Variation of Neisseria gonorrhoeae protein II among isolates from an outbreak caused by a single gonococcal strain.

Gonococci isolated from localized urogenital infections usually possess one or more protein II (P.II) species in the outer membrane, but the structural and antigenic variation of these proteins among different gonococcal strains has made it difficult to determine if specific proteins of the P.II class are associated with particular sites or types of infection. A recent outbreak of gonorrhea in Durham, N.C., was unusual in that over 200 isolates were derived from a single strain, which provided an opportunity to address these questions. The P.II profile of 54 isolates was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of outer membrane proteins. At least seven distinct P.II proteins were seen; no single protein or combination of proteins predominated in the different isolates, and there was no association of P.II profile with site of isolation. Gonococci recovered from the same patient at different times had different P.II profiles, confirming that P.II variation occurred in vivo.