Rapid detection of food-borne pathogens is critical in today’s market place. Suppliers need a method to detect specific organisms quickly in order to satisfy shipping demands and quality assurance. Traditional microbiological methods are slow and time consuming, and often take up to one week to detect the presence of merely one type of pathogen; additional Polymerase Chain Reaction (PCR) steps are then required to identify and confirm with specificity the target organism.

The BAX® system uses state-of-the-art real-time PCR technology to detect and confirm the presence of these organisms within 24 hours, thereby providing suppliers and retailers the data they need in a timely fashion.

After a standard enrichment, cells are lysed to release the target DNA, and then placed into the BAX® system for detection. The BAX® system incorporates QPCR (Quantitative Polymerase Chain Reaction) technology to determine the presence or absence of an organism by using fluorophore labeled probe and primer sets that are specific for the target organism. This technology uses reporter and quencher molecules attached to a DNA probe, along with a primer set specific for the target region. The probe, which is a small piece of DNA, binds to a specific spot in the target genome. As long as the reporter and quencher are in close proximity, the reporter molecule does not fluoresce.

As the target DNA is copied, these molecules are released and the reporter is then able to fluoresce, thereby emitting a signal that the BAX® system can detect and read. Typically, this process takes four hours – after enrichment – to analyze 96 samples.

The BAX® system incorporates all the reagents for the PCR into a tablet form to minimize contamination risk and to eliminate multiple or erroneous pipetting steps that could trigger false positives or negatives. This system also contains a competitive control that allows for quick determination of false positives and negatives. It works by competing for reagents during the PCR process. If the target is not present, the curve generated by the control informs the technician that the PCR worked and that the negative reading is true. Conversely, the absence of this curve in positive samples informs the technician that the positive reading is true.

The BAX® system can detect a variety of familiar food-borne pathogens across a diverse set of matrices. This technology can detect Salmonella and other pathogens in meat, poultry, seafoods, dairy products, baked goods, animal feeds, as well as fruits and vegetables. The USDA-FSIS, along with other certifying agencies, have adopted the BAX® system to detect Salmonella and E.coli O157:H7 in most food processing.

The BAX® system can also detect multiple targets in the same run, thus allowing for even faster throughput. Ultimately, the capabilities outlined in this article serve to provide greater customer service and guarantee more consistent and reliable results.

For more information, please contact: microbac_info@microbac.com.