| 摘要: |
| 【目的】了解2010-2016年四川省食品动物源大肠杆菌产超广谱β内酰胺酶(ESBLs)情况及其耐药基因的变迁。【方法】以2010―2016年收集的444株食品动物源大肠杆菌(鸡源225株，猪源219株)为对象，采用纸片扩散法和微量肉汤稀释法分别检测其产ESBLs情况和药物敏感性；采用PCR测序法和脉冲场凝胶电泳(PFGE)检测携带ESBLs菌株的基因型特征和部分菌株的亲缘关系。【结果】444株大肠杆菌中，产ESBLs菌株的检出率为27.7%，其中鸡源菌和猪源菌检出率分别为42.2%和12.8%。2010-2016年产ESBLs菌株从16.9%升高至40.4%，鸡源菌株ESBLs检出率随时间变化比猪源菌更明显；ESBLs阳性菌株对大多数药物的耐药率显著高于阴性菌株，且多重耐药性问题更严重；产ESBLs菌株携带的耐药基因以blaTEM和blaCTX-M为主，并以blaTEM-1(63.3%)、blaTEM-52(32.1%)、blaCTX-M-55(42.2%)、blaCTX-M-65(27.8%)和blaCTX-M-14(21.1%)为主要流行亚型，且检出率及ESBLs基因亚型复杂性呈逐年上升趋势；ESBLs阳性菌株有广泛PFGE谱型，即便携带相同基因型的菌株也不存在亲缘关系。【结论】四川食品动物源大肠杆菌产ESBLs菌株检出率及其耐药基因亚型的复杂程度呈逐年上升趋势，ESBLs是造成多重耐药性的主要原因，ESBLs耐药基因以水平传播为主。 |
| 关键词: 食品动物源 大肠杆菌 超广谱β-内酰胺酶 耐药基因型 四川省 |
| DOI： |
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| 基金项目:国家自然科学基金项目(31872347) |
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| Drug resistance of Escherichia coli isolates from food-animals obtained from 2010 to 2016 in Sichuan |
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YANG Chenglin,SHU Gang,ZHAO Xiaoling,et al
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| Abstract: |
| 【Objective】This study obtained the prevalence of extended-spectrum β-1actamases (ESBLs) and ESBL genes in Escherichia coli isolates from food animals in different farms of Sichuan from 2010 to 2016.【Method】A total of 444 Escherichia coli isolates were collected during 2010-2016 from food animals (225 from chicken and 219 from swine) in Sichuan.The K-B and Microdilution broth methods were used to test ESBLs and antibiotic sensitivity,respectively.PCR-sequencing and PFGE were used to identify ESBL genes and homology of isolates.【Result】The detection rate of ESBLs from 444 Escherichia coli isolates was 27.7%,and that from chicken and swine were 42.2% and 12.8%,respectively.The prevalence of ESBL-producing Escherichia coli isolates during 2010-2016 increased from 16.9% to 40.4%,and the rate of ESBLs-producing isolates from chicken was higher than that of swine.ESBL producing isolates had significantly higher resistance to different antibiotics than ESBL-negative isolates.Genes blaTEM and blaCTX-M were the most common,and main sub-types included blaTEM-1 (detection rate 63.3%),blaTEM-52 (32.1%),blaCTX-M-55 (42.2%),blaCTX-M-65 (27.8%) and blaCTX-M-14 (21.1%).The detection rate of ESBLs genes and the complexity of gene subtypes increased year by year.The extensive PFGE types were found in ESBLs-producing isolates,and hereditary background was variable although the genotypes were the same in ESBL-producing isolates.【Conclusion】Detection rates of ESBL-producing isolates and ESBL gene types increased during 2010-2016.ESBLs were the main source of resistance and there was horizontal transmission of ESBL genes among different isolates. |
| Key words: food-producing animals Escherichia coli ESBLs drug-resistant gene types Sichuan province |
