作　　者： ; ; ; ; ; ;

机构地区： 中国动物卫生与流行病学中心

出　　处： 《中国动物检疫》 2010年第12期51-54,共4页

摘　　要： 目的为了解猪源大肠杆菌中Ⅰ型整合子的流行情况,探讨Ⅰ型整合子与大肠杆菌耐药表型的相关性。方法采用微量肉汤稀释法测定119株猪源大肠杆菌对8类14种抗菌药物的耐药性,并采用PCR法检测猪源大肠杆菌Ⅰ型整合酶基因(int I1)并扩增其可变区,对PCR产物进行酶切分析,测序分析整合子可变区携带的耐药基因盒。结果 119株大肠杆菌耐药现象十分严重,对四环素、磺胺异恶唑、新诺明全部耐药,所有菌株均呈多重耐药。119株猪源大肠杆菌中有92株含Ⅰ型整合子,检出率77.31%。扩增出7类大小不同的基因盒插入区片段,范围为1008bp～3149bp。7类Ⅰ型整合子在119株猪源大肠杆菌中存在13种流行组合。78.15%大肠杆菌菌株的Ⅰ型整合子携带2种或2种以上的基因盒,其中以携带编码氨基糖苷类药物耐药基因(aadA1、aadA2、aadA5、aadA22、aadB)最多,其次为编码磺胺类药物耐药基因(dfrA1、dfrA12、dfrA17、dfrA27),此外还携带编码利福平、林可霉素和氯霉素的基因lnuF、cmlA6、aar-3、orf。结论Ⅰ型整合子普遍存在于大肠杆菌中,且呈流行上升趋势;Ⅰ型整合子参与耐药及多重耐药,但单株细菌携带的耐药基因盒与其耐药表型无对应关系。 Objective： To study the distribution and epidemiology of class I integron in E.coli from swine, and explore the relationship between integron and its resistance. Methods： Micro-broth dilution method was performed to detect resistence the 119 E.coli strains to 14 drugs in 8 main classes, and class I integrase gene （int I1） and its variable region were amplified by PCR, the products were analyzed by restriction endonucleases and sequenced. Results： 119 E.coli strains had serious antibiotic resistance. The resistance rate the all of E.coli strains to TE,SZ, SM was 100%. All the strains were multi-resistant. 92 of 119 strains （77.31%） were found containing class I integron and 98.91% （91/92） of the Class I integron 1 positive strains owned the variable region. 7 kinds of integron variable segment （1008bp-3149bp）of the variable region of integrons were amplified showed 13 combination modes epidemiologically. 78.15% E.coli strains obtained multi gene cassettes. Of all resistant gene, Aminoglycosides-resistant genes （aadA 1, aadA2, aadA5, aadA22, aadB） were most, followed by Sulfanilamide-resistant genes （dfrAl,dfrA12.dfrA17,dffA27）,and lnuF.cmlA6.aar-3,orf. Conclusion：Class I integron existed widely in E. coli, and the epdemiological trend appears to increase rapidly. There was a good correlation between integron carried and the resistance and multi-resistance, but the antimicrobial resistance patterns did not consist with the gene cassettes.

关 键 词： 大肠杆菌 型整合子 基因盒 耐药性 多重耐药

领　　域： [农业科学] [农业科学] [农业科学]