ANTIBIOTIC SUSCEPTIBILITY OF NEISSERIA GONORRHOEAE IN RELATION TO SEROGROUPS

Abstract

Susceptibility testings, by means of the agar-dilution method, were performed on 9 antibiotics (benzylpenicillin sodium, ampicillin sodium, cefuroxime sodium, streptomycin sulfate, spectinomycin hydrochloride, doxycycline hydrochloride, erythromycin base, chloramphenicol and rifampicin) of 138 non-PPNG (.beta.-lactamase-producing = PPNG) strains, 17 of which originated from Thailand, and 88 PPNG isolates. The gonococcal strains [clinical isolates (human)] were sero-grouped by the co-agglutination method and classified among the sero-groups W I, W II or W III. Statistically significant differences in antibiotic susceptibility between non-PPNG strains of 3 sero-groups were demonstrated with strains belonging to sero-group W I as the most sensitive and W III isolates as the most resistant. Non-PPNG strains from Thailand were significantly more resistant than the other non-PPNG isolates of the same sero-group. There was, however, no significant difference in resistance between non-PPNG strains from Thailand and PPNG isolates of the same sero-group. PPNG strains of sero-group W I were significantly more sensitive than PPNG strains of sero-group W II; there was no significant difference between PPNG isolates of sero-groups W II and W III. Non-PPNG strains, not from Thailand, of sero-groups W I and W II were significantly more susceptible to non .beta.-lactam antibiotics than PPNG strains of corresponding sero-groups; no such difference was demonstrated for non-PPNG and PPNG isolates of sero-group W III.