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MicroBio Exam 3
| Question | Answer |
|---|---|
| Which of the following is associated with antigen presentation by phagocytes, but not by epithelial cells? | MHC2 picks up an antigen from the phagolysosome |
| Which of the following is NOT common to all three complement activation pathways? | The adaptive immune response is needed for activation of the pathway. |
| Bacteria respond to phagocytosis by . . . | producing leukocidins |
| MHC Class II receptors . . . | Are found only on phagocytes and B-cells |
| How does interferon fight a viral infection in an infected host? | It is produced in virus-infected cells and induces AVP in neighboring cells. |
| Choose the option with one PHAGOCYTE antigen presenting cell (APC) and one LYMPHOCYTE APC. | Macrophages and B cells |
| Which of the following is correct regarding the body's interferon defense system? | Interferon induces the production of antiviral proteins in adjacent cells. |
| The three complement activation systems share many common features, but there are also differences. Which of the following is NOT common to all three complement pathways? | Properdin is required to stabilize the C5 convertase |
| Why does a bacterium produce antioxidants? | To survive the harsh environment inside the phagolysosome |
| Some bacteria live and divide inside the phagolysosome. What will be a symptom associated with a chronic infection of a patient with such a bacterium? | lumps of infected macrophages and TH cells will be seen in the patient's tissues |
| Which of the following is associated with antigen presentation by dendritic cells, but not by epithelial cells? | MHC2 picks up an antigen from the phagolysosome |
| Which of the following is NOT a consequence of activating the complement cascade on the surface of a bacterium? | Peptide C3a induces B cells to produce antibodies that attach to the bacterium. |
| One of the complement activation pathways is called the “alternate” pathway. What is different between this pathway and the “classical” pathway? | It can be activated even before the humoral immune response is active |
| Which of the following is required for granuloma formation? | persistent antigen presence inside macrophages |
| Which of the following could be considered to be a phagocyte? | antigen presenting cell |
| We said that MHC2 is mainly for presentation of exogenous antigens, whereas MHC1 is mainly for presentation of endogenous antigens. Why is this so? | MHC2 passes through the endocytic vesicle on its way to the cell surface |
| What is the purpose for our immune system to opsonize bacterial cells? | It adds surface features to the bacterium that makes it easier for our cells to recognize. |
| Granuloma formation involves all of the following EXCEPT . . . | antibodies |
| Which of the following statements is true of MHC-II, but not of MHC-I? | It mainly displays antigens from the phagolysosome |
| How is interferon produced during an infection? | A second-messenger pathway induces it when viral RNA binds to an RLR receptor. |
| Which of the following is true of infections that are characterized by granuloma formation? | Bacteria prevent lysosomes in infected macrophages from fusing with phagosomes |
| What is the function of a Toll-like receptor? | It allows macrophages and dendritic cells to bind specifically to pathogens |
| What molecule is typically recognized by the immune system to signal that a cell has been infected by a virus? | Double stranded RNA |
| How does interferon (IFN) function during a viral infection? | IFN is an inducer that turns on genes for antiviral proteins in neighboring cells |
| Some bacteria have evolved the ability to prevent lysosome fusion to a phagosome. These bacteria can therefore avoid . . . | the oxidative burst |
| What is a leukocidin? | a toxin produced by bacteria to kill macrophages |
| Which of the following is true about antigen presentation on MHC class I? | It requires protein digestion by the proteasome. |
| Antigens displayed on MHC class II come from . . . | the phagolysosome of the cell that displays them |
| What is the role of antibodies in the innate immune response? | They can activate the synthesis of antimicrobial peptides |
| Which of the following correctly distinguishes MHC-I from MHC-II? | MHC-I can display self antigens on the surface of uninfected cells |
| Which of the following is true regarding interferon α and β? | They are released from a cell to bind to receptors on nearby cells |
| There are three complement activation pathways. How do these pathways differ? | The way C3 and C5 proteins are hydrolyzed |
| Two things happen once a pathogen binds specifically to a dendritic cell (DC). They are . . . | The pathogen is engulfed, and the DC produces co-stimulatory molecules. |
| Bacteria that can survive inside the phagolysosome can do so because . . . | they produce antioxidants |
| Which of the following is a difference between endogenous and exogenous antigen presentation? | Endogenous antigens are processed by the proteasome, exogenous by the phagolysosome |
| How does interferon prevent viral replication? | By signaling cells to be ready to apoptose if a virus invades |
| Which complement molecule is correctly matched with its function? | C5a – chemokine signaling molecule |
| Which of the following are produced inside a phagolysosome? | Peroxides and Antimicrobial complement peptides |
| A patientWhich complement-associated term is NOT correctly matched with its function? | Lectin – digests the C5 protein |
| In general, antibodies can defend against pathogens in any of six ways. However, IgM and IgA can only use a few of these methods. Which of the following could be used by IgM or IgA to inactivate pathogens? | Agglutination |
| What parts of antibodies have great variability due to somatic recombination? | the Fab part only |
| The antibody type that is secreted by plasma cells one day after primary infection would most likely be: | IgM |
| Some antigens (T-independent) can activate B cells without the involvement of cellular immunity. Which of the following would still occur in response to these antigens? | B cell receptors would bind to the antigen |
| A B cell recognizes an antigen, but there is no TH cell that also recognizes the antigen. What will happen? | The B cell will become anergic |
| The process that ensures no circulating B cells recognize self antigens is called: | clonal deletion |
| How do antibodies actually kill foreign bacteria? | They opsonize the bacterium, making it easier to phagocytize |
| What is the major difference between IgG and IgA? | The Fc region of the IgA heavy chain allows dimerization |
| Which antibody class can cross the placenta to protect the fetus? | IgG |
| What parts of antibodies have great variability due to somatic recombination? | the Fab part only |
| What causes a B cell to become anergic? | Its MHC2 receptors present an antigen that is not recognized by a TH cell |
| Immunoglobulin M (IgM) . . . | is the first antibody produced in response to an infection |
| The process responsible for antibody diversity . . . | is a genetic recombination that can only happen once in each B cell |
| How are TH cells involved in the humoral immune response? | Cytokines from TH cells cause B cells to turn into antibody-producing plasma cells |
| Why are only a very small number of B cells activated in response to an infection? | Only a few B cells bind to both the specific antigen and a TH cell |
| What is the most correct statement about the selection process B cells must undergo before they are released to the blood? | Recognizing any antigens in bone marrow causes B cells to apoptose |
| Which of the following can antibodies do to “fight” against both bacteria and viruses? | neutralize receptor binding proteins |
| The antibody type shown at right has what special feature? | It is the major antibody found in mucus membranes |
| What cellular process allows billions of different antibody Fabfragments to be produced from only a few hundred genes? | Somatic Recombination |
| Antibodies can "fight" bacterial infections in all of the following ways EXCEPT . . . | activate TH cells to secrete cytokines |
| What can you conclude if you find the structure at the right in a patient? | The patient has been recently infected |
| What is the role of T cells in the antibody response? | TH cells stimulate B cell division and differentiation |
| Which parts of the antibody shown at the right undergo somatic recombination? | all 4 parts labeled 'A' |
| The antibody shown below can help your body "fight" against pathogens in all of the following ways EXCEPT . . . | activation of ADCC |
| How are T cells involved in antibody production? | Cytokines from TH cells cause proliferation and differentiation of B cells into plasma cells |
| When does a B cell undergo the genetic switch to begin producing IgG instead of IgM? | several days after the initial infection with a pathogen |
| What happens during the process called "clonal deletion"? | B cells apoptose if their receptors recognize proteins present in bone marrow |
| Which of the following statements about antibody types is TRUE? | The most effective antibody for agglutinating antigens is IgM |
| Which of the following steps occurs during the immune response to BOTH polysaccharide vaccines AND protein-conjugate vaccines? | B cell receptors bind to polysaccharide components of vaccine antigens |
| Which of the following B cells would become anergic? | A B-cell that is displaying an antigen to which no T-cell has bound |
| What is meant by the abbreviation ADCC? | Tagging a cell so that NK cells bind to and destroy it |
| Which of the following antibody types is correctly matched with a feature of that antibody? | IgM – only Ig produced in response to T-independent antigens |
| Why does a second exposure to the same pathogen usually result in a much stronger immune response against it? | When a second infection occurs, Bmemory cells produce IgG without class switching |
| What happens if you are exposed to an antigen but none of your circulating B cells has receptors that recognize it? | New B cells can be released from your bone marrow that may recognize it, even though no circulating B cells do |
| Which of the following is one way our immune system avoids producing antibodies that recognize self antigens? | B cells become anergic if they are not also stimulated by TH cells |
| You are working in pharmaceutical research, and you want to make a vaccine against a bacterial polysaccharide slime layer. You know that you will need to make a conjugated vaccine. Which of the following is true about such a vaccine? | The conjugated protein may be the antigen that is displayed on a B cell's MHC-II |
| How can IgG prevent a viral infection? | It can neutralize viral binding to host receptors |
| In a T-dependent B cell response . . . | a B cell must endocytose an antigen and display it on MHC-I |
| Which of the following is correctly associated with a B cell that has become anergic? | The B cell displays an antigen that no T cell recognizes |
| How many type(s) of antibody is produced from a single B cell? | 1 |
| Can B-cells produce antibodies without TH cell help, and what type of antibody is predominantly produced in this scenario? | Yes, a small population of B cells can produce IgM antibodies without TH cell help |
| In DiGeorge's Syndrome, the patient is born without a thymus. Such a patient obviously lacks some of his immune system. Which of the following best represents his antibody titer after initial and booster vaccination? | No thymus = no T cells |
| What is the main function of TC cells in the immune system? | to release perforin and granzymes |
| What happens when an effector TC cell binds to an antigen on an epithelial cell’s MHC1? | The TC cell kills the epithelial cell |
| Which of the following does NOT happen once TH cells have become activated? | The TH cells produce MHC2 on their surface |
| Immune tolerance in T cells involves positive selection. What does that mean? | T cells are only released if their TCR recognizes thymus cells’ MHC1 |
| What is the difference between TH and TC cells? | TH cells secrete cytokines, TC cells secrete perforin |
| If a TH cell binds to an MHC on “cell A” that is presenting an antigen, but binds to nothing else, what happens? | The body assumes this is a mistake; the TH cell becomes unresponsive |
| Effector TH cells can do all of the following EXCEPT . . . | Phagocytize nearby bacteria |
| What is the most correct statement about the selection process T cells must undergo before they are released to the blood? | TCRs must recognize self MHCs, but must not recognize antigens on the MHCs |
| What type of cells do NK cells kill? | any cells without MHC1 (or its equivalent) on their surface |
| What is the role of the B7 protein in the immune response? | It is produced by infected macrophages to help stimulate T cells |
| A TH cell is secreting interleukin-2 (IL-2). This means that . . . | nearby TC cells will become activated once they bind to an antigen-MHC1 complex |
| How do activated macrophages differ from non-activated (naïve) macrophages? | They contain more lysosomes |
| What is the role of NK cells in the immune response? | They participate in antibody-dependent cellular cytotoxicity |
| Which of the letters in the diagram at the right refers to the variable region of a T cell receptor (TCR)? | A |
| What is a major difference between TH and TC cells? | TC can bind to almost any infected cell; TH only bind infected antigen presenting cells |
| Which of the following correctly refers to the second signal that is required for T cell activation? | It is only produced when a pathogen is recognized by the immune system |
| Upon receipt of cytokine signals from effector TH cells, macrophages . . | produce a more potent oxidative burst that includes nitric oxide |
| What do TH and TC cells have in common? | Both need an infection-specific “second signal” to avoid becoming anergic |
| Humans with the mutation IL<tm1hor> fail to produce interleukin-2. Which of the following would you expect to be a direct result of this mutation? | TC cells could only be activated by binding to infected APCs |
| Which T cell type is correctly matched with a function? | Tregulatory cells - Decrease the intensity of the cellular immune response |
| What is wrong with the picture at the right? | The TC cell shown in the drawing should become anergic, not activated |
| During pre-clinical testing, a certain pharmaceutical drug is found to stimulate the production of interleukin-2 (IL-2) in human cell cultures. This finding is . . . | bad, because producing IL-2 without an infection will overstimulate TC cells |
| To what do NK cells bind? | "Killer receptors" on any eukaryotic cell |
| The protein called B7 is produced by ________ to ensure that an immune response is only produced in response to the presence of a pathogen | dendritic cells |
| What type of cells do NK cells kill? | mainly cancer cells and virally-infected cells |
| Which of the lines in the following table is INCORRECT? | presents antigens from |
| What is the role of Treg cells in the immune response? | They produce the cytokine IL-10 to reduce the effectiveness of TH and TC cells |
| How do NK cells function? | They kill cells to which they bind unless inhibitory signals outweigh stimulatory ones |
| Which part of this T cell receptor is produced only AFTER the T cell has bound an antigen? | None of it. It is all produced BEFORE antigen binding |
| The following table tries to define the differences between TH and TC cells, but it gets a lot of things wrong. Which line in the table is correct? | T cell binds to... |
| Which of the following is true about T cells that recognize self antigens? | They form because V-J joining is random, but they apoptose in the thymus |
| Which of the following cell types is LEAST likely to be killed by NK cells? | Cells in your body that are overproducing MHC- |
| What is meant by "cellular" immunity? | Immunity related specifically to T cells or NK cells |
| Which of the following is a type of cell involved in the immune response? | macrophage |
| How do Treg cells differ from TH cells? | When Treg cells bind B7, they engulf and destroy it |
| Which of the following can be killed by NK cells? | Any cell that lacks MHC-I or has antibodies bound to it |
| Giving a shot of tetanus toxoid antibodies after a patient has been infected with tetanus is an example of. . . | passive, artificial immunity |
| Which of the following could be a possible interpretation of the agglutination test shown in circle A? | The antibodies recognize soluble antigens in the serum |
| A major advantage of using inactivated vaccines rather than live vaccines is that . . . | inactivated vaccines can be given to immunocompromised patients |
| The current vaccine against Streptococcal pneumonia is produced by attaching the capsule polysaccharide from S. pneumoniae to a protein and injecting it into the patient. What purpose does the protein serve? | It is recognized by T H cells, allowing a stronger B cell response to the vaccine |
| What is the vaccine in question #4 called? | A subunit conjugate vaccine |
| A patient is injected with antibodies against tetanus toxin. What is the purpose of this injection? | To bind and immediately inactivate tetanus toxin in a life-threatening intoxication |
| Which of the following is generally the LEAST effective type of vaccine? | Polysaccharide vaccine |
| A promising new vaccine technology involves injecting DNA from a pathogen into a patient's cells. How does such a vaccine work? | The patient's MHCs display translated foreign proteins, activating cellular immunity |
| What do precipitin and agglutination tests have in common? | Both require that the antibodies have at least two antigen binding sites |
| How do live attenuated vaccines produce a strong immune response in a vaccinated host? | They can replicate in the host and persist for a long time |
| How can an antibody's titer be determined most easily? | by observing its reaction with an antigen |
| In the precipitin test shown by this picture, well C contains IgG against diphtheria toxin. Which of the following must be true? | Well A contains diphtheria toxin |
| Injection of a patient with tetanus immune globulin is an example of . . . | artificial, passive immunity |
| The test shown below . . | can determine which bacterial surface molecules to use in a subunit vaccine |
| Which of the following is true for a direct ELISA, but not for an indirect ELISA? | To begin the test, known antibodies are bound to the bottom of a microtiter well |
| An example of passive immunity is . . . | getting injected with blood serum from a patient who formerly had diphtheria |
| One advantage of a live attenuated vaccine (LAV) over an inactivated subunit vaccine (ISV) is . . . | memory T cells are produced in response to the LAV |
| Pharmaceutical companies are finally beginning to develop DNA-based vaccines. These vaccines work by causing a vaccinated person to . . | produce one of a pathogen's proteins in order to elicit a T cell response |
| Are we concerned about herd immunity levels when using passive immunizations? Why or why not? | No. Passive immunization is too temporary for herd immunity to be important |
| Which of the following statements about live attenuated vaccines (LAV) and inactivated vaccines (INV) is correct? | LAV can be either orally administered or injected, whereas INV must be injected |
| To what can a Western blot be most accurately compared? Why? | to immunoelectrophoresis, since both involve using antibodies to detect separated antigens |
| Two examples of passive immunity are . . . | Fetal IgG protection and Diphtheria immune globulin |
| What is an adjuvant? | A substance in some vaccines that helps to elicit a cellular immune response |
| Which of the following tests DOES NOT use two antibodies, one labeled and one unlabeled? | Immunodiffusion test |
| A friend of yours who knows you took Bio 221 is planning to invest in a company that says they are working on an anti-cancer vaccine. The friend asks your advice about his investment. What would you say to him? | It's a DNA vaccine designed to boost your TC cell response to cancer-specific antigens |
| Pharmacologists have learned that conjugated vaccines are much more effective than their polysaccharide vaccine counterparts. What is so special about conjugated vaccines? | They contain a protein epitope that blocks an antigen from binding to multiple B cell receptors simultaneously |
| Which of the following is an advantage of administering a vaccine for Typhoid fever orally? | It leads to the production of IgA, which protects the portal of entry for this infection |
| How do you know that a person has been exposed to a particular pathogen within the past year or so? | If the person's antibody titer against the pathogen, which was 1:8, is now 1:128 |
| Class switching in B cells from _______ to _______ is responsible for the allergic response | IgM to IgE |
| Which of the following is NOT part of an allergic response? | Activated B cells bind allergen a second time |
| In rheumatoid arthritis, both B- and T-cells recognize the auto-antigen collagen, and circulating antibodies are produced against collagen. Which of the following is caused by those antibodies? | They bind to collagen and are deposited as immune complexes in joints |
| Bob has had tuberculosis. If a TB skin test is performed on Bob, what will happen? | After a few days he will show a red rash at the site where the TB antigen was injected |
| The most common immune disorder in the US is selective IgA deficiency. People who suffer from this will be more likely to get ______________ than other people | respiratory and digestive illnesses |
| Which of the following describes a Type II hypersensitivity reaction? | IgG binds to a hapten on a cell, recruiting complement and NK cells |
| In the disease rheumatoid arthritis, a person makes antibodies against her own collagen. Antibody- antigen complexes form in the capillaries of joints, causing inflammation leading to arthritis. This is an example of . . . | Type III hypersensitivity |
| In the disease Lupus, autoantibodies are directed against | DNA |
| Inheritance of the immunodeficiency disease agammaglobulinemia results in the failure to produce B cells. A patient with this disease would . . . | Be very susceptible to bacterial toxins |
| Some allergies can be overcome by injecting small amounts of the allergen repeatedly into the patient. How does this work? | The patient produces IgG, which binds the allergen instead of the IgE on mast cells |
| In the disease lupus, your B cells recognize your own DNA, making antibodies that form antigen- antibody complexes with DNA. This is an example of which type of hypersensitivity? | Type III |
| During vaccine clinical trials, it was discovered that a vaccine antigen could bind to a receptor on the patient's epithelial cells. The vaccine development was cancelled. Why? | IgG bound to the vaccine antigen might direct ADCC against the patient's own cells |
| Serious type IV hypersensitivity reactions are usually treated . . . | by suppressing T cell response |
| What is a hapten? | It is a small molecule that binds to a cell and triggers a type II hypersensitivity |
| A person who is allergic to pollen has small amounts of pollen injected under his skin. What is the purpose of this? | It causes him to make more anti-pollen IgG, rather than IgE |
| In the disease lupus, your B cells recognize your own DNA, causing a type III hypersensitivity. How does this cause damage to your body? | DNA-Antibody complexes form and get stuck between cells, causing inflammation |
| Which of the following is a similarity between Type I and Type IV hypersensitivity reactions? | the need for prior exposure to the antigen that causes the reaction |
| Systemic Lupus Erythematosus . . . | involves formation of immune complexes containing your own DNA |
| The measles virus is considered to cause an immunodeficiency disease because . . . | it infects T cells and damages your cellular immune system |
| A person with rheumatoid arthritis makes antibodies against the protein collagen, which is found in cartilage. These antibodies can cause a Type III hypersensitivity reaction. Which of the following best describes this reaction? | Neutrophils recruited by complement peptides release inflammatory cytokines |
| Interestingly, though food proteins are foreign, we usually do not have hypersensitivity reactions against them. What do we think is the reason for this? | Oral presentation of antigens somehow stimulates regulatory T cells |
| Type I (juvenile-onset) diabetes is caused by which of the following? | self-recognizing TC cells that have not been deleted |
| Which of the following is the best statement of the "hygiene hypothesis"? | Lack of oral exposure to normal flora fails to induce the development of Treg cells |
| People born with SCID can't perform somatic recombination. Which of the following best characterizes this condition? | lack of both cellular and humoral immunity, but normal innate immunity |
| What is the purpose of a RhoGAM shot, as given to a pregnant Rh(-) woman? | To compete with her B cells for binding to fetal red blood cells |
| How does a Type III hypersensitivity reaction damage your tissues? | Complement activation in capillaries recruits PMNs, which secrete perforins |
| A TB test involves a Type IV hypersensitivity reaction. If you have been sensitized to TB before you take such a test . . . | Tmemory cells in your body that recognize TB will cause the test to be positive |
| Which of the following is an example of an acquired immunodeficiency disease? | Measles |
| How is IgA involved in the allergic response? | IgA is not involved in the allergic response |
| If you are an Rh(-) woman and your husband is Rh(+), why do you need a RhoGAM shot, even for your first pregnancy? | To avoid your B cells coming in contact with the Rh antigen |
| Which of the following is most responsible for the symptoms associated with poison ivy? | TH cells that activate macrophages in the skin |
| According to the "hygiene hypothesis" . . . | lack of exposure to gut flora leads to fewer Treg cells and more autoimmune diseases |
| Which of the following would be characteristic of a highly evolved pathogen? | Incidence of infection 90%, mortality 1 in 1,000 |
| What are “pathogenicity islands”? | Clusters of virulence factor genes that can be transmitted by horizontal gene transfer |
| How do bacteria with Type III secretion systems (T3SS) typically enter host cells? | Effectors secreted through the T3SS cause the host cell to enfold the bacteria in membrane ruffles |
| Which of the following is a method for bacteria to evade the host immune defenses? | They have capsules to avoid phagocytosis |
| Several organisms (Staphylococcus, Pseudomonas, Enterococcus) cause disease in catheterized patients much more frequently than in non-catheterized patients. What is the most important virulence factor for these organisms? | Ability to form biofilms on the catheter |
| A male patient ingests a dose equal to the ID50 of E. coli that expresses the type P pilus. What would be the most likely outcome? | No infection |
| A pathogen that has evolved for a long time in the same environment as its host will exhibit which of the following? | High prevalence and low mortality |
| Elderly patients on long-term oral penicillin therapy often acquire the infectious disease pseudomembranous colitis, caused by Clostridium difficile. How does penicillin use affect the course of this disease? | Penicillin kills native flora, allowing C. difficile to colonize |
| Which of the mechanisms below can bacteria use to escape phagocytosis? | Production of lysins to lyse the phagocyte |
| A pathogen that has recently emerged in a particular region of the world would be expected to have which of the following epidemiological characteristics? | High virulence and low prevalence |
| What is a major difference between an infection and an intoxication? | An intoxication cannot be treated with antibiotics |
| Many pathogenic bacteria have evolved a C5a peptidase. What is the function of this virulence factor? | It reduces the host's ability to recruit phagocytes to the site of infection |
| Which of the following is the best example of balanced pathogenicity? | a virus that causes mild diarrhea and is spread fecal-oral with an ID50 of 20 organisms |
| The picture at right shows a bacterium (arrow) entering an epithelial cell. The elaborate structure that surrounds the bacterium forms ______. | in response to a bacterial protein secreted by a Type III secretory system |
| Neisseria gonorrhoeae (Ng) can bind a host's C3b regulatory protein. Why does Ng do that? | to inactivate C3b when it binds to Ng |
| What is the function of the Staphylococcal protein A? | Fc receptor |
| Which of the following would you expect to be the eventual outcome of an evolutionary selection process in a pathogenic bacterium? | It will change from an acute infection to a chronic one |
| Correctly order the following steps in the Shigella infection cycle. | M cell entry → macrophage entry → epithelial cell entry → actin polymerization |
| Which of the following would typically NOT be true of an attenuated organism? | Its ID50 is very low |
| A microbiologist tells you that there is no model organism for the disease he is studying. What does he mean by this? | The disease only affects humans |
| Which bacterial invasion and colonization (I/C) factor is correctly matched with its role in an infection? | siderophore – steals iron from the eukaryotic host |
| How are bacterial type III secretion system effectors involved in causing disease? | They rearrange the host cytoskeleton and allow the bacterium to enter host cells |
| At the right is a photomicrograph showing the bacterium Listeria monocytogenes (Lm) infecting a human cell. What can you conclude about how this bacterium lives in its host? | Lm is able to use actin from its host to avoid humoral immunity |
| What are fimbriae? | Special pili with adhesive proteins at their tips |
| The genes for which of the following would be LEAST likely to be located on a pathogenicity island? | LPS biosynthesis |
| Which of the following is a mechanism that bacteria use to avoid the host's immune response? | Bacteria cover themselves with antibodies |
| All of the following are important for bacterial survival in a host EXCEPT the ability to _____. | induce autoimmune antibodies |
| What do the structures in these two pictures have in common? | Both involve rearrangements of the host's cytoskeletal proteins |
| When we say that a patient has a "disseminated" bacterial infection, what can we assume? | The patient has or has had bacteremia |
| Throughout the 20th century, we have had to modify Koch's postulates as we learned more about host-pathogen interactions. All of the following observations have required modification of Koch's postulates, EXCEPT _____ | Bacteria eventually evolve less virulence as hosts evolve more resistance. |
| Shigella are intestinal bacteria that can break out of the phagosome. What strategy do they use to infect a host? | Get into macrophages as quickly as possible through intestinal M-cells |
| Which of the following is a method for viruses to evade the host immune defenses? | They produce their own “cancel kill” signal for NK cells |
| Which of the following is true of endotoxin, but not of an exotoxin? | Endotoxin stimulates interleukin release, which results in fever |
| Most of the really dangerous pathogenic fungi can do which of the following? | Get inhaled as mold spores and transition to yeast in the host’s body |
| How does your body respond to the presence of a superantigen toxin? | By secreting lots of cytokines and mounting a massive inflammatory response |
| What is the function of the B part of A-B toxins? | It binds to surface receptors on the host cell |
| Which of the following is usually true of an exotoxin, but not true of endotoxin? | The genes encoding it can be passed among cells on a pathogenicity island |
| How does a phospholipase toxin kill cells? | By removing the head groups, thus destroying the amphipathic nature of the phospholipid |
| How does Toxic Shock Syndrome Toxin function? | It crosslinks the TCR of TH cells to MHC2 that is not presenting an antigen |
| The bacterium Listeria monocytogenes can live in phagocytes by breaking down the phagolysosome membrane. Which of the following toxins could help L. monocytogenes do this? | A phospholipase |
| How is LPS toxic to humans? | It binds strongly to macrophages, causing a response that can lead to hypovolemia |
| What is the function of the A part of an AB toxin? | It enters the cytoplasm and kills the host cell, often by altering cell metabolism |
| For which bacterial toxins have we found a pharmaceutical use to make anesthetics more readily able to penetrate through skin and other tissues? | hyaluronidases |
| One reason why a vaccine against malaria has proven difficult to design is that the malaria parasite | lives in red blood cells, where it can avoid both cellular and humoral immunity |
| How does production of phospholipase enhance bacterial survival inside macrophages? | It disrupts the phagosome membrane, allowing the bacterium to escape |
| Diphtheria toxin is an AB toxin. What does this mean? | There is a receptor for it on a host cell membrane |
| Which of the following is NOT a way protozoans can avoid their host’s immune system? | Formation of syncytia |
| What is this diagram depicting? | The function of a superantigen toxin |
| Why do some viruses produce an analog of MHC1? | To stop NK cells from killing cells infected by the virus |
| Which of the following statements is accurate when comparing Anthrax toxin to LPS? | The genes for Anthrax toxin are more likely to be located on a plasmid |
| The bacterium that causes necrotizing fasciitis produces a hyaluronidase toxin. This toxin gives an advantage to the bacterium because it allows the bacterium to . . . | spread more rapidly between the cells in a tissue |
| Some viruses like Papillomavirus encode an inhibitor of the eukaryotic protein p53. Why? | so that they can prevent infected cells from undergoing apoptosis |
| During some viral infections, infected cells fuse to form___________because_____________. | syncytia ; it allows the virus to avoid serum antibodies |
| Why can't we produce a successful vaccine against endotoxin? | It can't be inactivated because it isn't a protein. |
| For which type of bacterial toxin is there a medical use - to make anesthetics more readily able to penetrate through skin and other tissues? | hyaluronidases |
| The malaria parasite has a particularly effective method of avoiding both humoral and cellular host immune defenses. Which of the following is correct about this parasite? | It lives in red blood cells |
| What would be the most effective way to protect a patient against bacterial endotoxin? | Test to see if intravenous fluids given to the patient coagulate Limulus blood cells |
| All of the following are characteristic of bacterial A-B toxins EXCEPT . . . | They hydrolyze the A part of phospholipids away from the B part |
| Why is there not yet a vaccine directed against bacterial endotoxin? | Endotoxin cannot be inactivated to produce a toxoid |
| How does a bacterial A-B toxin work? | The B part binds to receptors; the A part enters the host cell |
| How could you tell if a particular pathogen produced a superantigen toxin when it infected a patient? | Look for the release of cytokines from TH cells that do not recognize the pathogen |
| Viruses use all of the following strategies to avoid the immune system EXCEPT . . | production of an IgA protease |
| Can the structure shown at the right be toxic? If so, how? If not, why not? | Yes, the part labeled 'B' can bind to a protein that induces a strong cytokine response from macrophages |
| A naked virus, HPV, produces a protein called E6. Recalling what infection HPV causes, how does the E6 protein contribute to the infection? | It prevents the action of the p53 tumor suppressor gene in the host |
| The malaria parasite spends most of the human part of its life cycle in red blood cells (RBCs). What does this imply about the body's response to the presence of this parasite? | The parasite is exposed to neither humoral nor cellular immune responses |
| What is the primary method of tissue damage in meningitis and pelvic inflammatory disease? | Phagocytes recruited by inflammation damage host’s tissue |
| Acute rheumatic fever is caused by which of the following? | Antibodies for Strep M recognize an autoantigen in heart muscle, leading to induced autoimmune disease |
| The condition shown may be caused by which of the following? | Exfoliative toxin |
| For a chronic disease that is transmitted poorly between hosts (e.g. HIV) . . | prevalence would be MUCH higher than incidence |
| Which of the following is an important difference between droplet transmission and aerosol transmission of a disease? | Droplet transmission rarely results in a common-source outbreak |
| The most effective way to reduce the incidence of nosocomially spread infections is to . . . | Have health care workers wash their hands between each patient they touch |
| A newborn with a case of trachoma is an example of . . . | Vertical disease transmission |
| A person has a Staphylococcal skin infection. Another person acquires the same infection by sleeping on the same sheet as the first person. The sheet in this scenario serves as . . . | A fomite |
| An example of an emerging or re-emerging disease is . . . | Tuberculosis in Europe |
| Which of the following requires the strictest isolation between an infected patient and a healthcare worker? | Airborne precautions |
| Who or what is a fomite? | An inanimate object that spreads infection via indirect contact |
| The most common nosocomial infections are . . . | respiratory infections due to Staphylococcus transmitted in aerosols |
| Which of the following isolation procedures commonly used in hospitals is the least rigorous (i.e. requires the minimum use of additional protective barriers between patient and healthcare worker)? | Body substance precautions |
| In a recent mumps outbreak the case incidence rate over time is recorded as shown (x-axis is in weeks). This is an example of . . . | A person-to-person epidemic |
| Which of the following is a major portal of entry, but not a major portal of exit? | Wounds |
| The incidence of a particular disease was followed for two years (graph at right). Which of the following is the most reasonable statement about its epidemiology based on the graph? | It is spread by a mechanical vector |
| The average monthly prevalence of a disease in several countries for the period 2004-2008 is shown in the table at right as cases per 100,000 people. What can you say about the disease? | It is endemic in the United States |
| In nursing, Standard Precautions are taken to prevent transmitting disease via the nurse. In addition, there are Supplemental Precautions based on . . . | the mode of transmission of the disease the patient has |
| Anthrax spores can survive for many years in soil. Soil is a ______ for anthrax | reservoir |
| The incidence of a particular disease was followed for a year (graph at right). Which of the following is the most reasonable statement about its epidemiology? | It is likely spread by a biological vector |
| All of the following factors would presumably be especially important in nosocomial disease transmission EXCEPT . . | prevalence of an organism in a zoonotic reservoir |
| Which of the following is LEAST likely to be a portal of exit for a disease organism? | Sweat |
| Which of the following is an example of vertical transmission of a disease? | An HIV-positive baby is born to a mother with AIDS |
| A particular disease has a high seasonal incidence in the United States during February. Which of the following is probably true about this disease? | It is spread through respiratory droplets |
| What does it mean for a disease to be a "notifiable" disease? | The disease is serious enough that each case must be reported to the authorities |
| Which of the following organisms is NOT found more commonly in a nosocomial setting than as a community-acquired disease? | Pasteurella multocida |
| An example of an emerging or re-emerging disease is . . . | Lyme Disease in the United States |
| A chronic disease with a seasonal incidence peak in the summer would most likely . . . | be vector-borne, like Lyme Disease |
| Which of the following best explains the trend in the incidence of infectious diseases in the US since 1980? | Increased use of antibiotics, especially in nosocomial settings |
| When following certain supplemental precautions, not only the nurse, but the patient also must wear a face mask. Such a patient is also usually in a negative pressure room. What are we trying to prevent with these precautions? | Spread of an airborne infection from the patient to others in the hospital |
| A new virus is discovered. It is airborne, has a reservoir in geese, has a high ID50 for humans, has a segmented genome, and has not yet evolved balanced pathogenicity. Which part of this information is good news, and why? | The high ID50. At least it takes a lot of it to kill you |
| Which of the following has been most responsible for the trend in infectious disease incidence since 1980? | More global travel for tourism and economic migration |
| A stroke victim is admitted to a hospital's intensive care unit and placed on a respiratory ventilator. She develops pneumonia characterized by green sputum and a high fever. How did she most likely acquire this infection? | By formation of a biofilm on the ventilator tube |
| Rotavirus is frequently transmitted in daycare centers. Recalling what this virus causes, which of the following is the most likely route of transmission? | Fecal-ora |
| In the last 50 years, deaths in the US due to infectious diseases have . . . | increased again for the last 30 years after initial decrease |
| Nosocomial transmission of diseases is typically prevented by all of the following EXCEPT | positive pressure in rooms, negative in halls and common areas |
| Several infants in the neonatal ward of a hospital show symptoms including red, inflamed skin with peeling of the epidermal layer. They are likely infected with _____. | Staphylococcus aureus |
| A 30-year-old patient presents to a clinic with heart arrhythmia and joint pain. A few weeks previously, while camping in the Maine woods, he had noticed an unusual rash “like a bulls’ eye” that had gone away. How had he likely become infected? | by the bite of a small tick |
| The causative agent of tetanus is an AB toxin. Which of the following is true about it? | The A part inhibits release of a neuroinhibitor. |
| Rubella (“German measles”) is most serious in _____. | fetuses |
| Which of the following is NOT true of the chickenpox virus? | The spots in the rash all look the same a week after the onset of the disease. |
| Red skin rashes and white cheesy growth in moist areas of the body are caused by _____ | Candida albicans |
| What would be the most apparent way to distinguish rubeola from rubella? | White spots are present in the lining of the mouth in cases of rubeola |
| A major bacterial virulence factor that contributes to the condition seen in the picture is _____. | the enzyme coagulase |
| Which of the following could best be described as an opportunistic pathogen with high levels of R plasmid-mediated antibiotic resistance whose biofilms colonize patients with a weakened innate immune system? | Pseudomonas aeruginosa |
| The Varicella-Zoster virus _____. | remains dormant in nerve tissue and re-erupts after many years |
| Rapidly spreading abscess and lymphatic swelling after a dog or cat bite would most likely be caused by _____ | Pasteurella |
| A patient developed a roughened circular patch of skin on his face after playing with a cat. What infection would you suspect? | Ringworm |
| Infection with Pseudomonas is best treated preventatively. It is very difficult to treat once an infection has already occurred. Why? | It forms biofilms which are very difficult to treat with antibiotics |
| A patient presents himself to a clinic in Connecticut with a concentric, "bulls' eye" rash, muscle aches and low-grade fever. What symptoms would likely be in this patient's future? | Heart arrhythmia and joint pains |
| A 9-year-old boy has a cough, fever, and runny nose. He also has a fine, macular rash and small white spots in his mouth. What is the danger from this disease? | Damage to his T-cells may lead to serious secondary infections |
| What do tetanus and gangrene have in common? | They both require anaerobic conditions for the bacteria to grow |
| A wart such as the one shown at the right is caused by a _____. | virus |
| "German" Measles and Measles infections are mostly different, but there are some similarities. Which of the following is similar between these two viruses? | They are both transmitted by respiratory droplets |
| A baby develops a thick white growth in his mouth and on his tongue. What microbial agent is probably responsible for this? | Candida albicans |
| A woman who had shaved only her lower legs all winter decided to shave her thighs to prepare for summer. A few days later she developed small red bumps all over her thighs. What is likely the cause? | Staphylococcal folliculitis |
| Infections with which of these organisms are most associated with biofilm formation? | Staphylococcus epidermidis and Pseudomonas aeruginosa |
| The most serious symptoms of Lyme disease are caused by _____. | antibodies made against the bacterium that causes the disease |
| The Latin word 'tinea' means "moth-like," referring to the roughened patches of skin associated with this type of disease. The disease is caused by a ______________ that has _____________ as one of its main virulence factors | fungus ; keratinase |
| Which of the following disease organisms is correctly matched with the main symptoms of the disease that it causes? | Rubella – congenital syndrome with blindness, deafness and mental retardation |
| Which of the following statements about Human Papillomavirus (HPV) is correct? | Only a few HPV types can insert their DNA as a provirus into the host's chromosome |
| The organism that produces the infection shown in the picture has what major virulence factor? | keratinase |
| Medical and nursing students are taught to recognize infections with Pseudomonas aeruginosa as quickly as possible. How and why? | green pigment forms biofilms that are almost impossible to treat |
| Tetanus and Gangrene are both diseases associated with traumatic tissue injuries. How are they different? | Tetanus can be treated with passive immunity while gangrene cannot |
| A main virulence factor of both Staphylococcus and Pseudomonas is _____ | the ability to form dense biofilms |
| All of the following diseases EXCEPT ___________ are more serious in the fetus because of the fetus's lack of cellular immunity. | Rubeola |
| One form of the organism that causes the symptoms shown in the picture enters the body on the point of a thorn. It then changes to another form and progressively spreads along a lymphatic vessel. What is the disease? | Sporotrichosis |
| Which of the following can be diagnosed by a characteristic rash and is usually transmitted to humans by a biological vector? | Lyme Disease |
| Which of the following is a childhood disease that is potentially serious because it leaves a patient immunocompromised. It is now rare in the United States because of an effective vaccine | Measles |
| The infant shown in this picture has an itchy red rash that is making him fussy and irritated. The organism that is most likely causing this rash is _____ | a yeast like Candida |
| Which of the following may appear in many places in the body, all of which usually involve biofilms, often with a greenish pigment, forming on inadequately protected tissues? | Pseudomonas |
| A person who developed the skin rash shown at right might have what complication later on? | She might get a painful skin rash many years later, because this is a latent virus |
| What is usually the eventual cause of death in diphtheria patients? | Heart and kidney damage due to an AB cytotoxin that is absorbed in the blood |
| It is important to treat Strep throat aggressively as soon as it is noticed. Why? | Antibodies produced against it could damage heart valves and kidneys |
| A common cause of both “pinkeye” and ear infections in children is . . . | Haemophilus influenzae |
| A 7-year-old child presents at a clinic with heartbeat abnormalities, a fever, and a whitish membrane across the back of his throat. How should he be treated? | He should receive a passive IgG injection |
| Upon looking at over-the-counter (OTC) medicines for “cold” and “cold with fever” you find that the medicines are pretty much the same. What can you say about this, given your knowledge of the organisms that cause these conditions? | They’re very different viruses, but there is no specific treatment for either one |
| Many of the organisms that cause eye infections also cause ear infections and sinusitis. There are important exceptions, though. Organisms that cause eye infections but NOT ear ot sinus infections are probably acquired . . . | by direct or indirect contact with an infected source |
| Upper respiratory infection whose symptoms may look like Strep throat | Adenovirus |
| Which of the following is NOT a morphological or physiological feature of the respiratory system and associated organs that protects it against infection by pathogens? | low pH |
| The pathological structure indicated by the arrow in the throat of this 14-year old immunocompetent patient is most likely caused by . . | a bacterial AB toxin that is damaging throat epithelial cells |
| Haemophilus influenzae is a major cause of . . | eye, ear, nose and throat infections and meningitis |
| The upper part of the healthy respiratory tract has a native flora, but the lower part is axenic. What is mainly responsible for this? | ciliated epithelial cells that line the upper respiratory tract |
| Which of the following is a difference between rhinovirus and adenovirus? | One is acid-sensitive, the other can pass unharmed through the stomach |
| The major symptoms in a case of diphtheria are caused by . . . | an AB toxin that interferes with protein synthesis |
| A patient has an upper respiratory infection caused by Haemophilus influenzae. It would not be unusual if the patient developed __________ within the next week | otitis media |
| What is pneumonia? | fluid secretion into the lungs as part of our immune response to an infection |
| The common cold is most frequently caused by . . . | Human rhinovirus |
| All of the following are true about diphtheria EXCEPT . . . | Symptoms are caused by granuloma formation and cytokines |
| There are both 13-valent and 23-valent Pneumococcal vaccines. Which provides more effective long-term protection, and why? | The 13-valent because it contains polysaccharide capsule antigens conjugated to proteins |
| Which of the following is a common cause of otitis media in children, as well as an important cause of more serious diseases such as meningitis and septicemia? | Haemophilus influenzae |
| Which of the following symptoms would be considered unusual in a case of Strep throat? | cough |
| If you travel to the former Soviet Union and return with a case of Diphtheria, the Doctor will likely give you a shot of Diphtheria Immune Globulin. What is that? | A passive antitoxin |
| Adenovirus is commonly cited as a way to deliver genes or drugs into human cells, because it naturally infects our cells. Which 3 symptoms does this virus usually cause? | Conjunctivitis, cold and diarrhea |
| A man returning from Russia developed a high fever with throat inflammation and a dirty grey membrane across the back of his throat. The doctor told him that antibiotics wouldn't help much with this infection, but he gave the patient a shot anyway. Why? | The shot is an immune globulin that can block the action of a toxin |
| Which of the following is transmitted more commonly as a community-acquired infection than as a nosocomial infection? | Otitis media due to Haemophilus influenzae |
| After a visit from her 4-year-old granddaughter Sally, who had an ear infection, an elderly nursing home resident, Mary, developed pneumonia. What would have been the most effective way to prevent this infection? | Mary should have been vaccinated with a 23-valent vaccine |
| A frequent cause of the common cold, this acid-resistant virus can be transmitted by the fecal-oral route as well as the respiratory route | Adenovirus |
| Which of the following viruses is characterized by being an enveloped virus with a single-stranded RNA (ssRNA) incorporated into its structure? | Coronavirus |
| Which virulence factor of Group A Streptococcus functions by dissolving blood clots, contributing to its pathogenicity? | Streptokinase |
| A cigarette smoker presented with a high fever and a hacking cough that had developed over the course of a few days. Extreme shortness of breath was apparent. A sputum sample showed PMNLs and Gram positive cocci. The diagnosis would most likely be . . . | Streptoccal pneumonia |
| he coughs had become so severe that she began vomiting, and her mother was afraid she couldn't breathe. Which of the following vaccines could have prevented this disease? | an acellular subunit vaccine conjugated to another vaccine |
| An acute inflammatory respiratory disease associated with inhalation of aerosols from rodent feces, and especially prevalent in the southwest US is . . . | Hantavirus |
| This organism forms two different types of spores - arthrospores in the environment, and endospores in the host. There is a strong inflammatory response to the endospores, resulting in lung and tissue granuloma formation. What is the organism? | Coccidioides immitis |
| student presented with low grade fever and a cough that had developed over the course of a few weeks. She felt tired. No lymph node swelling. Chest X-ray is shown. A sputum sample was stained,no organisms visible. The diagnosis would most likely be . . . | Mycoplasmal pneumonia |
| Which of the following is true with respect to tuberculosis? | The disease can be spread by aerosols in addition to respiratory droplets |
| The vaccine currently used to provide protection against whooping cough is . . . | An acellular subunit vaccine |
| This organism has two spores in its life cycle - endospores, released in the body from spherules, and the distinctive spores at right, which are inhaled from the environment. | Coccidioidomycosis |
| Respiratory disease common in the midwest US spread by contact with aerosols from bird droppings and bat guano. | Histoplasmosis |
| Which of the following is NOT associated with tuberculosis? | vertical transmission |
| A major difference between the injected influenza vaccine and the "FluMist" nasal spray is that . . . | "FluMist" induces active IgA immunity in a major portal of entry for the virus |
| A homeless man develops a chronic cough. When it gets so bad that he begins to cough up blood, he goes to a community clinic, where the following X-ray is taken. What should be done for this patient? | DOT should be started while awaiting the results of a PPD test |
| Antigenic drift in influenza virus is . . . | a minor change in the virus spike proteins caused by mutation of the RNA |
| This organism is associated with a frequently fatal respiratory syndrome with capillary leakage leading to pulmonary edema. It is spread primarily in the southwest United States by inhalation of dust aerosols contaminated with rodent urine or feces | Sin Nombre hantavirus |
| The United States recently switched from the DPT vaccine with a DT booster to the DTaP vaccine with a DTaP booster. What is one reason why this change was made? | Many adults were found to lack immunity to pertussis, so it was added to the booster |
| Antigenic drift is especially rapid in influenza virus because . . . | it uses RNA as its genetic material |
| The most common cause of lower respiratory tract infections in young children causes irritation to the bronchiole lining, with the characteristically damaged cellular appearance seen at right. What is this disease? | Respiratory Syncytial Virus |
| Which of the following is true with respect to tuberculosis? | It can affect the bones and liver as well as the lungs |
| Which of the following statements about antigenic shift is NOT true? | It is caused by the lack of proofreading by RNA polymerase |
| Which of the following fungal diseases is NOT correctly matched with a risk factor? | Candidiasis – failure to be vaccinated against it |
| What is primarily responsible for the current trend in Pertussis incidence in the USA? | Adult immunity decreasing below the herd immunity threshold |
| Mycobacterium tuberculosis (Mtb) can prevent phagosome / lysosome fusion. Therefore . . . | granulomas can form in some cases of Mtb infection |
| Which of the following is a difference between antigenic DRIFT and antigenic SHIFT in influenza viruses? | DRIFT is somewhat predictable, SHIFT is not |
| How does Mycobacterium tuberculosis cause the formation of the structure indicated in the X-ray at the right? | It survives in macrophages, which continue to secrete cytokines. |
| Which of the following statements about influenza is FALSE? | It only infects humans, so can potentially be eradicated |
| Histoplasmosis is very common in Indiana. Which of the following is the most likely way to be infected with this illness? | You tear down a shed that has a large accumulation of bird feces inside it |
| A 20-year-old student developed a cough and mild fever of 4 weeks' duration. The causative organism attached to his lung epithelial cells and caused irritation by secreting H2O2. What is unusual about this organism? | It has no cell wall. |
| Which of the following is typical in cases of miliary tuberculosis, but not in other TB cases? | Granuloma formation in the liver with eventual liver failure |
| Antigenic shift in influenza virus . . . | happens because influenza has a segmented genome |
| The most common cause of viral pneumonia in young children is . . . | Respiratory Syncytial Virus |
Created by:
Victoria Guadiano
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