30株鸡大肠杆菌ESBLs基因型检测及耐药性分析

Detection of extended-spectrum β-lactamases genotype and antibiotic resistance analysis among 30 E.coli isolates from chicken

采用2倍稀释法检测30株鸡大肠杆菌对常见药物耐药性,用表型筛选和确证试验检测产超广谱β-内酰胺酶(ESBLs)情况,并分别用TEM、SHV和CTX-M等3种通用引物进行PCR扩增以确定其基因型。结果显示23株大肠杆菌为产ESBLs株,占76.7%。PCR扩增表明TEM、CTX-M、SHV阳性率分别为73.9%、43.5%和0%,有7株同时检测出TEM和CTX-M基因(占30.4%),3株未检测出TEM、CTX-M和SHV 3种基因(占13.0%)。药敏试验结果显示产ESBLs大肠杆菌对药物的多重耐药性明显比非产酶大肠杆菌严重,产酶菌对氨苄西林和头孢噻呋的耐药率最高,为95.7%,对氨基糖苷类、恩诺沙星和复方新诺明的耐药率均高于78%,氨苄西林和三代头孢与酶抑制剂联用或2种不同种类的药物联用均能明显增强抗菌活性。以上结果表明河南省76.7%的临床分离鸡大肠杆菌为产ESBLs株,其基因型主要是TEM和CTX-M,尚无SHV型,β-内酰胺类与酶抑制剂联用或不同种类药物联用是防治鸡产酶大肠杆菌感染的有效措施之一。

Twenty-three extended-spectrum β-lactamases （ESBLs） positive Escherichia coli strains isolated fi＇om chicken were analysed for antibiotic resistance. Three different genotypes were detected among these ESBL positive isolates by polymerase chain reaction （PCR）： TEM-positive （73.9 %）, CTX-M-positive （43.5 %）, TEM-and CTX-M-positive （30.4 %）, and non-TEM, non-SHV, non-CTX-M ESBL types （13 %）. The antibiotic resistance was tested by two-fold dilutions. The results showed that the multi-resistance rate among ESBL-positive strains was higher than that of the ESBL-negative strains, with 95.7 % resistance rates against arnpicillin and ceftiofur, and more than 78 % against other third-generation cephalosporins, aminoglycosides, enrofloxacin and trimethoprirn-sulfamethoxazple （1/5）.