Identification and characterizations of gonococci type 5: one step forward in understanding the attachment of gonococci to mucosal cells.

The characteristic of the organisms from gonococcal type 5 morphology and their interaction with human epithelial cells are least studied among different types of gonococci. Organisms from type 5 morphology which were isolated from the fallopian tube of a woman with gonococcal salpingitis exhibited very intense opacity without piliation. After 48 hours of incubation at 37°C with a 2% CO2 environment, organisms from type 5 morphology transformed to type 4 morphology. SDS-PAGE of whole cell lysates of organisms from colonial type 5 revealed presence of a 27kd protein molecule which was absent in the whole cell lysates of the organisms with type 4 morphology, which were obtained as results of colonial type 5 passage. Also silver-stained SDS-PAGE profiles of pronase-treated whole cell lysates of gonococci showed some or all higher peaks in lanes filled with type 4 gonococci than did lanes with type 5 gonococci. This observation suggests that type 4 gonococci may have more lipooligosaccharide or a different form of these molecules than do type 5 gonococci. Attachment to buccal cells of gonococci organisms of colony type 1,4 and 5 differed markedly with the following order: 1>5>4. Colony type 5 gonococci were not piliated, nor were type 4 colonies, so some factor other than pili in type 5 is responsible for the greater attachment of type 5. Since pili are the only attachment factor identified to date, pursuit of the attachment factor used by type 5 gonococci seems warranted.