Antibiotics (May 2023)

Co-Harboring of Beta-Lactamases and <i>mcr-1</i> Genes in <i>Escherichia coli</i> and <i>Klebsiella pneumoniae</i> from Healthy Carriers and Backyard Animals in Rural Communities in Ecuador

  • Carlos Bastidas-Caldes,
  • Emily Cisneros-Vásquez,
  • Antonella Zambrano,
  • Andrea Mosquera-Maza,
  • William Calero-Cáceres,
  • Joaquín Rey,
  • Yoshimasa Yamamoto,
  • Mayumi Yamamoto,
  • Manuel Calvopiña,
  • Jacobus H. de Waard

DOI
https://doi.org/10.3390/antibiotics12050856
Journal volume & issue
Vol. 12, no. 5
p. 856

Abstract

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Few studies have addressed drug resistance of Enterobacterales in rural communities in developing countries. This study aimed to determine the coexistence of extended-spectrum β-lactamase (ESBL) and carbapenemase genes in Escherichia coli and Klebsiella pneumoniae strains carrying the mcr-1 gene in rural communities in Ecuador from healthy humans and their backyard animals. Sixty-two strains, thirty E. coli and thirty-two K. pneumoniae strains carrying the mcr-1 gene were selected from a previous study. PCR were performed for the presence of ESBLs and carbapenemase genes. The strains were further characterized, and the genetic relationship was studied with multi-locus sequencing typing (MLST) of seven housekeeping genes. Fifty-nine of the sixty-two mcr-1 isolates (95%) harbored at least on β-lactam resistance gene. The most prevalent ESBL genes were the blaTEM genes (present in in 80% of the E. coli strains) and the blaSHV gene (present in 84% of the K. pneumoniae strains). MSLT analysis revealed 28 different sequence types (ST); 15 for E. coli and 12 for K. pneumoniae, with most ST never described in humans and animals. The coexistence of mcr-1 and β-lactams resistant genes in E. coli and K. pneumoniae strains is alarming and threatens the efficacy of last-resort antibiotics. Our findings highlight backyard animals as a reservoir of mcr-1/β-lactams resistant genes.

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