Characterization of Virulence Genes and Antimicrobial Resistance in Salmonella enterica from Chicken Gizzards in Côte d'Ivoire

Salmonella causes global foodborne illnesses, with poultry as a key source. Antibiotic resistance, particularly against tetracyclines, threatens treatment efficacy. This study confirms the identification of Salmonella strains previously isolated from chicken gizzards and determines their virulence and antibiotic resistance profiles, focusing on tetracycline resistance. Thirty-nine presumptive Salmonella strains previously isolated from the gizzard were revived. PCR targeting the invA gene confirmed Salmonella spp. in 94.87% of the strains. Duplex PCR identified S. enterica serovar Typhimurium in 24.32% of isolates, while no Enteritidis strains were detected. All remaining strains were confirmed as S. enterica by sequencing the invA amplicon. Virulence genes (fimA, stn, pefA, and spvC) and tetracycline resistance genes (tetABCDEGOW) were analysed by PCR. Susceptibility to 13 antibiotics was assessed by disk diffusion. The fimA and stn genes were present in 97.30% of the isolates, pefA in 43.24%, and spvC in 21.62%. The tetA gene was detected in 86.49%, while multidrug resistance was observed in 56.76%, with tetracycline resistance being the most frequent. These findings highlight the public health risks associated with S. enterica in chicken gizzards, emphasising the need for strict food safety measures and continuous monitoring in order to prevent contamination, particularly in regions where regulations are less stringent.