Rapid technique to detect C. botulinum in trial phase, says LFI
LFI, in partnership with the National Institute of Allergy and Infectious Diseases at the US Department of Health and Human Services, said that it is planning to start a series of trials to evaluate the specificity and sensitivity of the new PCR-based assay method to quantitatively detect C. botulinum toxins in real food systems.
C. botulinum is a group of bacteria commonly found in soil, which produces a botulin toxin. Foodborne botulism, caused by eating foods that contain the botulin toxin, is a rare but paralytic illness that can be fatal.
According to the US Center for Disease Control and Prevention (CDC), around 22 cases of foodborne botulism are reported each year.
Rapid test requirement
The LFI stresses that while botulism is rare, testing by the food industry is crucial.
“The urgent need for a rapid diagnostic test capable of detecting all serotypes of C. botulinum is well known,” claims the research group.
The current gold standard test for the bacterium is the mouse bioassay, but detection using this method is slow, expensive, geographically restricted, and often requires in vitro culture of sample for up to two weeks, claims Leatherhead.
According to LFI, the new PCB-based assay technique can detect tiny quantities of C. botulinum DNA, which it said is a definite indicator of the bacterium’s presence, and the method is also extremely sensitive, being able to detect as few as ten bacteria.
In addition, the LFI claims, the new technology can detect any variant of any subtype.
The LFI said that it is seeking additional funding to progress the project.
Short shelf-life
Meanwhile, a recent guidance document from the UK food regulator recommends a restricted shelf-life for vacuum packed (VP) and modified atmosphere packed (MAP) food products to avoid C. Botulinum growth.
Although Clostridium botulinum food poisoning is very rare in the UK, its very serious nature means that any business engaged in producing VP or MAP foods must understand the risks associated with it, claims the Food Standards Agency (FSA).
The bacterium thrives in atmospheres without air, leaving vacuum packed and MAP products more at risk. Some strains of C. botulinum are able to grow and produce toxin above 3° C.
Control measures
The FSA guidelines state that vacuum and MAP packed foods should have a short shelf-life, no greater than 10 days, unless the operator can show key control measures are in place.
The guidelines recommend that, in addition to maintenance of chill temperatures throughout the food chain, control factors such as heat treatment, food acidity, salt content, water activity and preservatives should be used to inhibit the growth and toxin production of C. botulinum.
"While we are not aware of any reported cases of Botulism linked to chilled foods over the past five years, the high level of VP and MAP products on the market means we are keen to take preventative steps to stop any outbreaks occurring," an FSA spokesperson previously told FoodProductionDaily.com
"We also know from our conversations with Local Authorities and Environmental Health Officers that whilst many manufacturers observe good storage practices, some are simply not aware of the hazards," she added.
