Question 1

Which structural feature of Mycobacterium species is responsible for their resistance to Gram-staining, desiccation, and many antimicrobial drugs?

Accepted Answer

Cell wall containing mycolic acid

Question 2

A patient presents with a thick, grayish pseudomembrane in the throat. Which diagnostic test would best confirm Corynebacterium diphtheriae as the causative agent?

Accepted Answer

Potassium-tellurite agar culture

Question 3

Which mechanism allows Mycobacterium tuberculosis to survive within macrophages during primary tuberculosis?

Accepted Answer

Prevention of lysosome-vesicle fusion

Question 4

Which combination of drugs is commonly used in the initial phase of tuberculosis treatment?

Accepted Answer

Isoniazid, rifampin, ethambutol or streptomycin, and pyrazinamide

Question 5

A patient with AIDS develops a disseminated infection affecting multiple organs. Which pathogen is most likely responsible?

Accepted Answer

Mycobacterium avium-intracellulare

Question 6

Which form of leprosy is characterized by a strong cell-mediated immune response and is nonprogressive?

Accepted Answer

Tuberculoid leprosy

Question 7

Cutibacterium acnes is most commonly associated with which human disease?

Accepted Answer

Acne

Question 8

Which of the following is a major prevention strategy for diphtheria?

Accepted Answer

Immunization with diphtheria vaccine

Question 9

A patient presents with abscesses connected by channels in the skin after a dental procedure. Which organism is most likely responsible?

Accepted Answer

Actinomyces

Question 10

Which equation best represents the rate of bacterial growth for Mycobacterium tuberculosis, given its slow growth due to mycolic acid?

Accepted Answer

$$N(t) = N_0$ e$$^{\mu t}$$, where $$\mu$$ is low$

Question 11

Which of the following is NOT a characteristic of Mycobacterium cell walls?

Accepted Answer

Contains endospores

Question 12

A patient develops a mycetoma after a traumatic injury involving soil. Which organism is most likely responsible?

Accepted Answer

Nocardia asteroides

Question 13

Which diagnostic method is used to identify exposure to Mycobacterium tuberculosis?

Accepted Answer

Tuberculin skin test

Question 14

Which of the following is a reason why lifelong treatment may be necessary for some patients with leprosy?

Accepted Answer

Mycobacterium leprae cannot be eliminated completely by immune response

Question 15

Which of the following is a plausible consequence of disseminated tuberculosis?

Accepted Answer

Complications at multiple organ sites

Question 16

Which prevention strategy is recommended for Nocardia asteroides infections?

Accepted Answer

Avoiding exposure to soil rich in organic matter

Question 17

Which of the following is a plausible reason why Mycobacterium leprae grows best in cooler regions of the human body?

Accepted Answer

It is sensitive to high temperatures

Question 18

Which of the following is a plausible explanation for why Corynebacterium diphtheriae strains that do not produce toxin are not pathogenic?

Accepted Answer

The toxin is required to inhibit polypeptide synthesis in host cells

Question 19

Which of the following is a plausible reason why combination therapy is used to treat tuberculosis?

Accepted Answer

To prevent the development of drug resistance

Question 20

Which of the following is a plausible explanation for why Actinomyces infections are difficult to diagnose?

Accepted Answer

Other organisms cause similar symptoms

Pathogenic Gram-Positive Bacteria: Structure, Diseases, and Clinical Management

Study Guide - Practice Questions

Study Guide - Flashcards