辽宁地区猪源大肠埃希菌氨基糖苷类抗生素耐药基因的检测与分析

为了解辽宁地区猪源大肠埃希菌对氨基糖苷类抗生素的耐药情况,采用K-B纸片法对65株猪源大肠埃希菌菌株进行6种氨基糖苷类抗生素的药敏试验,同时采用PCR方法对耐药菌株rpsl基因和4种氨基糖苷类钝化酶基因aac(3)-Ⅳ、aad A、aac(6')-Ⅰb-cr、aac C4进行检测及序列分析,并将阳性样品与Gen Bank中登录的序列进行同源性比较。结果显示,辽宁地区猪源大肠埃希菌对链霉素、妥布霉素、新霉素、卡那霉素、丁胺卡那霉素、庆大霉素的耐药率分别为26.2%、15.4%、18.5%、29.2%、4.6%、21.5%;23株耐药菌株rpsl基因检出率为100%;4种氨基糖苷类钝化酶基因aac(3)-Ⅳ、aad A、aac(6')-Ⅰb-cr、aac C4检出率分别为13.0%、8.7%、69.6%、4.3%。以上结果表明,在氨基糖苷类抗生素中耐药性最低的是丁胺卡那霉素,rpsl基因及氨基糖苷类钝化酶基因普遍存在于辽宁地区猪源大肠埃希菌中。

Detection and Analysis of Resistance Genes to Aminoglycoside Antibiotics among Swine Escherichia coli Strains in Liaoning Area

In order to investigate the aminoglycoside resistance of Escherichia coli isolated from swine in Liaoning,the drug sensitivity to six kinds of aminoglycosides antibiotics in 65 strains of E.coli were analyzed by K-B method.Meanwhile,PCR was used to detect and analyze the sequences of the rpsl gene as well as four aminoglycoside modifying enzyme genes including aac(3)-Ⅳ,aadA,aac(6'')-Ⅰb-cr and aacC4.The homologous comparison were processed among the detected genes from the aminoglycoside-resistant strains with the sequences published in GenBank.The results indicated that the resistance rates to streptomycin,tobramycin,neomycin,kanamycin,amikacin and gentamicin were 26.2%,15.4%,18.5%,29.2%,4.6% and 21.5%,respectively.In all twenty-three aminoglycoside-resistant strains,the detection rate of rpsl was 100%,and the detection rates of aac(3)-Ⅳ,aadA,aac(6'')-Ⅰb-cr and aacC4 were 13.0%,8.7%,69.6% and 4.3%,respectively.These results suggested that these E.coli strains presented lowest aminoglycoside resistance to amikacin,and also rpsl gene and aminoglycoside modifying enzyme genes were commonly found in E.coli isolated from swine in Liaoning.