Serological classification in relation to auxotypes, plasmid contents, and susceptibilities to antimicrobials of PPNG and non-PPNG strains isolated in Greece.

Thirty three penicillinase producing Neisseria gonorrhoeae (PPNG) and 152 non-PPNG strains were serologically classified in relation to their patterns of resistance to antimicrobials, nutritional requirements (auxotypes), and plasmid contents. Of the 185 strains, 65 (35%) belonged to the WI and 120 (65%) to the WII/III serogroup, the predominant serovars of which were Arost and Bropt, respectively. Associations between serotype and susceptibility to antimicrobial agents, auxotype, and plasmid content were observed. Of the 152 non-PPNG strains, 112 (74%) belonged to serogroup WI. The WI non-PPNG strains were more sensitive to penicillin, thiamphenicol, tetracycline, and cefotaxime than the WII/III non-PPNG strains. Auxotyping and serogrouping the strains showed no differentiation other than that arginine, hypoxanthine, and uracil dependent (AHU-) strains belonged to serogroup WI. The proline, citrulline, and uracil dependent (PCU-) strains belonged, as expected, to serogroup WII/III. Analysing the 33 PPNG strains showed that of 21 carrying the 4.5 megadalton (Asian type) penicillin resistance plasmid, 17 (81%) belonged to serogroup WI, with serovar Arst predominating, and only four (19%) to serogroup WII/III. Of 11 isolates carrying the 3.2 megadalton (African type) resistance plasmid, seven (64%) belonged to serogroup WI (serovar Av predominating) and four (36%) to WII/III (with serovar Bropyst predominating). One strain carried the 3.05 megadalton penicillin resistance plasmid (Toronto type), belonged to the WI serogroup, and had serovar Arost.