A Hybrid Pathogen Detection System

Cryptosporidium parvum, a protozoan parasite that invades the gastrointestial system, is a serious threat to the nation's water supply. Assays for pathogen using self-contained microelectrochemical detection are desirable because precise detection can be performed with simple instrumentation on colored and turbid samples minimizing pre-treatment procedures. In addition, electrochemical detection immediately adjacent to surface bound assay components provide rapid signals even for very low analyte concentrations based on short transport distances for reporter molecutes. The Phase I project involves antibody caputer coupled with mRNA-hybridization assay with electrochemical detection analysis of Cryptosporidium parvum oocysts. The studies are expected to demonstate improvement ofer the EPA Methods 1623 and 1622 in several respects. The proposed new approach with tow-fold specificity has the potential to achieve rapid, on-site detection of ultra-low concentrations from large sample volumes with minimal or limited sampale filtration or preparation. The detection of C. parvum oocyst from water samples will be used to demonstrate the preformance of the approach. Success oif this project will lead to the development of devices that will not only allow better, less expensive, and timely quality assurance and control of water supplies, but also provide opportunities to study the fate of C. parvum in the environment from various sources to water intake sites as a function of weather and season. Such estensive and routine studies are not practial with the current EPA methods of analysis.