Microbiology – MCQ 73 – 20 year old male with genital ulcer

A 20 years old male patient presents to the STD clinic with a genital ulcer. The gram stain of the smear from ulcer shows gram negative coccobacilli. The most appropriate media for culture would be:
A. Thayer Martin Medium
B. Blood agar with X & V factors
C. Chocolate agar with IsoVitaleX
D. Teilurite blood agar

Correct answer : C. Chocolate agar with IsoVitaleX

The clinical picture is suggestive of soft sore (chancroid) caused by Haemophilus ducreyi. Chocolate agar with IsoVitaleX is used for its culture.

Other culture media:
Thayer Martin Medium – Gonococci
Blood agar with X & V factors – Haemophilus influenzae
Tellurite blood agar – Corynbacterium diphtheriae