Resistome and plasmidome genomic features of mcr-1.1-harboring E. coli: a One Health approach

Gabriela Simões de Oliveira; Silvia Adriana Mayer Lentz; Camila Zanfelice Müller; Rafaela Ramalho Guerra; Tanise Vendruscolo Dalmolin; Fabiana Caroline Zempulski Volpato; Daiana de Lima-Morales; Priscila Lamb Wink; Afonso Luís Barth; Peter Rabinowitz; Andreza Francisco Martins

doi:10.1093/jambio/lxaf019

Resistome and plasmidome genomic features of mcr-1.1-harboring E. coli: a One Health approach

J Appl Microbiol. 2025 Jan 14:lxaf019. doi: 10.1093/jambio/lxaf019. Online ahead of print.

Authors

Gabriela Simões de Oliveira^{1

2

3}, Silvia Adriana Mayer Lentz⁴, Camila Zanfelice Müller^{3

5}, Rafaela Ramalho Guerra^{2

3}, Tanise Vendruscolo Dalmolin⁶, Fabiana Caroline Zempulski Volpato⁷, Daiana de Lima-Morales⁸, Priscila Lamb Wink⁸, Afonso Luís Barth^{1

2

5

8}, Peter Rabinowitz⁹, Andreza Francisco Martins^{1

2

3

5

8}

Affiliations

¹ Hospital de Clínicas de Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil.
² Programa de Pós-Graduação em Ciências Farmacêuticas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
³ Laboratório de Microbiologia e Saúde Única, Instituto de Ciências Básicas de Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
⁴ Programa de Pós-Graduação em Microbiologia Agrícola e do Ambiente, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
⁵ Programa de Pós-Graduação em Ciências Médicas, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
⁶ Laboratório de Microbiologia e Imunologia Clínica, Departamento de Farmácia, Faculdade de Ciências da Saúde, Universidade de Brasília, Brasília, Distrito Federal, Brazil.
⁷ Centro de Ciências Médicas e Farmacêuticas, Universidade Estadual do Oeste do Paraná, Cascavel, Paraná, Brazil.
⁸ Laboratório de Pesquisa em Resistência Bacteriana, Hospital de Clínicas de Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil.
⁹ Department of Environmental and Occupational Health Sciences, Center of One Health Research, University of Washington, Seattle, Washington, USA.

PMID: 39809568
DOI: 10.1093/jambio/lxaf019

Abstract

Aims: This study evaluated the phenotypic and genotypic traits of mcr-1.1-harboring Escherichia coli isolates from chickens, pigs, humans, and farm environments. The resistome and the mobile genetic elements associated with the spread of mcr-1.1 in Southern Brazil were also characterized.

Methods and results: The 22 mcr-1.1-harboring E. coli isolates from different origins were selected for antimicrobial susceptibility testing and whole genome sequencing for characterization of the resistome, plasmids, and STs. All isolates presented several resistance genes and harbored the mcr-1.1 gene in a highly similar IncX4 plasmid. Furthermore, the mcr-1.1 gene co-occurred with the mcr-3.12 gene in a multidrug-resistant isolate from the farm environment.

Conclusions: These findings demonstrate that the mcr-1.1 gene in E. coli isolates from Brazil is spreading mainly by horizontal transfer of the IncX4 plasmid. The co-occurrence of mcr-1.1 and mcr-3.12 highlights pig farming as an important reservoir of colistin resistance.

Keywords: E. coli; One Health; mcr; IncX4 plasmid; plasmidome; resistome.