This Phase I Small Business Technology Transfer (STTR) project aims to demonstrate the feasibility of a method for detecting individual E. coli bacteria (to simulate a foodborne or waterborne pathogen) with a breadboard system. The innovative technique proposed for detecting pathogenic microorganisms in food or water has critical advantages over alternatives. It is: (1) capable of detecting single microorganisms (current techniques need over 104 microorganisms); (2) capable of completely examining a large volume of food or water in real time; (3) inherently automatic; (4) sensitive only to selected bacteria or viruses; and (5) capable of using multi-probe, multi-wavelength redundancy to eliminate false positive detections even in complex media. This technique is based on laser induced fluorescence in which a stream of solution containing the microorganisms is labeled with fluorescent probes and then is illuminated with a laser diode (commonly called flow cytometry). The resulting fluorescence is detected with a CCD imager using a novel integration scheme. The proposed device will use fiber optics and a laser diode to provide a low-cost, rugged package. Phase I will also determine the optimum performance parameters for the prototype to be built In Phase II. The most profitable applications of this technique are the detection of infectious microorganisms in contaminated food and water. Foodborne microbial pathogens account for approximately 7 million illnesses and 9,000 deaths in the U.S. annually, with an estimated economic loss of at least $6 billion.
