Identification of mcr-1 Genes and Characterization of Resistance Mechanisms to Colistin in Escherichia coli Isolates from Colombian Hospitals

Autores organización

• 

  Elsa Piedad De La Cadena Vivas

  Autor

• 

  Juan Carlos Garcia Betancur

  Autor

• 

  Christian Jose Pallares Gutierrez

  Autor

• 

  Maria Virginia Villegas Botero

  Autor

Autores

• Mahecha M
• Velandia AM
• Rojas LJ
• Porras J

Grupos de investigación

• Grupo de Investigación en Resistencia Antimicrobiana y Epidemiología Hospitalaria RAEH

  

  Investigador

  Maria Virginia Villegas Botero

Resumen

We report the presence of the mcr-1 gene among 880 Escherichia coli clinical isolates collected in 13 hospitals from 12 Colombian cities between 2016 and 2019. Seven (0.8%) isolates were colistin resistant (MIC = 4 µg/mL). These colistin-resistant isolates were screened for the presence of the mcr-1 gene; five carried the gene. These five isolates were subjected to whole genome sequencing (WGS) to identify additional resistomes and their ST. In addition, antimicrobial susceptibility testing revealed that all E. coli isolates carrying mcr-1 were susceptible to third generation-cephalosporin and carbapenems, except one, which carried an extended-spectrum ß-lactamase (CTX-M-55), along with the fosfomycin resistance encoding gene, fosA. WGS indicated that these isolates belonged to four distinct sequence types (ST58, ST46, ST393, and a newly described ST14315) and to phylogroups B1, A, and D. In this geographic region, the spread of mcr-1 in E. coli is low and has not been inserted into high-risk clones such as ST131, which has been present in the country longer. © 2023 by the authors.

Keywords

• antiinfective agent; carbapenem derivative; cephalosporin; colistin; extended spectrum beta lactamase; fosfomycin; piperacillin plus tazobactam; virulence factor; amino acid substitution; antibiotic resistance; antibiotic resistome; Article; bacterium identification; bacterium isolate; broth dilution; Colombian; controlled study; Escherichia coli; gene identification; gene sequence; genome analysis; minimum inhibitory concentration; missense mutation; nonhuman; open reading frame; polymerase chain reaction; prospective study; whole genome sequencing