lipooligosaccharide (LOS) is thought to play a role in inflammation associated with otitis media. All virulent strains produce neuraminidase and an IgA protease, but the role of these extracellular enzymes in invasion is unproven. Fimbriae increase the adherence of bacteria to human mucosal cells in vitro, and they are required for successful colonization of the nasopharynx. The Anton antigen, as defined in red blood cells, appears to be the receptor.
Virulence for haemophilus