鸡大肠杆菌O78对喹诺酮类药物高耐药株的分子鉴定  

Molecular Characterization of High-level Fluoroquinolones Resistance in Escherichia coli O78

作　　者：李乾学[1] 邓旭明[2] 郭建顺[2] 周学章[2] 刘立国[2] 曾凡勤[2] 

机构地区：[1]军事医学科学院军事兽医研究所,吉林长春130062 [2]吉林大学畜牧兽医学院,吉林长春130062

出　　处：《中国兽医学报》2006年第2期192-193,196,共3页Chinese Journal of Veterinary Science

基　　金：国家自然科学基金资助项目(30270999)

摘　　要：就临床分离的鸡大肠杆菌O 78对喹诺酮类药物的最低抑菌浓度(M IC)进行了测定,得到对喹诺酮类药物有不同耐药水平的细菌23株。根据G enB ank已公布的QRDR s序列,设计了分别扩增gyrA、gyrB、parC和parE基因的4对引物,以筛选的23株耐药菌DNA为模板,进行了PCR扩增。序列分析及A crA的W estern b lotting检测结果表明,临床分离的鸡大肠杆菌对喹诺酮类药物的耐药水平与G yrA和ParC的突变密切相关,而A crAB外输泵的表达水平无显著变化。提示临床分离的鸡大肠杆菌O 78的耐药水平与喹诺酮类药物的选择性压力有关,它诱导了DNA旋转酶和拓扑异构酶IV的基因突变,可能不能激活A crAB外输泵。Fluoroquinolone minimal inhibition concentration（MIC） was determined in Escherichia coli O78 isolated from diseased chickens. 23 isolates of different level of resistance to fluoroquinolones were obtained. Primers were designed for gyrA, gyrB, parC and parE of E. coli O78 on the basis of published QRDRs sequence of GenBank, fragments were amplified by PCR. And then the expressing level of AcrAB was detected by Western blotting. The results indicated that the level of resistance to fluoroquinolones of isolates appeared closely correlated with substitution in GyrA and ParC, but expressing level of AcrAB had not significant changes. It suggested that the level of resistance of isolates would be related to selecting pressure of fluoroquinolones and induced gene mutations of DNase and topoisomerase IV could not activate AcrAB efflux pump system.

关 键 词：鸡大肠杆菌 喹诺酮类药物 耐药 

分 类 号：S852.62[农业科学—基础兽医学]