Q: Which equation best represents the delayed hypersensitivity reaction observed in the Mantoux test for tuberculosis?

$$\text{PPD injection} \rightarrow \text{Induration} + \text{Reddening in 48 hours}$$

Q: Which equation best represents the process of antigenic shift in influenza viruses?

$$\text{Antigenic shift} = \text{Genetic recombination between different strains}$$

Q: Which equation best represents the competitive inhibition by normal flora in the upper respiratory system?

$$\text{Normal flora} + \text{Pathogen} \rightarrow \text{Suppression of pathogen}$$

Question 1

Which of the following best describes the normal microbiota of the respiratory system?

Accepted Answer

The upper respiratory system contains normal flora that suppress pathogens by competitive inhibition, while the lower respiratory system is sterile.

Question 2

A patient presents with a sore throat, fever, and a gray membrane in the throat. Gram-positive rods without endospores are cultured from the membrane. Which organism is most likely responsible?

Accepted Answer

Corynebacterium diphtheriae

Question 3

Which test is used to measure immunity to diphtheria?

Accepted Answer

Schick test

Question 4

Which of the following is a complication of Streptococcal pharyngitis caused by lysogenized S. pyogenes?

Accepted Answer

Scarlet fever

Question 5

Which of the following statements about the DTaP vaccine is correct?

Accepted Answer

It contains inactivated toxoids for diphtheria and tetanus, and acellular fragments for pertussis.

Question 6

Which organism is most commonly associated with acute otitis media in children?

Accepted Answer

Streptococcus pneumoniae

Question 7

Which stage of pertussis is characterized by violent coughing sieges?

Accepted Answer

Paroxysmal stage

Question 8

Which diagnostic method is preferred for detecting tuberculosis in individuals who have received the BCG vaccine?

Accepted Answer

Blood tests measuring release of IFN-γ from white blood cells

Question 9

Which of the following best describes the pathogenesis of tuberculosis?

Accepted Answer

Tubercle bacilli survive in macrophages, form tubercles, and may remain dormant in a caseous center.

Question 10

Which equation best represents the delayed hypersensitivity reaction observed in the Mantoux test for tuberculosis?

Accepted Answer

$$	ext{PPD injection} ightarrow 	ext{Induration} + 	ext{Reddening in 48 hours}$$

Question 11

Which organism is responsible for primary atypical (walking) pneumonia, and what is a key diagnostic feature?

Accepted Answer

Mycoplasma pneumoniae; PCR and serological testing (IgM)

Question 12

Which of the following is a major risk factor for Legionellosis?

Accepted Answer

Inhalation of aerosols from water sources, especially in older men who smoke or drink heavily

Question 13

Which form of pneumonia is most likely to affect immunocompromised patients, such as those with AIDS or undergoing transplants?

Accepted Answer

Pneumocystis pneumonia

Question 14

Which equation best represents the process of antigenic shift in influenza viruses?

Accepted Answer

$$	ext{Antigenic shift} = 	ext{Genetic recombination between different strains}$$

Question 15

Which of the following is a characteristic symptom of scarlet fever?

Accepted Answer

Pink-red rash and strawberry tongue

Question 16

Which organism is most likely to cause pneumonia in a patient with alcoholism, poor nutrition, cancer, or diabetes?

Accepted Answer

Haemophilus influenzae

Question 17

Which equation best represents the competitive inhibition by normal flora in the upper respiratory system?

Accepted Answer

$$	ext{Normal flora} + 	ext{Pathogen} ightarrow 	ext{Suppression of pathogen}$$

Question 18

Which of the following is a key feature of Histoplasma capsulatum infection?

Accepted Answer

Transmission by inhaling conidia from soil containing bat droppings

Question 19

Which equation best represents the process of liquefaction in tuberculosis pathogenesis?

Accepted Answer

$$	ext{Caseous center} ightarrow 	ext{Liquefaction} ightarrow 	ext{Tuberculous cavity}$$

Question 20

Which organism is responsible for Q fever, and what is a possible route of transmission?

Accepted Answer

Coxiella burnetii; unpasteurized milk

Microbial Diseases of the Respiratory System: Structure, Pathogenesis, and Clinical Features

Study Guide - Practice Questions

Study Guide - Flashcards