THE EFFECT OF VARIATIONS IN THE EXPRESSION OF PILI ON THE INTERACTIONOF NEISSERIA-MENINGITIDIS WITH HUMAN NASOPHARYNGEAL EPITHELIUM

Bacterial adherence is essential to colonization of the nasopharynx by Neisseria meningitidis, and pill may facilitate adherence. Scanning e lectron microscopy and immunogold labeling were used to study the inte raction of 2 piliated and 1 nonpiliated variant of N. meningitidis wit h nasopharyngeal mucosa in an adenoid organ culture system with an air -mucosal interface. Meningococcal infection caused epithelial damage, loss of ciliated epithelium, and ciliary disorganization, which progre ssed with time and were greater with the piliated strains. Pill increa sed adherence of meningococci to the mucosa, and there was tropism of piliated strains for nonciliated cells containing microvilli, damaged epithelium, and sites of cell separation, Bacterial adherence was asso ciated with a change in the appearance of the microvilli.