The sputum of a 75-year-old man with chronic lung infections yields the following: • Many gram-negative coccobacilli in Gram stain
• X and V factors required for growth
• Nonhemolytic on rabbit blood agar
The organism can be identified as:

Question

Quizplus · Accepted Answer

H.influenzae is nonhemolytic on rabbit blood and requires both X and V factors to grow.Although H.aegyptius and H.haemolyticus both require X and V factors for growth, they are hemolytic on rabbit blood.H.parainfluenzae requires only V factor and is variable for beta-hemolysis.

The Sputum of a 75-Year-Old Man with Chronic Lung Infections