LPS.
Term
What complement protein binds to CRP?
Definition
C1.
Term
What does C1 do?
Definition
It is the first component in activation of the classical pathway by C-reactive protein or immunoglobulin.
Term
What are the 3 cellular responses to type I interferons?
Definition
Increased resistance to viral replication in all cells.
Increased expression of ligands for receptors on NK cells.
Activate NK cells to kill virus-infected cells.
Term
What do NK cells produce to activate adaptive (T cell) immunity?
Definition
IFN-gamma.
Term
Do NK cell receptors deliver positive or negative signals?
Definition
Both.
Term
What is KIR?
Definition
An inhibitory receptor on NK cells.
Term
What is NKG2D?
Definition
An activating receptor on NK cells.
Term
Ligands for what NK cell receptor are produced in response to viral infection?
Definition
NKG2D.
Term
What cytokines are involved in activation of blood vessel endothelium?
Definition
IL-1 and TNF-alpha.
Term
What cytokines are involved in fever?
Definition
IL1, IL6, TNF-alpha.
Term
What cytokine is involved in induction of IL6 synthesis?
Definition
IL1.
Term
What cytokine is responsible for increased vascular permeability?
Definition
TNF.
Term
What cytokine causes localized tissue destruction?
Definition
IL1.
Term
What cytokine causes acute-phase protein production by hepatocytes?
Definition
IL6.
Term
What cytokine induces resistance to viral replication?
Definition
Type I interferons.
Term
What cytokines activate NK cells?
Definition
IL12, type I interferons.
Term
What cytokine is involved in leukocyte chemotaxis?
Definition
IL8.
Term
What cytokine is involved in activation of binding by beta-2 integrins (LFA-1, CR3)?
Definition
IL8.
Term
What cytokine is involved in septic shock?
Definition
TNF-alpha.
Term
What cytokine is involved in mobilization of metabolites?
Definition
TNF-alpha.
Term
Which body site harbors the greatest number of bacteria?
Definition
Large intestine.
Term
What is a biofilm?
Definition
A structured, multi-layered community of adherent bacteria
Term
Why are biofilms important?
Definition
Safety in numbers.
Term
Where are single species biofilms found?
Definition
Normally sterile sites (heart valves, bone, implanted devices).
Term
Where are multi-species biofilms found?
Definition
Exposed sites (teeth, skin).
Term
List three beneficial functions of normal flora.
Definition
Nutrition.
Protection from bad microbes.
Immune stimulation.
Term
What immunoglobulin is produced in Peyer's patches in response to the gut flora?
Definition
sIgA.
Term
What results from the immune response to commensals?
Definition
Release of cytokines that bolster the mucus layer and protect from pathogens and food antigens.
Term
What are two ways that commensal organisms protect against bad microbes?
Definition
Exclusion and production of bactericidal compounds.
Term
What causes bacterial vaginosis?
Definition
Dysbiosis: Normal healthy lactobacilli replaced by harmful anaerobic bacteria.
Term
What are the symptoms of bacterial vaginosis?
Definition
Thin, watery discharge.
Fishy odor.
Itching.
Term
What does bacterial vaginosis increase the risk for?
Definition
STDs and pre-term labor.
Term
What are the Amsel criteria for diagnosis of bacterial vaginosis?
Definition
Thin, grayish-white discharge.
Increased vaginal pH.
Positive whiff test.
Clue cells.
Term
What is a harmful effect of normal flora?
Definition
Opportunistic infection.
Term
How can S. aureus cause opportunistic folliculitis?
Definition
Penetrate razor-burned skin.
Term
What is the leading cause of device-related infections?
Definition
Staphylococcus epidermidis.
Term
Why are patients susceptible to Streptococcus pneumoniae after transplantation surgery?
Definition
Immunosuppressive drugs.
Term
What is a likely cause of antibiotic-associated pseudomembraneous colitis?
Definition
Clostridium difficile.
Term
What antibiotic is particularly likely to cause C. diff infection?
Definition
Clindamycin.
Term
List Koch's postulates.
Definition
1. The microorganism must always be found in similarly diseased animals but not in healthy ones.
2. Microorganisms must be isolated from diseased animals and grown in pure culture.
3. The isolated organism must cause the original disease when inoculated into a susceptible animal.
4. The microorganism can be reisolated from the experimentally infected animal.
Term
What are two roles of adherence of pathogens?
Definition
Avoid physical removal by host defenses and aid in nutrient uptake.
Term
State the requirement of bacteria for carbon dioxide.
Definition
All bacteria require carbon dioxide in a catalytic amount.
Term
What are capnophiles?
Definition
Bacteria that require carbon dioxide in a greater concentration than found in air.
Term
Give an example of a capnophile.
Definition
Campylobacter.
Term
Give two examples of enriched media.
Definition
Blood agar and chocolate agar.
Term
Give two examples of selective media.
Definition
Salmonella-Shigella agar, Mod. Thayer-Martin.
Term
Give three examples of differential media.
Definition
EMB, blood agar, MacConkey.
Term
Give an example of a medium that is both selective and differential.
Definition
MacConkey agar.
Term
What does MacConkey agar select for?
Definition
Gram-negative enteric bacteria.
Term
What do pink colonies on MacConkey agar mean?
Definition
The bacteria are Lac+.
Term
What is beta hemolysis?
Definition
Complete lysis.
Term
What is alpha hemolysis?
Definition
Partial lysis, green (oxidation of Hg).
Term
What is gamma hemolysis?
Definition
No lysis.
Term
Which stain is used to detect Mycobacteria in clinical specimens?
Definition
Acid fast stain.
Term
Give an example of a medium that is only an enriched medium.
Definition
Chocolate agar.
Term
What biochemical test detects the presence of a clotting enzyme?
Definition
Coagulase.
Term
What does the Quellung reaction detect?
Definition
Capsule.
Term
What is an advantage of using nucleic acid based tests?
Definition
No need to culture.
Term
What is the definition of a bacteriostatic drug?
Definition
Addition of the drug results in growth arrest.
Term
Where are the antigen-binding sites on a TCR or antibody?
Definition
Hypervariable regions (CDRs).
Term
How many CDRs are there?
Definition
3.
Term
What is an epitope?
Definition
The antigenic region or the part of the molecule that is recognized by TCR or Ig.
Term
How many gene segments are in the variable region of the light chain?
Definition
Two (V and J).
Term
How many gene segments are in the variable region of the heavy chain?
Definition
Three (V, D, and J).
Term
List four mechanisms of antigen-independent development of diversity.
Definition
1. The presence of multiple V genes.
2. V-D-J and V-J recombinations.
3. Combinations of chains.
4. Junctional diversity.
Term
What is the B cell antigen recognition receptor?
Definition
Membrane Ig.
Term
What is the effector protein for adaptive humoral immune responses?
Definition
Secreted Ig.
Term
What other membrane proteins are associated with membrane Ig?
Definition
Ig-alpha and Ig-beta.
Term
What is somatic hypermutation?
Definition
In response to antigen, somatic hypermutation targets the rearranged gene segments encoding the variable region. Mutations are introduced to the V region at a high rate.
Term
What is the result of somatic hypermutation?
Definition
Increased affinity for antigen or affinity maturation.
Term
What determines the function of Ig?
Definition
Heavy chain regions (Fc).
Term
What stimulates isotype switching?
Definition
Antigen.
Term
What occurs at the genetic level during isotype switching?
Definition
VDJ associates with a secondary CH.
Term
Does co-expression of IgM and IgD require antigen or DNA rearrangement?
Definition
No.
Term
List the other proteins required for TCR expression.
Definition
CD3 (gamma, delta, and epsilon) and zeta.
Term
What type of receptor is expressed by most T cells?
Definition
Alpha, beta.
Term
Define antigen processing.
Definition
The intracellular generation of peptides from protein.
Term
Define antigen presentation.
Definition
Association of peptides with MHC on the cell membrane.
Term
What does TCR recognize?
Definition
Both peptide and MHC.
Term
Does TCR recognize peptide presented by non-self MHC?
Definition
No.
Term
What determines MHC class binding?
Definition
CD4 and CD8.
Term
Where are pathogens that live inside the cell located?
Definition
In the cytosol.
Term
Where are pathogens that are taken up by the cell located?
Definition
Vesicular system.
Term
Where does processing of antigen for class II occur?
Definition
Phagolysosome.
Term
Where does processing of antigen for class I occur?
Definition
Proteasome.
Term
What is the function of TAP?
Definition
It carries peptides into the ER to associate with MHC class I.
Term
What is the function of calnexin?
Definition
Chaperone that stabilizes MHC class I.
Term
What is required for MHC class I to be expressed in the membrane?
Definition
A peptide must be in the groove.
Term
What type of peptide is contained by most MHC class I molecules?
Definition
Self peptide.
Term
What is the function of invariant chain (li)?
Definition
It associates with MHC class II in the ER and sits in the binding groove.
Term
What happens to li in the vesicle?
Definition
It is cleaved, but the CLIP fragment remains in the groove.
Term
What is the function of HLA-DM?
Definition
It causes the release of CLIP from the peptide binding groove in MHC class II.
Term
What cells express MHC class I?
Definition
All cells except erythrocytes (any cells that might need to be killed).
Term
What cells express MHC class II?
Definition
Cells that can activate CD4s (T cells, B cells, macrophages, dendritic cells, and thymic epithelium).
Term
What is the name of the gene cluster in which MHC class I, II, and III is found?
Definition
HLA (human leukocyte antigen).
Term
How many classical class I genes are there?
Definition
3 (A, B, and C).
Term
How are class II genes organized?
Definition
In clusters: DP, DQ, DR.
Term
What does it mean to say that MHC genes are polymorphic?
Definition
There are multiple forms (alleles) of each class I chain and each class II gene in the population.
Term
Define haplotype.
Definition
The combination of alleles on an individual's chromosome.
Term
How many class I proteins does each person express?
Definition
6 (A, B, and C from each parent).
Term
How many class II proteins does each person express?
Definition
8 or more.
Term
What residues of peptides contact MHC?
Definition
Anchor residues.
Term
What peptide residues determine the set of peptides with which each MHC interacts?
Definition
Anchor residues.
Term
What is alloreactivity?
Definition
Response against MHC proteins from a different allele.
Term
What process accounts for mothers making antibodies against the fetus?
Definition
Alloreactivity.
Term
Where are the genes for MICA and MICB?
Definition
In the MHC complex.
Term
Where are MICA and MICB expressed?
Definition
Fibroblasts and intestinal epithelium.
Term
What does it mean to say that MHC molecules have promiscuous binding affinity?
Definition
A particular MHC molecule has the potential to bind to different peptides.
Term
Give two examples of groups of bacteria that are often naturally transformable.
Definition
Many streptococci and Neisseria species.
Term
Explain the example discussed in class about how S. pneumoniae can acquire resistance to penicillin.
Definition
Transformation of a chromosomal pbp gene from oral streptococci.
Term
Do Corynebacteria require special media for cultivation?
Definition
Yes.
Term
What is the morphology of Corynebacteria?
Definition
Bacilli.
Term
How do Corynebacteria Gram-stain?
Definition
Gram-positive.
Term
What bacteria have an unusual Chinese letter morphology?
Definition
Corynebacteria.
Term
What bacteria are visualized with metachromatic granules stain?
Definition
Corynebacteria.
Term
What bacteria cause an adherent membrane in the throat?
Definition
Corynebacterium diphtheriae.
Term
What bacteria can cause a bull neck due to swelling of lymph nodes?
Definition
Corynebacterium diphtheriae.
Term
What substance is responsible for most symptoms of diphtheria?
Definition
Diphtheria toxin.
Term
What carries the gene encoding diphtheria toxin?
Definition
Corynephage beta.
Term
Are C. diphtheriae strains lacking the toxin virulent?
Definition
No.
Term
What is the treatment for diphtheria?
Definition
Antibiotics and antitoxin.
Term
Are C. diphtheriae normal flora that can cause opportunistic infections like infective endocarditis?
Definition
Yes.
Term
How does B. anthracis gram-stain?
Definition
Gram-positive.
Term
What is the morphology of B. anthracis?
Definition
Bacillus.
Term
What bacterium is characterized by large size, central spores, and a rectangular morphology?
Definition
Bacillus anthracis.
Term
How is anthrax transmitted?
Definition
From contact with infected animals or animal products (mainly herbivores) or bioterrorism (not human-to-human transmission).
Term
List the three forms of anthrax.
Definition
Cutaneous, inhalation, and gastrointestinal.
Term
How does cutaneous anthrax occur?
Definition
Spores enter a wound.
Term
What disease is characterized by an initial papule that develops into a painless black necrotic eschar?
Definition
Cutaneous anthrax.
Term
What bacteria can cause mediastinal widening?
Definition
B. anthracis.
Term
How does widespread dissemination of B. anthracis occur?
Definition
Bacilli multiply within lymph nodes prior to widespread dissemination.
Term
What bacterium has a poly-D-glutamyl capsule?
Definition
B. anthracis.
Term
What is the colony morphology of B. anthracis?
Definition
Mucoid.
Term
How does the poly-D-glutamyl capsule function as a virulence factor for B. anthracis?
Definition
Resistance to phagocytosis.
Term
Describe the structure and function of the anthrax toxin.
Definition
Protective antigen is the binding subunit.
Edema factor has adenylate cyclase activity.
Lethal factor is a protease that kills cells.
Term
How does endospore formation function as a virulence factor for B. anthracis?
Definition
Provides environmental persistence and facilitates transmission.
Term
Is B. anthracis aerobic or anaerobic?
Definition
Aerobic.
Term
What is the major problem that develops in inhalation anthrax?
Definition
Hemorrhagic necrosis.
Term
How is anthrax treated?
Definition
Antibiotics.
Term
How does Bacillus cereus Gram-stain?
Definition
Gram-positive.
Term
What is the cellular morphology of B. cereus?
Definition
Rods.
Term
Where is Bacillus cereus normally found?
Definition
Soil, rice, beans.
Term
List two diseases caused by B. cereus.
Definition
Food-borne intoxication and endophthalmitis.
Term
Is Bacillus cereus food poisoning an intoxication or infection?
Definition
Intoxication.
Term
How is B. cereus food poisoning treated?
Definition
No treatment required (self-limiting).
Term
How do Listeria monocytogenes Gram-stain?
Definition
Gram-positive.
Term
What is the cellular morphology of Listeria monocytogenes?
Definition
Rods.
Term
Is Listeria monocytogenes catalase positive or catalase negative?
Definition
Positive.
Term
What type of motility does Listeria monocytogenes have?
Definition
Tumbling.
Term
Is Listeria monocytogenes spore-forming?
Definition
No.
Term
What are the symptoms of mild listeriosis?
Definition
Gastrointestinal or influenza-like.
Term
How does listeriosis manifest itself in the immunocompromised?
Definition
Miningitis and minigoencephalitis.
Term
What is the consequence of listeriosis in pregnant women?
Definition
It can lead to spontaneous abortions or generalized neonatal infections.
Term
What disease is associated with Mexican-style cheese?
Definition
Listeriosis.
Term
What disease is associated with hot dogs, luncheon meats, and deli meats?
Definition
Listeriosis.
Term
What is the treatment for listeriosis?
Definition
Antibiotics.
Term
How does Listeria monocytogenes move around in cells?
Definition
It hijacks the host actin cytoskeleton.
Term
What protein allows Listeria monocytogenes to form an actin cloud?
Definition
ActA.
Term
What environment is conducive to Listeria monocytogenes growth?
Definition
High salt, low temperature.
Term
What is the best way to prevent diphtheria?
Definition
Vaccination with a toxoid.
Term
How do Staphylococci Gram-stain?
Definition
Gram-positive.
Term
What is the cellular morphology of Stapylococci?
Definition
Cocci in clusters.
Term
Are Staphylococci catalase-positive or catalase-negative?
Definition
Positive.
Term
Are Streptococci catalase-positive or catalase-negative?
Definition
Negative.
Term
Is S. aureus coagulase-positive or coagulase-negative?
Definition
Positive.
Term
Is S. epidermidis coagulase-positive or coagulase-negative?
Definition
Negative.
Term
What does it mean to say that Staphylococci are pyogenic or suppurative?
Definition
They attract neutrophils, leading to pus formation.
Term
What are the most important defenses against Staph?
Definition
Neutrophils and opsonophagocytosis.
Term
What causes Chediak-Higashi syndrome?
Definition
Secretory granule dysfunction.
Term
What causes Job-Buckley syndrome?
Definition
Hyper-IgE.
Term
What bacteria have protein A as a virulence factor?
Definition
Staph.
Term
What does protein A do?
Definition
It is a virulence factor in Staph that binds to Fc and inhibits opsonophagocytosis.
Term
What is the function of alpha-toxin in Staph?
Definition
Lyses erythrocytes.
Term
What is the function of gamma toxin in Staph?
Definition
Lyses red and white blood cells.
Term
What is Panton Valentine Leukocidin associated with?
Definition
MRSA.
Term
What are TSST-1, Staphylococcal enterotoxins, and exfoliatin?
Definition
They are superantigen toxins of Staph.
Term
What is the likely cause of toxic shock, high fever, red rash, and sloughing off of skin on the extremities?
Definition
Colonization by a TSST-producing strain of Staph.
Term
What bacteria are associated with food poisoning as a result of eating contaminated salty foods, like ham?
Definition
Staph.
Term
What causes Staphylococcal enteritis?
Definition
Staphylococcal enterotoxins.
Term
What toxin and bacteria causes scalded skin syndrome (sunburn-like rash)?
Definition
Exfoliatin secreted by Staph.
Term
What is the most common cause of localized skin and soft tissue infections?
Definition
S. aureus.
Term
Are aggressively spreading skin infections like cellulitis and necrotizing fasciitis more commonly associated with S. aureus or Group A Strep?
Definition
Group A Strep.
Term
What is impetigo associated with?
Definition
Staph.
Term
What is a common cause of CF-related pneumonia?
Definition
S. aureus.
Term
What is the most common cause of acute endocarditis?
Definition
Staphylococci.
Term
What is the most common cause of bacteremia and pneumonia in IV drug users?
Definition
Staph.
Term
What is the most common cause of food poisoning?
Definition
Staph.
Term
What is the most common cause of osteomyelitis?
Definition
Staph.
Term
What is the most common cause of pyomyositis?
Definition
Staph.
Term
What is the most common cause of mastitis?
Definition
Staph.
Term
What is the most common cause of abscesses?
Definition
Staph.
Term
What is the most common cause of prosthetic joint infections?
Definition
Staph.
Term
What is the most common cause of catheter-associated infections?
Definition
S. epidermidis.
Term
What is the most common contaminant of blood cultures?
Definition
S. epidermidis.
Term
What is the main virulence factor of S. epidermidis?
Definition
Polysaccharide intercellular adhesin (slime).
Term
How is S. saprophyticus distinguished from other coagulase negative Staph?
Definition
Novobiocin resistance.
Term
What is the most common cause of UTIs in sexually active women?
Definition
E. coli (S. saprophyticus is also common).
Term
How do Streptococi Gram-stain?
Definition
Gram-positive.
Term
What is the cellular morphology of Strep?
Definition
Cocci in chains.
Term
What type of hemolysis does Strep pyogenes do?
Definition
Beta.
Term
What type of hemolysis does Strep agalactiae do?
Definition
Beta.
Term
Is S. pyogenes Group A or Group B?
Definition
Group A.
Term
Is S. agalactiae Group A or B?
Definition
B.
Term
What type of hemolysis does S. pneumoniae do?
Definition
Alpha.
Term
What type of hemolysis does Strep viridans do?
Definition
Alpha.
Term
What type of hemolysis does Enterococcus do?
Definition
Gamma.
Term
What group is Enterococcus in?
Definition
Group D.
Term
Is the spread of Staph generally through symptomatic or asymptomatic individuals?
Definition
Asymptomatic.
Term
Is the spread of S. pyogenes mainly via symptomatic or asymptomatic individuals?
Definition
Symptomatic.
Term
What is the main reservoir of S. pyogenes?
Definition
Humans.
Term
What antibiotic is S. pyogenes sensitive to?
Definition
Bacitracin.
Term
List 5 virulence factors of S. pyogenes.
Definition
M protein
Hyaluronic capsule
Hemolysins
Streptococcal pyrogenic exotoxins
Enzymes
Term
What is the most important virulence factor of S. pyogenes?
Definition
Protein M.
Term
What is the function of M protein in S. pyogenes?
Definition
It is anti-phagocytic and binds fibrin.
Term
What virulence factor of S. pyogenes is likely involved with rheumatic fever?
Definition
M protein.
Term
What bacterium is associated with scarlet fever in children and toxic shock syndrome in adults?
Definition
S. pyogenes, via pyrogenic exotoxins.
Term
Which is better able to spread through tissues, Group A Streptococci or S. aureus?
Definition
Group A Strep.
Term
What is cellulitis most likely associated with?
Definition
Streptococcal infection.
Term
What is the most common cause of bacterial pharyngitis?
Definition
Group A Strep.
Term
What bacteria is most likely to cause a sandpaper-like rash?
Definition
S. pyogenes (GAS)
Term
What causes peurperal fever (postpartum endometritis)?
Definition
Strep.
Term
What bacteria cause acute post-streptococcal glomerulonephritis?
Definition
GAS.
Term
What is the most common cause of life-threatening infections in neonates?
Definition
S. agalactiae (Group B Strep).
Term
What is the major virulence factor of S. agalactiae (Group B strep)?
Definition
Antiphagocytic capsule.
Term
What is the cellular morphology of S. pneumoniae?
Definition
Diplococci.
Term
What is the most common cause of community-acquired pneumonia?
Definition
S. pneumoniae.
Term
What is the most common cause of bacterial meningitis at any age except neonates?
Definition
S. pneumoniae.
Term
What is the most common cause of otitis media?
Definition
S. pneumoniae.
Term
What is the major virulence factor of S. pneumoniae?
Definition
Antiphagocytic polysaccharide capsule.
Term
What type of bacteria commonly colonize teeth and lead to caries?
Definition
Viridans Strep.
Term
Do anaerobes have catalase?
Definition
No.
Term
Do anaerobes have superoxide dismutase?
Definition
No.
Term
Are Clostridium tetani Gram-negative or Gram-positive?
Definition
Gram-positive.
Term
What is the cellular morphology of Clostridium tetani?
Definition
Tennis racket.
Term
What bacteria cause myonecrosis or gas gangrene and food-borne infection?
Definition
Clostridium perfringens.
Term
Are Clostridium species aerobic or anaerobic?
Definition
Anaerobic.
Term
Is the growth of Clostridium perfringens rapid or slow?
Definition
Rapid.
Term
What is the mechanism of action of binary clostridial enterotoxin?
Definition
ADP-ribosylates actin.
Term
What bacteria have a double zone of hemolysis?
Definition
Clostridium perfringens.
Term
What bacteria cause myonecrosis (gas gangrene)?
Definition
Clostridium perfringens.
Term
What is the Gram-stain of Clostridia?
Definition
Gram-positive.
Term
What is the cellular morphology of Clostridia?
Definition
Rods.
Term
Which Clostridium botulinum subgroup is the most common cause of disease in the United States?
Definition
A.
Term
What bacteria cause "failure to thrive" and "floppy baby syndrome."
Definition
Clostridium botulinum.
Term
What bacteria have a terminal spore with distension?
Definition
Clostridium tetani.
Term
What bacteria cause spastic paralysis?
Definition
Clostridium tetani.
Term
What is the predominant genus found in the colon?
Definition
Bacteroides.
Term
What is the most common Bacteroides species in infections?
Definition
Bacteroides fragilis.
Term
How is Bacteroides fragilis infection disseminated?
Definition
Bacteremia and abscess following surgery or trauma to the gut.
Term
Is Bacteroides fragilis Gram-positive or Gram-negative?
Definition
Gram-negative.
Term
What bacteria are associated with a polysaccharide capsule that can initiate abscesses?
Definition
Bacteroides fragilis.
Term
What bacteria are associated with intra-abdominal abscesses?
Definition
Bacteroides fragilis.
Term
What bacteria are associated with gynecological infections and abscesses?
Definition
Bacteroides fragilis.
Term
What is the most common anaerobe isolated from the blood in bacteremia?
Definition
Bacteroides fragilis.
Term
Is Bacteroides fragilis aerobic or anaerobic?
Definition
Anaerobic.
Term
What toxin secreted by B. fragilis causes gastroenteritis?
Definition
Fragylisin.
Term
What is the cellular morphology of Bacteroides fragilis?
Definition
Slender Gram-negative rods.
Term
What is CD34?
Definition
A stem cell marker used clinically for stem cell transplantation.
Term
What is IL-7?
Definition
A critical cytokine in lymphocyte development.
Term
At what stage is IL-7Ralpha expressed in B cell development?
Definition
B cell precursor.
Term
What is the first identifiable B cell that has a limited capacity for self-renewal?
Definition
Pro-B cell.
Term
At what stage of B cell development does D-J rearrangement of the heavy chains occur?
Definition
Early pro-B cell.
Term
At what stage of B cell development does V-DJ rearrangement of the heavy chains occur?
Definition
Late pro-B cell.
Term
At what stage of B cell development does V-J rearrangement of the light chains occur?
Definition
Small pre-B cell.
Term
What is the role of CAMs in B cell development?
Definition
Adherence to bone marrow stromal cells.
Term
What is the role of integrins like VLA-4 in B cell development?
Definition
Adherence to VCAM-1 on bone marrow stromal cells.
Term
What is the role of Kit in B cell development?
Definition
Kit is a receptor on the pro-B cell that binds to SCF on the bone marrow stromal cells.
Term
What rearrangement leads to expression of the pre-BCR?
Definition
Heavy chain rearrangement.
Term
What is the light chain on the pre-BCR?
Definition
Surrogate light chain (VpreB).
Term
Is pre-BCR expression required for development?
Definition
Yes.
Term
What stops heavy chain rearrangement and starts light chain rearrangement?
Definition
Heavy chain expression with surrogate light chain.
Term
What is allelic exclusion in B cell development?
Definition
Only one heavy chain is expressed.
Term
What is light chain isotype exclusion?
Definition
Only one light chain (lambda or kappa) can be expressed).
Term
What immunoglobulin does an immature B cell express?
Definition
mIgM.
Term
What is the advantage of allelic and light chain isotype exclusion?
Definition
Monospecificity.
Term
What is the function of RAG-1 and RAG-2?
Definition
Lymphoid-specific recombinase in B cell development.
Term
What is the function of TdT?
Definition
N-nucleotide addition in B cell development.
Term
What is the function of Btk in B cell development?
Definition
Signal transduction.
Term
What protein in B cell development is associated with inherited immune deficiency?
Definition
Btk.
Term
What causes B cell tumors?
Definition
Aberrant rearrangements in which an Ig gene is placed next to a proto-oncogene.
Term
What happens to non-self reacting B cells?
Definition
They express mIgD and exit to the blood.
Term
What happens to B cells that bind multivalent self-antigens?
Definition
They are retained in the bone marrow and get a second chance.
Term
What happens to a B cell if it binds to soluble univalent self-antigen?
Definition
It becomes anergic.
Term
Where do B cells enter a lymph node?
Definition
They arrive at the T cell area in an HEV.
Term
What is the key survival step when a B cell enters secondary lymphoid tissue?
Definition
Entry into a primary follicle.
Term
What is a primary follicle populated by?
Definition
Follicular dendritic cells that both retain antigen and give a non-specific survival signal.
Term
What does CCL21 do?
Definition
It attracts immature B cells to the HEV.
Term
What does CXCL13 do?
Definition
It attracts B cells into the primary follicle.
Term
What interactions drive maturation of immature B cells in a lymph node?
Definition
Interactions with follicular dendritic cells and cytokines.
Term
What happens to B cells that find antigen in the T cell zone?
Definition
They form a primary focus. Some mature to plasma cells.
Term
Where do B cells go from the primary focus?
Definition
To the follicle to form a a germinal center.
Term
Where do isotype switching, affinity maturation, and memory cell development occur in B cell development?
Definition
Germinal center.
Term
What is the normal cell equivalent of ALL?
Definition
Lymphoid progenitor.
Term
What is the normal cell equivalent of pre-B cell leukemia?
Definition
Pre-B cell.
Term
What is the normal cell equivalent of mantle cell lymphoma?
Definition
Resting naive B cell.
Term
What is the normal cell equivalent of chronic lymphocytic leukemia?
Definition
Activated or memory B cell.
Term
What is the normal cell equivalent of follicular center cell lymphoma or Burkitt's lymphoma?
Definition
Mature memory B cell that resembles a germinal center B cell.
Term
What is the normal cell equivalent of Hodgkin's lymphoma?
Definition
Germinal center B cell.
Term
What is the normal cell equivalent of Waldenstrom's macroglobulinemia?
Definition
IgM-secreting B cell.
Term
What is the normal cell equivalent of multiple myeloma?
Definition
Plasma cell (various isotypes).
Term
What type of cells, highlighted in red in the PowerPoint, is present in the cortex of the thymus?
Definition
Epithelial cells.
Term
What part of they thymus contains epithelial cells, dendritic cells, macrophages, and thymocytes?
Definition
Medulla.
Term
What happens to the thymus as it ages?
Definition
It atrophies.
Term
How does the lifespan of T cells compare with that of B cells?
Definition
Mature peripheral T cells are long-lived and self-renewing, while B cells are not. B cells are continually replenished from the bone marrow.
Term
When a cell first commits to the T cell lineage, does it express CD4 or CD8?
Definition
No.
Term
What cytokine drives T cell development?
Definition
IL-7.
Term
What does Notch do?
Definition
Notch is a receptor on thymocytes that keeps a cell on the T cell path and away from the B cell path.
Term
What is expressed as a result of a beta victory in T cell development?
Definition
Pre-T cell receptor.
Term
Is CD4 or CD8 expressed when the pre-TCR is expressed?
Definition
Both.
Term
What happens to beta rearrangement when the pre-TCR is expressed?
Definition
It stops.
Term
What happens to alpha, gamma, and delta rearrangement when the pre-TCR is expressed?
Definition
It starts.
Term
What cells mediate the positive selection for MHC recognition?
Definition
Cortical epithelial cells.
Term
Do most developing T cells recognize MHC?
Definition
No.
Term
What determines expression of CD4 or CD8?
Definition
Recognition of MHC.
Term
What does negative selection eliminate in T cell development?
Definition
Self-peptide-reactive T cells.
Term
What are the major cells that mediate negative selection in the thymus?
Definition
Dendritic cells and macrophages.
Term
What triggers apoptosis during negative selection in T cell development?
Definition
Tight binding of TCR.
Term
What is AIRE?
Definition
AIRE is a transcription factor that promotes expression of tissue-specific antigens in the thymus for negative selection. It is expressed by epithelial cells in the medulla.
Term
What type of antigens do regulatory T cells recognize?
Definition
Self-antigen.
Term
What two molecules characterize regulatory T cells?
Definition
CD25 and the transcription factor FoxP3.
Term
What is the cellular morphology of N. gonorrhoeae?
Definition
Small diplococci.
Term
Are N. gonorrhoeae motile?
Definition
Non-motile.
Term
What is the Gram-stain of N. gonorrhoeae?
Definition
Gram-negative.
Term
Are N. gonorrhoeae oxidase-positive or oxidase-negative?
Definition
Oxidase-positive.
Term
Are N. gonorrhoeae fastidious?
Definition
Yes.
Term
What grows selectively on Thayer-Martin medium and non-selectively on chocolate agar?
Definition
N. gonorrheae.
Term
What organism undergoes high-frequency variation in its pilus?
Definition
N. gonorrheae.
Term
What virulence factor allows N. gonorrheae to attach to the epithelium?
Definition
Pili.
Term
What genus has opacity proteins (Opa) that make colonies appear opaque?
Definition
Neisseria.
Term
What bacteria have PorB in the outer membrane?
Definition
Neisseria.
Term
How are porin, peptidoglycan, and LOS released by Neisseria?
Definition
Blebs (not lysis).
Term
What bacteria have lactoferrin receptor (phase variable), hemoglobin receptor (phase variable), and transferrin receptor (not phase variable)?
Definition
Neisseria.
Term
What bacteria have IgA protease to evade the host immune response?
Definition
Neisseria.
Term
What are 3 consequences of high frequency variation in Neisseria gonorrheae?
Definition
No vaccine.
Infection is not protective.
Recurrent infections common.
Term
What is the most common cause of septic arthritis in young adults?
Definition
N. gonnorhoeae.
Term
What causes severe ophthalmia neonatorum?
Definition
N. gonnorhoeae.
Term
What is the most common bacterial infection in the world?
Definition
N. gonorrhoeae.
Term
What is the cellular morphology of Neisseria miningitidis?
Definition
Gram-negative diplococci.
Term
What medium is used to culture N. meningitidis from sterile sites?
Definition
Chocolate agar.
Term
What virulence factor is present in N. meningitidis but absent in N. gonorrhoeae?
Definition
Capsule.
Term
Is N. meningitidis oxidase-positive or oxidase-negative?
Definition
Oxidase-positive.
Term
What is the most common cause of meningitis in young adults?
Definition
N. meningitidis.
Term
What is the most common cause of meningitis?
Definition
S. pneumoniae.
Term
What is the only cause of epidemic miningitis?
Definition
N. meningitidis.
Term
What causes bilateral destruction of the adrenal glands?
Definition
Meningococcemia.
Term
What causes Waterhouse-Friderichsen syndrome?
Definition
Meningococcemia.
Term
Does N. meningitidis oxidize glucose or maltose?
Definition
Both.
Term
People without what organ are more susceptible to infection with encapsulated organisms?
Definition
Spleen.
Term
What gonococcal virulence factor is not subject to high-frequency antigenic variation?
Definition
Porin proteins.
Term
What best describes the discharge associated with gonococcal infection?
Definition
Purulent.
Term
Who is most at risk for meningococcal disease?
Definition
Infants and young adults.
Term
What is the Gram-stain of E. coli?
Definition
Gram-negative.
Term
What is the cellular morphology of E. coli?
Definition
Rod.
Term
What is the Gram-stain of Salmonella?
Definition
Gram-negative.
Term
What is the morphology of Salmonella?
Definition
Rod.
Term
What is the Gram-stain of Campylobacter?
Definition
Gram-negative.
Term
What is the morphology of Campylobacter?
Definition
Rods.
Term
What is the Gram-stain of Shigella?
Definition
Gram-negative.
Term
What is the morphology of Shigella?
Definition
Rod.
Term
What is the Gram-stain of Vibrio?
Definition
Gram-negative.
Term
What is the morphology of Vibrio?
Definition
Rod.
Term
What is the Gram-stain of Yersinia?
Definition
Negative.
Term
What is the morphology of Yersinia?
Definition
Rod.
Term
What is the Gram-stain of H. pylori?
Definition
Negative.
Term
What is the morphology of H. pylori?
Definition
Rod.
Term
What is the Gram-stain of Klebsiella?
Definition
Negative.
Term
What is the morphology of Klebsiella?
Definition
Rod.
Term
What is the Gram-stain of Serratia?
Definition
Negative.
Term
What is the morphology of Serratia?
Definition
Rod.
Term
What is the Gram-stain of Proteus?
Definition
Negative.
Term
What is the morphology of Proteus?
Definition
Rod.
Term
What type of diarrhea is caused by STEC?
Definition
Bloody, hemorrhagic.
Term
List three bacteria associated with undercooked meat and poultry.
Definition
Salmonella, Campylobacter, STEC.
Term
List 3 bacteria associated with unpasteurized milk, juice, and soft cheeses.
Definition
Salmonella, Campylobacter, and Y. enterocolitica.
Term
State a bacterium associated with raw eggs.
Definition
Salmonella.
Term
State a bacterium associated with raw seafood.
Definition
Vibrio.
Term
List four bacteria that rarely cause infections in the United States but are common in developing countries due to poor sanitation.
Definition
Salmonella Typhi, V. cholera, EPEC, and EIEC.
Term
What causes traveler's diarrhea?
Definition
ETEC.
Term
State a bacterium that rarely causes food-borne illness in the United States but is common in other developed nations.
Definition
Y. enterocolitica.
Term
Does ETEC have a pre-formed toxin or does it make the toxin once ingested?
Definition
It makes a toxin once ingested.
Term
Does Vibrio have a pre-formed toxin, or does it make the toxin once ingested?
Definition
It makes the toxin once ingested.
Term
Does STEC have a pre-formed toxin, or does it make a toxin once ingested?
Definition
It makes the toxin once ingested.
Term
What kind of diarrhea does ETEC cause?
Definition
Watery.
Term
What type of diarrhea does Vibrio cause?
Definition
Watery.
Term
What type of diarrhea does STEC cause?
Definition
Bloody.
Term
What type of diarrhea does Salmonella cause?
Definition
Inflammatory, bloody.
Term
What type of diarrhea does Shigella cause?
Definition
Bloody, inflammatory.
Term
What type of diarrhea does Campylobacter cause?
Definition
Bloody, inflammatory.
Term
What is an S-shaped Gram-negative bacterium that causes food-borne illness?
Definition
Campylobacter.
Term
What is the primary source of E. coli O157:H7 infection?
Definition
Undercooked beef.
Term
What type of diarrhea is caused by E. coli O157:H7?
Definition
Bloody.
Term
Are E. coli Lac+ or Lac-?
Definition
Lac+.
Term
List three types of E. coli that cause watery diarrhea.
Definition
ETEC, EPEC, EAEC.
Term
List two types of E. coli that cause bloody diarrhea.
Definition
EHEC, EIEC.
Term
What type of E. coli colonizes the genitourinary tract?
Definition
UPEC.
Term
What type of E. coli causes neonatal meningitis?
Definition
K12.
Term
What type of E. coli has the Type III secretion system?
Definition
EPEC.
Term
What is the most common E. coli foodborne disease in the U.S.?
Definition
EHEC.
Term
What pathogen is HUS associated with?
Definition
EHEC.
Term
Why is EHEC not treated with antibiotics?
Definition
It potentiates HUS because more SLT is produced.
Term
What is the major source of Campylobacter infections?
Definition
Undercooked chicken.
Term
What type of diarrhea is caused by Campylobacter?
Definition
Bloody or non-bloody.
Term
Can Campylobacter ferment carbohydrates?
Definition
No.
Term
Describe the growth conditions for Campylobacter.
Definition
Microaerophile, capnophile, does not grow on MacConkey or other enteric agars.
Term
Does Campylobacter have catalase?
Definition
Yes.
Term
Does campylobacter have oxidase?
Definition
Yes.
Term
What type of bacteria grows on Preston media under microaerophilic conditions?
Definition
Campylobacter.
Term
Is Shigella exclusively a human pathogen?
Definition
Yes.
Term
Is Salmonella exclusively a human pathogen?
Definition
No.
Term
Is Salmonella capable of fermenting lactose?
Definition
No.
Term
Is Shigella capable of fermenting lactose?
Definition
No.
Term
Which bacteria (Salmonella or Shigella) produces hydrogen sulfide?
Definition
Salmonella.
Term
What is the most common foodborne infection?
Definition
Salmonella.
Term
Which Salmonella serovar is systemic and life-threatening?
Definition
Typhi.
Term
How is Salmonella serovar Typhi transmitted?
Definition
Ingesting human feces.
Term
Which Salmonella serovar requires treatment with antibiotics (the others are self-limiting)?
Definition
Typhi.
Term
What bacteria form black colonies on Hektoen?
Definition
Salmonella.
Term
What bacteria cause rose spots?
Definition
Salmonella.
Term
Which type of Shigella is rare in the U.S.?
Definition
S. dysenteriae.
Term
Which Shigella species makes Shiga toxin?
Definition
S. dysenteriae.
Term
What bacterium causes currant jelly stool?
Definition
Shigella dysenteriae.
Term
What bacteria causes food-borne illness and has a darting motility?
Definition
Campylobacter.
Term
When should antibiotics be used to treat Campylobacteriosis?
Definition
After 1 week.
Term
Which Vibrio species can be massively destructive and lead to sepsis if it invades soft tissue?
Definition
V. vulnificus.
Term
What bacteria have shooting star motility?
Definition
Vibrio.
Term
What bacteria form large, yellow, opaque colonies on TCBS agar?
Definition
Vibrio.
Term
Is Yersinia enterocolitica Lac+ or Lac-?
Definition
Lac-.
Term
What are the oxygen requirements of Yersinia enterocolitica?
Definition
Facultative anaerobe.
Term
What bacterium causes diarrhea and colonizes Peyer's patches to cause a painful syndrome that mimics appendicitis?
Definition
Yersinia enterocolitica.
Term
What GI disease-causing bacteria are associated with undercooked pork and raw milk?
Definition
Yersinia enterocolitica.
Term
What bacteria are associated with gastric ulcers?
Definition
H. pylori.
Term
What H. pylori virulence factor promotes ulcer formation?
Definition
Cytotoxin.
Term
What is diagnosed with urease breath assay, gastric biopsy, or serologic assay?
Definition
H. pylori.
Term
Why is a proton pump inhibitor used in the treatment of H. pylori infection?
Definition
H. pylori requires a proton pump to pump protons out of itself and keep its pH near neutral.
Term
How is Serratia marcescens transmitted?
Definition
It is an opportunistic infection.
Term
What two types of infections does Serratia marcescens cause?
Definition
Lower respiratory and urinary tract infections.
Term
Does Serratia marcescens ferment lactose?
Definition
No.
Term
What bacteria produce a red pigment (prodigiosin)?
Definition
Serratia marcescens.
Term
How is Klebsiella pneumoniae transmitted?
Definition
It is opportunistic.
Term
What bacteria causes necrotizing lobar pneumonia?
Definition
Klebsiella pneumoniae.
Term
What bacteria causes pneumonia, bacteremia, UTIs, and infection of burn wounds?
Definition
K. pneumoniae.
Term
Is Klebsiella pneumoniae Lac+ or Lac-?
Definition
Lac+.
Term
What bacteria have a luxurious capsule?
Definition
Klebsiella pneumoniae.
Term
What does Proteus mirabilis cause?
Definition
UTIs (mainly). In immunocompromised, it can cause pneumonitis and septicemia.
Term
Is Proteus mirabilis Lac+ or Lac-?
Definition
Lac-.
Term
What bacteria has a swarming motility and forms concentric circles on agar?
Definition
Proteus mirabilis.
Term
What virulence factor of Proteus mirabilis raises urine pH and causes struvite kidney stones?
Definition
Urease.
Term
What is the Gram-stain and cellular morphology of H. influenzae?
Definition
Gram-negative rod.
Term
What is the Gram-stain and cellular morphology of B. pertussis?
Definition
Gram-negative rods.
Term
What is the Gram-stain and cellular morphology of Legionella pneumophila?
Definition
Gram-negative rods.
Term
What is the Gram-stain and cellular morphology of Pseudomonas aeruginosa?
Definition
Gram-negative rods.
Term
What agar is used to grow H. influenzae?
Definition
Chocolate.
Term
What respiratory pathogens are pleomorphic coccobacilli?
Definition
H. influenzae.
Term
What is the source of H. influenzae?
Definition
Normal flora of human upper respiratory tract.
Term
What distinguishes pathogenic from non-pathogenic strains of H. influenzae?
Definition
Pathogenic strains usually have a capsule.
Term
How is H. influenzae transmitted?
Definition
Respiratory droplets.
Term
What is the primary disease caused by H. influenzae?
Definition
Community-acquired broncho-pneumonia.
Term
List 3 risk factors for H. influenzae.
Definition
Very young or very old.
Immunocompromised.
American Indian.
Term
What is a serious secondary disease that H. influenzae can cause?
Definition
Meningitis.
Term
What respiratory pathogen can cause cellulitis?
Definition
H. influenzae.
Term
What is the main virulence factor of H. influenzae?
Definition
Capsule.
Term
How is Hib prevented?
Definition
Conjugate vaccine.
Term
What bacterium causes whooping cough?
Definition
Bordetella pertussis.
Term
Does B. pertussis have a capsule?
Definition
Usually.
Term
What secondary diseases can result from B. pertussis?
Definition
Convulsions, apnea, encephalopathy.
Term
What does pertussis toxin do?
Definition
It paralyzes cilia.
Term
What bacteria grow on Bordet-Gengou medium?
Definition
B. pertussis.
Term
Is B. pertussis aerobic or anaerobic?
Definition
Aerobic.
Term
How is B. pertussis treated?
Definition
Antibiotics early to prevent brain damage.
Term
What bacteria cause a mild pertussis-like illness?
Definition
B. parapertussis.
Term
What is the source of Legionella?
Definition
They grow in amebae in water.
Term
How is Legionnaire's disease prevented?
Definition
Decontamination of water systems.
Term
What bacteria cause Pontiac fever in healthy individuals?
Definition
Legionella pneumophila.
Term
Is Legionnaire's disease spread person-to-person?
Definition
No.
Term
What is the pathogenesis of Legionnaire's disease?
Definition
Legionella multiply in lung macrophages.
Term
List 3 ways that Legionnaire's disease is diagnosed.
Definition
Chest X-ray, urine antigen test, and culturing.
Term
Is Pseudomonas aeruginosa Lac+ or Lac-?
Definition
Lac-.
Term
What is the source of P. aeruginosa?
Definition
Ubiquitous in the environment.
Term
How is P. aeruginosa spread?
Definition
It is a nosocomial pathogen and person-to-person spread is rare.
Term
What bacteria are CF patients vulnerable to?
Definition
P aeruginosa.
Term
What bacteria undergo mucoid conversion?
Definition
P. aeruginosa.
Term
What bacteria are associated with chronic lung disease, keratitis, external otitis, and hot tub vasculitis (skin rash)?
Definition
P. aeruginosa.
Term
What bacteria cause ecthyma gangrenosum (black necrotic ulcers) in IV drug users?
Definition
P. aeruginosa.
Term
What bacteria produce toxic blue-green pigments?
Definition
P. aeruginosa.
Term
What virulence factor gives P. aeruginosa high antibiotic resistance?
Definition
Multidrug efflux complex.
Term
What bacteria have quorum sensing mechanisms to control virulence genes?
Definition
P. aeruginosa.
Term
How is Brucella transmitted?
Definition
Transmitted to humans by contact with infected animals.
Term
What are the 2 virulence factors of Brucella?
Definition
Ability to multiply in host phagocytes and LPS.
Term
What is the main symptom of Brucellosis?
Definition
Fever.
Term
What bacteria cause Rabbit Fever/Deerfly Fever/Tularemia?
Definition
Francisella tularensis.
Term
What bacterium is associated with rabbits and arthropod bites?
Definition
Francisella tularensis.
Term
Where is tularemia most common?
Definition
South central United States.
Term
List the three types of tularemia.
Definition
Ulceroglandular, oculoglandular, and pneumonic.
Term
Where does Francisella tularensis multiply in hosts?
Definition
Phagocytes, especially macrophages.
Term
What bacteria cause a small abscess at the site of a cat scratch or bite, followed by fever and lymphadenopathy?
Definition
Bartonella henselae.
Term
What bacteria cause trench fever (fever with maculopapular rash)?
Definition
Bartonella quintana.
Term
What is the reservoir for Bartonella quintana?
Definition
Humans.
Term
How is Bartonella quintana transmitted?
Definition
Body louse.
Term
What bacteria cause cellulitis following a cat scratch?
Definition
Pasteurella multocida.
Term
What are the 2 virulence factors of Pasteurella multocida?
Definition
LPS and capsule.
Term
What type of bacteria has caused 3 major plague pandemics?
Definition
Yersinia pestis.
Term
How does Yersinia pestis get into the lymphatic system?
Definition
Flea bite.
Term
Where does Yersinia pestis multiply?
Definition
Phagocytes.
Term
What bacteria are associated with buboes?
Definition
Yersinia pestis.
Term
What bacteria cause hemorrhagic necrosis of lymph nodes and hemorrhagic lesions throughout the body?
Definition
Yersinia pestis.
Term
List the 4 virulence factors of Yersinia pestis.
Definition
Complex interaction with flea.
Pla protease which prevents blood from clotting.
Yop proteins which are antiphagocytic.
Capsule which is antiphagocytic.
Term
List the two forms of human plague.
Definition
Bubonic and pneumonic.
Term
What bacteria have bipolar staining?
Definition
Yersinia pestis.
Term
What class of drug is penicillin?
Definition
Beta-lactam.
Term
What class of drug is cephalosporin?
Definition
Beta lactam.
Term
What class of drug are carbapenems?
Definition
Beta-lactam.
Term
What class of drug are monobactams?
Definition
Beta-lactam.
Term
What does vancomycin target?
Definition
Cell wall.
Term
What does bacitracin target?
Definition
Cell wall.
Term
What do sulfonamides target?
Definition
Folate synthesis.
Term
What does trimethoprim target?
Definition
Folate synthesis.
Term
What do quinolones target?
Definition
DNA gyrase.
Term
What does rifampin target?
Definition
RNA polymerase.
Term
What do macrolides do?
Definition
Bond to the 50S subunit.
Term
What does clindamycin do?
Definition
Bind to the 50S subunit.
Term
What does linezolid do?
Definition
Bind to the 50S subunit.
Term
What does chloramphenicol do?
Definition
Bind to the 50S subunit.
Term
What do streptogramins do?
Definition
Bind to the 50S subunit.
Term
What do tetracyclines do?
Definition
Bind to the 30S subunit.
Term
What do aminoglycosides do?
Definition
Bind to the 30S subunit.
Term
What do polymyxins target?
Definition
Cell membrane.
Term
What does daptomycin target?
Definition
Inner membrane of Gram-positives.
Term
What is daptomycin rapidly bactericidal for?
Definition
S. aureus (esp MRSA).
Term
How do polymixins work?
Definition
They act like a cationic detergent on the outer membrane of Gram-negatives.
Term
What is the limitation of polymixin use?
Definition
Nephrotoxicity.
Term
Polymixins are used as a drug of last resort for what type of bacteria?
Definition
Multiresistant Gram-negatives.
Term
What is the prototypical macrolide?
Definition
Erythromycin.
Term
What is gentamicin?
Definition
An aminoglycoside.
Term
Are protein synthesis inhibitors bacteriocidal or bacteriostatic?
Definition
Static.
Term
How do aminoglycosides work?
Definition
They cause mis-reading of mRNA.
Term
What results in resistance to macrolides, lincosamides, and streptogramins?
Definition
Dimethylation of adenine at the antibiotic binding site.
Term
What causes drug-drug interactions involving macrolides?
Definition
Blocking of cytochrome P450.
Term
What antibiotics cause QTC prolongation?
Definition
Macrolides.
Term
What is the major side-effect of clindamycin?
Definition
C. difficile-associated colitis.
Term
Are aminoglycosides bactericidal or bacteriostatic?
Definition
Bactericidal.
Term
What causes aminoglycoside resistance?
Definition
Reduced ribosomal binding.
Term
What is the main use for aminoglycosides?
Definition
Gram-negative bacilli.
Term
Do aminoglycosides have anaerobic activity?
Definition
No.
Term
A combination of aminoglycoside with what antibiotic is synergistic for Enterococcus?
Definition
Penicillin.
Term
What are the two main organs that aminoglycosides are toxic towards?
Definition
Kidneys and ears.
Term
How tetracyclines bacteriostatic or bactericidal?
Definition
Static.
Term
What is the mechanism of tetracyclines?
Definition
Blocks the association of aminoacyl-tRNA with the 30S ribosome.
Term
Give two mechanisms of resistance to tetracyclines.
Definition
Efflux and ribosomal protection.
Term
What is the spectrum of tetracycline activity?
Definition
Broad-spectrum.
Term
What are the adverse drug reactions of tetracyclines?
Definition
Phototoxicity, discoloration of teeth, and inhibition of bone maturation.
Term
What do beta-lactamases do?
Definition
They provide resistance to beta-lactams by breaking the ring.
Term
How do beta-lactams get through the outer membrane?
Definition
Porin.
Term
What is the molecule that beta-lactams target?
Definition
PBP.
Term
What are three mechanisms of resistance to beta-lactams?
Definition
Beta-lactamases, alteration of porin channels, and modification of PBP.
Term
Describe the spectrum of penicillin.
Definition
Narrow spectrum.
Term
What are two aminopenicillins?
Definition
Ampicillin and amoxicillin.
Term
Describe the spectrum of aminopenicillins.
Definition
Enhanced Gram-negative activity.
Term
Describe the spectrum of anti-staphylococcal penicillins.
Definition
Enhanced Gram-positive activity.
Term
Describe the spectrum of penicillin-beta-lactamase inhibitor combinations.
Definition
Very broad spectrum.
Term
Describe the spectrum of carbapenems.
Definition
Broadest spectrum beta-lactams.
Term
What does penicillin have coverage against?
Definition
Some Gram-positives and anaerobes.
Term
What do aminopenicillins cover?
Definition
Gram-positives, Gram-negatives, and some anaerobes.
Term
What do cephalosporins cover?
Definition
Gram-positives, Gram-negatives, and some anaerobes.
Term
Why don't penicillin-like antibiotics work against Mycoplasm?
Definition
No cell wall.
Term
What type of beta-lactam hypersensitivity reaction involves IgE, urticaria, and anaphylaxis?
Definition
Type I.
Term
What is vancomycin the workhorse for?
Definition
MRSA.
Term
What is the mechanism of vancomycin?
Definition
It binds to D-ala-D-ala.
Term
What is vancomycin active against?
Definition
Gram-positive.
Term
What is the most important mechanism of vancomycin resistance?
Definition
Changing D-ala-D-ala to something else.
Term
What is vancomycin excreted by?
Definition
Kidney.
Term
What drug causes red man syndrome due to histamine release?
Definition
Vancomycin.
Term
What cells carry antigen into the lymph node during local infection?
Definition
Langerhans (dendritic) cells.
Term
Where is the T-cell zone in the lymph node?
Definition
Medulla.
Term
Which is better at T cell stimulation, macrophages or dendritic cells?
Definition
Dendritic cells.
Term
Which cells are more motile, dendritic cells or macrophages?
Definition
Dendritic cells.
Term
Can dendritic cells present antigen to CD4 or CD8 T cells?
Definition
Both.
Term
How do naive T cells enter the lymph node?
Definition
HEV.
Term
What is responsible for preferential interaction of naive T cells with HEVs via GlyCAM1 and CD34?
Definition
L-selectin.
Term
What receptor do naive T and B cells express that binds CCL21 and CCL19 produced by stromal cells?
Definition
CCR7.
Term
What receptor is expressed on T cells in response to chemokines bound to the extracellular matrix at the lymph node?
Definition
LFA-1.
Term
What does LFA-1 on a T cell form a tight interaction with?
Definition
ICAM-1.
Term
T cell entry into lymph nodes is similar to what kind of cells' entry into tissues?
Definition
Neutrophils.
Term
Is the initial interaction of a T cell with a dendritic cell antigen-specific?
Definition
No.
Term
What is a dendritic cell-specific adhesion molecule?
Definition
DC-SIGN.
Term
What molecule on T cells does DC-SIGN bind to?
Definition
ICAM-3.
Term
What is the purpose of the initial transient interaction of a T cell with a dendritic cell?
Definition
To screen the DC for specific peptide in the MHC.
Term
What happens to T cells that do not encounter their antigen in the lymph node?
Definition
They leave.
Term
What happens to T cells that encounter their specific antigen in the lymph node?
Definition
They proliferate and differentiate into effector cells. They downregulate their S1P receptors and therefore are not pushed away by S1P.
Term
What is the second signal required for activation of naive T cells?
Definition
B7 on APC binds to CD28 on the T cell.
Term
What cells can activate naive T cells?
Definition
Dendritic cells, macrophages, and B cells.
Term
What molecule is expressed by professional APCs?
Definition
B7.
Term
What happens to a T cell stimulated in the absence of co-stimulation?
Definition
It becomes anergic.
Term
What is the function of CTLA4?
Definition
It replaces CD28 in an activated T cell and gives a negative signal.
Term
What are ITAMs?
Definition
Motifs in T cells that have tyrosines that can be phosphorylated, leading to activation.
Term
What is ZAP-70?
Definition
A T cell specific kinase that triggers activation of common signaling pathways.
Term
What is Lck?
Definition
A kinase that phosphorylates ZAP-70.
Term
What is the difference between the IL-2 receptors expressed in naive and activated T cells?
Definition
Activated T cells express a higher-affinity receptor.
Term
What does IL2 do?
Definition
It is secreted by activated T cells and drives T cell activation, proliferation, and differentiation.
Term
What cytokine drives clonal selection of T cells?
Definition
IL2.
Term
What is the oligomeric structure of most cytokine receptors?
Definition
Heterodimeric.
Term
What is the structure of chemokine receptors?
Definition
GPCR.
Term
What is a common signaling pathway for cytokines?
Definition
JAK/STAT.
Term
What do common gamma chain cytokines do?
Definition
Promote lymphocyte survival.
Term
What is the function of IL2?
Definition
T cell growth.
Term
What is the function of IL7?
Definition
Lymphocyte (early) survival.
Term
What are 3 functions of IL4?
Definition
TH2 differentiation, effector function, and isotype switching to IgE.
Term
What secretes IL12?
Definition
Macrophages.
Term
What is the function of IL12?
Definition
Stimulates secretion of IFN-gamma and induces TH1 differentiation.
Term
What are 2 functions of IFN-gamma?
Definition
Activates macrophages and stimulates isotype switching (IgG subtypes).
Term
What are two functions of TNF-alpha?
Definition
T cell activation of macrophages and vascular leakage.
Term
What is the function of FasL?
Definition
It is a cytokine that promotes T cell apoptosis and plays a role in killing by CD8 T cells.
Term
What is the function of CD40L?
Definition
T cell activation of macrophages and B cells.
Term
What are three functions of TGF-beta?
Definition
Inhibits T cell proliferation.
Inhibits inflammation.
Treg mediator.
Term
What is the function of IL6?
Definition
Induces TH17 differentiation.
Term
What are two functions of IL10?
Definition
Suppresses macrophage production of IL12.
Inhibits T cell proliferation.
Term
What cytokines are secreted by TH1 cells?
Definition
IL2 and IFN-gamma.
Term
What is the function of TH1 cells?
Definition
Macrophage activation.
Term
What cytokines are secreted by TH2 cells?
Definition
IL4 and IL5.
Term
What is the function of TH2 cells?
Definition
B cell activation.
Term
What cells do TH17 cells interact with?
Definition
Neutrophils.
Term
What transcription factor is active in Treg cells?
Definition
FoxP3.
Term
What type of leprosy involves TH1 cytokines and is therefore less severe?
Definition
Tuberculoid.
Term
What type of leprosy involves only TH2 cytokines?
Definition
Lepromatous.
Term
What are two ways that CD8 T cells can be activated?
Definition
By CDs alone or with CD4 assistance.
Term
Which cells are more easily activated, effector T cells or naive T cells?
Definition
Effector.
Term
Does activation of effector T cells require B7?
Definition
No.
Term
What happens to expression of L-selectin in an activated CD4 T cell?
Definition
L-selectin expression decreases and VLA-4 expression increases, making the T cell less likely to go to a lymph node and more likely to go to a site of inflammation.
Term
What happens to expression of LFA-1 in an activated CD4 T cell, and what is the significance of this?
Definition
LFA-1 increases, allowing T cells to bind and be activated by non-professional APCs with lower ICAM expression.
Term
What happens to expression of CD44 in an activated CD4 T cell?
Definition
It increases.
Term
What is the first way of CD8 killing?
Definition
Lytic granules.
Term
What is the second way of CD8 killing?
Definition
Interaction of FasL with Fas on target cells. This is a minor mechanism for infected cells but is important for unwanted lymphocytes.
Term
What causes autoimmune lymphoproliferative syndrome?
Definition
Defective Fas.
Term
What causes granuloma formation?
Definition
Intravesicular pathogen resistance to killing.
Term
Groups at risk for IE include:
Definition
Parenteral drug users.
Term
What is the most common cause of IE in patients with a normal valve and no IV drug use?
Definition
Viridans streptococci.
Term
What is the most common cause of IE in IV drug users?
Definition
S. aureus.
Term
What is the most common cause of IE in patients who had a valve replacement less than a year ago?
Definition
Coag negative Staph.
Term
What is the most common cause of IE in patients who had a valve replacement more than a year ago?
Definition
Viridans streptococci.
Term
What are conjunctival petechiae associated with?
Definition
IE.
Term
What are splinter hemorrhages associated with?
Definition
IE.
Term
What are Janeway lesions associated with?
Definition
IE.
Term
What are Osler's nodes associated with?
Definition
IE.
Term
Do Janeway lesions contain the bacteria causing IE?
Definition
Yes.
Term
Do Osler's nodes contain the bacteria causing IE?
Definition
No.
Term
What are Roth spots associated with?
Definition
IE.
Term
On what side of the heart does IE often occur in IV drug users?
Definition
Right.
Term
What are septic pulmonary emboli associated with?
Definition
IE.
Term
What is the most important test in the work-up of endocarditis?
Definition
Blood cultures.
Term
What are the most frequent causes of IE in oral and dental procedures?
Definition
Viridans strep.
Term
List the four conditions that necessitate prophylaxis to avoid IE.
Definition
Prosthetic valve replacement or repair.
Previous IE.
Congenital heart defect.
Cardiac transplant with valvulopathy.
Term
Are sulfonamides bactericidal or bacteriostatic?
Definition
Static.
Term
What is the mechanism of action of sulfonamides?
Definition
PABA analogues that are competitive inhibitors of dihydropteroate synthetase.
Term
What is the mechanism of action of diaminopyrimidines like trimethoprim?
Definition
Inhibit dihydrofolate reductase to block folic acid synthesis. Often used synergistically with sulfonamides.
Term
What is the mechanism of resistance to sulfonamides and trimethoprim?
Definition
Acquisition of new target enzymes (DHPS and DHFR).
Term
What type of drug causes erythema multiforme?
Definition
SMX-TMP.
Term
What type of drug causes Stevens Johnson syndrome?
Definition
SMX-TMP.
Term
What is the mechanism of action of fluoroquinolones?
Definition
Inhibit DNA gyrase.
Term
What class of drugs end in floxacin?
Definition
Fluoroquinolones.
Term
What are two mechanisms of quinolone resistance?
Definition
Mutations in DNA gyrase and active efflux.
Term
Are quinolones bacteriostatic or bactericidal?
Definition
Bactericidal.
Term
What is the spectrum of quinolones?
Definition
Gram-negatives and Strep pneumoniae.
Term
What is the mechanism of action of rifampin?
Definition
It inhibits DNA-dependent RNA polymerase.
Term
What is the mechanism of resistance towards rifampin?
Definition
Modification of the b-subunit of RNA polymerase.
Term
What is the spectrum of rifampin?
Definition
Active against many Gram-positives, some Gram-negatives, mycobacteria, and fungi.
Term
What bacteria often infect prosthetic devices?
Definition
Coagulase-negative Staph.
Term
List two adverse effects of rifampin.
Definition
Hepatic toxicity and induction of P450s.
Term
What is the spectrum of metronidazole?
Definition
Anaerobes.
Term
What is the mechanism of action of metronidazole?
Definition
It is a prodrug that is converted by oxidation to a compound that reacts with DNA.
Term
Is metronidazole bacteriostatic or bactericidal?
Definition
Bactericidal.
Term
What is the mechanism of resistance to metronidazole?
Definition
Failure to convert prodrug to active/toxic compound.
Term
What pathogen preferentially infects neutrophils?
Definition
Anaplasma phagocytophilum.
Term
Where do Rickettsia, Anaplasma, Ehrlichia, Orientia, and Coxiella burnetii live inside hosts?
Definition
All are obligate intracellular bacteria.
Term
What is the Gram-stain of the Rickettsiales and C. burnetii?
Definition
Gram-negative.
Term
What organisms are typically visualized with Giemsa stain because they Gram-stain poorly?
Definition
Rickettsiales and C. burnetii.
Term
What infection can be acquired by inhaling dessicated bacteria in a barnyard?
Definition
Coxiella burnetii.
Term
Rickettsia species infect what human cell type?
Definition
Endothelial cell.
Term
What two virulence factors does Rickettsia use to move within and between cells?
Definition
Phosopholipase C to break out of vacuoles.
Ability to use host actin.
Term
What happens if Rickettsia infection is left unchecked?
Definition
Systemic vascular collapse.
Term
What causes Rocky Mountain spotted fever?
Definition
R. ricketsii.
Term
What transmits Rocky Mountain Spotted Fever?
Definition
Dog tick.
Term
What disease is characterized by a rash first on the extremities and then spreading to other body areas?
Definition
Rocky Mountain Spotted Fever.
Term
Where are the greatest number of cases of Rocky Mountain Spotted Fever?
Definition
Southeast and South Central United States.
Term
What type of lesion at the site of a tick bite occurs as a result of R. parkeri infection?
Definition
Eschar.
Term
How is Rickettsia prowazekii transmitted to humans?
Definition
Via louse feces.
Term
What bacterium causes epidemic typhus?
Definition
R. prowazekii.
Term
What is the geographic distribution of epidemic typhus?
Definition
Africa and places with overcrowding and poor sanitation; rarely in Eastern U.S., associated with flying squirrels.
Term
What bacteria cause a macular or maculopapular rash that occurs on trunk first and spreads to the extremities?
Definition
R. prowazekii.
Term
What bacterium causes murine typhus, a disease with symptoms very similar to epidemic typhus, but milder?
Definition
R. typhi.
Term
What spreads murine typhus?
Definition
Fleas carried on urban rodents.
Term
What is the geographic distribution of scrub typhus?
Definition
Asia-Pacific region.
Term
What spreads scrub typhus?
Definition
Chiggers (mite larvae).
Term
What disease is associated with rice fields?
Definition
Scrub typhus.
Term
What is the causative agent of scrub typhus?
Definition
Orientia tsutsugamushi.
Term
What is the rash pattern in scrub typhus?
Definition
Trunk first, then extremities.
Term
What is the vector for human granulocytic anaplasmosis?
Definition
Deer tick.
Term
What cells do Ehrlichia chaffeensis invade?
Definition
Monocytes.
Term
What bacteria have a mulberry appearance?
Definition
Ehrlichia chaffeensis and Anaplasma phagocytophilum.
Term
What is the geographic distribution of human granulocytic anaplasmosis?
Definition
Northeast and upper midwest.
Term
What spreads human monocytic ehrlichiosis?
Definition
Lonestar tick.
Term
What symptom distinguishes HME from HGA?
Definition
Nausea.
Term
What is the geographic distribution of human monocytic ehrlichiosis?
Definition
Southeast and South Central United States.
Term
What organism causes Q fever?
Definition
Coxiella burnetii.
Term
What is the classic symptom of Q fever?
Definition
Interstitial pneumonitis.
Term
What cells do Coxiella burnetii infect?
Definition
Alveolar macrophages and monocytes.
Term
Can you wait until a definitive diagnosis before treating Rickettsial infections and Q fever?
Definition
No.
Term
Why is doxycycline the drug of choice for Rickettsial infections?
Definition
It crosses eukaryotic cell membranes.
Term
How does memory affect the B cell response time?
Definition
Development of memory leads to rapid response.
Term
What is B cell activation initiated by?
Definition
BCR crosslinking.
Term
How do the signal transduction cascades initiated by different isotypes of Ig differ from each other?
Definition
They all initiate the same cascade.
Term
What allows receptor-associated kinases to phosphorylate ITAMs during B cell activation?
Definition
Clustering of BCRs.
Term
What is the function of blk, lyn, and fyn?
Definition
Phosphorylate ITAM on Ig-beta and Ig-alpha.
Term
What is the function of Syk?
Definition
It is the B-cell equivalent of ZAP-70. It binds to phosphorylated ITAMs and sets off the cascade.
Term
What are the three components of the B-cell co-receptor?
Definition
CD19, CD21 (CR2), and CD81.
Term
What component of the B-cell co-receptor is a complement receptor?
Definition
CR2.
Term
What interaction causes the BCR and co-receptor to be juxtaposed?
Definition
CR2:C3d.
Term
What happens as a result of juxtaposition of BCR and co-receptor?
Definition
Lyn phosphorylates CD19.
Term
What co-BCR signaling component amplifies BCR signaling more than 100x?
Definition
CD19.
Term
How many signals do B cells require for activation?
Definition
2.
Term
What type of receptors do TI1 antigens use to give the second signal?
Definition
TLRs.
Term
What TLR is activated by bacterial DNA?
Definition
TLR9.
Term
What are TI-2 antigens?
Definition
Repetitive epitopes.
Term
Does T-cell-independent activation of B cells produce a memory response?
Definition
No.
Term
Where do T-dependent responses occur?
Definition
In lymphoid tissue.
Term
After a B cell has been activated by a dendritic cell in the B cell area, where does it go?
Definition
To the boundary region.
Term
What molecule on the surface of T cells forms an interaction with a molecule with a similar name on the surface of B cells?
Definition
CD40L.
Term
What is recognized by the T cell and B cell in a cognate interaction?
Definition
Same antigen, but not the same epitope.
Term
How does close T-B contact contribute to specificity?
Definition
It prevents IL-4 from assisting irrelevant B cells.
Term
What cytokine stimulates B cell proliferation?
Definition
TH2-derived IL4.
Term
What cytokines stimulate B cell differentiation?
Definition
IL5 and 6.
Term
Where is the primary focus for expansion of antigen-activated B cells?
Definition
Medullary cords.
Term
Where is the secondary focus for expansion of activated B cells?
Definition
Germinal center.
Term
What are the two fates of B cells in the primary focus?
Definition
Become plasma cells or form a secondary focus at the germinal center.
Term
What are centroblasts?
Definition
Rapidly dividing B cells in the dark zone of a germinal center.
Term
Where does somatic hypermutation occur?
Definition
Dark zone.
Term
What are centrocytes?
Definition
Non-dividing progeny of centroblasts that move to the light zone.
Term
Which centrocytes are rescued?
Definition
Those with high affinity BCRs.
Term
When does isotype switching occur?
Definition
Germinal center reaction.
Term
What does TGF-beta stimulate isotype switching to?
Definition
IgA.
Term
What is the influence of IL5 on isotype switching?
Definition
Augments switching to IgA.
Term
What does IL4 cause isotype switching to?
Definition
IgG4 and IgE.
Term
What cell direct isotype switching via cytokines?
Definition
T cells.
Term
What interaction is essential for isotype switching?
Definition
CD40-CD40L.
Term
What cells are essential for formation of germinal centers?
Definition
T cells.
Term
What directs the fate of centrocytes?
Definition
T cell derived cytokines.
Term
What cytokine drives the development of centrocytes into memory cells?
Definition
IL4.
Term
What cytokine drives the development of centrocytes into plasma cells?
Definition
IL10.
Term
When do infants start to make Ig?
Definition
About 6 months.
Term
What determines the anatomical location and function of Ig isotypes?
Definition
Fc portion.
Term
What immunoglobulins predominate in plasma?
Definition
IgG and IgM.
Term
What immunoglobulin crosses the placenta?
Definition
IgG.
Term
What immunoglobulin is associated with epithelial surfaces?
Definition
IgE.
Term
What immunoglobulin predominates in mucosal secretions?
Definition
IgA.
Term
What is transcytosis?
Definition
Unidirectional transport of macromolecules through a cell.
Term
What can IgM be transported across?
Definition
Epithelial cells.
Term
What types of antibodies block viral infection?
Definition
Neutralizing (IgM, IgG, IgA).
Term
What types of antibodies block bacteria infection?
Definition
Neutralizing.
Term
What types of antibodies block toxin binding?
Definition
Neutralizing.
Term
What cells remove immune complexes?
Definition
Erythrocytes.
Term
What receptor on RBCs plays a role in the clearance of immune complexes?
Definition
CR1.
Term
Where are immune complexes destroyed?
Definition
Liver or spleen.
Term
What is the function of FCR-gamma?
Definition
It allows activation of monocytes, macrophages, and dendritic cells by IgG and also facilitates pathogen clearance
Term
What is the function of ITIMs on FcRs?
Definition
Allows inhibitory signaling through FcRs.
Term
What is the function of FcR on NK cells?
Definition
It binds to IgG1 on target cells and signals the NK cell to kill the target.
Term
What immunoglobulin binds to the Fc-epsilon receptor on mast cells?
Definition
IgE.
Term
What do most Fc receptors recognize?
Definition
IgG.
Term
What chain mediates the activating signal in Fc receptors?
Definition
Gamma.
Term
What 2 cell types are most types of Fc receptor expressed on?
Definition
Macrophages and neutrophils.
Term
Why is it hard to fight Streptococcus and Haemophilus without an antibody response?
Definition
They have capsules which prevent complement activation. You need an antibody response to get complement activation.
Term
What is the morphology of mycobacteria and actinomycetes?
Definition
Long, slender rods that look like fungi.
Term
What bacteria stain acid-fast?
Definition
Mycobacteria and actinomycetes.
Term
What molecule is responsible for acid-fast staining of mycobacteria?
Definition
Mycolic acid.
Term
Is M. tuberculosis aerobic or anaerobic?
Definition
Aerobic.
Term
Is M. tuberculosis motile?
Definition
No.
Term
Is M. tuberculosis spore-forming?
Definition
No.
Term
Is M. tuberculosis slow-growing or fast-growing?
Definition
Slow.
Term
Is M. tuberculosis catalase-positive or catalase-negative?
Definition
Catalase-positive.
Term
List the 4 virulence factors of M. tuberculosis.
Definition
Resistance to killing by macrophage.
Catalase.
Mycolic acid.
Cord factor.
Term
What gives M. tuberculosis its resistance to drying and disinfectants?
Definition
Mycolic acid.
Term
It M. tuberculosis heat-resistant?
Definition
No.
Term
What is the target of isoniazid?
Definition
Mycolic acid.
Term
What type of immunity works on M. tuberculosis?
Definition
Cell-mediated immunity.
Term
What causes the symptoms of M. tuberculosis?
Definition
The immune response. IL1 causes fever. TNF-alpha decreases lipid metabolism and leads to weight loss. Proteases cause tissue destruction.
Term
How is M. tuberculosis spread?
Definition
Person-to-person via aerosol.
Term
What are Ghon foci?
Definition
Calcified tubercles.
Term
What disease is characterized by tiny granulomas all throughout the lung?
Definition
Miliary Tb.
Term
Where does secondary Tb usually occur?
Definition
Apices of lungs.
Term
What type of tuberculosis is cavitary?
Definition
Secondary.
Term
What disease has an initial presentation of anorexia, weight loss, and cough?
Definition
Pulmonary Tb.
Term
Where does primary tuberculosis usually occur?
Definition
Midlung.
Term
Are mycobacteria other than TB sensitive to INH?
Definition
No.
Term
Are Mycobacteria other than TB communicable?
Definition
No (except M. leprae).
Term
What is non-cultivatable mycobacteria?
Definition
M. leprae.
Term
How is M. leprae spread?
Definition
Nasal spread.
Term
Which type of leprosy has a brisk TH1 response?
Definition
Tuberculoid.
Term
What is the natural reservoir of all NTM?
Definition
Soil and water.
Term
Is NTM spread person-to-person?
Definition
No.
Term
What does M. kansasii cause?
Definition
Pulmonary disease resembling M. tb. Seen in AIDS patients in endemic areas.
Term
What causes swimmin pool granuloma?
Definition
M. marinum.
Term
What population is susceptible to M. avium complex?
Definition
AIDS patients with low CD4 counts.
Term
How is M. avium transmitted?
Definition
Ingestion or inhalation of contaminated water.
Term
What causes non-painful Buruli ulcers in the tropics?
Definition
M. ulcerans
Term
Are Actinomycetes Gram-positive or Gram-negative?
Definition
Gram-positive.
Term
Are Actinomycetes aerobic or anaerobic?
Definition
Anaerobic.
Term
What bacterium is associated with destructive abscesses of the jaw, lung, and viscera; sulfur granules; and minigitis?
Definition
Actinomyces israelii.
Term
What do thermophilic actinomycetes cause?
Definition
Hypersensitivity pneumonitis (fever, cough, wheezing, and shortness of breath).
Term
What causes farmer's lung?
Definition
Thermophilic actinomycetes.
Term
Where do thermophilic actinomycetes grow?
Definition
Barns.
Term
What is the main limitation for INH use?
Definition
Hepatotoxicity.
Term
Which drug in the standard TB therapy penetrates well into cells?
Definition
Rifampin.
Term
What is the mechanism of action of ethambutol?
Definition
Unknown.
Term
What is the mechanism of resistance to INH?
Definition
Altered mycolic acid and reduced conversion of the drug to the active form.
Term
What is the toxicity of ethambutol?
Definition
Optic neuritis.
Term
Is ethambutol bactericidal or bacteriostatic?
Definition
Static.
Term
What is the purpose of ethambutol in TB treatment?
Definition
Prevent resistance.
Term
What is the mechanism of action of pyrizinamide?
Definition
Inactivates RpsA and interferes with trans-translation.
Term
What is the mechanism of resistance to pyrizinamide?
Definition
Mutation of the gene required to convert the prodrug to the active form.
Term
What is the standard group of drugs used to treat TB?
Definition
INH, rifampin, ethambutol, and pyrizinamide.
Term
What is the morphology of mycoplasma?
Definition
Pleomorphic, very small.
Term
Are mycoplasma sensitive to cell wall-targetting drugs?
Definition
No.
Term
What is the Gram-stain of mycoplasma?
Definition
They don't Gram-stain.
Term
What stabilizes the membranes of mycoplasma and is required for their growth?
Definition
Cholesterol.
Term
Describe the oxygen requirements of mycoplasma.
Definition
Microaerophilic except for M. pneumoniae, which is an aerobe.
Term
Are mycoplasma fast-growers or slow-growers?
Definition
Slow.
Term
Do mycoplasma have peptidoglycan?
Definition
No.
Term
What often causes community acquired atypical "walking" pneumonia?
Definition
Mycoplasma pnemoniae.
Term
What is a symptom that can distinguish Mycoplasma pneumoniae from Streptococcus pneumoniae?
Definition
Dry cough.
Term
What bacterium discussed in class causes a patchy, diffuse bronchopneumonia?
Definition
M. pneumoniae.
Term
What virulence factor of M. pneumoniae leads to hemolytic anemia?
Definition
Cold agglutinins.
Term
What is the preferred method of diagnosing Mycoplasma pneumoniae?
Definition
PCR.
Term
What two diseases does Ureaplasma cause?
Definition
Urethritis and endometritis.
Term
What bacteria cause PID, postpartum fever, and pregnancy complications?
Definition
M. hominis.
Term
List the four conditions caused by the Trachoma biovar of Chlamydia trachomatis.
Definition
Non-gonococcal urethritis.
Cervicitis.
Conjunctivitis.
Trachoma.
Term
What bacteria cause LGV?
Definition
Chlamydia trachomatis.
Term
What type of pneumonia is caused by Chlamydia pneumoniae?
Definition
Atypical.
Term
What causes psittacosis or parrot fever?
Definition
Chlamydia psittaci.
Term
Are Chlamydiae Gram-positive or Gram-negative?
Definition
Gram-negative structure.
Term
What is the elementary body?
Definition
Infectious but not replicative form of Chlamydia.
Term
What is the reticulate body?
Definition
Fragile but replicative form of Chlamydia.
Term
List 5 virulence factors of Chlamydia.
Definition
Type III secretion system.
Invasion and actin recruitment.
Inhibition of phagolysosomal fusion.
Modulation of host cell apoptosis.
Subversion of host cell trafficking - nutrients.
Term
What bacteria cause mucoid, watery discharge from the urethra?
Definition
C. trachomatis.
Term
List two bacteria that cause an atypical pneumonia similar to that caused by Chlamydia pneumoniae.
Definition
M. pneumoniae and L. pneumophila.
Term
What type of bacteria have corkscrew motility and an endoflagella?
Definition
Spirochetes.
Term
What is the Gram-stain of Spirochetes?
Definition
Gram-negative.
Term
Do most spirochetes have LPS?
Definition
No.
Term
Does Leptospira have LPS?
Definition
Yes.
Term
What genus causes syphilis and periodontal disease?
Definition
Treponemes.
Term
What genus causes Lyme disease and relapsing fever?
Definition
Borrelia.
Term
What genus causes leptospirosis and Weil's disease?
Definition
Leptospira.
Term
Give an example of a host-dependent treponeme.
Definition
Borrelia.
Term
Give an example of a free-living treponeme.
Definition
Leptospira.
Term
What organism causes syphilis?
Definition
Treponema pallidum.
Term
Briefly describe the 3 stages of syphilis.
Definition
Stage 1: Primary chancre.
Stage 2: Disseminated syphilitic rash, with lesions loaded with bacteria.
Tertiary syphilis: 10-20 years later, granulomatous lesions (gumma) on organs and tissue, neurological complications and dementia.
Term
What organism discussed in class causes periodontal disease?
Definition
T. denticola.
Term
Are T. denticola aerobic or anaerobic?
Definition
Anaerobic.
Term
What organism causes lyme disease in North America?
Definition
Borrelia burgdorferi.
Term
What disease is caused by Ixodes ticks?
Definition
Lyme disease.
Term
What disease involves erythema migrans?
Definition
Lyme.
Term
What disease has neurologic complications that include Bell's palsy, peripheral neuropathy, and meningitis?
Definition
Lyme.
Term
What disease often causes monoarticular arthritis after tick bites?
Definition
Lyme disease.
Term
What test is used to confirm the diagnosis of Lyme disease?
Definition
Two-tiered serological test.
Term
Where does Lyme disease primarily occur in the U.S.?
Definition
Northeast.
Term
What disease is caused by Borrelia hermsii and B. turicatae in North America and by B. crocidurae in other countries?
Definition
Endemic relapsing fever.
Term
Is bacteremia seen in endemic relapsing fever?
Definition
Yes.
Term
What is the molecular basis of relapsing fever?
Definition
Genetic recombination of Vmp genes allows antigenic variation.
Term
What bacteria have a long morphology with hooks at the end of cells?
Definition
Leptospira.
Term
What is the most common zoonotic disease worldwide?
Definition
Leptospirosis.
Term
Where is the incidence of L. interrogans high?
Definition
Hawaii and tropical areas. Associated with flooding and carried by livestock or rodents.
Term
Is S. aureus food poisoning a toxinosis or infection?
Definition
Toxinosis.
Term
What a rigors a sign of, in general?
Definition
Bacteremia.
Term
What bacteria causes painful bullae and is associated with raw oysters?
Definition
Vibrio vulnificus.
Term
What causes mucosal injury in C. diff infection?
Definition
Release of toxins A and B.
Term
What does toxin A of C. diff do?
Definition
Causes fluid accumulation in the bowel.
Term
What does toxin B do in C. diff infection?
Definition
Promotes cell lysis and death.
Term
What organism can cause toxic megacolon?
Definition
C. diff.
Term
What can be used as a stand-alone test to diagnose C. diff?
Definition
PCR.
Term
If a patient has gonorrhea, what disease must you also treat them for?
Definition
Chlamydia.
Term
What age group most frequently gets hematogenous osteomyelitis?
Definition
Children.
Term
What age group is most susceptible to long bone osteomyelitis?
Definition
Children.
Term
What group of people is susceptible to direct inoculation (contiguous-focus) osteomyelitis?
Definition
Diabetics.
Term
What age group most commonly gets spinal osteomyelitis?
Definition
Older than 45.
Term
What type of bacteria commonly cause diabetic foot ulcers?
Definition
Anaerobes.
Term
What type of bacteria commonly cause prosthetic joint infections?
Definition
Coagulase-negative Staphylococci.
Term
If a person has a prosthetic joint infection, should you give antibiotics before or after arthrocentesis?
Definition
After.
Term
Give an example of an antibiotic that should never be administered alone.
Definition
Rifampin, due to resistance.
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