Question

An isolate on chocolate agar from a patient with epiglottitis was suggestive of Haemophilus species. Additional testing showed that the isolate required NAD for growth and was nonhemolytic. The organism is most likely Haemophilus:

a) Ducreyi
b) Parainfluenzae
c) Haemolyticus
d) Influenzae

Answer 1

The organism that requires NAD for growth and is nonhemolytic on chocolate agar most likely causing epiglottitis is Haemophilus influenzae. Option d is correct.

Step-by-step explanation:

The organism likely causing epiglottitis in a patient, which requires NAD (nicotinamide-adenine-dinucleotide) for growth and is nonhemolytic when cultured on chocolate agar, is Haemophilus influenzae. Haemophilus species are known to be small, gram-negative, aerobic or facultatively anaerobic bacteria that can be demanding in their growth requirements, often necessitating both the X factor (hemin) and the V factor (NAD).

Specifically, H. influenzae demonstrates such fastidious growth characteristics and is often associated with infections including epiglottitis, meningitis, and pneumonia.