Question 1

Which of the following best describes the difference between colonization, infection, and disease?

Accepted Answer

Colonization is when microbes live on or in the body without causing harm; infection is when microbes enter tissues and multiply; disease is when the effects of infection damage or disrupt tissues and organs.

Question 2

A patient develops pneumonia after being hospitalized for a surgical procedure. This is an example of:

Accepted Answer

A healthcare-associated infection (HAI)

Question 3

Which of the following is NOT a typical portal of entry for pathogens?

Accepted Answer

Liver

Question 4

The infectious dose (ID) is best defined as:

Accepted Answer

The minimum number of microbes necessary to cause an infection to proceed

Question 5

Which of the following is a correct statement about exotoxins and endotoxins?

Accepted Answer

Exotoxins are secreted proteins with specific effects; endotoxins are part of the Gram-negative bacterial cell wall and have more general effects.

Question 6

A microbe that can only cause disease when the host’s immune system is compromised is called:

Accepted Answer

An opportunistic pathogen

Question 7

Which of the following is a virulence factor that helps bacteria evade phagocytosis?

Accepted Answer

Capsule

Question 8

A patient is infected with a bacterium that produces hyaluronidase. What is the most likely effect of this enzyme?

Accepted Answer

It digests and damages connective tissues, helping the microorganism spread.

Question 9

Which of the following best describes a superantigen?

Accepted Answer

A molecule that non-specifically activates a large fraction of T cells, causing excessive cytokine release

Question 10

Which of the following is an example of a nonliving reservoir for infectious agents?

Accepted Answer

Contaminated water

Question 11

A patient is exposed to a pathogen but does not develop symptoms. The pathogen is present and active in the tissues. This is best described as:

Accepted Answer

An asymptomatic or subclinical infection

Question 12

Which of the following is NOT a step in the process by which a microbe causes disease in a host?

Accepted Answer

Sporulation in the environment

Question 13

Which of the following statements about zoonoses is correct?

Accepted Answer

Zoonoses are infections indigenous to animals but naturally transmissible to humans.

Question 14

Which of the following is a correct pairing of exotoxin type and its effect?

Accepted Answer

Cytotoxin – damages a variety of cell types by interfering with cellular mechanisms or lysing cells

Question 15

A patient is infected with a Gram-negative bacterium. Which component is responsible for the general symptoms of fever and shock?

Accepted Answer

Lipid A (endotoxin)

Question 16

Which of the following best explains why Streptococcus pyogenes can cause infections in multiple body sites?

Accepted Answer

It is adapted to multiple portals of entry, including skin, urogenital tract, and respiratory tract.

Question 17

Which of the following is NOT a common healthcare-associated infection (HAI)?

Accepted Answer

Chickenpox

Question 18

A patient’s blood culture grows bacteria, but the patient has no symptoms. This is best described as:

Accepted Answer

Bacteremia

Question 19

Which of the following is a function of an infection control officer in a hospital?

Accepted Answer

Tracking potential outbreaks and training healthcare workers in aseptic techniques

Question 20

Which of the following best describes the role of the human microbiome in health?

Accepted Answer

It consists of all microbes found on and in a normal human, most of which are beneficial but can cause disease under certain circumstances.

Interactions Between Microbes and Humans: Pathogenesis, Virulence, and Disease Progression

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