$$\text{Disease Outcome} = \text{Pathogenicity} \times \text{Virulence}$$

Question 1

Which term best describes the ability of a microbe to cause disease in a host?

Accepted Answer

Pathogenicity

Question 2

A patient presents with a fever and elevated blood pressure. These are examples of:

Accepted Answer

Signs

Question 3

Which affix in medical terminology indicates inflammation?

Accepted Answer

-itis

Question 4

A patient is infected with a pathogen but does not show any noticeable symptoms. This is best described as:

Accepted Answer

Subclinical infection

Question 5

Which of the following is an example of an opportunistic infection?

Accepted Answer

Pseudomonas aeruginosa infecting a wound in an immunocompromised patient

Question 6

During antibiotic treatment for a bacterial infection, a patient develops a yeast infection. This is an example of:

Accepted Answer

Secondary infection

Question 7

Which of the following best describes a systemic infection?

Accepted Answer

An infection that affects the entire body

Question 8

Which step in Koch’s postulates involves infecting a healthy test subject with a suspected pathogen?

Accepted Answer

Step 3

Question 9

Which molecular technique is most useful for identifying pathogenic strains that cannot be cultured?

Accepted Answer

Polymerase Chain Reaction (PCR)

Question 10

Which of the following is a virulence factor that allows pathogens to evade the immune system?

Accepted Answer

Capsule formation

Question 11

A pathogen produces collagenase. What is the primary function of this enzyme?

Accepted Answer

Breaks down connective tissue to facilitate invasion

Question 12

Which toxin is only produced by Gram-negative bacteria and can cause septic shock?

Accepted Answer

Endotoxin

Question 13

The AB toxin mechanism involves:

Accepted Answer

Two subunits: one binds to the host cell, the other enters and disrupts cellular function

Question 14

Which of the following is a superantigen’s effect on the immune system?

Accepted Answer

Activates T cells inappropriately, causing excessive cytokine release

Question 15

A patient with cholera is experiencing severe diarrhea. Which type of toxin is responsible?

Accepted Answer

Enterotoxin

Question 16

Which immune evasion strategy involves changing surface antigens to avoid antibody detection?

Accepted Answer

Antigenic variation

Question 17

A bacterium survives inside a phagocyte by preventing the formation of the phagolysosome. This is an example of:

Accepted Answer

Immune evasion

Question 18

Which of the following equations best represents the relationship between pathogenicity, virulence, and disease outcome?

Accepted Answer

$$	ext{Disease Outcome} = 	ext{Pathogenicity} 	imes 	ext{Virulence}$$

Question 19

Which of the following is a plausible scenario for a latent infection?

Accepted Answer

A patient is infected but the pathogen remains dormant for years before symptoms appear

Question 20

Which of the following is NOT a step in the establishment of pathogenicity?

Accepted Answer

Antibody production

Pathogenicity and Mechanisms of Infectious Disease

Study Guide - Practice Questions