Identification of strain-specific markers on Neisseria gonorrhoeae that are capable of differentiating gonococci into a large number of distinct classes could facilitate analysis of patterns of gonorrhea transmission and application of gonorrhea control measures. A panel of 12 monoclonal antibodies to gonococcal outer membrane protein IA (PrIA) and IB (PrIB) was used to classify 1,433 strains serologically in a worldwide survey. Eighteen PrIA and 28 PrIB serovars were identified, and a nomenclature is proposed. Gonococcal strains were classified further by auxotyping. Auxotyping and serotyping served to classify the 1,433 isolates into 107 unique auxotype/serovar classes. Dual classification by auxotype and serovar can be used to identify epidemiologically related gonococcal infections in order to test the effectiveness of innovative, focused measures to control gonorrhea.

Disseminated gonococcal infection occurs in 1%-3% of patients with gonorrhea in Seattle. Most strains of Neisseria gonorrhoeae recovered from patients with disseminated gonococcal infection are susceptible to less than or equal to 0.015 mug of penicillin G/ml. Strains susceptible to less than or equal to 0.015 mug/ml, whether isolated from patients with disseminated gonococcal infection or from those with uncomplicated infection, did not grow on chemically defined medium prepared with several lots of agar, whereas less susceptible isolates grew well. Use of methanol-extracted nontoxic agar permitted growth of the penicillin-susceptible strains and demonstrated that all of them required arginine, hypoxanthine, and uracil (Arg-Hyx-Ura-) for growth. These Arg-Hyx-Ura- strains accounted for 89% of the cases of disseminated gonococcal infection in Seattle, 38% of uncomplicated infections in Seattle, 18% of infections in Milwaukee, and none of 104 uncomplicated gonococcal infections acquired in the Philippines and Taiwan, where disseminated gonococcal infection is unusual. Regional variations in the prevalence of these Arg-Hyx-Ura- strains may correlate with regional variations in the incidence of disseminated gonococcal infection. The genetic, physiologic, and immunologic bases for concurrence of penicillin and agar susceptibility. Arg-Hyx-Ura- phenotype, and association with disseminated gonococcal infection remain undefined, as do host factors that determine whether or not disseminated gonococcal infection will result in patients infected by such strains.

The pathogenic Neisseria spp., N. gonorrhoeae and N. meningitidis, have been studied extensively and rapid identification procedures have been designed to distinguish these species from the commensal Neisseria and related species that are normal flora of the oro- and nasopharynx. The commensal Neisseria spp. have been largely ignored except for isolated studies. It is important that we know about these species, however, because not only may some be misidentified as pathogenic species if identified with inappropriate procedures, but also they may occasionally be isolated from unusual sites and must be correctly identified to the species level for clinical purposes.

Similar to Neisseria gonorrhoeae, tetracycline-resistant isolates of N. meningitidis, Kingella denitrificans, and Eikenella corrodens contained 25.2-megadalton plasmids carrying the TetM determinant. In contrast, tetracycline-resistant N. subflava biovar perflava-N. sicca and N. mucosa isolates carried the TetM determinant in the chromosome.