Background Gonorrhoea continues to be a common sexually transmitted disease (STD) in developing countries. Over the last decade, N.gonorrhoeae has developed resistance against antimicrobial agents such as penicillin, tetracycline and quinolones in several countries including India. Monitoring the antimicrobial susceptibility of gonococcal isolates is essential for early detection of antimicrobial resistance.
Methods In our STD laboratory, all gonococcal isolates are subjected to antimicrobial susceptibility testing by disc diffusion method as per CLSI guidelines. ß-lactamase production is determined by chromogenic cephalosporin test. Minimum Inhibitory Concentration (MIC) for ceftriaxone is determined by E-test. WHO reference strains are used for quality control. We regularly participate in an External quality assurance scheme (EQAS) - Gonococcal Antimicrobial Susceptibility Program (GASP) under WHO.
Results The number of cases of gonorrhoea and hence gonococcal isolates has declined in our hospital over the years. A significant increase in penicillinase producing N.gonorrhoeae (PPNG) has been observed. The percentage of PPNG increased from 8% in 1997 to13% in 2007 and 84.2% in 2011–2013. Quinolone resistant N.gonorrhoeae (QRNG) showed a significant increase from 12% in 1997 to 98.7% in 2007, while 89.47% isolates were found to be QRNG by 2011–2013. Although the percentage of tetracycline resistant N.gonorrhoeae (TRNG) has decreased over the years, overall percentage of isolates resistant to tetracycline increased. In January 2013 we detected our first gonococcal isolate with decreased susceptibility to third generation cephalosporins; Ceftriaxone, Cefixime and Cefpodoxime.
Conclusion The results of our study highlighted an alarming increase in the percentage of PPNG and QRNG strains over the last 16 years. Emergence of N.gonorrhoeae isolates with decreased susceptibility to third generation cephalosporins is a cause of concern. Thus continuous monitoring of antimicrobial susceptibility of all gonococcal strains circulating in a community should be performed to prevent treatment failures and further spread of resistant strains.
- Antimicrobial Resistance
- Neisseria gonorrhoeae