T4-05 Bacteriophage-based Dipstick: Inkjet Printing of Bacteriophages to Detect Different Foodborne Pathogens

Monday, July 10, 2017: 2:30 PM
Room 16 (Tampa Convention Center)
Hany Anany , Agriculture and Agri-Food Canada , Guelph , Canada
Jennifer Sohar , University of Guelph, Food Science Department , Guelph , Canada
Heather Fenn , University of Guelph, Food Science Department , Guelph , Canada
Noha Eldougdoug , Microbiology Department, Benha University , Benha , Egypt
Nada Alasiri , University of Guelph, Food Science Department , Guelph , Canada
Luba Brovko , University of Guelph, Food Science Department , Guelph , Egypt
Mansel Griffiths , University of Guelph , Guelph , Canada
Introduction: Foodborne pathogens continue to burden our economy and society with illness. Therefore, the rapid detection of foodborne pathogens is vital to a safe and secure food supply. Bacteriophages (phages) are viruses capable of infecting and replicating within bacteria in a strain-specific manor. The ubiquitous and selective nature of phages makes them ideal for the detection and biocontrol of bacteria.

Purpose: The objective of this research was to develop and test two phage based biosensors for the detection of Escherichia coli O157:H7, Escherichia coli O45:H2 and Salmonella Newport from inoculated spinach, ground beef, and chicken homogenates, respectively.

Methods: Both detection methods use a phage-based amplification approach followed by real-time PCR to detect E. coli in only eight hours. The first method used phage immobilized to modified paramagnetic silica beads that can be mixed with the food sample. The second sensor was developed as a paper dipstick by printing phage onto commercial paper with a piezoelectric printer. This phage dipstick was used to capture and infect the host bacteria from inoculated food samples.

Results: The detection limit was found to be 102 to 103 CFU/ml for phage immobilized on the modified beads in spinach homogenate and 10 CFU/ml and 103 for phage immobilized on paper (dipstick) in spinach homogenate and ground beef homogenate, respectively. Two other lytic phages against E. coli O45 and Salmonella Newport were printed on ColorLok paper and the developed bioactive paper was used to detect target bacterial strains in broth and meat samples. The detection limit was found to be around 10 CFU/ml in broth and around 50 CFU/ml in ground beef and chicken homogenates, for both targets, within less than eight hours.

Significance: This detection method is rapid, cost-effective, and can be applied to a broad range of foodborne pathogens.