Question 1

Which of the following features contributes most to the virulence of Staphylococcus aureus in causing skin infections?

Accepted Answer

Secretion of coagulase enzyme

Question 2

A patient presents with a rapidly progressing pneumonia. Laboratory tests reveal Gram-positive diplococci. Which organism is most likely responsible?

Accepted Answer

Streptococcus pneumoniae

Question 3

Which Gram-negative bacterium is known for producing a blue-green pigment called pyocyanin, often seen in burn wound infections?

Accepted Answer

Pseudomonas aeruginosa

Question 4

Which of the following bacteria is classified as a Lancefield Group A Streptococcus and is responsible for causing pharyngitis?

Accepted Answer

Streptococcus pyogenes

Question 5

A child develops severe muscle spasms after stepping on a rusty nail. Which Gram-positive bacterium is most likely responsible, and what is its unique virulence factor?

Accepted Answer

Clostridium tetani; tetanospasmin toxin

Question 6

Which bacterium is responsible for causing leprosy, and what is a unique characteristic of its disease progression?

Accepted Answer

Mycobacterium leprae; slow, chronic infection affecting skin and nerves

Question 7

Which Gram-negative bacterium is transmitted by respiratory droplets and is a major cause of meningitis in young adults?

Accepted Answer

Neisseria meningitidis

Question 8

A patient presents with severe watery diarrhea after traveling to a region with poor sanitation. Which bacterium is most likely responsible, and what is its unique mechanism of disease?

Accepted Answer

Vibrio cholerae; production of cholera toxin that increases cAMP

Question 9

Which bacterium is responsible for causing whooping cough, and what is a key prevention strategy?

Accepted Answer

Bordetella pertussis; vaccination with DTaP

Question 10

A patient develops a black, necrotic lesion after handling animal hides. Which Gram-positive bacterium is most likely responsible, and what is its mode of transmission?

Accepted Answer

Bacillus anthracis; contact with contaminated animal products

Question 11

Which bacterium is responsible for peptic ulcers and gastritis, and what is a unique feature of its pathogenesis?

Accepted Answer

Helicobacter pylori; production of urease to neutralize stomach acid

Question 12

Which bacterium is transmitted by ticks and causes Rocky Mountain spotted fever?

Accepted Answer

Rickettsia rickettsii

Question 13

A newborn develops meningitis shortly after birth. Which Gram-positive bacterium is most likely responsible, and how is it typically transmitted?

Accepted Answer

Streptococcus agalactiae; vertical transmission from mother

Question 14

Which bacterium is responsible for causing Lyme disease, and what is its primary vector?

Accepted Answer

Borrelia burgdorferi; Ixodes tick

Question 15

Which Gram-negative bacterium is known for causing typhoid fever, and what is a key prevention strategy?

Accepted Answer

Salmonella enterica serovar Typhi; proper sanitation and hygiene

Question 16

Which bacterium is responsible for causing syphilis, and what is a unique characteristic of its morphology?

Accepted Answer

Treponema pallidum; spiral-shaped spirochete

Question 17

A patient presents with severe diarrhea and abdominal pain after antibiotic treatment. Which Gram-positive bacterium is most likely responsible, and what is a key prevention strategy?

Accepted Answer

Clostridium difficile; proper hand hygiene and infection control

Question 18

Which bacterium is responsible for causing cat scratch disease, and what is its typical mode of transmission?

Accepted Answer

Bartonella henselae; scratch or bite from infected cats

Question 19

Which bacterium is responsible for causing diphtheria, and what is a unique feature of its disease?

Accepted Answer

Corynebacterium diphtheriae; formation of a thick pseudomembrane in the throat

Study Notes: Pathogenic Bacteria – Gram-Positive, Gram-Negative, and Other Notable Groups

Study Guide - Practice Questions

Study Guide - Flashcards