'Development of a Foodborne Pathogens and Toxins Screening Panel in Foods Using a Liquid MicroArray Detection System.'Currently food testing labs use conventional FDA Bacteriological Analytical Manual(BAM) protocols for microbiological analysis of foods. While these methods representthe gold standard in food testing, they are labor intensive and relatively slow, requiringfive to nine days for confirmation. Current molecular technologies, such as Real TimePolymerase Chain Reaction (rti PCR) provide rapid, accurate, and cost effective methodsof 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 thesimultaneous detection of multiple organisms are very limited.. Multiplex PCR reactionsare problematic in large part due to the complexity of DNA itself. With only fourdifferent bases, it is difficult to design multiple primer sets that will not form some typeof primer-primer adduct.. Also, there is a limited number of fluorophores whose emissionspectra do not overlap. When added to the limited number of detection channels in the rtiPCR 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 usingMicro Array xTAG Technology. The xTAG technology is a Luminex technology thatuses nucleotide oligo probes attached to Luminex beads. These oligo probes anneal tocomplimentary DNA sequences in the target genes and are subsequently detected.Luminex xTAG technology combines flow-cytometry with a flexible detectionmethodology that can detect the presence or absence of a given DNA sequence. Detectionis accomplished by measuring the label strepavidin-R-phycoerythrin (SAPE)fluorescence, one bead at a time, while simultaneously determining which type of bead isbeing read. The label value is stored in a 'bin' for that bead type. The SAPE can bequantitatively 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 toexpand as new pathogens emerge. Currently, this level of multiplexing is only availablewith a liquid array system such as Luminex.
of this Project: Reducing the time necessary to identify the agent and source of a Foodborne Disease Outbreaks (FBDO) will reduce, if not prevent the further spread of the food contaminant and can decrease the number of clinical cases affected by the outbreak. Additionally, the faster an agent and source can be traced, the higher public's confidence and trust in those agencies responsible for making our food safe.
