STTR Phase I: Feasibility of multi-layer microplate test for rapid detection and enumeration of Salmonella spp. in raw poultry and processing environment samples

The broader impact of this Small Business Technology Transfer (STTR) Phase I project will be reduced incidence of infections and outbreaks from Salmonella, one of the most frequently reported bacterial causes of food-borne illness in the US. Each year Salmonella causes over 1.35 M illnesses and 26,500 hospitalizations, with 20 percent of infections attributable to poultry.

Given that the number of Salmonella illnesses has increased about 30 percent over the past decade, the US poultry industry - the world's largest producer and the second largest exporter of poultry meat - must minimize the risk of Salmonella infection. The market for the Salmonella microplate test with US poultry processors and the associated sanitation service providers is estimated at $240 M.This project develops and implements a rapid, simple and low-cost test for Salmonella detection and quantification in 15 hours with no pre-enrichment step.

It enables processors to run on-site screening for Salmonella in the processing environment and on raw poultry samples to get faster results, enabling faster corrective action to minimize Salmonella and reducing downstream risks to consumers.

The proposed project will show the feasibility of a multi-layer, 96-well microplate test method for Salmonella detection and enumeration by demonstrating: ≥ 90% sensitivity (true positive) and specificity (true negative) with pure cultures and samples of the processing environment and raw poultry; detection in 15 (± 2) hours, with no pre-enrichment; and stability: ≥ 60 days. The test base formulation has shown ≥ 95% sensitivity and specificity with 7 pure cultures of Salmonella and 5 non-target organisms, and detection in 15 hours (± 2) hours.

The main technical challenges of this research are achieving desired sensitivity, specificity, speed and stability across 35 Salmonella organisms and 20 non-targets, with a variety of target matrices, in a method easy to use and cost-effective. Controlling for non-target organisms requires evaluation of selective and differential agents as well as sequential and/or preferred use of nutrients by target and non-target organisms in the culturing environment of the microplate.

The following methods will be used to optimize test performance: (a) Inclusivity testing; (b) Exclusivity testing; (c) Matrix testing; (d) Stability testing; and (e) Reproducibility testing.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.