Frequent contamination of edible freshwater fish with colistin-resistant Escherichia coli harbouring the plasmid-mediated mcr-1 gene

Mar Pollut Bull. 2022 Nov:184:114108. doi: 10.1016/j.marpolbul.2022.114108. Epub 2022 Sep 24.

Abstract

The threat of antimicrobial resistance is increasing. Microbial food contamination poses a serious public health risk; however, there are only a few studies on the prevalence of colistin-resistant Escherichia coli (COL-E) contamination in freshwater fish. This study aimed to characterise the antibiotic resistance genes and antibiotic susceptibility profiles of COL-E in freshwater fish in Vietnam. In total, 103 fish were collected and 63 COL-E were isolated. COL-E was investigated by genotyping mcr and AmpC/extended-spectrum β-lactamase (ESBL)-related genes. The results show that COL-E and AmpC/ESBL-producing COL-E were confirmed in 24.3 % and 14.6 % of the fish, respectively. Multiplex PCR for mcr-1-9 showed that all 63 COL-E harboured mcr-1, while mcr-3 was detected in 7.9 % of COL-E. The minimum inhibitory concentration of colistin ranged from 2 to 256 μg/mL. Meanwhile, antibiotic susceptibility results show that all COL-E were resistant to ampicillin, streptomycin, and chloramphenicol.

Keywords: AmpC/ESBL-producing E. coli; Channa striata; Colistin-resistant E. coli; Pangasius bocourti; mcr gene.

MeSH terms

  • Ampicillin
  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Chloramphenicol / analysis
  • Colistin / pharmacology
  • Drug Resistance, Bacterial / genetics
  • Escherichia coli
  • Escherichia coli Infections*
  • Escherichia coli Proteins* / genetics
  • Fresh Water
  • Microbial Sensitivity Tests
  • Plasmids
  • Streptomycin
  • beta-Lactamases / genetics

Substances

  • Colistin
  • Escherichia coli Proteins
  • beta-Lactamases
  • Anti-Bacterial Agents
  • Ampicillin
  • Streptomycin
  • Chloramphenicol
  • MCR-1 protein, E coli