Question 1

Which of the following best describes the concept of 'tropism' in host-microbe interactions?

Accepted Answer

The preference of a pathogen for a specific host or tissue within the host.

Question 2

A patient develops sepsis after E. coli from their appendix enters the abdominal cavity. This is an example of:

Accepted Answer

A commensal becoming an opportunistic pathogen.

Question 3

Which of the following statements about endotoxins is TRUE?

Accepted Answer

They are released from Gram-negative bacteria when the cell wall breaks apart.

Question 4

A bacterial toxin has an $$LD_{50} of$$ $$0.001\ \mu g/kg$$ body weight in mice. What does this value indicate?

Accepted Answer

The toxin is more lethal than one with an $$LD_{50} of$$ $$1\ \mu g/kg.$$

Question 5

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

Accepted Answer

All of the above are portals of entry

Question 6

Which of the following organisms does NOT produce an endotoxin?

Accepted Answer

Staphylococcus aureus

Question 7

A microbe that can cause disease only when the host’s immune system is compromised is best described as a(n):

Accepted Answer

Opportunistic pathogen

Question 8

Which of the following best explains why most sexually transmitted pathogens evolve virulence factors that are minimally symptomatic?

Accepted Answer

To maximize transmission by keeping the host healthy enough for contact.

Question 9

Which of the following is a function of siderophores produced by bacteria?

Accepted Answer

Snatching iron from transferrin in the host

Question 10

A patient is infected with a pathogen that periodically alters its surface molecules to evade the immune system. This is an example of:

Accepted Answer

Antigenic variation

Question 11

Which of the following is a correct pairing of toxin type and its target?

Accepted Answer

Hepatotoxins – liver

Question 12

Which of the following is a characteristic of exotoxins but NOT endotoxins?

Accepted Answer

Can be converted into toxoids for vaccines

Question 13

A hospital patient develops a C. difficile infection after antibiotic therapy. This is most likely due to:

Accepted Answer

Dysbiosis resulting from disruption of normal microbiota

Question 14

Which of the following best describes the role of adhesins in infection?

Accepted Answer

They enable pathogens to stick to host cells, facilitating colonization.

Question 15

Which of the following is a true statement regarding biosafety levels (BSL)?

Accepted Answer

BSL-2 agents include Staphylococcus aureus and most influenza strains.

Question 16

A pathogen that can survive inside host cells and cause persistent or recurrent disease is exhibiting which of the following?

Accepted Answer

Latency

Question 17

Which of the following is the most common portal of entry for pathogens?

Accepted Answer

Respiratory tract

Question 18

Which of the following best explains why pathogens grown in cell culture often become attenuated?

Accepted Answer

They lose virulence factors needed to cause disease in a host.

Question 19

Which of the following is a multi-step process that a pathogen must complete to establish an infection?

Accepted Answer

Adhere to host tissues, invade tissues, replicate, and transmit to a new host

Question 20

Which of the following precautions is most appropriate for preventing the spread of MRSA in a healthcare setting?

Accepted Answer

Contact precautions

Host–Microbe Interactions and Pathogenesis: Principles and Mechanisms

Study Guide - Practice Questions