Haemophilus (Exam 2) Flashcards
What is the gram stain morphology of Haemophilus sp.?
Gram negative coccobacilli or rods
Are most Haemophilus species pathogenic or nonpathogenic?
Nonpathogenic
What are the common agar growth requirements and why?
Haemophilus species often require chocolate agar for growth instead of SBA because they need X, V or X and V and SBA only contains X.
H. influenzae growth requirements (X, V, X and V)?
Both X and V
H. flu biogroup aegyptius growth requirements (X, V, X and V)?
Both X and V
H. parainfluenzae growth requirements (X, V, X and V)?
Only V
H. haemolyticus growth requirements (X, V, X and V)?
Both X and V
H. parahaemolyticus growth requirements (X, V, X and V)?
Only V
H. ducreyi growth requirements (X, V, X and V)?
Only X
Does H. influenzae lyse HB or RB?
Neither
Does H. flu biogroup aegyptius lyse HB or RB?
RB
Does H. parainfluenzae lyse HB or RB?
RB (variable)
Does H. haemolyticus lyse HB or RB?
Both
Does H. parahaemolyticus lyse HB or RB?
Both
Does H. ducreyi lyse HB or RB?
Neither
Which Haemophilus species are ALA positive, or in other words, are X independent?
H. parainfluenzae and H. parahaemolyticus
Which organism is known to have a “mousy” odor?
H. influenzae
Which organism is the leading cause of meningitis in children less than 5 yo?
H. influenzae
Which organism is one of the three most common organisms associated with conjunctivitis?
H. influenzae
Of the H. influenzae serotypes, which is the most invasive prior to vaccination development?
Serotype B
Which Haemophilus species is known to cause BFP (Brazilian purpuric fever) and conjuctivitus?
H. flu biogroup aegyptius
Which Haemophilus species has tan, translucent, sometimes mucoid colonies?
H. influenzae
Which Haemophilus species has the same colony morphology as H. influenzae, but smaller at 48 hrs?
H. flu biogroup aegyptius
Which Haemophilus species is known to cause soft genital chancres?
H. ducreyi
What are the growth conditions for H. ducreyi and where is the organism most commonly found?
High humidity and warm temperature (33C incubation); commonly found in disadvantaged populations in the tropics - swab must be placed on media within 10 minutes of collection
Which Haemophilus species has small, flat, translucent, smooth and “scooty” colonies?
H. ducreyi
Which Haemophilus species has a gram stain that looks like a school of fish or railroad tracks?
H. ducreyi
