Until 1992, virtually all strains of N. gonorrhoeae tested were susceptible to fluoroquinolones, including ciprofloxacin (minimal inhibitory concentrations of less than or equal to 0.06 μg/mL).1 However, gonococcal strains with decreased susceptibilities to ciprofloxacin (MICs of 0.13-0.25 μg/mL) have been isolated sporadically from patients in the United States through the Gonococcal Isolate Surveillance Project (GISP), which measures antimicrobial susceptibilities of urethral isolates from men each month.2 This report describes findings from Ohio and Hawaii that suggest the emergence of fluoroquinolone resistance in N. gonorrhoeae.
Ohio.
From January 1992 through June 1993, 450 isolates of N. gonorrhoeae in the GISP sample were tested; 25 (5.6%) had decreased susceptibilities to ciprofloxacin. When tested at CDC, these isolates had MICs of 0.13-0.25 μg/mL of ciprofloxacin. Expanded screening of all isolates from men at one sexually transmitted disease (STD) clinic during November-December 1993 identified 17 (13.7%) of 124 isolates with MICs of