耐氟喹诺酮类药物鸡毒支原体DNA回旋酶及拓扑异构酶Ⅳ的突变特征  

Characterization of Mutations in DNA Gyrase and Topoisomerase Ⅳ Involved in Quinolone Resistance of Clinical Mycoplasma gallisepticum Isolates

作　　者：魏飞龙[1] 周云雷[1] 沈祥广[1] 蒋红霞[1] 

机构地区：[1]华南农业大学兽医学院广东省兽药研制与安全评价重点实验室,广州510642

出　　处：《中国畜牧兽医》2010年第9期43-47,共5页China Animal Husbandry & Veterinary Medicine

基　　金：国家自然科学基金资助项目(30871890)

摘　　要：采用二倍稀释法测定临床分离的4株鸡毒支原体对常用抗菌药物的敏感性,PCR方法和基因测序法对鸡毒支原体DNA回旋酶编码基因gyrA、gyrB及拓扑异构酶Ⅳ编码基因parC和parE耐药决定区进行分析。敏感性测定结果表明,4株分离鸡毒支原体对泰乐菌素、泰妙林、沃尼妙林和替米考星有很高的敏感性,对四环素和红霉素中度敏感,对林可霉素、氟苯尼考和氟喹诺酮类药物呈现不同程度的耐药性。4株耐氟喹诺酮类药物鸡毒支原体均在GyrA和ParC的喹诺酮类耐药决定区(QRDR)发生氨基酸的改变,GyrA的氨基酸取代模式有两种,分别为Ser81→Gly和Ser83→Ile,ParC仅在80位发生氨基酸取代(Ser80→Leu),GyrB和ParE均未发生氨基酸改变。Susceptibilities of 4 isolated M.gallisepticum to common used antimicrobials were determined by broth dilution method.PCR and sequencing were applied for analysis of quinolone resistance-determining regions of the four target genes encoding DNA gyrase and topoisomerase Ⅳ from 4 isolates.The results showed that 4 isolates presented higher susceptible to tylosin,tiamulin,valnemulin and tilmicosin,moderate susceptible to tetracycline and erythromycin,and resistant to lincomycin,florfenicol and 3 fluroquinolone drugs to a certain extent.Several mutations were found in the two fluoroquinolone targets GyrA and ParC.Double mutations within QRDR of GyrA were found among 4 isolated M.gallisepticum,with the same substitution patterns of Ser81→Gly and Ser83→Ile.There was only one alteration existed within QRDR of ParC（Ser80→Leu） among 4 isolates.No mutations were found within QRDR of GyrB and ParE in 4 isolates.

关 键 词：鸡毒支原体 最低抑菌浓度 DNA回旋酶 拓扑异构酶Ⅳ 

分 类 号：S859.7[农业科学—临床兽医学]