NATURALLY-OCCURRING ISOLATES OF NEISSERIA-GONORRHEA, WHICH DISPLAY ANOMALOUS SEROVAR PROPERTIES, EXPRESS PIA PIB HYBRID PORINS, DELETIONS IN PIE OR NOVEL PIA MOLECULES/

The por gene of Neisseria gonorrhoeae encodes the Protein I porin resp onsible for serovar specificity. In this study the por genes have been sequenced from clinical isolates which exhibited anomalous serovar re activity. One group of 'intermediate' strains differed significantly f rom both Protein IA and IB strains, were more closely related to IA bu t appeared to represent a distinct class of Protein I. Another strain was closely related to Protein IB of serovar IB-6 but contained a dele tion of six amino acids in surface exposed loop 6 which removed epitop es recognised by IB specific monoclonal antibodies. The third group of strains, which reacted with both IA and IB specific monoclonal antibo dies, expressed hybrid Protein I molecules containing both IA and IB e pitopes. These strains appeared to originate from a double crossover b etween Proteins IA and IB with the amino and carboxy terminal residues homologous to IB while the surface exposed loop 6 demonstrated close homology to IA. This is the first demonstration of naturally occurring gonococci expressing a hybrid Protein IA/IB. (C) 1998 Federation of E uropean Microbiological Societies. Published by Elsevier Science B.V.