Development of Foodborne Pathogens and Toxins Screening Panel in Foods Using a

<p>'Development of a Foodborne Pathogens and Toxins Screening Panel in Foods Using a Liquid Micro Array Detection System.' Currently food testing labs use conventional FDA Bacteriological Analytical Manual(BAM) protocols for microbiological analysis of foods. While these methods represent the gold standard in food testing, they are labor intensive and relatively slow, requiring five to nine days for confirmation. Current molecular technologies, such as Real Time Polymerase Chain Reaction (rti PCR) provide rapid, accurate, and cost effective methods of detecting pathogens when compared with traditional culture and biochemical methods. While there is a wide array of rti PCR platforms to chose from, multiplex assays for the simultaneous detection of multiple organisms are very limited.. Multiplex PCR reactions are problematic in large part due to the complexity of DNA itself. With only four different bases, it is difficult to design multiple primer sets that will not form some type of primer-primer adduct.. Also, there is a limited number of fluorophores whose emission spectra do not overlap. When added to the limited number of detection channels in the rti PCR instrument itself, there is a real, and significant, upper limit to rti PCR multiplexing. We are proposing to develop a screening panel for bacteria, viruses and toxins using Micro Array xTAG Technology. The xTAG technology is a Luminex technology that uses nucleotide oligo probes attached to Luminex beads. These oligo probes anneal to complimentary DNA sequences in the target genes and are subsequently detected. Luminex xTAG technology combines flow-cytometry with a flexible detection methodology that can detect the presence or absence of a given DNA sequence. Detection is accomplished by measuring the label strepavidin-R-phycoerythrin (SAPE) fluorescence, one bead at a time, while simultaneously determining which type of bead is being read. The label value is stored in a 'bin' for that bead type. The SAPE can be quantitatively detected by a second, green laser in the Luminex detection system. Because Luminex can handle up to 100 analytes at one time, it can be used for high-throughput testing in a large-scale outbreak investigation and it has the flexibility to expand as new pathogens emerge. Currently, this level of multiplexing is only available with a liquid array system such as Luminex.</p>