Genomic Characterisation of a Multiple Drug Resistant IncHI2 ST4 Plasmid in Escherichia coli ST744 in Australia

Abstract

Antibiotic resistance genes (ARGs) including those from the blaCTX-M family and mcr-1 that encode resistance to extended spectrum β–lactams and colistin, respectively, have been linked with IncHI2 plasmids isolated from swine production facilities globally but not in IncHI2 plasmids from Australia. Here we describe the first complete sequence of a multiple drug resistance Australian IncHI2-ST4 plasmid, pTZ41_1P, from a commensal E. coli from a healthy piglet. pTZ41_1P carries genes conferring resistance to heavy-metals (copper, silver, tellurium and arsenic), β-lactams, aminoglycosides and sulphonamides. The ARGs reside within a complex resistance locus (CRL) that shows considerable sequence identity to a CRL in pSDE_SvHI2, an IncHI2:ST3 plasmid from an enterotoxigenic E. coli with serotype O157:H19 of porcine origin that caused substantial losses to swine production operations in Australia in 2007. pTZ41_1P is closely related to IncHI2 plasmids found in E. coli and Salmonella enterica from porcine, avian and human sources in Europe and China but it does not carry genes encoding resistance to clinically-important antibiotics. We identified regions of IncHI2 plasmids that contribute to the genetic plasticity of this group of plasmids and highlight how they may readily acquire new resistance gene cargo. Genomic surveillance should be improved to monitor IncHI2 plasmids.

Characterization of the Complete Nucleotide Sequences of mcr-1-Encoding Plasmids From Enterobacterales Isolates in Retailed Raw Meat Products From the Czech Republic

“…However, IncHI2 plasmids, carrying mcr-1 gene, showed higher diversity than other plasmid groups. As previously described in other IncHI2 plasmids (Wyrsch et al, 2015 ; Zingali et al, 2020 ), diversity of these molecules was mainly observed in MDR regions, and could be explained by acquisition and/or loss of transposons, insertion sequences, and antimicrobial resistance genes. In addition, mobile elements play a significant role in the formation of hybrid plasmids and instances where resistance plasmids have fused are known (Mangat et al, 2017 ).…”

“…IncHI2 plasmid backbones were composed of regions for replication ( reHI2 ), conjugative transfer ( tra genes), and plasmid maintenance ( par gene). Additionally, IncHI2 plasmids (except pMCR_1139_D1) carried tellurium resistance genes ( terZABCDEF ), commonly associated with this plasmid family, in addition to terY1, terY2 , and terW (Zingali et al, 2020 ). Also, IncHI2 plasmids (except pMCR_915_E1 and pMCR_1085_C1) carried the operons encoding sil and pco , conferring resistance to copper and silver.…”

“…Therefore, it is common to identify bacterial populations, with genetic determinants conferring resistance to heavy metals, in the gastrointestinal flora of intensively reared farm animal species. Previous studies have suggested that the presence of pco and sil operons in IncHI2 plasmids may have arisen due to co-selection pressures afforded by the use of heavy metals in feed additives (Wyrsch et al, 2015 ; Zingali et al, 2020 ). In IncHI2 plasmids, mcr-1.1 gene was found downstream of the mobile element IS Apl1 .…”

Whole-Genome Sequence Analysis of an Extensively Drug-Resistant Salmonella enterica Serovar Agona Isolate from an Australian Silver Gull (Chroicocephalus novaehollandiae) Reveals the Acquisition of Multidrug Resistance Plasmids

“…Analysis of NCBI databases using MEGABLAST revealed the 10 plasmids most closely related to pSG17-135-HI2 were not of Australian origin. While MDR IncHI2 plasmids have reportedly been isolated within Australian porcine operations (41)(42)(43)(44), these plasmids vary in their pMLST types and carry different AMR gene cargo in comparison with pSG17-135-HI2. Instead, this analysis revealed that pSG17-135-HI2 is more closely related to IncHI2 plasmids from China and Taiwan from various sources (Table S3), particularly pCFSA1096 (GenBank accession number CP033347).…”

Detection of Five mcr-9 -Carrying Enterobacterales Isolates in Four Czech Hospitals

“…IncHI2 plasmid backbones were composed of regions for replication ( reHI2 ), conjugative transfer ( trh genes), and plasmid maintenance ( par gene). Additionally, IncHI2 plasmids carried tellurium resistance genes ( terZABCDEF ), commonly associated with this plasmid family, in addition to terY1 , terY2 , and terW ( 20 ). Also, genes conferring arsenic resistance ( arsCBRH ) were found in IncHI2 plasmids.…”