Selective Isolation and Concentration of Foodborne Bacterial Pathogens in a Microfluidic Device

Abstract

Listeria monocytogenes is a bacterium that is present in contaminated food products including dairy, vegetables and meat. It is a deadly foodborne pathogen that has contributed to multiple outbreaks, and the disease caused by this pathogen has high mortality rates. The conventional methods used for Listeria detection include standard microbiology or biochemical procedures, which require time-consuming sample pretreatment techniques that can take up to 72 hours. There is a growing need for methodologies that reduce the test time for Listeria detection from days to an hour or less, while also allowing for scalability and high-volume processing. The challenge lies in processing and pretreating large volumes of food samples to generate sufficient quantities of analyte for detection tests within a short time period, without compromising the selectivity of the test. We have previously worked on the development of separation and detection methods for bacterial cells [1, 2]. This work describes a multi-chamber microfluidic cell sorting device that uses magnetophoresis to detect, separate, and concentrate tagged Listeria monocytogenes from food samples. Bacteriophage-functionalized magnetic particles will be used to isolate the bacteria in a food sample for pre-concentration, which will allow for more rapid and selective cell sorting followed by impedimetric detection of Listeria in an electrochemical cell. Ghuman, A., et al., Magnetic Separation of Food-Borne Pathogens in a Microfluidic Device, in IBE 2018 Annual Conference. 2018.Zhou, Y., et al., Isolation and Separation of Listeria monocytogenes Using Bacteriophage P100-Modified Magnetic Particles. Colloids and Surfaces B: Biointerfaces, 2018. Under Review.