Identification of Salmonella carriers by amplification of FimA, Stn and InvA genes and bacterial culture methods in fecal samples of buffalo

Vet Res Forum. 2023;14(1):21-28. doi: 10.30466/vrf.2022.544308.3312. Epub 2023 Jan 15.


Salmonellosis is one of the most important bacterial diseases in human and animals. Rapid diagnosis and sub sequence accurate treatment of Salmonella carriers help reduce the salmonellosis in human and livestock animals. In this study, 420 fecal samples were taken during year 2019 from buffalo in the Urmia, Khoy and Piranshahr regions in west Azerbaijan province, Iran. Samplings were carried out in different seasons. Presence of Salmonella invasion genes (FimA, Stn and InvA) were evaluated by polymerase chain reaction. The bacterial culture and biochemical tests were performed on feces samples for isolation of bacterium Salmonella; however, all samples were negative in culture method. PCR findings showed that, 50 (11.90%) fecal samples were positive to the genes. The analysis of results showed that frequency of salmonellosis outbreak in different parts of west Azerbaijan province followed a similar pattern and the incidence of salmonellosis according to forecast in the warm seasons (spring and summer) was more than in cold seasons (autumn and winter). The prevalence of Salmonella in buffalo's feces based on warm and cold seasons were 32 (64.00%) and 18 (36.00%), respectively. The results showed significant difference between cold and warm season in the prevalence of salmonellosis. Therefore, the application of molecular technics is essential for the prevention and treatment of salmonellosis. The results also showed that specificity of PCR method was better than culture method for detection of Salmonella in feces sample.

Keywords: Feces; PCR; Ruminants; Salmonellosis; Virulent genes.