Gonococcal Antimicrobial Susceptibility and the Prevalence of blaTEM-1 and blaTEM-135 Genes in Neisseria gonorrhoeae Isolates from Thailand

We studied the antimicrobial susceptibility and prevalence of the blaTEM-1 and blaTEM-135 genes in Neisseria gonorrhoeae isolates obtained in Thailand. The isolates were tested using the disk diffusion method, and 100% of 370 isolates were found susceptible to cefixime, ceftriaxone, cefotaxime, ceftazidime, cefepime, spectinomycin, and azithromycin. Some of the isolates were resistant to penicillin (85.7%), ciprofloxacin (88.0%), ofloxacin (97.4%), or tetracycline (89.1%). Penicillinase-producing N. gonorrhoeae accounted for 83.8% of isolates, with 70.0% of these further identified as penicillinase-producing plus tetracycline resistant N. gonorrhoeae. Penicillin, tetracycline, and ciprofloxacin are not recommended for treatment because of the high prevalence (89.7%) of multidrug resistant gonococci. A study of genes controlling enzyme of beta-lactamase production (blaTEM-1 and blaTEM-135) was performed using mismatch amplification mutation assay PCR method and DNA sequencing. Beta-lactamase positive N. gonorrhoeae carried blaTEM-1 (69.6%) and blaTEM-135 (30.4%), indicating that there is a significant increase and spread of blaTEM-135 among gonococci in Thailand.