PT - JOURNAL ARTICLE AU - U Chaudhry AU - K Ray AU - M Bala AU - D Saluja TI - Mutation patterns in <em>gyr</em>A and <em>par</em>C genes of ciprofloxacin resistant isolates of <em>Neisseria gonorrhoeae</em> from India AID - 10.1136/sti.78.6.440 DP - 2002 Dec 01 TA - Sexually Transmitted Infections PG - 440--444 VI - 78 IP - 6 4099 - http://sti.bmj.com/content/78/6/440.short 4100 - http://sti.bmj.com/content/78/6/440.full SO - Sex Transm Infect2002 Dec 01; 78 AB - Aim: To analyse mutations in the gyrA and parC genes leading to possible increase in ciprofloxacin resistance (high MIC values for ciprofloxacin) in clinical isolates of Neisseria gonorrhoeae in Delhi, India. Method: MIC of ciprofloxacin for 63 clinical isolates of N gonorrhoeae were examined by the Etest method. Subsequently, gyrA and parC genes of these isolates were amplified and sequenced for possible mutations. Results: Out of the 63 clinical isolates tested, only five (8%) isolates were found to be susceptible to ciprofloxacin (MIC &lt;0.06 μg/ml). DNA sequence analysis of the gyrA and the parC genes of all these isolates (n = 63) revealed that all isolates which were not susceptible to ciprofloxacin (n=58) had mutation(s) in gyrA and parC genes. 12 isolates (19%) exhibited high resistance with an MIC for ciprofloxacin of 32 μg/ml. Two out of these 12 isolates (UD62 and UD63), harboured triple mutations (Ser-91 to Phe, Asp-95 to Asn and Val-120 to Leu) in the gyrA gene. The third mutation of Val-120 to Leu, lies downstream of the quinolone resistance determining region (QRDR) of the gyrA and has not been described before in gonococcus. In addition, both these isolates had a Phe-100 to Tyr substitution in the parC, a hitherto unknown mutation. Conclusions: Emergence of ciprofloxacin resistance with high levels of MIC values (up to 32 μg/ml) in India is alarming. Double and triple mutations in gyrA alone or together in gyrA and parC could be responsible for such a high resistance.