AUXOTYPES, SEROVARS, AND TRENDS OF ANTIMICROBIAL RESISTANCE OF NEISSERIA-GONORRHOEAE IN KIGALI, RWANDA (1985-93)

Objective: To investigate the in vitro antimicrobial susceptibility an d the auxotype/serovar distribution of Neisseria gonorrhoeae in Kigali , Rwanda, during 1985-93. Methods: As part of a monitoring programme t he in vitro susceptibility of 1604 isolates of N gonorrhoeae was deter mined by agar dilution. Auxo- and serotyping was performed on 1350 and 1313 isolates respectively. Results: The prevalence of penicillinase producing N gonorrhoeae (PPNG) remained stable at a rate of 39% during 1985-91 and increased to 61% in 1992-3. Chromosomal resistance to pen icillin was common among non-PPNG and resistance to thiamphenicol and tetracycline was common among both PPNG and non-PPNG. High level, plas mid mediated resistance to tetracycline (TRNG) was observed for the fi rst time at the end of 1989 and increased from 2% of the isolates in 1 990 to 50% by 1993. A trend for increasing resistance to norfloxacin a nd ofloxacin was observed during 1985-90 but disappeared in 1991-93. F ive isolates with high level resistance to norfloxacin (MIC 2 mg/l) we re observed in 1990. Resistance to trimethoprimsulphamethoxazole (TMP- SMZ) emerged at the end of 1990 and was observed among 10% of the isol ates during 1991-3. All strains remained susceptible to ofloxacin, cip rofloxacin, spectinomycin, and ceftriaxone. Overall, 75% of the isolat es were prototrophic or required proline for their growth and 62% belo nged to serovars IA-6 and IB-1. The prevalence of serovar IB-4 increas ed strongly during the last 3 years of the study. Conclusion: Resistan ce to penicillin, thiamphenicol, and tetracycline was common in N gono rrhoeae during 1985-1993. The rapid spread of TRNG after 1989 and the steep increase of PPNG during 1992-3 were the most striking facts of t he study period. The auxotype and serovar distribution was comparable with findings from other African countries.