中文摘要：

目的探讨parC基因的改变与乳酸菌耐氟喹诺酮类抗生素的相关性。方法采用纸片法和打孔法测定15株菌对诺氟沙星和氧氟沙星的敏感性。PCR扩增检测parC基因氟喹诺酮类耐药决定区相关片段并测序，比对敏感菌株和耐药菌株的测序结果，分析突变位点。结果NN、NN2、NN3等7株为耐药菌株，4对引物PCR扩增检测parC基因，耐药菌株和对照菌株比较，没有发现parC基因的变化。结论乳酸菌对氟喹诺酮类药物的耐药性与其拓扑异构酶ⅣparC基因的突变无关。

英文摘要：

Objective To investigate the correlation between parC gene alterations and lactic acid bacteria resistance to fluoroquinolones. Methods Disk diffusion and beating holes methods are used to measure the sensitivity of 15 strains to norfloxacin and ofloxacin. PCR amplify the fluoroquinolones resistance determining region ofparC gene. Single nucleotide polymorphisms were found by the sequences alignment of the sensitive and resistant strains. Results 7 resistant strains included NN, NN2, NN3, etc. Four pairs of primers were used to amplify parC genes. The sequence results indicate that there are no sequence difference between fluoroquinolones resistant strains and control strains. Conelusion The resistance of lactic acid bacteria to fluoroquinolone have no relationship with the topoisomerase IV parC gene mutation.