Detecting food-borne pathogens

Detecting food-borne pathogens rapidly, reliably and early in the supply chain is essential for food industries to prevent spoilage and food poisoning. Current standard bacterial detection methods may take several days to reveal the presence of a pathogen, making it difficult to avoid an outbreak.

To improve pathogen detection, the EU-funded PATHFINDER (Rapid and reliable detection of foodborne pathogens by employing multiplexing biosensor technology) project developed a way to identify low concentrations of multiple bacterial species in food.

To do this, PATHFINDER used biosensors that recognise bacteria specifically, triggering a detectable signal. An example of a biosensor is an assay that employs an antibody that specifically recognises and binds to a bacterium, much as it would in a person's immune system.

Using three common food-borne pathogens as a model, researchers tested whether different biosensors could simultaneously detect multiple bacterial species. To simulate contamination of food, they inoculated cooked and raw chicken-based meals with varying concentrations of the food-poisoning bacteria Salmonella, Listeria and Campylobacter.

After allowing the bacteria to grow, researchers tested the sensitivity of different detection methods. The best one, in which tiny polystyrene beads were coated with different bacteria-capturing antibodies, identified food inoculated with just a single bacterial cell after short periods of increasing bacteria numbers.

PATHFINDER's rapid, accurate and economical method for detecting bacterial contamination in the food chain will reduce costs for the food industry while improving public health.