A new way of detecting deadly Listeria contamination in food and a vaccine for troublesome Norovirus are being reported by major research universities.
University of Georgia College of Engineering researchers report they have a new method for Listeria detection, and the Virginia-Maryland College of Veterinary Medicine at Virginia Tech announced it will evaluate a potential live oral vaccine for norovirus, which is the No. 1 cause of foodborne illness.
Listeriosis, an infection caused by eating food contaminated by the bacterium Listeria monocytogenes, is known for causing severe illness in children, pregnant women, newborns, the elderly, and people with compromised immune systems.
It is the third leading cause of death from foodborne illness, or food poisoning, in the United States. An estimated 1,600 people get sick each year and about 260 die, according to the Centers for Disease Control and Prevention (CDC).
At present, Listeria contamination in food products is identified only through molecular tests conducted in diagnostic laboratories on samples taken at specific control points during the manufacturing and distribution process.
Although very accurate, this method requires significant processing time, transportation of samples, and expensive skilled labor and equipment.
In a new study published in the Journal of The Electrochemical Society, UGA researchers introduce a rapid diagnostic method based on electrochemical biosensing principles.
Electrochemical biosensors are promising alternatives to molecular detection methods because of their ease of use, high specificity, sensitivity, and low cost, according to the researchers.
The UGA researchers use bacteriophages, viruses that infect and replicate within bacteria, as receptors to identify Listeria monocytogenes using an electrochemical sensor.
Meanwhile, Lijuan Yuan, professor of virology and immunology at the Virginia-Maryland College of Veterinary Medicine at Virginia Tech, announced the progress being made around a norovirus vaccine. It was developed by Indiana University’s John Patton and colleagues using the Rotarix rotavirus vaccine as a platform.
Using reverse genetics, they will insert a norovirus protein into Gene 7 of the rotavirus. The virus will then express the norovirus protein in the gut, inducing an immune response against norovirus.
Yuan’s Virginia Tech lab will evaluate the replication capacity, immunogenicity, and protective efficacy of the vaccine using gnotobiotic pig models of human rotavirus and norovirus infection and diarrhea. A gnotobiotic animal is one that has been specially raised to contain zero germs or bacteria so researchers can better study the effects of bacteria and viruses such as rotavirus and norovirus.
The CDC says norovirus as the leading cause of vomiting and diarrhea from acute gastroenteritis in the United States, resulting in 19 million to 21 million illnesses every year.
Norovirus tends to affect young children and the elderly the most. It’s responsible for about 24,000 hospitalizations and 925,000 outpatient visits for American children each year, according to the National Center for Biotechnology Information. Rotavirus also causes acute gastroenteritis and hits young children the hardest.
“Together, rotavirus and norovirus cause over 415,000 deaths every year, and norovirus also has a very significant burden even in the countries that don’t have a lot of deaths. The economic cost is huge, with $4.2 billion in direct costs and $60 billion in indirect societal costs. You hear about norovirus outbreaks on the news all the time in hospitals, nursing homes, and cruise ships and how it’s closing down restaurants, so it’s got a lot of economic implications,” said Yuan.
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