A survey of the drug susceptibilities of gonococcal isolates from 100 consecutive patients attending clinics in the Tel Aviv area of Israel during the period from February to September 2000 has shown a 61% rate of ciprofloxacin resistance (MICs, >1 g/ml); 51 isolates were highly resistant (MICs, >4 g/ml). Ciprofloxacinresistant strains were more prevalent among isolates with chromosomally mediated resistance to penicillin and tetracycline. Therapeutic failures with ciprofloxacin correlated with MICs of >1 mg/ml (P < 0.01). The high rate of ciprofloxacin resistance coinciding with a sharp rise in the incidence of gonorrhea precludes the use of fluoroquinolone drugs for the empirical treatment of gonococcal infections acquired in Israel.Gonorrhea was rarely reported in Israel in the 1990s, with an average annual incidence of 0.9 cases per 100,000 population (14). As most laboratories did not carry appropriate media, diagnosis was usually made on the basis of Gram-stained smears, and susceptibility testing of Neisseria gonorrhoeae was not routinely performed. More recently, however, the incidence of gonorrhea has been increasing and was up to 13 reported cases per 100,000 population in 2001 (10). The documentation of a case of gonococcal urethritis with clinical and laboratory failure of ciprofloxacin therapy (9) prompted a study of the antimicrobial susceptibilities of N. gonorrhoeae isolates in the Tel Aviv area of Israel.Gonococcal strains with reduced in vitro susceptibilities to fluoroquinolones (MIC of ciprofloxacin, 0.125 to 0.5 g/ml) were first described in the mid-1980s (5) and since then have been identified in the Far East (7,8,20), Australia (21, 22), Africa (3), Europe (12,13,23), and the United States (4). Fluoroquinolone-resistant N. gonorrhoeae (ciprofloxacin MICs, Ն1 g/ml) emerged during the early 1990s and became well established in several Asian countries (16). Strains for which ciprofloxacin MICs were Ն8 g/ml were first isolated in 1994 (15) and have mostly been detected in the Far East (1, 24). Two cases of gonorrhea caused by strains for which the MIC was 16 g/ml were recently reported in the United States (5). These changes in the susceptibility patterns of N. gonorrhoeae may lead to the reassessment of the current recommendations for empirical therapy of gonococcal infection (6). Continuous surveillance of the epidemiology of N. gonorrhoeae based on type characterization and detailed in vitro testing of the antimicrobial susceptibilities of isolates are imperative for establishing empirical treatment guidelines.
MATERIALS AND METHODSSource of isolates. N. gonorrhoeae strains were isolated from clinical specimens (mostly urethral discharges from male patients) at the Central Laboratory of Maccabi Health Services, Rishon-le-Zion, Israel. The Central Laboratory serves a population of 400,000 in the Tel Aviv area, situated in central Israel. All isolates recovered from February 2000 and on were transferred to the Infectious Diseases Research Laboratory at the E. Wolfson Hospital, Holon, Israel. ...