鸡源大肠杆菌整合子及基因盒分子流行病学研究

对河南省鸡源大肠杆菌Ⅰ类、Ⅱ类和Ⅲ类整合子及其携带的耐药基因盒进行了分子流行病学研究。结果表明：51株鸡源大肠杆菌中86．3％（44／51）检出Ⅰ类整合子，3．9％（2／51）检出Ⅱ类整合子，未检出Ⅲ类整合子。Ⅰ类整合子共检出5种类型的基因盒，分剐是sat基因盒（100％），dfrAl＋aadAl基因盒（45．4％，20／44），dfrAl7＋aadA5基因盒（22．5％，9／44），dfrAl＋sat＋aadA2基因盒（6．8％，3／44）和4800bp未知基因盒（27．3％，12／44），其中4800bp未知基因盒的下游携带有ESBLCTX-M基因，Ⅱ类整合子的基因盒携带dfrAl＋sat＋aadAl3种基因。

Molecular epidemiology on integrons and gene cassettes of Escherichia coli isola- ted from chicken

An epidemiology investigation on integrons and gene cassettes in 51 Escherichia coli strains isolated from chicken of Henan province by PCR,restriction enzy analysis, sequence, and contrast. The results showed that forty- four stains（86.3%） harbored class Ⅰ integrons, two strains contained class Ⅱ integrons, and none of the isolates carried class Ⅲ integrons. Five types gene cassettes were detected in class Ⅰ integrons, including sat cassette （100%）, dfrA1 ＋ aadA1 cassette （45.4%,20/44 ）, dfrA17 ＋ aadA5 cassette （22. 5%, 9/44）, dfrA1 ＋ sat ＋ aadA2 cassette （6.8%, 3/44） and 4 800 bp unknown cassette （27. 3%, 12/44）. The ESBLCTX-M gene located in the downstream of 4 800 bp unknown cassette. The class Ⅱ integron harbored dfrAl＋sat＋aadA1 cassette.