Background The emergence of cephalosporin resistance in Neisseria gonorrhoeae threatens gonorrhoea control programmes worldwide. Data on gonococcal antimicrobial susceptibility in the United States come from the Gonococcal Isolate Surveillance Project, which monitors susceptibility in male urethral isolates. Little is known about the susceptibility of isolates obtained from extra-genital sites. We sought to describe and compare antimicrobial susceptibility patterns of pharyngeal, rectal, and urethral gonococcal isolates obtained from men who have sex with men (MSM) at selected sentinel surveillance sites.
Methods We assessed the antimicrobial susceptibility of pharyngeal, rectal, and urethral gonococcal isolates collected from MSM at five sexually transmitted disease clinics throughout the United States. Minimum inhibitory concentrations (MICs) were determined by agar dilution at two regional laboratories, and elevated MICs were confirmed at the Centers for Disease Control and Prevention.
Results During December 2011-August 2012, a total of 85 pharyngeal, 99 rectal, and 315 urethral isolates from MSM were submitted. The proportion of isolates with an elevated cephalosporin or azithromycin MIC did not significantly differ by anatomic site: 1.2% of pharyngeal, 3.0% of rectal, and 3.2% of urethral isolates had an elevated cefixime MIC (≥ 0.25 µg/mL) (p = 0.79); 5.9% of pharyngeal, 7.1% of rectal, and 8.3% of urethral isolates had an elevated cefpodoxime MIC (≥ 0.25 µg/mL) (p = 0.86); 1.2% of pharyngeal, 2.0% of rectal, and 4.1% of urethral isolates had an elevated ceftriaxone MIC (≥ 0.125 µg/mL) (p = 0.47); and 2.4% of pharyngeal, 1.0% of rectal, and 1.6% of urethral isolates had an elevated azithromycin MIC (≥ 2.0 µg/mL) (p = 0.91).
Conclusion Among MSM, the proportion of urethral isolates with an elevated cephalosporin or azithromycin MIC was similar to that of pharyngeal and rectal isolates. These findings suggest that, at the population level, gonococcal antimicrobial susceptibility surveillance based on urethral isolates from MSM adequately represents antimicrobial susceptibility of N. gonorrhoeae circulating among MSM.
- Antimicrobial Resistance
- Neisseria gonorrhoeae