Project Number: 8072-42000-086-001-A
Project Type: Cooperative Agreement
Start Date: Apr 20, 2021
End Date: Apr 19, 2024
Objective 1: Development and evaluation of innovative sensor technologies for the detection and characterization of biological, chemical, and physical contaminants of concern in foods that can be implemented for improved food safety and/or assessment of food integrity and adulteration. Sub-objective 1A: Lysogenic phage-based detection of Shiga toxin producing E. coli and Salmonella serovars. Sub-objective 1B: Cell phone-based technologies for pathogen detection. Sub-objective 1C: Portable laser-induced breakdown spectroscopy system for on-field multiplexed detection of pathogens. Sub-objective 1D: Multiplexed detection platform technologies for food safety threats. Sub-objective 1E: Development of a novel yeast biosensor for continuous real-time monitoring of produce safety. Sub-objective 1F: Development of a handheld LIBS unit, assays, and analysis tools for use in label-free food fingerprinting and tracing to improve food defense and combat food adulteration, contamination, and fraud.
The annual burden of foodborne illness in the United States, as estimated by the Centers for Disease Control and Prevention, is 48 million cases, 128,000 hospitalizations, and 3,000 deaths along with a cost of $152 billion in medical expenses, lost productivity and business, lawsuits, and compromised branding. Of these outbreaks, less than half ultimately get attributed to an identifiable food as the source of infection, which clearly demonstrates the value of proactive testing of foods. Rapid, low-cost, sensitive (1 cell/25-325 g sample) methods for detecting pathogens that are available to regulators, food producers and/or processors, and researchers are fundamental to identifying and minimizing foodborne disease outbreaks and preventing foodborne disease. Culturing and plating of microorganisms remains the gold standard for foodborne pathogen detection. Culturing allows the detection of a small percentage of target cells from within a mixed population by the use of selective enrichment. Selective enrichment from food or environmental samples amplifies the signal from initially low numbers of pathogenic bacteria to detectable levels. Such selectively amplified samples can then be used in down-stream assays such as polymerase chain reaction (PCR)-based methods for identification. Other advantages of this traditional detection method include recovery of live cells for further analyses (e.g., genome sequencing), ease of interpretation, and limited need for specialized equipment. However, a major limitation of this approach is the time required for organisms to grow, often requiring several days of selective enrichment prior to plating and 24-48 hours of culturing on selective media. This is problematic for industry and regulatory agencies alike given that products with short shelf lives may spoil before test results are available, and time is also critical when identifying and controlling foodborne disease outbreaks. Furthermore, it requires some a priori knowledge of the type of contaminant involved in order to apply the correct selective media. An ideal pathogen detection platform would not only have utility across diverse food matrices, but also deal with three major challenges. First, to facilitate meaningful implementation of the zero tolerance policies in place for various human pathogenic bacteria, it would ideally be able to detect a single live pathogenic cell in a food sample and be able to distinguish live cells, even those with diminished viability, from those that are truly dead. Second, it would be able to detect cells in situations where they are not uniformly distributed in the food matrix, something that probably occurs more commonly than we currently believe. Third, it would be both inexpensive and portable – ideally costing pennies per test and using equipment or supplies that can be taken easily to the testing site. Although no single assay may be able to address all these needs, and different techniques may be needed for pathogen detection versus detecting chemical or physical hazards, the advanced foodborne hazard detection technologies described in this proposal work together towards these general goals through deve.