Susceptibility pattern of Neisseria gonorrhoeae to antimicrobial agents in Dar es Salaam

East Afr Med J. 1999 Jun;76(6):330-4.

Abstract

Objective: To determine the susceptibility pattern of local strains of Neisseria gonorrhoeae from Dar es salaam, Tanzania to locally used antibiotics.

Method: Out of 429 Neisseria gonorrhoeae strains isolated between 1993 and 1995, one hundred and ninety nine were recovered and tested. Minimum inhibitory concentrations (MIC) of penicillin, doxycycline, erythromycin, cefuroxime and ciprofloxacin were determined by the E-test method while that of spectinomycin was measured by the agar dilution method. Penicillinase producing N. gonorrhoeae were identified by the chromogenic cephalosporin method.

Results: Of the 199 strains tested 128 (64%) were found to be penicillinase producing Neisseria gonorrhoeae (PPNG). Only 19 (10%) were penicillin sensitive while all penicillin resistant strains were found to be PPNG. One hundred and seventy five (88%), 11(5%) and 13 (7%) of the tested isolates were resistant, less susceptible and fully susceptible to doxycycline respectively. Resistance to cotrimoxazole, cefuroxime and ciprofloxacin was 36 (18%), 11 (6%), and 3 (2%) respectively. The trend of antibiotic susceptibility rates over the three year period of study showed a significant increase in the proportion of susceptible strains to cotrimoxazole. All of the 75 strains tested against spectinomycin were susceptible. There was a statistically significant difference between the susceptibility patterns of non-PPNG and PPNG. Non-PPNG isolates were more susceptible to doxycycline (chi 2 = 78.2, df 2, p = < 0.0001).

Conclusion: These findings have shown that spectinomycin, ciprofloxacin and cefuroxime could continue to be used to treat gonorrhoea in our settings. Continuous surveillance of susceptibility to the commonly used antibiotics is important in order to detect emergence of resistance early and control the possible wide spread of resistant strains.

PIP: This article presents a study on the susceptibility pattern of local strains of Neisseria gonorrheae (NG) to antimicrobial agents (penicillin, doxycyline, erythromycin, cefuroxime, ciprofloxacin, cotrimoxazole, and spectinomycin) in Dar Es Salaam, Tanzania. Out of the 429 isolated strains of NG in 1993-95, 199 were included in the study. Susceptibility patterns to the six antimicrobials was determined through the E-test method, a test that measures their minimum inhibitory concentrations (MICs). On the other hand, the spectinomycin MIC was determined through the antibiotic agar dilution method. Results revealed the following patterns of susceptibility of isolates: spectinomycin (100%), ciprofloxacin (97%), Cefuroxime (89%), erythromycin (57%), cotrimoxazole (40%), doxycycline (7%), and penicillin (10%). It was also noted that NG strains are highly resistant to penicillin (64%) and doxycycline (88%). The study concludes that three drugs--spectinomycin, ciprofloxacin, and spectinomycin--could be effective in treating gonorrhea. However, a continued surveillance of common antibiotics against gonococcus is necessary for the early detection and control of strain resistance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / therapeutic use
  • Developing Countries
  • Drug Monitoring
  • Drug Resistance, Microbial
  • Drug Utilization
  • Gonorrhea / drug therapy
  • Gonorrhea / epidemiology
  • Gonorrhea / microbiology*
  • Humans
  • Microbial Sensitivity Tests
  • Neisseria gonorrhoeae / drug effects*
  • Patient Selection
  • Population Surveillance
  • Tanzania / epidemiology
  • Urban Health / statistics & numerical data

Substances

  • Anti-Bacterial Agents