In this study, a rare strain of Escherichia coli co-harboring bla_CTX-M-32 and bla_CTX-M-2 genes was characterized by whole genome sequencing. Escherichia coli strain was recovered from a bovine cecal sample collected at slaughter. The strain was resistant to third and fourth generation cephalosporins, fluoroquinolones, aminoglycosides, tetracycline and sulfamethoxazole, which was in concordance with the genotype: bla_CTX-M-32 and bla_CTX-M-2, aac(3)-Via and tet(A) and sul1 genes, respectively. The E. coli strain was characterized as pathogenic, and belongs to the ST226 (CC226), serotype O141ab/ac:H5, phylogenetic group A and fumC27/fimH41 types. No virulence genes were found in the genome. According to the plasmid analysis, IncFIB, IncHI2 and p0111 were present. The analysis of the contigs revealed that the bla_CTX-M-32 was located in the chromosome, upstream IS5-like/ISKpn26 and IS1380-like/ISEc9 sequences, whereas bla_CTX-M-2 was in the p0111 plasmid, within an integron class 1, and flanked by Orf3/qacEΔ1 and IS91/ISCR1. To our knowledge, this is the first report of a multidrug resistant Escherichia coli strain co-harboring two CTX-M enzymes in a healthy bovine from Portugal. This finding allows a better understanding on the dissemination of these resistance mechanism among bacteria of animal origin.

中文翻译：

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牛中罕见的多药耐药大肠杆菌共存 blaCTX-M-32 和 blaCTX-M-2 基因的出现

在这项研究中，一种罕见的大肠杆菌菌株共同携带bla _CTX-M-32和bla _CTX-M-2基因，通过全基因组测序进行了表征。大肠杆菌菌株是从屠宰时收集的牛盲肠样本中回收的。该菌株对第三代和第四代头孢菌素、氟喹诺酮类、氨基糖苷类、四环素和磺胺甲恶唑耐药，与基因型一致：bla _CTX-M-32和bla _CTX-M-2、aac(3) -Via和tet( A)和sul1基因，分别。该大肠杆菌该菌株具有致病性，属于 ST226 (CC226)、血清型 O141ab/ac:H5、系统发育组 A 和 fumC27/fimH41 型。在基因组中未发现毒力基因。根据质粒分析，存在 IncFIB、IncHI2 和 p0111。contigs的分析表明bla _CTX-M-32位于染色体上游IS 5- like/IS Kpn26和IS 1380- like/IS Ec9序列，而bla _CTX-M-2位于p0111质粒中，在 1 类整合子内，两侧是Orf3 / qacEΔ1和 IS 91 /IS CR1. 据我们所知，这是葡萄牙一头健康牛体内含有两种 CTX-M 酶的多重耐药大肠杆菌菌株的首次报告。这一发现有助于更好地了解这些抗性机制在动物源细菌中的传播。