Journal Article

Genomic patterns and characterizations of chromosomally-encoded mcr-1 in Escherichia coli populations

Zhong, Lan-Lan, Tian, Guo-Bao, Zhang, Guili, El-Sayed Ahmed, Mohamed Abd El-Gawad, Dai, Min, Liu, Yang, Li, Hong-Yu, Shen, Cong, Liao, Kang, Huang, Songyin, Xia, Yong, Ma, Furong, Doi, Yohei, Zhang, Liyan, Yan, Bin

2020

Overview

The emergence and transmission of the mobile colistin resistance gene ( mcr - 1 ) threatened the extensive use of polymyxin antimicrobials. Accumulated evidence showed that the banning of colistin additive in livestock feed efficiently reduce mcr - 1 prevalence, not only in animals but also in humans and environments. However, our previous study has revealed that a small proportion of Escherichia coli could continually carry chromosomally-encoded mcr - 1 . The chromosomally-encoded events, indicated the existence of stabilized heritage of mcr - 1 and revealed a potential threat in the antimicrobial stewardship interventions, are yet to be investigated. In this study, we systematically investigated the genetic basis of chromosomally-encoded mcr - 1 in prevalence and potential mechanisms of lineage, plasmid, insertion sequence, and phage. Our results demonstrated that the emergence of chromosomally-encoded mcr - 1 could originate from multiple mechanisms, but mainly derived through the recombination of IS Apl1 /Tn 6330 . We reported a specific transmission mechanism, which is a phage-like region without lysogenic components, could associate with the emergence and stabilization of chromosomally-encoded mcr - 1 . These results highlighted the potential origin and risks of chromosomally-encoded mcr - 1 , which could be a heritable repository and thrive again when confronted with new selective pressures. To the best of our knowledge, this is the first study to systematically reveal the genomic basis of chromosomally-encoded mcr - 1 , and report a specific transmission pattern involved in phage-like region. Overall, we demonstrate the origin mechanisms and risks of chromosomally-encoded mcr - 1 . It highlights the need of public attention on chromosome-encoded mcr - 1 to prevent from its reemergence.

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Antibacterial agents / Antimicrobial agents / Antimicrobial resistance / Chromosome / Chromosomes / Colistin / Drug resistance / Drug resistance in microorganisms / E coli / Epidemiology / Escherichia coli / Gastroenterology / Genes / Genetic aspects / Genomes / Genomic pattern / Insertion / Insertion sequence / Livestock / mcr-1 / Medical Microbiology / Medicine / Medicine & Public Health / Parasitology / Phages / Plasmids / Public health / Recombination / Short Report