Prevalence, antibiotic resistance, virulence and antimicrobial resistance gene profiles of Salmonella species recovered from retail beef and poultry processing environments

BMC Microbiol. 2025 Mar 28;25(1):174. doi: 10.1186/s12866-025-03871-2.

Abstract

Background: This study investigates the prevalence, antimicrobial resistance, genotypic resistance profiles, and virulence gene distribution of Salmonella isolates from poultry and beef processing environments in Shahrekord, Iran.

Method: A total of 680 samples were collected from poultry (n = 300) and beef (n = 380) products between January and December 2023.

Results: Salmonella was detected in 21% (63/300) of poultry samples and 15.8% (60/380) of beef samples, with non-typhoidal Salmonella (NTS) being the predominant serovar. High antimicrobial resistance (AMR) rates were observed across both food types, with the most common resistances found in ciprofloxacin (48%), tetracycline (44%), and ampicillin (39%). Genotypic analysis revealed the presence of key resistance genes, including blaTEM (35%), tetA (29%), and sul1 (23%). Virulence gene analysis identified invA (92%), agfA (80%), and hilA (76%) as the most prevalent genes. Comparative analysis of resistance patterns between poultry and beef samples revealed higher resistance in poultry isolates to ciprofloxacin and tetracycline.

Conclusion: This study highlights significant antimicrobial resistance and the presence of virulence factors in Salmonella isolates from retail beef and poultry, suggesting a potential risk to public health and the need for enhanced surveillance and control measures in food processing environments.

Clinical trial number: Not applicable.

Keywords: Salmonella; Antimicrobial resistance; Beef; Poultry; Prevalence; Processing environment; Virulence.

MeSH terms

  • Animals
  • Anti-Bacterial Agents* / pharmacology
  • Cattle
  • Drug Resistance, Bacterial* / genetics
  • Drug Resistance, Multiple, Bacterial* / genetics
  • Food Microbiology
  • Genotype
  • Iran / epidemiology
  • Meat / microbiology
  • Microbial Sensitivity Tests
  • Poultry* / microbiology
  • Prevalence
  • Red Meat* / microbiology
  • Salmonella* / drug effects
  • Salmonella* / genetics
  • Salmonella* / isolation & purification
  • Salmonella* / pathogenicity
  • Virulence / genetics
  • Virulence Factors / genetics

Substances

  • Anti-Bacterial Agents
  • Virulence Factors