Genome Characterization of mcr-1–Positive Escherichia coli Isolated From Pigs With Postweaning Diarrhea in China

Abstract

Diarrheagenic Escherichia coli is the causative agent of diarrhea in infants and animals worldwide. Many isolated strains recovered from pigs with postweaning diarrhea are multidrug resistance (MDR), and hybrids of E. coli are potentially more virulent, as enterotoxigenic E. coli (ETEC)/Shiga-toxigenic E. coli (STEC) hybrids. Here, we used whole-genome sequencing to analyze clinical isolates of the five colistin-resistant E. coli. The E. coli CAU15104, CAU15134, and CAU16060 belonged to ETEC/STEC hybrids, displaying the same serotype O3:H45 and sequence type ST4214. The E. coli CAU16175 and CAU16177 belonged to atypical enteropathogenic E. coli (aEPEC), display O4:H11 and O103:H2, ST29, and ST20, respectively. The E. coli CAU16175 carries six plasmids. An IncHI2-type plasmid, pCAU16175_1, harbors an IS26-enriched MDR region, which includes 16 antimicrobial-resistant genes. An IncFII-type plasmid, pCAU16175_3, harbors mcr-1.1, tet(M), and bla TEM−1B , whereas mcr-1.1 is located within a Tn2 derivative. Our findings indicate that the ETEC/STEC strains of the O3:H45 serotype as well as the aEPEC strains of the O4:H11 and O103:H2 serotypes are associated with postweaning diarrhea in swine and that some of diarrheagenic E. coli contains IS26-enriched MDR region and the mcr-1 gene located within a Tn2 derivative on IncFII plasmid.

Exopolysaccharides from Bifidobacterium animalis Ameliorate Escherichia coli-Induced IPEC-J2 Cell Damage via Inhibiting Apoptosis and Restoring Autophagy

“…It adheres to the mucosa of the intestines, resulting in acute and persistent watery diarrhea in humans and animals worldwide [2]. EPEC is a major E. coli pathotype that is estimated to be responsible for piglet postweaning diarrhea in China, and a total of 94.15% of 171 E. coli isolates from 56 swine farms were multidrug-resistant [3,4]. A new strategy is necessary for the prevention of pathogen infections since antimicrobial resistance becomes general [5].…”

Occurrence of Mobile Colistin Resistance Genes mcr-1–mcr-10 including Novel mcr Gene Variants in Different Pathotypes of Porcine Escherichia coli Isolates Collected in Germany from 2000 to 2021

“…The majority of prior studies investigating the presence of mcr genes in E. coli isolates from diseased or healthy pigs with defined E. coli pathotypes/VAG-typed E. coli did not test for mcr-6 to mcr-10 (Table S3) [44][45][46][47][48]. Only two out of seven studies investigating for mcr-6 to mcr-10 reported mcr-9-positive E. coli from pigs with diarrhea (Table S3) [49][50][51][52]. The first occurrence and distribution of mcr-1-mcr-10 were reviewed recently [6].…”

Stability and genetic insights of the co-existence of blaCTX-M-65, blaOXA-1, and mcr-1.1 harboring conjugative IncI2 plasmid isolated from a clinical extensively-drug resistant Escherichia coli ST744 in Shanghai

“…Previous studies have reported mcr-1-harboring plasmids found in different Inc. types, while IncI2, IncHI2, and IncX4 appear to be the most common carriers of mcr-1 (3,(10)(11)(12). The mobility of mcr-1 is difficult to control because mcr-1-harboring plasmids often carry other antimicrobial resistance (AMR) genes, including those encoding resistance to β-lactams, fluoroquinolones, and tetracyclines (8,13,14). For example, Wang et al reported E. coli strain QE11-421, which was isolated from a sputum sample of a 90-year-old male patient receiving treatment in the ICU, was an mcr-1-positive colistin-resistant isolate that co-harbored the bla KPC-2 gene conferring carbapenem resistance (15).…”