Detection of multidrug-resistant Salmonella Enterica strains in chickens (Gallus gallus domesticus) from markets in Abidjan
Salmonella is a genus of Gram-negative bacilli, causing illnesses in humans, such as typhoid fever, which remain major public health concerns. Based on biochemistry and genomic data, Salmonella is divided into many serovars. In West Africa, Salmonella infection in humans and in food matrices is reported each year. Recently, the emergence of antibiotic-resistant strains of Salmonella represents a high risk for public health. In Côte d’Ivoire, poultry activities and poor hygiene conditions contribute to the emergence of Salmonella infection. The main objective of this study is to detect Salmonella species strains in chicken from local markets in the city of Abidjan. Four sampling sites in the Abidjan district were selected in the local markets of Yopougon (Siporex and Bagnon), Songon, Adjamé, and Abobo. Several chicken intestines (Gallus gallus domesticus) were collected in batches of in each market. The pre-treatment of solation was performed with classic methods for Salmonella-Shigella (SS). Biochemical characterization and antibiotic susceptibility testing were conducted for all isolated strains. The target of the invasive gene (invA) of Salmonella was used for molecular confirmation and DNA sequencing. Among the 22 Salmonella spp. isolates studied, 68% (15/22) of the poultry strains underwent biochemical testing (oxidase, catalase, Gram stain, and motility), with five strains testing positive. Antibiotic susceptibility testing revealed strong resistance to ampicillin and pefloxacin, and weak resistance to gentamicin and clavulanic acid. Furthermore, 59% (13/22) of the isolates were positive by Polymerase chain reaction (PCR) targeting the invA gene. Phylogenetic analysis showed a high similarity to the reference strain Salmonella Enterica serovar Paratyphi. These findings demonstrate the circulation of multidrug-resistant Salmonella strains in poultry in Côte d’Ivoire and highlight the need for continuous surveillance to enhance food safety.