Salmonella Heidelberg and Salmonella Minnesota in Brazilian broilers: Genomic characterization of third-generation cephalosporin and fluoroquinolone-resistant strains

Environ Microbiol Rep. 2023 Apr;15(2):119-128. doi: 10.1111/1758-2229.13132. Epub 2023 Jan 11.

Abstract

Salmonella serovars Heidelberg and Minnesota encoding antimicrobial resistance to third-generation cephalosporins and fluoroquinolones are often detected in poultry/poultry meat. We analysed the genomes of 10 Salmonella Heidelberg (SH) and 4 Salmonella Minnesota (SM) from faecal isolates of Brazilian poultry. These featured virulent and multidrug-resistant characteristics, with AmpC beta-lactamase (blaCMY-2 ) predominance (9/14), for all SM (4/4) and some SH (3/10) located on IncC plasmid replicons. IncC carrying blaCTX-M-2 was only detected among SH (3/10). Mutation in the gyrA/parC genes was present in all SH, whereas SM harboured parC mutation plus qnrB19 on ColRNAI plasmids (3/4). In silico resistance overall corroborated with phenotypic results. Core genome phylogenies showed close clustering and high similarities between the Brazilian and poultry meat/food isolates from Europe, and to human isolates from European countries with documented import of Brazilian poultry meat. Conjugation assays with SM successfully transferred blaCMY-2 , and qnrB19 to an Escherichia coli recipient. The findings reinforce the ongoing antimicrobial resistance acquisition of SH and Minnesota and the risks for disseminating resistant strains and/or mobile elements which may increasingly affect importing countries and the need for controlling AMR in major poultry-exporting countries like Brazil.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents* / pharmacology
  • Brazil
  • Cephalosporins / pharmacology
  • Chickens / genetics
  • Drug Resistance, Multiple, Bacterial / genetics
  • Escherichia coli / genetics
  • Fluoroquinolones* / pharmacology
  • Genomics
  • Humans
  • Plasmids / genetics
  • Poultry / genetics
  • Salmonella / genetics
  • beta-Lactamases / genetics

Substances

  • Fluoroquinolones
  • Anti-Bacterial Agents
  • beta-Lactamases
  • Cephalosporins

Supplementary concepts

  • Salmonella enterica subsp. enterica