Animal and Plant Health Agency (Weybridge), Addlestone, UK.
SRUC (Inverness Campus), Edinburgh, UK.
J Appl Microbiol. 2019 Apr;126(4):1081-1095. doi: 10.1111/jam.14211. Epub 2019 Feb 27.
This study investigated the occurrence and genetic diversity of Enterobacteriaceae with extended-spectrum β-lactamase (ESBL)-, AmpC- and carbapenemase-mediated resistance in British beef cattle, and related risk factors.
Faecal samples (n = 776) were obtained from farms in England and Wales (n = 20) and Scotland (n = 20) in 2015. Isolates from selective agars were identified by MALDI ToF mass spectrometry. Selected isolates were characterized by multiplex PCR (bla bla bla and bla genes), whole-genome sequencing (WGS), minimum inhibitory concentrations and pulsed-field gel electrophoresis. None of the faecal samples yielded carbapenem-resistant Escherichia coli. Ten (25%) of the farms tested positive for ESBL-producing CTX-M Enterobacteriaceae, 15 (37·5%) of the farms were positive for AmpC phenotype E. coli and none were positive for carbapenem-resistant E. coli. WGS showed a total of 30 different resistance genes associated with E. coli, Citrobacter and Serratia from ESBL agars, and colocation of resistance genes with bla . Buying bulls and bringing in fattening cattle from another farm were identified as significant risk factors for positive samples harbouring CTX-M Enterobacteriaceae or AmpC phenotype E. coli respectively.
Beef cattle on a proportion of farms in GB carry ESBL-producing Enterobacteriaceae. Factors, such as operating as a closed herd, may have an important role in reducing introduction and transmission of resistant Enterobacteriaceae. The results indicate management factors may play an important role in impacting ESBL prevalence. In particular, further study would be valuable to understand the impact of maintaining a closed herd on reducing the introduction of resistant Enterobacteriaceae.
This is the first study showing the presence of ESBL-producing Enterobacteriaceae in British beef cattle.
本研究调查了具有扩展谱β-内酰胺酶（ESBL）、AmpC 和碳青霉烯酶介导耐药性的肠杆菌科在英国肉牛中的发生和遗传多样性，并分析了相关风险因素。
2015 年，从英格兰和威尔士（n=20）和苏格兰（n=20）的农场中采集了 776 份粪便样本。使用 MALDI ToF 质谱对选择性琼脂上的分离株进行鉴定。通过多重 PCR（bla bla bla 和 bla 基因）、全基因组测序（WGS）、最低抑菌浓度和脉冲场凝胶电泳对选定的分离株进行了表征。没有粪便样本产生耐碳青霉烯类的大肠埃希菌。10 个（25%）农场的产 ESBL 型 CTX-M 肠杆菌科呈阳性，15 个（37.5%）农场的产 AmpC 表型大肠埃希菌呈阳性，没有农场的大肠埃希菌呈耐碳青霉烯类阳性。WGS 显示，从 ESBL 琼脂中分离出的大肠埃希菌、柠檬酸杆菌和沙雷氏菌共携带 30 种不同的耐药基因，bla 基因与耐药基因共定位。从另一个农场购买公牛和育肥牛被确定为携带 CTX-M 肠杆菌科或 AmpC 表型大肠埃希菌阳性样本的重要风险因素。
英国部分农场的肉牛携带产 ESBL 肠杆菌科。例如，作为一个封闭牛群进行养殖操作等因素可能在减少耐药肠杆菌科的引入和传播方面发挥了重要作用。研究结果表明，管理因素可能对 ESBL 流行率产生重要影响。特别是，进一步的研究将有助于了解保持封闭牛群对减少耐药肠杆菌科引入的影响。
该研究首次表明，英国肉牛中存在产 ESBL 的肠杆菌科。
