Buzzwords

FDA has maintained a zero-tolerance policy for several foodborne pathogens. For example, a policy of “zero-tolerance” for Listeria monocytogenes in ready-to-eat foods means that the detection of any L. monocytogenes in either of two 25 gram samples of a food renders the food adulterated; the infectious dosage of E. coli O157:H7 has been determined to be 10 cells; the Environmental Protection Agency standard for E. coli O157:H7 in water is 40 cells per liter. The current detection methods suffer from one or more of the following limitations: 1) the requirement of pre-enrichment and enrichment to increase the number of target pathogens, e.g., bio-chemical assays and immunoassays, 2) high detection limit, e.g., 10^3 – 10^5 CFU per ml or per gram of sample for immunoassays, 3) inability to distinguish viable from non-viable cells, e.g., PCR-based detection methods, 4) small sample volume capacity, e.g., microfluidic-based biosensors (µl instead of the required ml to liter capacity), 5) tedious detection procedures, and 6) the current high per-assay cost.

The aim of this project is develop a Universal Self-Amplified (USA) Biosensor that addresses the aforementioned disadvantages of current detection methods. This two component system utilizes a universal signal amplification bacterial system and a unique pathogen-specific detection counterpart for a one-step detection of target microorganisms in a scalable volume.