Question 1

Which of the following bacteria is Gram-positive, cocci-shaped, and commonly associated with skin infections, including MRSA?

Accepted Answer

Staphylococcus aureus

Question 2

Which virulence factor allows Streptococcus pyogenes (GAS) to evade phagocytosis by host immune cells?

Accepted Answer

M protein

Question 3

A patient presents with pneumonia. Laboratory results show Gram-positive diplococci. Which organism is most likely responsible?

Accepted Answer

Streptococcus pneumoniae

Question 4

Which of the following bacteria is known for producing endospores and causing tetanus?

Accepted Answer

Clostridium tetani

Question 5

Which Gram-negative diplococcus is the causative agent of bacterial meningitis and can be transmitted via respiratory droplets?

Accepted Answer

Neisseria meningitidis

Question 6

Which of the following bacteria utilizes a Type III secretion system to inject virulence factors directly into host cells?

Accepted Answer

Salmonella enterica

Question 7

A patient develops severe diarrhea after drinking contaminated water. The causative agent is a Gram-negative, comma-shaped bacterium. What is the most likely pathogen?

Accepted Answer

Vibrio cholerae

Question 8

Which of the following bacteria is a Gram-positive rod, can grow at refrigerator temperatures, and is associated with foodborne illness in pregnant women?

Accepted Answer

Listeria monocytogenes

Question 9

Which of the following is NOT a characteristic of Enterobacteriaceae family members?

Accepted Answer

Gram-positive cell wall

Question 10

Which Gram-negative bacillus is commonly associated with urinary tract infections and exhibits swarming motility on agar plates?

Accepted Answer

Proteus mirabilis

Question 11

A patient is diagnosed with botulism after consuming improperly canned food. Which bacterial species is responsible, and what is its Gram-stain and shape?

Accepted Answer

Clostridium botulinum; Gram-positive rod

Question 12

Which of the following bacteria is a Gram-negative diplococcus that causes sexually transmitted infections?

Accepted Answer

Neisseria gonorrhoeae

Question 13

Which of the following bacteria is associated with the production of a capsule that is a major virulence factor in causing pneumonia?

Accepted Answer

Streptococcus pneumoniae

Question 14

Which of the following bacteria is a Gram-negative rod, lactose fermenter, and a common cause of neonatal meningitis?

Accepted Answer

Escherichia coli

Question 15

Which of the following bacteria is known for causing food poisoning due to the production of heat-stable enterotoxins?

Accepted Answer

Staphylococcus aureus

Question 16

Which of the following bacteria is a Gram-positive, spore-forming anaerobe that causes pseudomembranous colitis after antibiotic use?

Accepted Answer

Clostridium difficile

Question 17

Which of the following bacteria is transmitted by ticks and causes Rocky Mountain spotted fever?

Accepted Answer

Rickettsia rickettsii

Question 18

Which of the following bacteria is an obligate intracellular pathogen and cannot be visualized with a Gram stain?

Accepted Answer

Chlamydia trachomatis

Question 19

Which of the following bacteria is a Gram-negative rod, non-lactose fermenter, and is associated with typhoid fever?

Accepted Answer

Salmonella typhi

Question 20

Which of the following bacteria is a Gram-negative coccobacillus and is the causative agent of whooping cough?

Accepted Answer

Bordetella pertussis

Study Guide: Pathogenic Bacteria (Gram-Positive, Gram-Negative, and Miscellaneous Bacterial Pathogens)

Study Guide - Practice Questions

Study Guide - Flashcards