Multiplex PCR for the direct detection of Salmonella enterica from chicken, lamb and beef food products.

Abstract

Three sets of known Salmonella enterica-specific primers were used collectively, for the first time, to evaluate the use of multiplex polymerase chain reaction (m-PCR) as a diagnostic tool to detect Salmonella enterica in naturally contaminated meat and poultry products. For this purpose a total of 300 samples representing the most frequently used fresh and frozen meat (beef and lamb) and poultry (chicken) products (whole, cut, ground, and processed) were collected from eight locations within Irbid city (Jordan). After an enrichment step, DNA was extracted directly from each food sample and amplified using six Salmonella enterica specific primers. Samples were also analyzed using conventional microbiological methods for the confirmation of Salmonella enterica presence. Out of 300 samples, 93 samples were positive by m-PCR. On the other hand, 67 samples were positive by conventional microbiological methods and only 26 samples were positive by m-PCR alone. The primer pairs, used here, proved to be highly specific for Salmonella enterica. Using m-PCR, Salmonella enterica detection could be achieved easily and the results had been confirmed effortlessly within a short period of time (24-36 hours) compared to 3-8 days for the conventional microbiological methods. Our findings emphasize the value of using a combination of specific primer pairs instead of a single primer pair in the detection process to minimize any chance for any inherent experimental or natural error.