Antibiotic sensitivities of Neisseria gonorrhoeae in the Far East: comparison of plasmid species in isolates from six countries.

In vitro susceptibility testing of 36 strains of Neisseria gonorrhoeae isolated in the Far East in 1979 and 1980 demonstrated that 27 penicillinase-producing (PPNG) isolates and nine non-penicillinase-producing (non-PPNG) isolates were susceptible to chloramphenicol, thiamphenicol, spectinomycin, trimethoprim-sulfamethoxazole, cefoperazone, moxalactam, cefotaxime, and ceftriaxone. In comparison, 50% of the strains had MICs of tetracycline of greater than 2 micrograms/ml, and 75% had MICs, of streptomycin of greater than 128 micrograms/ml. Eighty-two per cent of PPNG and 100% of non-PPNG isolates examined had MICs of kanamycin of greater than 32 micrograms/ml. None of the nine non-PPNG strains had MICs of ampicillin and penicillin of greater than 1 microgram/ml. A 4.4-megadalton plasmid, previously associated with beta-lactamase production, was found in all 27 PPNG isolates examined; 93% of PPNG and 22% of non-PPNG isolates contained a 24-megadalton plasmid previously associated with transfer of the 4.4-megadalton plasmid.