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Emergence of plasmid-mediated mcr genes from Gram-negative bacteria at the human-animal interface

Humera Javed1,2, Sidrah Saleem1, Aizza Zafar2

  • 1Department of Microbiology, University of Health Sciences, Lahore, Pakistan.

Gut Pathogens
|December 9, 2020
PubMed
Abstract

Insights

Plasmid-mediated colistin resistance (Col-R) due to mcr genes is emerging in gram-negative rods from humans and animals in Pakistan. The high prevalence of mcr-1 and mcr-2 genes in animal isolates is concerning for public health.

Area of Science:

  • Microbiology
  • Antimicrobial Resistance
  • One Health

Background:

  • Plasmid-mediated colistin resistance (Col-R) from mcr genes in gram-negative rods (GNRs) threatens last-resort antibiotics.
  • The emergence of Col-R in GNRs poses a significant global health risk.

Purpose of the Study:

  • To investigate the prevalence and characteristics of mcr gene-mediated Col-R in GNRs from human and animal sources in Pakistan.
  • To assess the association of specific GNRs with human versus animal origins and their resistance profiles.

Main Methods:

  • Standard microbiological techniques for isolation and identification of GNRs.
  • MIC determination for colistin susceptibility and multiplex PCR for mcr-1 to mcr-5 gene detection.
  • API 20E and API 20NE systems were utilized for pathogen identification.

Main Results:

  • Col-R phenotypes were identified in 126 animal (88.1%) and 17 human (11.9%) isolates.
  • Escherichia coli and Proteus mirabilis were significantly associated with animal isolates, while Acinetobacter baumannii was linked to human isolates.
  • mcr genes (mcr-1 and mcr-2) were detected in 76.9% of Col-R strains, predominantly mcr-1 (98.2%).

Conclusions:

  • The substantial detection of mcr-1 and mcr-2 genes in animal isolates is a significant public health concern.
  • The presence of mcr genes in clinical pathogens highlights the potential for widespread resistance.
  • The spread of mcr genes could accelerate the arrival of a post-antibiotic era.
Keywords:
Antibacterial profileAntimicrobial resistanceColistin resistanceMobile colistin resistancePlasmid-mediated resistancemcr genes

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