Comparison of polymerase chain reaction (PCR) and conventional cultivation methods for detection of carriers of Salmonella spp. in cattle and buffalo

Abstract

In this study, polymerase chain reaction (PCR) method and culturing strategies were used to detect carriers of Salmonella spp. in cattle and buffalo. In order to perform the assay, 100 faecal samples were obtained from both buffalo and cattle in Urmia, Iran, in July 2008. Samples were tested for Salmonella isolation by culturing techniques and biochemical testes. Faecal samples were enriched in enrichment broth and DNA was extracted and amplified by PCR using specific primers of Salmonella invasion gene (invA). PCR products were visualised using 1.2% agarose gel electrophoresis. The bacterial culturing results were negative for all samples, whilst results from the PCR method and electrophoresis confirmed the presence of Salmonella in one cattle faecal sample (1%) and three buffalo faecal samples (3%). These results indicate that the PCR method is highly sensitive and rapid for Salmonella detection in faeces compared to other routine methods.