AUTHOR=Lin Hongguang , Chen Wenxin , Zhou Rushun , Yang Jie , Wu Yong , Zheng Jiaomei , Fei Shuyue , Wu Guiting , Sun Zhiliang , Li Jiyun , Chen Xiaojun 

TITLE=Characteristics of the plasmid-mediated colistin-resistance gene mcr-1 in Escherichia coli isolated from a veterinary hospital in Shanghai

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.1002827

DOI=10.3389/fmicb.2022.1002827

ISSN=1664-302X

ABSTRACT=<p>The mobile colistin-resistance <italic>(mcr)-1</italic> gene is primarily detected in <italic>Enterobacteriaceae</italic> species, such as <italic>Escherichia coli</italic> and <italic>Salmonella enterica</italic>, and represents a significant public health threat. Herein, we investigated the prevalence and characteristics of <italic>mcr-1</italic>-positive <italic>E</italic>. <italic>coli</italic> (MCRPEC) in hospitalized companion animals in a pet hospital in Shanghai, China, from May 2021 to July 2021. Seventy-nine non-duplicate samples were collected from the feces (<italic>n</italic> = 52) and wounds (<italic>n</italic> = 20) of cats and dogs and the surrounding hospital environment (<italic>n</italic> = 7). Seven MCRPEC strains, identified using screening assays and polymerase chain reaction, exhibited multidrug-resistant phenotypes in broth-microdilution and agar-dilution assays. Based in whole-genome sequencing and bioinformatics analyses, all seven isolates were determined to belong to sequence type (ST) 117. Moreover, the Incl2 plasmid was prevalent in these MCRPEC isolates, and the genetic environment of the seven <italic>E</italic>. <italic>coli</italic> strains was highly similar to that of <italic>E</italic>. <italic>coli</italic> SZ02 isolated from human blood. The isolates also harbored the β-lactamase gene <italic>bla</italic><sub>CTX-M-65</sub>, and florfenicol resistance gene <italic>floR</italic>, among other resistance genes. Given that horizontal transfer occurred in all seven strains, <italic>E</italic>. <italic>coli</italic> plasmid transferability may accelerate the emergence of multidrug-resistant bacteria and may be transmitted from companion animals to humans. Therefore, the surveillance of MCRPEC isolates among companion animals should be strengthened.</p>