Rapid Agricultural Water On Site Contaminant Detection Method to Improve Food Safety

Consumption of contaminated produce accounts for nearly half of the 48 million outbreak-associated foodborne illnesses in the United States. Although foodborne outbreaks were associated with approximately 20 different fresh produce commodities, agricultural water was one of the main recognized routes of on-farm contamination. Produce can also become contaminated at any point in the production chain as long as a source of the pathogen is present in the vicinity. Local rivers, lakes, ponds, and streams have been shown to be a central reservoir for pathogen contamination. Although producers and suppliers are committed to good practices to reduce the risk of contamination, the fact that specimens need to reach a qualified E. coli testing lab ideally within six to seven hours but absolutely within 24 hours after the water sample is collected makes shipping costly and the logistics of arranging this difficult for rural farms. Furthermore, the turnaround time for culture methods that
enumerate CFUs take from 24 to 48 hours. This means that results of a water sample collected at the time of harvest might not be received until product has been distributed and might have consequential recalls. Recalls might impact consumer confidence through negative publicity, result in consequential decreased demand, and could result in significant economic loss for all parts of the supply chain.VisuGen Global, LLC is seeking USDA SBIR phase I funding to develop a highly innovative method that addresses this issue by enabling rapid (30 minute) testing of 100 milliliters of water directly on the farm with a simple to use device. The objectives to be accomplished in phase I will prove the feasibility of the concept using E. coli obtained directly from contaminated environmental waters. We will use quantitiative Polymerase Chain Reaction (qPCR) to provide initial measurable results that verify heat induced RNA release and binding to a proprietary material that captures and
concentrates the nucleic acid. However, the final integrated platform will be based on direct hybridization of bead conjugated probes to RNA molecules released from E. coli cells with the beads then visualized as they are captured as they flow through a specifically designed microfluidic chip. Although the integrated molecular process is sophisticated, the user steps are simple and consist of 1) add water to a zip lock bag and allow the water to flow through a capture chip, 2) remove the bag and attach a vial in a specially designed wicking cassette, and 3) visualize results using a cell phone reader. During phase I VisuGen Global will also initiate discussions with vegetable growers in Colorado to solicit their input on how best to integrate our product with new regulatory requirements soon to be enforced for compliance with the Food Safety Modernization Act produce rule.