Question 1

Which of the following is a key virulence factor of Neisseria gonorrhoeae that allows it to evade neutrophil-mediated killing?

Accepted Answer

Pili-mediated resistance to phagocytosis

Question 2

A 22-year-old college student presents with fever, headache, and a petechial rash. Gram stain of cerebrospinal fluid reveals Gram-negative diplococci. Which organism is most likely responsible?

Accepted Answer

Neisseria meningitidis

Question 3

Which laboratory test is most appropriate for rapid presumptive diagnosis of gonorrhea from a urethral exudate?

Accepted Answer

Gram stain for Gram-negative diplococci

Question 4

A newborn develops severe conjunctivitis and purulent eye discharge within days of birth. Which preventive measure is most effective in reducing this risk?

Accepted Answer

Immediate administration of prophylactic eye drops after birth

Question 5

Which of the following best explains why Neisseria meningitidis is more likely to cause outbreaks in college dormitories?

Accepted Answer

It is part of the normal nasopharyngeal flora and spreads easily in close quarters

Question 6

A patient with untreated syphilis develops gummas and cardiovascular symptoms decades after initial infection. Which stage of syphilis is this?

Accepted Answer

Tertiary syphilis

Question 7

Which of the following is a distinguishing feature of Treponema pallidum compared to Neisseria species?

Accepted Answer

It is a spirochete with periplasmic flagella

Question 8

A patient presents with a painless genital ulcer and regional lymphadenopathy. Which diagnostic test would most specifically confirm Treponema pallidum infection?

Accepted Answer

Darkfield microscopy of lesion exudate

Question 9

Which of the following best describes the mechanism of antigenic variation in Neisseria gonorrhoeae?

Accepted Answer

Switching of outer membrane proteins to evade immune detection

Question 10

A 30-year-old hiker develops a bull’s-eye rash, fever, and joint pain after a tick bite. Which organism is most likely responsible?

Accepted Answer

Borrelia burgdorferi

Question 11

Which of the following is the mainstay of treatment for early syphilis?

Accepted Answer

Single intramuscular injection of benzathine penicillin

Question 12

Which of the following is a common complication of untreated gonorrhea in women?

Accepted Answer

Pelvic inflammatory disease (PID) and ectopic pregnancy

Question 13

A patient with relapsing fever is found to have spirochetes in the blood that change their outer surface proteins. Which genus is most likely responsible?

Accepted Answer

Borrelia

Question 14

Which of the following best explains why Neisseria gonorrhoeae infections can recur in the same individual?

Accepted Answer

Antigenic variation of pili and outer membrane proteins

Question 15

Which of the following is a recommended prophylactic measure for close contacts of a patient with meningococcal meningitis?

Accepted Answer

Prophylactic antibiotics such as rifampin or ciprofloxacin

Question 16

A 7-year-old child in Central Africa presents with multiple skin lesions and bone deformities. Which Treponema species is most likely responsible?

Accepted Answer

Treponema pallidum subspecies pertenue (Yaws)

Question 17

Which of the following is a characteristic finding in secondary syphilis?

Accepted Answer

Generalized non-itchy rash including palms and soles

Question 18

Which of the following best describes the pathogenesis of Leptospira interrogans in humans?

Accepted Answer

Entry through skin abrasions, causing endothelial damage and possible Weil disease

Question 19

Which of the following is the most reliable current treatment for Neisseria gonorrhoeae infection, given rising antibiotic resistance?

Accepted Answer

Intramuscular ceftriaxone

Question 20

A patient with a history of tick exposure presents with fever, headache, and relapsing episodes of illness. Which laboratory finding is most likely during febrile episodes?

Accepted Answer

High levels of spirochetes in the blood

Gram-Negative Cocci and Medically Important Spirochetes: Neisseria, Treponema, Borrelia, and Leptospira

Study Guide - Practice Questions

Study Guide - Flashcards