Biosensors to Detect Pathogens in Sprouts

Biosensors-based processes for detection of bacteria in the food processing environment

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana

Session 6, Foodborne pathogens in the food processing environment and their control
S.-I. TU, Microbial Biophysics & Residue Chemistry Research Unit, USDA-ARS-Eastern Regional Research Center, 600 E. Mermaid Ln., Wyndmoor, PA 19038-8598

The presence of pathogenic bacteria in foods is a serious concern to public health. About 76 million people get sick, more than 300,000 are hospitalized, and 5,000 Americans die each year from foodborne illnesses. To minimize the potential health and economical impacts of foodborne pathogens, it is necessary to have rapid, selective and specific detection methods. A practical detection process must have good sampling protocols for different food systems, universal separation and concentration approach for targeted pathogens, capability of assuming multiple platforms for multiple pathogen detection, automated and high-throughput controls, and ability to yield testing results in real or near-real time. With these guidelines, our laboratory has developed a few biosensor-based pathogen detection processes involving the uses of brief culture enrichment, immunomagnetic beads for pathogen capture and concentration and biosensors for capture signal amplification. Depending on the selection of biosensor, the viability and intactness of the pathogens may also be ascertained. When applied to the detection of Escherichia coli O157:H7 in ground beef, all developed processes have a detection sensitivity of ~ 1CFU/g after an enrichment of 5 to 6 h at 37 oC. Among developed processes, time-resolved fluorescence (TRF) approach has been applied to simultaneously detect multiple pathogens and or toxins in meats and sprouts. With increased availability of automated processors, TRF may satisfy all requirements for a practical pathogen detection process.