奶牛源葡萄球菌tetK基因碱基及氨基酸序列差异的功能分析  

Functional analysis of tetK gene base and its amino acid sequence difference in Staphylococcus isolated from cows

作　　者：冯清[1] 林伟东[1] 张大帅[1] 黄攀[1] 戴迪[1] 廖俊[1] 梁祥焕 王建 张军[2] 秦爱建[1] 金文杰[1] FENG Qing LIN Weidong ZHANG Dashuai HUANG Pan DAI Di LIAO Jun LIANG Xianghuan WANG Jian ZHANG Jun QIN Aijian JIN Wenjie(Coll of Vet Med/Key Lab of Poul Prey IVied of MOE/Jiangsu Co-Exp Dairy Farm, Yangzhou Univ, Yangzhou 225009, China Wujin Anita Dis Prey and Cont Cent of Changzhou City, Changzhou 213000, China)

机构地区：[1]扬州大学兽医学院/教育部禽类预防医学重点实验室/江苏省动物重要疫病与人兽共患病防控协同创新中心,江苏扬州225009 [2]扬州大学实验农牧场,江苏扬州225009 [3]常州市武进区动物疫病预防控制中心,江苏常州213000

出　　处：《扬州大学学报（农业与生命科学版）》2017年第2期5-9,共5页Journal of Yangzhou University：Agricultural and Life Science Edition

基　　金：江苏省青蓝工程项目(2012-05);扬州市社会发展科技攻关项目(YZ2011091);江苏省农业科技自主创新资金项目[CX(14)2088];江苏高校优势学科建设工程项目(PAPD);常州市科技支撑计划项目(CE20152006)

摘　　要：为探究奶牛源葡萄球菌中部分四环素耐药基因tetK不产生耐药性的原因,采用平行试验对四环素抗性菌株(MP00159)与四环素敏感菌株(MP00109)所携带的tetK基因和tetK′基因的碱基及氨基酸序列差异进行分析;随后将两者分别克隆至表达载体pET-32a(+)后导入大肠埃希菌感受态细胞BL21(DE3)内,比较转化前后对四环素的耐药性。结果表明:四环素敏感菌株携带的tetK′基因与抗性菌株的tetK基因存在5个碱基位点差异,对应的氨基酸出现4个差异;转入敏感菌株tetK′基因的BL21仍表现对四环素敏感,转入抗性菌株tetK基因的BL21表现了四环素抗性。由此推测发生突变的碱基位点是决定tetK耐药表型的关键位点。The tetK gene of Staphylococcus aureus isolated from cows plays an important role in tetracycline resistance.The S.aureus strains MP00109 and MP00159were sensitive and resistance to tetracycline respectively.The tetK′and tetK genes of MP00109 and MP00159were amplified by PCR.Then the competent BL21（DE3）cells were transformed with the expression plasmids of tetK′and tetKrespectively.Compared with the sequences of tetK′and tetK,five nucleotides and four amino acids were different.The BL21 transformed with tetK′was sensitive to tetracycline while the BL21 transformed with tetK was resistant to tetracycline.Thus,we speculate the mutation of partial nucleotide positions in tetK gene causes the tetracycline-resistance change in Staphylococcus aureus.

关 键 词：奶牛源葡萄球菌 四环素耐药基因tetK 耐药表型 基因突变 

分 类 号：S858.23[农业科学—临床兽医学]