Horizontal transfer of a plasmid possessing mcr-1 marked with a single nucleotide mutation between Escherichia coli isolates from community residents

Abstract

Objectives The widespread dissemination of phenotypic colistin-resistant (COR) bacteria in the community threatens public health. The horizontal gene transfer of the mobile colistin resistance gene via plasmids is thought to be one of the main mechanisms for dissemination. However, genotypic evidence to prove this in community settings is limited. This study used genome analysis to demonstrate the direct horizontal colistin resistance gene transfer via plasmids in isolates from the community. Results A total of 19 isolates of COR Escherichia coli from stool specimens of 23 residents from seven households in the Vietnamese community were assessed in this study. The whole-genome sequence data of isolates were acquired using a combination of DNBSEQ short-reads and Nanopore long-read sequencing. Analysis of genomic data was performed using online tools such as Geneious. Analysis of the genomic information of COR E. coli isolates revealed that the isolates from two residents of different households had a similar IncP1 plasmid possessing mcr-1.1, marked with a single nucleotide mutation at the same position. The study provided direct evidence to prove that mcr was horizontally transmitted among bacteria in community residents.

Comparative genome analysis of colistin-resistant Escherichia coli harboring mcr isolated from rural community residents in Ecuador and Vietnam

“…Colistin-resistant E . coli carrying mcr has also been found in high frequencies in domestic livestock in local communities of Vietnam, as reported in our previous studies [ 10 , 14 ]. In another study, the prevalence of mcr-1 and mcr-3 detected in human and animal stools in a rural community of Vietnam were higher than that in previous reports [ 15 ].…”

“…Thus far, at least ten mcr variants from mcr-1 to mcr-10 have been described globally [ 7 , 8 ]. It is widely accepted that the major mechanism of the horizontal spread of colistin-resistant bacteria is the transfer of the mobile mcr genes among bacteria [ 9 , 10 ].…”

Prevalence of Colistin Pan Resistance among Multidrug-Resistant and Extensively Drug-Resistant Escherichia Coli O157:H7

“…This diminishes its affinity for colistin (Forde et al,2018). Furthermore, the mcr-1 gene has the ability to disseminate to other bacteria through horizontal gene transfer (Yamamoto et al, 2022). The proliferation of colistin resistant strains of E. coli hampers the availability of effective treatment choices, resulting in clinical complexities like pneumonia or sepsis, prolonged stays in hospitals, increased costs for treatment and additionally elevated death rates (Wangchinda et al, 2018).…”

The battle against colistin-resistant E. coli and the need for a one health approach

“…[ 15 ]. Moreover, the mcr-1 gene can spread to other bacteria through horizontal gene transfer [ 16 ]. Some colistin-resistant isolates from livestock animals lacked mcr-1 gene suggesting that there may be other mechanisms contributing to the resistance of these isolate to colistin [ 17 ].…”