Introduction

The prevalence of Extended-Spectrum Beta-Lactamase (ESBL)-producing Enterobacteriaceae is increasing worldwide and the Agri-Food sector acts as a reservoir of clinically relevant ESBL genes. Our study aimed at detecting and characterizing ESBL-producing Enterobacteriaceae responsible for intestinal colonization of Brazilian bovines.

Material and methods

ESBL-producing E. coli isolates were recovered from fecal samples of healthy cattle in Northwest Brazil. Antimicrobial susceptibility was determined by disk diffusion. Resistance and virulence genes were identified by PCR and amplicons were sequenced, clonality was assessed by PFGE and MLST, and plasmids were characterized by replicon typing, S1-PFGE and Southern blot hybridizations. Transferability of ESBL genes was assessed by conjugation assay.

Results

A total of 40 ESBL-producing E. coli were characterized, which originated from 34/191 animals (17.8 %) and 15/22 farms (68.2 %). The bla_CTX-M-8 gene was the most frequent ESBL gene (62.5 %), followed by bla_SHV-2a (20.0 %), bla_CTX-M-2 (10.0 %), and bla_CTX-M-15 (7.5 %). The bla_CTX-M-8 gene was localized on the IncI1/pST113 plasmid in multiple E. coli sequence types across unrelated animals and farms.

Discussion

We report the first characterization and a high prevalence of ESBL-producing E. coli in the beef cattle sector in Brazil, which is mainly supported by the spread of an epidemic IncI1/pST113/bla_CTX-M-8 plasmid. Since Brazil is one of the biggest beef meat exporters worldwide, the spread of this ESBL plasmid across other sectors, countries and continents should be considered with attention.

中文翻译：

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带有扩展频谱β-内酰胺酶（ESBL）bla _CTX-M-8基因的IncI1 / pST113质粒在巴西牛大肠杆菌中的流行病传播

介绍

全球范围内，生产广谱β-内酰胺酶（ESBL）的肠杆菌科细菌的患病率正在上升，农业食品部门是临床相关ESBL基因的库。我们的研究旨在检测和鉴定负责巴西牛肠道定植的产ESBL肠杆菌科。

材料与方法

从巴西西北部健康牛的粪便样本中回收到产生ESBL的大肠杆菌分离物。抗菌药敏性通过盘扩散测定。通过PCR鉴定抗性和毒力基因，并对扩增子进行测序，通过PFGE和MLST评估克隆性，并通过复制子分型，S1-PFGE和Southern印迹杂交表征质粒。ESBL基因的可转移性通过缀合测定法评估。

结果

共鉴定出40种产ESBL的大肠杆菌，它们来源于34/191只动物（占17.8％）和15/22个农场（占68.2％）。所述BLA _CTX-M-8基因是最常见的ESBL基因（62.5％），其次是血乳酸_SHV-2A（20.0％），BLA _CTX-M-2（10.0％），和BLA _CTX-M-15（7.5 ％）。所述BLA _CTX-M-8基因定位在多个所述IncI1 / pST113质粒的大肠杆菌横跨无关动物和农场序列类型。

讨论区

我们报告了在巴西肉牛部门生产ESBL的大肠杆菌的第一个特征和较高的流行率，这主要是由流行的IncI1 / pST113 / bla _CTX-M-8质粒的传播所支持。由于巴西是全球最大的牛肉出口国之一，因此应特别注意该ESBL质粒在其他行业，国家和大洲的传播。