食品动物源沙门菌oqxAB基因的检测及水平传播机制研究  

Detection and Dissemination of oqxAB Gene Among Salmonella Isolates from Food-Producing Animals

作　　者：刘继[1] 宋立[2] 魏飞龙[1] 汤电[1] 张静远[1] 张小华[1] 李健[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试验室,广东广州510642 [2]中国兽药监察所,北京100081

出　　处：《华南农业大学学报》2011年第4期105-109,共5页Journal of South China Agricultural University

基　　金：国家自然科学基金(30871890);国家自然科学基金-广东省自然科学基金联合基金重点项目(U0631006)

摘　　要：为了调查食品动物源沙门菌Salmonella oqxAB耐药基因的流行情况和水平传播机制,采用二倍琼脂稀释法测定临床分离的31株沙门菌对常用抗菌药物的敏感性,PCR方法特异扩增耐药基因oqxAB,并对扩增产物克隆测序.通过接合转移试验验证oqxAB基因的水平传播.试验结果表明,31株沙门菌对氨苄霉素的耐药率最高,达64.5%,对氨基糖苷类、氯霉素类、四环素类、氟喹诺酮类的耐药率介于42%～55%之间,对头孢菌素类的耐药率最低,约为20%.31株沙门菌中共检测到12株含有oqxAB基因,检出率为39%.以J53AziR为受体菌进行oqxAB基因阳性菌的质粒接合转移试验,结果得到5株oqxAB基因接合子.接合子的药敏结果显示,除了氟喹诺酮类药物的最低抑菌浓度(MIC)升高外,对链霉素、四环素及氯霉素的耐药性也有不同程度的增加,说明介导链霉素、四环素及氯霉素的耐药基因可能与oqxAB基因随质粒一起转移.Susceptibilities of total 31 Salmonella isolates were determined by agar dilution method, oqxAB gene was amplified among 31 Salmonella isolates using specific primers. PCR products were cloned into a vector pMD19-T for sequencing. Conjugation tests were conducted among oqxAB positive Salmonella using Escherichia coli J53AziR as a recipient. The susceptibilities of 31 Salmonella isolates for common use anti-microbials showed that the resistant occurrence for ampicillin was ranked the highest （64. 5% ） ,42% - 55% for aminoglycosides, chloramphenicols, tetracyclines and fluoroquinolones, and less than 20% forcephalosporins. The occurrence of the oqxAB gene in 31 Salmonella isolates was found to be 39%. Five oqxAB positive conjugants were obtained from matching tests. The minimum inhibitory concentration（MIC） results of 5 transconjugants suggested that streptomycin, tetracycline, chloramphenicol and enro- floxacin resistant determinants were transferable with oqxAB gene on the same plasmid, which was in linewith previous reports. Determinants indicated that β-lactams resistance was probably transferred with oqxAB on the same plasmid.

关 键 词：沙门菌 oqxAB基因 最低抑菌浓度 质粒 接合 

分 类 号：S859.79[农业科学—临床兽医学]