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10 Cards in this Set
- Front
- Back
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The removal of plasmids reduces virulence in which of the following organisms? |
Clostridium tetani |
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What is the LD50 for the bacterial toxin tested in the example below? |
C. Dilution 25, animals died- 3, animals survived- 3 |
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Which of the following is not a portal of entry for pathogens? |
Blood |
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All of the following can occur during bacterial infection. Which of the following would prevent all of the others? |
Vaccination against fimbriae |
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The ID50 for Campylobacter sp. is 500 cells; the ID50 for Cryptosporidium sp. is 100 cells. Which of the following statements is false? |
Campylobacter and Cryptosporidium are equally virulent; they cause infections in the same number of test animals |
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An encapsulated bacterium can be virulent because the capsule |
Resists phagocytosis |
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A drug that binds to mannose on human cells would prevent |
The attachment of pathogenic E. Coli |
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The earliest smallpox vaccines were infected tissue rubbed into the skin of a healthy person. The recipient of such a vaccine usually developed a mild case of small pox, recovered, and was immune thereafter. What is the most likely reason this vaccine did not kill more people? |
Skin is the wrong portal of entry for smallpox |
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Which of the following does not represent the same mechanism for avoiding host defenses as the others? |
Surface protein genes in Neisseria gonorrhoeae mutate frequently |
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Which of the following statements is true? |
A successful pathogen doesn’t kill its host before it is transmitted |
