Entry Date:
September 3, 2021

On-Site Analysis of Foodborne Pathogens Using Density-Shift Immunomagnetic Separation and Culture

Principal Investigator Rohit Karnik

Project Start Date July 2021


Can we rapidly detect foodborne pathogens at food processing sites before contaminated food reaches consumer hands?

Research Strategy:
(*) Develop a novel process to isolate, concentrate, and culture whole bacterial cells in small volumes using affinity ligand-functionalized microbeads.
(*) Develop sample preparation protocols to implement the developed process for detection of foodborne pathogens from different food matrices.
(*) Design, fabricate, and demonstrate an integrated bench-top device for rapid detection of low levels of foodborne pathogens.  

Foodborne pathogens are a major source of human morbidity, food recalls, and economic loss. Current detection methods for foodborne pathogens are culture-based and highly sensitive, but involve multiple labor-intensive steps and are available at only a handful of labs in the US. This means that food is often already in consumer hands when contamination is confirmed, leading to disease outbreaks and costly recalls. Rapid tests have emerged to address this challenge, but they typically lack sensitivity and are not necessarily compatible with assays used to identify where and how an outbreak originated. This project aims to develop a scalable, distributable, and sensitive foodborne pathogen analysis platform that returns results in 4-6 hours. The proposed method is based on affinity ligand-based whole-cell capture, concentration, and culture for sensitive pathogen detection in a format that preserves cells for further downstream testing.  The goal is to develop a food safety test that is suitable for implementation in an integrated benchtop fluidic device for use by moderately-trained technicians directly at production sites. Using this novel platform, the research team aims to demonstrate detection of Salmonella enteritidis from a variety of food matrices. This research represents a potential advance towards faster on-site foodborne pathogen testing that is complementary with regulatory diagnostic workflows, decreasing the cost of foodborne microbial contamination in terms of both human lives and economic losses.