Detection of Salmonella in Swine fecal samples by flow-through immunocapture

This study reports the preliminary evaluation of flow-through immunocapture (FTI) followed by real-time PCR (FTI-PCR) for the detection of different serotypes of Salmonella in pig fecal specimens. The FTI-PCR method was compared with the direct plating of FTI beads on xylose lysine desoxycholate agar, real-time PCR, and the conventional culturing methods, Rappaport-Vassiliadis and modified semisolid Rappaport-Vassiliadis. Artificially contaminated swine fecal specimens were used to evaluate and compare these methods. The results of our comparisons indicate that the FTI-PCR, FTI-plating, and modified semisolid Rappaport-Vassiliadis culture methods were accurate, specific, and sensitive. Moreover, FTI-PCR was the fastest method, providing results in fewer than 20 h, as opposed to the 48 to 96 h required for the other methods. Our results indicate that FTI-PCR could be a useful tool for detecting Salmonella in swine fecal specimens at a lower limit of 1.0 CFU/g.