Analysis of the antibiotic resistance and virulence factors of Salmonella strains isolated on a turkey and goose farm

The Salmonella (S.) enterica subspecies enterica is a major cause of foodborne gastroenteritis associated with the consumption of contaminated animal-derived food products (particularly of poultry origin). It is very important to be aware of the characteristics of Salmonella strains of poultry origin for the prevention and treatment of salmonellosis. The present study assesses the antibiotic resistance profiles and virulence factors of 64 Salmonella strains isolated from geese and turkeys, in line with the procedure defined in ISO 6579-1:2017. The isolated strains were then serotyped and analyzed phenotypically and genotypically for their resistance to various antibiotics, and their virulence potential was assessed on the basis of an analysis of 11 genes (sipA, sopD, sopB, sifA, sitC, sipD, sopE, sopE2, ssaR, spvC and pefA). Of the S. Senftenberg isolated from the turkey fecal samples, and the S. Saintpaul and S. Typhimurium from the goose fecal samples, 98.41%, 90.48% and 85.71% were found to be highly resistant to enrofloxacin, gentamicin and amoxicillin, respectively; 85.71% of the Salmonella spp. strains were multi-drug resistant and 82.54% carried int1. It was further determined that 85.71% of the strains carried blaTEM, 77.78% carried qnrB and 74.6% carried qnrS. Furthermore, sopE (98.41%) and sipD (96.82%) were detected in nearly all the Salmonella strains, and both of the identified S. Typhimurium strains (100%) were found to carry the sipD, sopE2, sitC, spvC and pefA genes. This analysis of the virulence potential of different Salmonella strains and their resistance to various antibiotics can be considered a comprehensive database, with the potential to support future studies addressing the topic. By revealing various characteristics of Salmonella strains, such as their virulence and resistance to antibiotics, which can seriously affect human health, the present study provides important data for possible disease or epidemic control.