Food Safety in the 21st Century: Rapid Toxin Detection in the Field

Ubiquitous in U.S. news cycles are reports of foodborne illness due to products contaminatedwith foodborne pathogens including Salmonella spp. Listeria monocytogenes E. coli H7:O157and even Clostridium Botulinum.The National Outbreak Reporting System (NORS)curated bythe Center for Disease Control (CDC) reports that between 2010 and 2016 these four foodbornepathogens caused over 1400 outbreaks and resulted in 139 fatalities.Most recently an outbreaklinked to E. coli contaminated Romaine lettuce from Yuma AZ resulted in 210 illness across 36states with 5 fatalities. The recent outbreak in Arizona highlights the problems associated withproducts that do not have an appropriate "kill step" in place for leafy-greens and other ready-to- eat foods that do not require the consumer to cook them before eating.The "kill-step" is a termtypically used to describe a method in the manufacturing or packing process where deadlypathogens are eradicated from the final product.Unfortunately products cannot withstand a kill- step such as heating (e.g. leafy greens) or the step is cost prohibitive (e.g. irradiation) or thestep simply may not be effective enough to eradicate the pathogen (e.g. heat resistant bacterialspores).In addition some pathogens such as E. coli and C. botulinum secrete deadly toxins thatcould be present in the food even after the bacteria has been removed.For example Botulinumneurotoxins (BoNT) are highly toxic and as little as 1 µg/kg of body weight could be lethal.Therefore it is critical to have a monitoring program in place to identify any products that maybe contaminated.Although the Food and Drug Administration curates and publishes protocolsfor foodborne pathogen and toxin testing they require trained personnel and have a long time-to- result.In addition because the tests are not field deployable they require samples to be sent outwhich can add even more time to results.But for some products such as leafy greens the shelflife does not allow for a test and hold program.Therefore a platform is needed that may be usedin the field by manufacturers or by inspectors to rapidly detect adulterated products.For this project PathSensors Inc. (PSI) proposes to develop a portable field-deployable® ® platform based upon CANARY technology.CANARY technology is an immuno-basedbiosensor technology that demonstrates unprecedented performance in terms of speedsensitivity and ease-of-use when compared with other standard commercial methods.TheUSDA recently evaluated the laboratory-based platform and determined it could efficiently andaccurately identify Botulinum neurotoxin in different food matrices. PSI intends to expand uponthis research by adding its expertise to develop new instrumentation and adapting the currentdiagnostic for on-site toxin testing.After developing the new platform PSI will collaborate withthe USDA-ARS to demonstrate the utility of the newly developed system by testing spikedsamples with BoNT type A and then will conduct performance testing in manufacturingfacilities.During the testing PSI will be able to further iterate the development to have a fullyfunctional field-ready prototype and diagnostic.After the diagnostic's full commercialization systems will be deployed at food manufacturingfacilities and be used by food safety auditors.The system also will be made available to USDAFSIS for testing and validation.After developing the platform the catalog of assays will be fullyexpanded to include testing for Botulinum neurotoxins types (B E F and H) Shiga toxins (stx1and stx2) and Staphylococcus enterotoxin B.