Sample Preparation Chip for PCR Detection of Water Borne Pathogens

Illnesses due to waterborne pathogens are a substantial health risk, as seen in the E. coli O157:H7 outbreaks of 2006 that were traced to fecal contamination of fresh produce irrigation water. Additionally, there is the possibility of deliberate contamination of our water, and hence our food supply, by terrorists. However, water samples are not analyzed directly and rapidly, because sample matrices are too dirty, and because the concentration level of pathogens of interest are usually too low. In Phase I of this USDA SBIR, we demonstrated that a pathogen (E. coli O157:H7) can be concentrated and purified from large water samples for PCR, improving the sensitivity of that subsequent analysis. Two turbulent mixing techniques were evaluated to enhance the pathogen capture. The objective of this Phase II SBIR is to develop a flow cell product to isolate and concentrate target pathogens from large samples or continuous flow of surface and irrigation water and prepare the DNA for real-time PCR detection. The effort involves development of a pathogen concentration flow cell that can handle 10-100 milliliter sample sizes to unrestricted continuous flow. We will also develop assays to utilize the features of the flow cell. Anticipated results are flow cells that can process water sample for DNA testing of pathogenic E. coli O157:H7 and Salmonella in 1-2 hours. Further development can expand the number of waterborne pathogens and expand the application to testing of food, drinking water, recreational water, reclaimed water, and to potential bioterrorism agents.