致初生仔猪腹泻大肠埃希氏菌氨基糖苷类耐药性检测及AAC(3)-Ⅱ基因序列分析  

Detection and analysis of AAC(3)-Ⅱgenes from Escherichia coli aminoglycoside resistance strains isolated from piglets with newborn diarrhea

作　　者：陈一兵[1] 苗晓青[1] 高崧[1] 彭大新[1] 刘秀梵[1] 

机构地区：[1]扬州大学农业部畜禽传染病学重点开放实验室

出　　处：《中国预防兽医学报》2007年第12期925-928,共4页Chinese Journal of Preventive Veterinary Medicine

基　　金：教育部科技重点项目(204050)

摘　　要：从1995年至2006年分离鉴定的菌株中选取173株致初生仔猪腹泻大肠杆菌,进行氨基糖苷类药物的药敏试验;根据耐氨基糖苷类药物主要钝化酶—氨基糖苷乙酰转移酶(aminoglycoside acetyltransferases,AAC)的基因序列,设计一对引物,PCR扩增耐药基因片段,探讨AAC基因的分布规律及其与氨基糖苷类抗生素耐药性的相关性。对上述分离株中90个耐庆大霉素的大肠杆菌分离株进行检测,结果表明aac(3)-Ⅱ为这些分离株的主要钝化酶,检出64株,检出率为71.1%;对其中的20株PCR产物进行测序,结果表明对耐庆大霉素而不耐丁胺卡那霉素菌株aac(3)-Ⅱ基因保守区为213位A、232位C、527位A;对应的推导氨基酸序列中71位为赖氨酸、78位为脯氨酸和176位为谷氨酸。两者均耐药的菌株aac(3)-Ⅱ基因保守区具213位G、232位T、527位G,对应的推导氨基酸序列中71位为谷氨酸、78位为亮氨酸、176位为谷氨酰胺。To analyze correlations between E.coli aminoglycoside resistance and the conserved region of aac （3）-Ⅱ gene, 173 strains of pathogenic E.coli isolated between 1995 and 2006 were screened for aminoglycoside resistance according to standard K-B method. The conserved regions of AAC （3）-Ⅱ gene from 90 selected aminoglycoside resistance isolates were PCR amplified and sequenced. The results showed that all isolates resistant to Gentamicin but not to Amikacin have a conserved A, C, and A at nucleotides position 213, 232, 527 with deduced amino acids of lysine, proline and glutamic acid at the position 71, 78 and 176 respectively. The isolates resistant to both had conserved nucleotides of G, T and G at position 213,232 and 517 encoding glutamic acid, leucine and glutamine at corresponding position of 71, 78 and 176, respectively.

关 键 词：大肠杆菌 耐药性 乙酰转移酶(AAC) aac(3)-Ⅱ 

分 类 号：S852.61[农业科学—基础兽医学] Q781[农业科学—兽医学]