Rapid Detection of Typhoid Salmonellas (Salmonella Gallinarum and Salmonella Pullorum) and non-Typhoid Salmonellas (Salmonella Enteritidis and Salmonella Typhimurium) in Poultry through Multiplex-PCR Molecular Method

Abstract

Abstract The Salmonella serotypes are detected mainly through traditional microbiologic methods, which are associated with problems. The invention of rapid molecular detection methods has somewhat resolved these problems. This study aimed to assess the possibility of rapid detection of typhoid and non-typhoid Salmonellas in poultry using the multiplex polymerase chain reaction (PCR). A total of 40 isolates of Salmonella from industrial poultry were collected veterinary laboratories in Tabriz, Iran. After microbiological and serological tests, we confirmed that 27 out of 40 isolates belonged to the Salmonella entrica species. Differential tests revealed that 15, 7, 2, and 3 isolates were Salmonella Gallinarum, Salmonella Enteritidis, Salmonella Typhimurium, and Salmonella Pullorum, respectively. We then used specific primers to multiply the genes invA, rfbJ, lygD, I137_08605, and speC. The 27 isolates were then genotypically analyzed through multiplex-PCR. The results showed that all 27 isolates and the standard strains of all 4 bacteria carry the invA gene, while this gene was absent in 13 non-Salmonella isolates. The I137_08605 gene was present in all isolates and the standard strains of S. Gallinarum and S. Pullorum; the rfbJ and lygD genes were present in all isolates of S. Enteritidis and S. Typhimurium and their standard strains; and the speC gene was present in all isolates of S. Gallinarum and some isolates of S. Typhimuriumand S. Entritidis and their standard strains. It seems that typhoid Salmonellas of poultry, i.e., S. Gallinarum and S. Pullorum, can be discriminated from non-typhoid Salmonellas through the multiplex-PCR molecular method.