ANTIBIOTIC SUSCEPTIBILITY SURVEY OF NEISSERIA-GONORRHOEAE IN THAILAND

The antibiotic susceptibilities of Neisseria gonorrhoeae isolates obtained from patients attending sexually transmitted disease clinics in Cholburi and Bangkok, Thailand, were determined by agar dilution. Some 28.2% of isolates produced beta-lactamase. A total of 97.9% of beta-lactamase-positive and 51% of beta-lactamase-negative isolates tested were resistant to penicillin (MICs, greater-than-or-equal-to 2-mu-g/ml), 70% of isolates tested were resistant to tetracycline (MICs, greater-than-or-equal-to 2-mu-g/ml), and 91% of isolates tested were susceptible to spectinomycin (MICs, less-than-or-equal-to 64-mu-g/ml). The MICs for 90% of isolates for the other drugs tested were 2-mu-g/ml for erythromycin, 2-mu-g/ml for cefoxitin, 1-mu-g/ml for cefuroxime, 0.125-mu-g/ml for cefpodoxime, 0.06-mu-g/ml for cefotaxime, 0.25-mu-g/ml for ceftazidime, 0.03-mu-g/ml for ceftizoxime, 0.03-mu-g/ml for ceftriaxone, 0.03-mu-g/ml for cefixime, 0.06-mu-g/ml for aztreonam, 0.008-mu-g/ml for ciprofloxacin, 0.125-mu-g/ml for norfloxacin, and 0.075-mu-g/ml for ofloxacin. Fewer than 1.5% of isolates were resistant to the extended-spectrum cephalosporins tested. Some 0.3% or fewer isolates were resistant to broad-spectrum cephalosporins, fluoroquinolones, or the monobactam aztreonam. Antibiotic resistance among N. gonorrhoeae isolates from Cholburi and Bangkok in May 1990 appeared to be primarily limited to penicillin and tetracycline, which are no longer used to control gonorrhea. Spectinomycin, which has been in general use against gonorrhea in Thailand since 1983, has dwindling utility, with resistance at a level of 8.9%.