A child presented with otitis media. The suspected organism is Hemophilus influenzae. All are TRUE about H. influenzae, EXCEPT:
The polyribose phosphate capsule of type b H influenzae is the major virulence factor. H influenzae was the most common cause of bacterial meningitis in children age 5 months to 5 years. H influenzae is differentiated from related gram-negative bacilli by its requirements for X and V factors and by its lack of hemolysis on blood agar. Also know: H influenzae does not grow on sheep blood agar except around colonies of staphylococci ("satellite phenomenon"). H influenzae does not produce exotoxin. Ref: Brooks G.F., Carroll K.C., Butel J.S., Morse S.A., Mietzneron T.A. (2010). Chapter 18. Haemophilus, Bordetella, Brucella, & Francisella. In G.F. Brooks, K.C. Carroll, J.S. Butel, S.A. Morse, T.A. Mietzneron (Eds), Jawetz, Melnick, & Adelberg's Medical Microbiology, 25e.
Requires Factors X and V for growth
In CNS, mostly causes meningitis
Outer membrane protein plays impoant role in pathogenesis in type 'b' H. influenzae
Not a common cause for meningitis in less than 2 months of life