Multidrug-resistant Salmonella strains from food animals as a potential source for human infection in Iran

Comp Immunol Microbiol Infect Dis. 2022 Nov-Dec:90-91:101898. doi: 10.1016/j.cimid.2022.101898. Epub 2022 Oct 22.

Abstract

This study aimed to determine the frequency and characterization of Salmonella isolates from food-producing animals and human diarrheal samples in Shiraz, Iran. Overall, 105 Salmonella isolates were obtained from chicken meat (70/100, 70.0%), beef (19/100, 19.0%), lamb (11/100, 11.0%), and human stool (5/295, 1.7%). S. Infantis (40.9%), S. Enteritidis (29.5%), and S. Paratyphi B (8.6%) were the most prevalent serotypes. Totally 59.1% of the isolates were multidrug-resistant. High resistance to nalidixic acid (67.6%), tetracycline (62.9%), and trimethoprim-sulfamethoxazole (42.3%) were observed. Mutations in the gyrA and parC genes were detected in nalidixic acid-resistant isolates from chicken meat and human stool. No qnrA, qnrB or qnrS genes were detected. The blaTEM and blaCMY-2 genes were detected in β-lactam-resistant isolates from beef and lamb. Despite the high genetic diversity of PFGE patterns, some isolates from different sources and times showed identical PFGE patterns suggesting specific Salmonella species circulate between various sources over time.

Keywords: Antimicrobial resistance; Multidrug-resistant Salmonella; PFGE; Resistance gene.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Cattle
  • Chickens*
  • Drug Resistance, Bacterial
  • Drug Resistance, Multiple, Bacterial / genetics
  • Humans
  • Iran / epidemiology
  • Microbial Sensitivity Tests / veterinary
  • Nalidixic Acid*
  • Salmonella
  • Sheep

Substances

  • Nalidixic Acid
  • Anti-Bacterial Agents