Antibiograms and randomly amplified polymorphic DNA-polymerase chain reactions (RAPD-PCR) as epidemiological markers of gonorrhea.

The development of antimicrobial resistance of Neisseria gonorrhoeae arising from wide dissemination of resistant clones is a major global health problem. In this study, a total of 235 isolates of N. gonorrhoeae isolated from patients of Bangrak Hospital were tested for their antibiotic susceptibilities to penicillin, norfloxacin, ofloxacin, ciprofloxacin, spectinomycin, and ceftriaxone. Mutation (Ser-91) in the quinolone resistance determining regions of gyrA and random amplification of the polymorphic DNA polymerase chain reaction (RAPD-PCR) were examined from 145 isolates. Among these, 55 isolates were obtained during January-March 2000, 46 isolates during January-March 2002, and 44 isolates during October-December 2002. The occurrence of combination resistance between penicillin and quinolone was 20% in January-March 2000, which was increased to 57.8% during the period of October-December 2002 (P<0.0001). Mutation of Ser-91 in gyrA could be directly linked with the resistance or declining of susceptibility to ciprofloxacin. Using RAPD-PCR, we could classify the 145 isolates into 4 and 5 groups by primers D11344 (5'-AGTGAATTCGCGGTGAGATGCCA-3') and D8635 (5'-GAGCGGCCAAAGGGAGCA GAC-3'), respectively. Combination of the data obtained from these two primers produced 11 fingerprint groups. Our findings conclude that monitoring of the Ser-91 mutation of gyrA and RAPD-PCR methods are most useful for epidemiological screening.