Biomolecular Phage Filter for the Detection of a Small Number of Pathogens in Large Volumes of Processing Water

Fresh specialty crop produce such as tomatoes, blueberries, strawberries, sprouts, cantaloupes, lettuce and leafy greens account for more instances of foodborne illness than any other food category. Recent announcements to consumers, by the United States (U.S.) Centers for Disease Control (CDCs), to discard all Romaine lettuce because of bacterial contamination has resulted in hundreds of millions of dollars in losses to growers and processors. Unfortunately, current microbiological testing of samples of specialty crops (whole fruits, leaves of spinach, etc.), as specified by FDA’s Bacteriological Analytical Manual (BAM), requires at least 48 hours to perform the complicated, time-consuming and costly steps of soaking, , concentration, enrichment, plate count or PCR to detect pathogens on these samples. Further complicating the BAM analyses are the realities that: 1) both PCR and ELISA are unable to distinguish between live and dead cells and 2) only a few samples out of as many as 100,000 fruits, vegetables or leaves of multi-ton batches of produce can be BAM tested. A Non-clogging Biomolecular Phage Filter has been developed to simultaneously capture, concentrate and isolate small numbers of pathogens from large volumes of produce wash water. This phage filter can then be evaluated to screen for live versus dead cells and ID the specific pathogen in minutes. Capture efficiencies of greater than 94% have been demonstrated.