淋球菌43株对环丙沙星的耐药性及gyrA和parC基因突变的检测

Detection of 43 ciprofloxacin resistant gonococcal strains and mutations in gyrA and parC

目的 :确定延安地区 2 0 0 2年分离的淋球菌对环丙沙星的耐药率和耐药菌株gyrA及parC基因突变情况 .方法 :从临床分离 4 3株淋球菌 ,进行药敏试验 .PCR扩增gyrA和parC基因 ,产物直接测序 .结果 :4 3株淋球菌菌株中 ,耐药株为 37株 ,耐药率为 86 % .耐药菌株gyrA基因的突变形式是Ser 91→Phe和Asp 95→Gly.parC基因最多见的突变是Asp 86→Asn和Ser 87→Arg,另外还检测到了Glu 91→Gly和Arg 1 1 6→Leu .gyrA突变见于所有的敏感性下降株和耐药株 ,parC突变见于耐药株 ,但有一株MIC为 0 .5 μg/mL的菌株也存在parC突变 .结论

AIM: To determine the occurrence of ciprofloxacin resistance among Neisseria gonorrhoeae strains isolated in Yan’an in 2002 and the frequency and patterns of mutations in gyrA and parC genes in these isolates. METHODS: Antibiotic susceptibility tests were performed in 43 isolates, gyrA and parC genes were amplified by PCR and the PCR products were directly sequenced. RESULTS: There were 37 strains resistant to ciprofloxacin in the isolates of gonococcal and the resisting frequency was 86%. Mutations in gyrA were Ser 91→Phe and Asp 95→Gly, and the most common mutations in parC were Asp 86→Asn and Ser 87→Arg. Glu 91→Gly and Arg 116→Leu were also detected in parC . Mutations in gyrA gene occurred in all the isolates with reduced susceptibility and resistance, and mutations in parC gene occurred in the isolates of resistance, but also occurred in one isolate with MIC 0.5 μg/mL. CONCLUSION: Mutations in gyrA and parC genes are mainly responsible for the gonococcal resistance to ciprofloxacin.