U.S – Researchers at the University of Georgia (UGA) College of Engineering are developing a biosensor-based rapid diagnostic test for Listeria monocytogenes in food, a method recently introduced through a study published in Journal of the Electrochemical Society.
The rapid diagnostic method is based on electrochemical biosensors. Advantages of the sensors such as ease of use, high specificity, sensitivity, and low cost has of late piqued the interest of scientists, who are seeking to apply it in the molecular detection in food safety.
Such scientists include those at the Michigan State University who have also been developing a similar rapid biosensor test for Salmonella and Campylobacter, as reported by Food Safety Magazine.
The method employs bacteriophages—viruses that exclusively infect and replicate certain bacteria—as bioreceptors to identify L. monocytogenes using an electrochemical sensor.
The bacteriophages’ specificity enables researchers to detect L. monocytogenes with little interference from other biological agents. Once the bacteriophages attack its target pathogen, they can translate its biochemical information into an electrical signal that alerts users to microbial contamination.
“Bacteriophages are viruses that attack bacteria – they are very specific and will only attack their target. We can take advantage of their specificity and make sure that only L. monocytogenes is detected on our sensor with little interference from biological agents,” said Or Zolti and Baviththira Suganthan, two doctoral students in the College of Engineering who served as the study’s Lead Authors.
The UGA researchers believe their method is “as good, if not better than” competing methods in terms of their limits of detection, and envision the technology being used as part of a food production line.
The developing technology offers a distinct advantage over traditional, time-consuming molecular testing conducted in diagnostic laboratories.
The molecular testing though accurate, requires industry to send samples taken at specific control points during manufacturing and distribution for testing—a process that can take anywhere from three days to two weeks.
At present, the UGA researchers have tested their system only in a laboratory setting, however, they are planning to apply the technology to contaminated food samples in the near future.
The method employs bacteriophages—viruses that exclusively infect and replicate certain bacteria—as bioreceptors to identify L. monocytogenes using an electrochemical sensor.
If successful, the researchers could further optimize the sensors for early and rapid diagnosis in the food industry.
“Our approach will allow food manufacturers to avoid recalls and find bacterial contamination within minutes on their production lines. This ability will also save lives and prevent contaminated products from reaching the shelves in supermarkets,” said Zolti.
Listeria contamination
Listeriosis, an infection caused by eating food contaminated by the bacterium Listeria monocytogenes.
According to the Centers for Disease Control and Prevention (CDC), it is the third leading cause of death from foodborne illness in the United States. An estimated 1,600 people get sick each year and about 260 die.
It can cause severe illness in pregnant women, newborns, the elderly and people with compromised immune systems.
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