新疆牛羊源耐药大肠杆菌β-内酰胺酶及16S rRNA甲基化酶基因检测

Detection of β-Lactamase and 16S rRNA Methylase Gene in Resistant Escherichia coli Isolates from Cattle and Sheep in Xinjiang

为了解新疆某羊场、牛场耐药大肠杆菌携带β-内酰胺酶和/或16S r RNA甲基化酶基因及其共存情况。通过PCR方法对168株羊源和32株牛源耐β-内酰胺类药物大肠杆菌进行β-内酰胺酶及16S r RNA甲基化酶基因检测,并对检出基因的PCR产物测序。检测结果为:羊源大肠杆菌携带的β-内酰胺酶基因为blaTEM(42.26%,71/168)和blaCTX-M(2.98%,5/168);牛源大肠杆菌携带的β-内酰胺酶基因为bla TEM(15.63%,5/32)基因,未检出blaCTX-M;两个养殖场均未检出其他被检基因。羊源、牛源大肠杆菌携带的16S r RNA甲基化酶基因为rmt B基因,其检出率分别为4.17%(7/168)和50.00%(16/32),均未检出arm A基因。基因共存情况:3(1.79%)株羊源菌同时携带blaTEM和blaCTX-M基因,7(4.17%)株羊源菌同时携带blaTEM和rmt B基因;2(6.25%)株牛源菌同时携带blaTEM和rmt B基因。羊源和牛源大肠杆菌中存在β-内酰胺酶和16S r RNA甲基化酶基因介导的细菌耐药,均以blaTEM和rmt B基因为主。此外,存在不同类型耐药基因共存于同一株耐药菌的现象。

The research aims at the resistant Escherichia coli carrying β-lactamases and or 16S rRNA methylase gene and its coexistence conditions in cattle and sheep farms in Xinjiang. β-1actamase and 16S rRNA methylase genes by PCR in β-1actam-resitance Escherichia coli were isolated from sheep farm （168 isolates） and cattle farm （32 isolates）. The products of PCR were analyzed by sequencing. The results showed that the blaTEM, （42.26%, 71/168） and blaCTX-M （2.98%, 51168） genes were mainly β-1actamase genes from sheep; blaaTEM （15.63%, 5/32）genes were mainly β-1actamase genes from cattle, blaCTX-M was not detected, and other resistance genotypes were not seized in the two farms. ArmA genes were not detected. The detected 16S rRNA methylase genes were rmtB gene from sheep and cattle isolates, its detection rate was 4.17% （71168） and 50.00% （16132）. Coexistence gene： three （1.79%, 31168） isolates from cattle were found to possess the blaTEM and blaCTX-M genes in the sheep farm. seven （4.17%, 71168） isolates from sheep were found to possess the blank and rmtB genes, and two （6.25%, 2/32） isolates were found to possess the blaTEM and rmtB genes in the cattle farm. The other detected β-lactamase and 16S rRNA methylase genes were not found in these farms. Escherichia coli isolates from cattle and sheep farms had β-lactamase and 16S rRNA methylase genes mediated bacterial resistance, and were dominated by blaTEM and rmtB genes in Xinjiang. In addition, different types of drug-resistant genes coexist in the same drug-resistance bacterial strain.