Every now and then a food product is recalled due to some contamination. For consumers of such products, a recall can raise doubts about the safety and reliability of what they eat and drink. In many cases, a recall will come too late to prevent some people from getting sick.
Despite the food industry’s efforts to combat pathogens, products are still contaminated and people continue to get sick. Much of the problem stems from the tools available to screen for harmful pathogens, which are often not effective enough in protecting the population.
In AIP progress, by AIP Publishing, researchers from Guangdong University of Technology and Pudong New District People’s Hospital developed a new method for detecting foodborne pathogens that is faster, cheaper and more effective than existing methods. The researchers hope their technique can improve screening processes and keep contaminated food out of the hands of consumers.
Even with the best detection method, finding contaminating pathogens is not an easy task.
“Detecting these pathogens is challenging, due to their diverse nature and the different environments in which they can thrive,” says author Silu Feng. “Additionally, low concentrations of pathogens in large food samples, the presence of similar non-pathogenic organisms, and the complex nature of different food types make accurate and rapid detection difficult.”
Existing detection methods, such as cell culture and DNA sequencing, do exist, but these are difficult to apply on a large scale. Not every batch of food can be thoroughly tested, so some contaminants inevitably slip through.
“In general, these methods face limitations such as long result times, the need for specialized equipment and trained personnel, and challenges in simultaneously detecting multiple pathogens, highlighting the need for improved detection techniques,” Feng said.
The study authors decided to take a different approach and design a microfluidic chip that uses light to detect multiple types of pathogens simultaneously. Their chip is made using 3D printing, making it easy to manufacture in large quantities and customize to target specific pathogens.
The chip is divided into four sections, each of which is tailored to detect a specific pathogen. If that pathogen is present in the sample, it will bind to a detection surface and change its optical properties. This setup allowed the researchers to detect several common bacteria, such as E. coli, salmonella, listeria and S. aureus, quickly and at very low concentrations.
“This method can quickly and effectively detect multiple different pathogens, and the detection results are easy to interpret, greatly improving the detection efficiency,” Feng said.
The team plans to further develop their device to make it even more applicable for food screening.
