Adherence of isolates of Neisseria meningitidis from patients and carriers to human buccal epithelial cells.

An in vitro assay was used to study the adherence of Neisseria meningitidis to human buccal epithelial cells. Both unencapsulated and encapsulated, piliated isolates obtained from throats of asymptomatic carriers demonstrated significantly higher levels of adherence to buccal cells than encapsulated, piliated isolates obtained from the blood and cerebrospinal fluid of patients (P < 0.001). Meningococcal adherence to buccal cells could not be correlated to a specific capsular polysaccharide serogroup, outer membrane protein serotype, or quantitative differences in pili. However, the data suggested that capsular polysaccharide impedes the adherence of meningococci to buccal cells, and the significantly smaller amount of capsular polysaccharide extracted from carrier isolates compared with case isolates (P < 0.001) could explain differences in meningococcal adherence to buccal cells. Increased adherence may facilitate host colonization, promote nasopharyngeal carriage, and possible reflect altered pathogenicity.