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

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 bla_TEM (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.