Chapter 15 Microbiology.

19) Which of the following cytopathic effects is cytocidal? A) inclusion bodies B) giant cells C) antigenic changes D) transformation E) release of enzymes from lysosomes

E) release of enzymes from lysosomes

38) Which of the following is NOT a cytopathic effect of viruses? A) cell death B) host cells fusing to form multinucleated syncytia C) inclusion bodies forming in the cytoplasm or nucleus D) increased cell growth E) toxin production

E) toxin production

23) Which of the following contributes to the virulence of a pathogen? A)Numbers of microorganisms that gain access to a host B)Cell wall C)Toxins D)Enzymes E)All of the above contribute to a pathogen's virulence.

E)All of the above contribute to a pathogen's virulence.

10) Cytopathic effects are changes in host cells due to A) viral infections. B) protozoan infections. C) fungal infections. D) bacterial infections. E) helminthic infections.

A) viral infections.

44) In response to the presence of endotoxin, phagocytes secrete tumor necrosis factor. This causes A) the disease to subside. B) a decrease in blood pressure. C) a fever. D) a aram-negative infection. E) an increase in red blood cells.

B) a decrease in blood pressure.

37) Antibiotics can lead to septic shock if used to treat A) viral infections. B) gram-negative bacterial infections. C) gram-positive bacterial infections. D) protozoan infections. E) helminth infestations.

B) gram-negative bacterial infections.

35) Endotoxins in sterile injectable drugs could cause A) infection. B) septic shock symptoms. C) giant cell formation. D) nerve damage. E) no damage, because they are sterile.

B) septic shock symptoms.

42) Bacteria that cause periodontal disease have adhesins for receptors on streptococci that colonize on teeth. This indicates that: A) streptococci get bacterial infections. B) streptococcal colonization is necessary for periodontal disease. C) bacteria that cause periodontal disease adhere to gums and teeth. D) bacteria that cause periodontal disease adhere to teeth. E) streptococci cause periodontal disease.

B) streptococcal colonization is necessary for periodontal disease.

4) The ID50 is A) a measure of pathogenicity. B) the dose that will cause an infection in 50 percent of the test population. C) the dose that will kill some of the test population. D) the dose that will cause an infection in some of the test population. E) the dose that will kill 50 percent of the test population.

B) the dose that will cause an infection in 50 percent of the test population.

43) Nonpathogenic Vibrio cholerae can acquire the cholera toxin gene by A) phagocytosis. B) transduction. C) conjugation. D) transformation. E) infecting a pathogenic Vibrio cholerae.

B) transduction.

Which of the following CANNOT be used for adherence? A)Fimbriae B)Cell membrane mannose C)Glycoproteins D)Lipoproteins E)Capsules

B)Cell membrane mannose

Which is a method of avoiding phagocytosis? A)Producing fimbriae B)Inducing endocytosis C)Producing toxins D)Inducing TNF E)Producing iron-binding proteins

B)Inducing endocytosis

2) Which of the following diseases is NOT usually contracted by the respiratory route? A)Pneumonia B)Infectious hepatitis C)Tuberculosis D)Whooping cough E)All of the above are usually contracted by the respiratory route

B)Infectious hepatitis

Which organism most easily causes an infection? A)E. coli O157:H7 ID50=20 B)Legionella pneumophila ID50=1 C)Shigella ID50=10 D)Treponema pallidum ID50=57 E)Can't tel

B)Legionella pneumophila

A needlestick is an example of which portal of entry? A)Skin B)Parenteral route C)Mucous membranes D)All of the above E)None of the above

B)Parenteral route

22) Which of the following statements about staphylococcal enterotoxin is FALSE? A) It causes vomiting. B) It causes diarrhea. C) It is an exotoxin. D) It is produced by Staphylococcus aureus growing in the host's intestines. E) It is a superantigen.

D) It is produced by Staphylococcus aureus growing in the host's intestines.

26) Which of the following statements about M protein is FALSE? A) It is found on Streptococcus pyogenes. B) It is found on fimbriae. C) It is heat- and acid-resistant. D) It is readily digested by phagocytes. E) It is a protein.

D) It is readily digested by phagocytes.

36) Gram-negative septic shock results from the following events. What is the second step? A) Body temperature is reset in the hypothalamus. B) Fever occurs. C) IL-1 is released. D) LPS is released from gram-negative bacteria. E) Phagocytes ingest gram-negative bacteria.

D) LPS is released from gram-negative bacteria.

11) Which of the following does NOT contribute to the symptoms of a fungal disease? A) capsules B) toxins C) allergic response of the host D) cell walls E) metabolic products

D) cell walls

Which of the following isNOT considered entry via the parenteral route? A) injection. B) bite. C) surgery. D) hair follicle. E) skin cut.

D) hair follicle.

33) Which of the following mechanisms is used by gram-negative bacteria to cross the blood-brain barrier? A) producing fimbriae B) inducing endocytosis C) producing toxins D) inducing TNF E) all the above

D) inducing TNF

12) Which of the following is NOT a method of avoiding host antibodies? A) antigenic changes. B) IgA proteases. C) invasins. D) membrane-disrupting toxins. E) inducing endocytosis.

D) membrane-disrupting toxins.

Septic shock due to gram-positive bacteria is caused by A)A-B toxins. B)Lipid A. C)Membrane-disrupting toxins. D)Superantigens. E)Erythrogenic toxin

D) superantigens.

21) Symptoms of protozoan and helminthic diseases are due to A)Tissue damage due to growth of the parasite on the tissues. B)Waste products excreted by the parasite. C)Products released from damaged tissues. D)All of the above. E)None of the above

D)All of the above.

Thirty-two people in San Francisco who ate jackfish caught at Midway Island developed malaise, nausea,blurred vision, breathing difficulty, and numbness from 3 to 6 hours after eating. The most likely cause of this food intoxication is A)A mycotoxin. B)Aflatoxin. C)Staphylococcal enterotoxin. D)Ciguatera. E)Cholera toxin.

D)Ciguatera.

A cell wall can increase a bacterium's virulence because cell wall lipid A A)Resists phagocytosis. B)Helps the bacterium attach. C)Destroys host tissues. D)Is toxic. E)All bacteria have a cell wall and all are not pathogenic; therefore, cell walls do not contribute to virulence

D)Is toxic.

6) Which of the following statements is FALSE? A) Leukocidins destroy neutrophils. B) Hemolysins lyse red blood cells. C) Hyaluronidase breaks down substances between cells. D) Kinase destroys fibrin clots. E) Coagulase destroys blood clots.

E) Coagulase destroys blood clots.

Which of the following organisms causes the most severe disease? A)E. coli O157:H7 ID50=20 B)Rhinovirus ID50=200 C)Shigella ID50=10 D)Treponema pallidum ID50=57 E)Can't tell

E)Can't tell

9) Which of the following is NOT a membrane-disrupting toxin? A) A-B toxin B) hemolysin C) leukocidin D) streptolysin O E) streptolysin S

A) A-B toxin

18) All of the following organisms produce exotoxins EXCEPT A) Salmonella typhi. B) Clostridium botulinum. C) Corynebacterium diphtheriae. D) Clostridium tetani. E) Staphylococcus aureus.

A) Salmonella typhi.

17) Botulism is caused by ingestion of a proteinaceous exotoxin; therefore, it can easily be prevented by A) boiling food prior to consumption. B) administering antibiotics to patients. C) not eating canned food. D) preventing fecal contamination of food. E) filtering food.

A) boiling food prior to consumption.

24) Lysogenic bacteriophages contribute to bacterial virulence because bacteriophages A) give new gene sequences to the host bacteria. B) produce toxins. C) carry plasmids. D) kill the bacteria, causing release of endotoxins. E) kill human cells.

A) give new gene sequences to the host bacteria.

1) The most frequently used portal of entry for pathogens is the A) mucous membranes of the respiratory tract. B) mucous membranes of the gastrointestinal tract. C) skin. D) parenteral route. E) All of these portals are used equally.

A) mucous membranes of the respiratory tract.

34) Injectable drugs are tested for endotoxins by A) the Limulus amoebocyte lysate test. B) counting the viable bacteria. C) filtering out the cells. D) looking for turbidity. E) culturing bacteria.

A) the Limulus amoebocyte lysate test.

5) All of the following contribute to a pathogen's invasiveness EXCEPT A) toxins. B) capsules. C) cell wall components. D) hyaluronidase. E) coagulases.

A) toxins

The administration of ampicillin before surgery A)Decreases the risk of staphylococcal infection. B)Increases the risk of staphylococcal infection. C)Has no effect on risk of infection. D)Replaces tetracycline. E)Can't tell

A)Decreases the risk of staphylococcal infection.

Pseudomonas aeruginosa produces a two-part exotoxin. The most likely pathologic effect of this toxin is A)Inhibition of protein synthesis. B)Flaccid paralysis. C)Tetani or lockjaw. D)A red rash. E)The bacteria will be able to grow in phagocytes.

A)Inhibition of protein synthesis.

7) Which of the following statements about exotoxins is generally FALSE? A) They are more potent than endotoxins. B) They are composed of proteins. C) They are resistant to heat. D) They have specific methods of action. E) They are produced by gram-positive bacteria.

C) They are resistant to heat.

45) Patients developed inflammation a few hours following eye surgery. Instruments and solutions were sterile, and the Limulus assay was positive. The patients' inflammation was due to A) bacterial infection. B) viral infection. C) endotoxin. D) exotoxin. E) The answer cannot be determined based on the information provided.

C) endotoxin.

3) Most pathogens that gain access through the skin A) can penetrate intact skin. B) just infect the skin itself. C) enter through hair follicles and sweat ducts. D) must adhere first while their invasive factors allow them to penetrate. E) must be injected.

C) enter through hair follicles and sweat ducts.

Poliovirus is ingested and gains access to tissues by which portal of entry? A)Skin B)Parenteral C)Mucous membranes D)All of the above E)None of the above

C) mucous membranes

8) Endotoxins are A) associated with gram-positive bacteria. B) molecules that bind nerve cells. C) part of the gram-negative cell wall. D) excreted from the cell. E) A-B toxins.

C) part of the gram-negative cell wall.

31) Cholera toxin polypeptide A binds to surface gangliosides on target cells. If the gangliosides were removed, A) polypeptide A would bind to target cells. B) polypeptide A would enter the cells. C) polypeptide B would not be able to enter the cells. D) Vibrio would not produce cholera toxin. E) Vibrio would bind to target cells.

C) polypeptide B would not be able to enter the cells.

13) Siderophores are bacterial proteins that compete with animal A) antibodies. B) red blood cells. C) transferrin D) white blood cells. E) receptors.

C) transferrin

20) All of the following are used by bacteria to attach to host cells EXCEPT A) M protein. B) ligands. C) fimbriae. D) capsules. E) A-B toxins.

E) A-B toxins.