Detection and characterization of pediatric serum antibody to the OMP P5-homologous adhesin of nontypeable Haemophilus influenzae during acute otitis media.

We reported earlier that antibody in sera collected from seven children with acute otitis media (AOM) due to nontypeable Haemophilus influenzae (NTHI) recognized immunodominant regions of P5-fimbrin just as we had observed in a chinchilla model of experimental NTHI-induced AOM. To expand upon those preliminary findings, we further characterized pediatric serum antibodies directed against this adhesin during AOM. Collectively, the data show that children respond immunologically to P5-fimbrin and they do so in a manner that allows for the distinction of sequence diversity within short linear peptides representing a focused region of this surface-exposed protein. The immune recognition we observed encourages us to further develop a P5-fimbrin based vaccine component.