Prevalence and genetic characteristics of Salmonella strains in wild Mallard ducks (Anas platyrhynchos) in Semnan suburb, Iran.

Abstract

Wild birds serve as major reservoirs for transmission of Salmonella to domestic animals and humans. Given the zoonotic potential of salmonellosis, the main goal of this research was to investigate the prevalence and molecular epidemiology of S. enterica infections in wild Mallard ducks. Faecal sam-ples (n=247) from wild Mallard ducks were tested for the prevalence of Salmonella spp., and geno-types of strains were then differentiated by multiplex PCR. From the 247 faecal samples, 18 (7.29%) were positive for Salmonella spp. Biochemically the most predominant serovars were S. Typhi-murium and S. Enteritidis (10 and 6 cases each, respectively), whereas only 2 serovars belonged to S. Infantis. Among the 10 S. Typhimurium serovars, nine strains were positive for rfbJ, fljB, invA, and fliC genes based on multiplex PCR assay and one strain contained only the invA gene. In S. Enteriti-dis serovars, PCR generated amplification products for spv and sefA genes, and a random sequence in all samples. The two S. Infantis contained the random sequence specific for Salmonella genus. With respect to the circulation of virulent Salmonella in wild ducks of Semnan suburbs, more work to as-sess the correlation of strains from wild life with human and livestock strains is needed.

Keywords

• Mallard ducks
• multiplex PCR
• Salmonella