D-081. Phosphorylcholine Confers a Selective Survival Advantage for Nontypeable Haemophilus influenzae in Vivo

W. Hong, B. Pang, R. Juneau, G. Foster, W. E. Swords;
Wake Forest Univ. Hlth. Sci., Winston-Salem, NC.

Nontypeable Haemophilus influenzae is a leading cause of otitis media and other opportunistic airway infections. Much work from our laboratory and others has shown that addition of phosphorylcholine (PCho) to the bacterial surface is correlated with resistance to host clearance. Additional data from our laboratory have shown that this modification is associated with increased density of bacterial biofilm communities within the chinchilla middle-ear chamber. In this study, we performed competitive infection experiments using a well characterized otitis media isolate (NTHi 86-028NP) and isogenic mutants lacking (licD) or consisting entirely of (licON) PCho+ variants. Populations within the fluid (planktonic) phase in middle-ear effusions, and associated with the middle-ear surface were enumerated and compared in different coinfections over time. The data clearly show that expression of PCho confers a selective survival advantage for NTHi, which may be most profound in the biofilm state.