Attachment of Neisseria meningitidis to human mucosal surfaces: influence of pili and type of receptor cell.

The factors that determine attachment of meningococci predominantly to the mucosa of the nasopharynx rather than to other mucosal surfaces are unknown. Isolates of Neisseria meningitidis from the nasopharynx of carriers and from patients with meningococcal disease were found to be heavily piliated. Isogenic piliated and nonpiliated meningococcal clones were derived from blood and cerebrospinal fluid isolates. Meningococci with pili consistently attached to human nasopharyngeal cells in greater numbers than meningococci without pili. Meningococci treated with trypsin or mechanical shear forces lost pili and exhibited decreased attachment. Attachment of piliated meningococci differed markedly among epithelial cells from different sites. In contrast, nonpiliated meningococci attached equally but in low numbers to all cell types. These data suggest that pili are important mediators of meningococcal attachment. The number and distribution of receptor sites for pili or pili-associated meningococcal ligands differ among human cells and may determine sites of meningococcal colonization.