Pathogenesis of pneumococcal inflammation: otitis media.

Pneumococci cause damage to the ear in otitis media and in association with bacterial meningitis. The pathogenesis of injury involves host response to cell wall and pneumolysin. Release of cell wall, particularly during antibiotic-induced bacterial lysis, leads to an influx of leukocytes and subsequent tissue injury. The signal transduction cascade for this response is becoming defined and includes CD14, Toll-like receptor 2, NFkB, and cytokine production. The second source of injury is the cytotoxicity of the pore forming toxin, pneumolysin. Decreasing the sequelae of otitis can be achieved by an increased understanding of the site-specific mechanisms of pneumococcal-induced inflammation.