Antimicrobial resistance and virulence gene profiles in multi-drug resistant enterotoxigenic Escherichia coli isolated from pigs with post-weaning diarrhoea
Antimicrobial resistance and virulence gene profiles in multi-drug resistant enterotoxigenic Escherichia coli isolated from pigs with post-weaning diarrhoea
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DOI：
10.1016/j.vetmic.2010.04.004
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发表时间：
2010-10-26
影响因子：
3.3
通讯作者：
Trott, D. J.
中科院分区：
文献类型：
--
作者：
Smith, M. G.;Jordan, D.;Trott, D. J.
本研究旨在表征从澳大利亚猪断奶后腹泻病例（1999-2005年）中收集的多药耐药肠毒素大肠杆菌（ETEC）分离株（n = 117）的抗菌药物耐药性和毒力基因。对分离株进行了12种抗菌药物的血清学分型、细菌学表型和30种质粒介导的抗菌药物耐药基因（ARG）、22种肠内和38种肠外大肠埃希菌的PCR基因分型。大肠杆菌毒力基因（VGs）。确定了9个血清群，最流行的是O 149（46.2%）、O 141（11.2%）和Ont（31.6%）。没有分离株对头孢噻呋或恩诺沙星耐药，9.4%对氟苯尼考耐药。未检测到相应的超广谱/AmpC β-内酰胺酶、氟喹诺酮或floR ARG。根据组合数据计算抗菌药物耐药性指数（ARI），并根据其对人类健康的重要性对每种抗菌药物进行加权。血清群0141分离株的ARI显著更高，这是由于氨基糖苷类ARG的流行率升高和拥有更多毒力基因（VG），包括缺乏正常相关F4和F18菌毛的产毒素菌株中的ExPEC或EHEC粘附素（bmaE sfa/focDE、fimH、ihA）。除了tetC、sfa/focDE和ompT外，ARG和VG之间几乎没有明显的关联，对于0141分离株的子集，这表明可能从ExPEC获得质粒。多重耐药ETEC ARG/VG图谱表明，菌株和质粒多样性相当大的可能性很高，反映了个体农场水平的各种选择压力，而不是MDR耐药/强毒克隆的出现和横向传播。(C)出版社：Elsevier B. V.
This study aimed to characterize antimicrobial resistance and virulence genes in multidrug resistant enterotoxigenic Escherichia coli (ETEC) isolates (n = 117) collected from porcine post-weaning diarrhoea cases in Australia (1999-2005). Isolates were serotyped, antibiogram-phenotyped for 12 antimicrobial agents and genotyped by PCR for 30 plasmid-mediated antimicrobial resistance genes (ARGs), 22 intestinal and 38 extra-intestinal E. coli virulence genes (VGs). Nine serogroups were identified, the most prevalent being O149 (46.2%), O141 (11.2%) and Ont (31.6%). None of the isolates showed resistance to ceftiofur or enrofloxacin and 9.4% were resistant to florfenicol. No corresponding extended-spectrum/AmpC beta-lactamase, fluoroquinolone or floR ARGs were detected. An antimicrobial resistance index (ARI) was calculated from the combined data with a weighting for each antimicrobial agent dependent upon its significance to human health. Serogroup 0141 isolates had a significantly higher ARI due to an elevated prevalence of aminoglycoside ARGs and possession of more virulence genes (VGs), including ExPEC or EHEC adhesins (bmaE sfa/focDE, fimH, ihA) in toxin-producing strains that lacked the normally associated F4 and F18 fimbriae. Few associations between ARGs and VGs were apparent, apart from tetC, sfa/focDE and ompT which, for a sub-set of 0141 isolates, suggest possible plasmid acquisition from ExPEC. The multi-drug resistant ETEC ARG/VG profiles indicate a high probability of considerable strain and plasmid diversity, reflecting various selection pressures at the individual farm level rather than emergence and lateral spread of MDR resistant/virulent clones. (C) 2010 Published by Elsevier B.V.