Antimicrobial susceptibility of Neisseria gonorrhoeae isolated in Jiangsu Province, China, with a focus on fluoroquinolone resistance

1 School of Public Health, Southeast University, Nanjing, Jiangsu, People's Republic of China 2 Wuxi Clon-Gen Technique Institute, Wuxi, Jiangsu, People's Republic of China 3 Department of Microbiology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong Special Adminstrative Region, People's Republic of China Correspondence Yue-pu Pu puyuepu{at}yahoo.com.cn Received 5 November 2005 Accepted 1 June 2006 In this study, the phenotypic and genotypic resistance to fluoroquinolones in Neisseria gonorrhoeae isolated in Jiangsu Province, China, was analysed. In vitro susceptibility testing of eight antimicrobial agents, including ciprofloxacin and levofloxacin, against 95 clinical isolates was carried out. Detection of mutations in the gyrA and parC genes was performed by sequence analysis. The clinical isolates demonstrated 100 % resistance to ciprofloxacin and 98.9 % non-susceptibility to levofloxacin. All of the isolates were susceptible to cefotaxime and ceftriaxone. For cefepime, spectinomycin and tetracycline, 98.9, 94.7 and 1.1 % of the isolates were susceptible, respectively. None of the isolates was susceptible to penicillin. Five types based on gyrA mutations could be categorized among 54 isolates with seven different mutation sites found on their parC gene. Analysis of sequence results showed that the gyrA mutation Asp-95 Ala and the parC mutations Ser-87 Arg and Ser-87 Asn made a significant contribution to the resistance to fluoroquinolones, in addition to double mutations found in each gene. Therefore, the use of fluoroquinolones in the treatment of N. gonorrhoeae infections in Jiangsu Province is not recommended, while the use of third- and fourth-generation cephalosporins and spectinomycin is recommended.