广州地区淋病奈瑟菌耐药性分析

Analysis of antibiotic resistance of Neisseria gonorrhoeae in Guangzhou

目的监测广州地区2005年分离的淋病奈瑟菌对青霉素、四环素、大观霉素、头孢曲松和环丙沙星的耐药性,分析耐药菌株的流行特点。方法采用琼脂稀释法测定菌株对5种抗生素的MIC,按WHO标准判定四环素MIC≥16mg/L为质粒介导的高度耐四环素淋病奈瑟菌(TRNG);纸片酸度法检测产β内酰胺酶淋病奈瑟菌菌株;碱裂解法提取质粒。结果104株淋病奈瑟菌中检出质粒介导对青霉素(PRNG)和四环素(TRNG)耐药菌株分别为14株(13.5%)和15株(14.4%),环丙沙星耐药率为76.9%(80/104);未发现对大观霉素和头孢曲松耐药菌株。青霉素、四环素和环丙沙星的MIC50及MIC90分别为8mg/L、>32mg/L,2mg/L、32mg/L和4mg/L、32mg/L;其MIC50及MIC90均已超过耐药标准。结论淋病奈瑟菌对大观霉素和头孢曲松的敏感性较高,可作为治疗的首选药物,对青霉素、四环素和环丙沙星高水平耐药,提示对淋病的治疗作用差。

Objective To investigate the antimicrobial susceptibility and the trend of resistance of Neisseria gonorrhoeae strains solated in Guangzhou in 2005. Methods Agar dilution method was used to determine the minimum inhibitory concentrations （MICs） of penicillin G, tetracycline, ciprofloxacin, ceftriaxone and spectinomycin against the N. gonorrhoeae isolates. High level plasmid-mediated tetracycline resistant N. gonorrhoeae （TRNG） were interpreted according to the criteria （MIC ≥ 16 mg/L） used in the project of surveillance of gonococcal susceptibility in WHO Western Pacific Region. Penicillinase-producing N. gonorrhoeae was dteetcted by disk acidometric method. Plasmid DNA was obtained by alkaline lysis method. Results A total of 104 strains of N. gonorrhoeae were studied. Fourteen （13.5%） strains were plasmid mediated penicillin-resistant isolates （PRNG）, and 15 （14. 4%） were tetracycline-resistant （TRNG）. The prevalence of ciprofloxacin-resistant isolates was 76. 9% （80/104）, while none appeared to be resistant to ceftriaxone or spectinomycin. MIC50 and MICro values of penicillin, tetracycline and ciprofloxacin were 8 mg/L and 〉32 mg/L, 2 mg/L and 32 mg/L, 4 mg/L and 32 mg/L, respectively. Their MIC50 and MICro values were significantly higher than the criteria for resistance. Conelusions High susceptibility of N. gonorrhoeae to ceftriaxone and spectinomycin suggests that these two antibiotics should be used as the first-line treatment for gonorrhoea. The N. gonorrhoeae isolates in our study are relatively resistant to penicillin, tetracycline and ciprofloxacin.