A garlic-derived compound could offer the food industry a quick and more effective antimicrobial tool in the fight against Campylobacter on poultry products, a US study has claimed.
Antimicrobial effect of diallyl sulphide on Campylobacter jejuni biofilms, which was conducted by researchers at Washington State University (WSU), examined the ability of diallyl sulphide to kill Campylobacter bacterium protected by biofilms.
The compound was found to be 100 times more effective than popular antibiotics, such erythromycin and ciprofloxacin, in combatting Campylobacter.
The Pullman-based team of researchers also found that diallyl sulphide would work in a fraction of the time – completely inactivating the bacterium cells within 5 hours compared to the 24 hours taken by erythromycin and ciprofloxacin.
WSU researcher Xiaonan Lu told FoodProductionDaily.com that the findings could lead to the development of new treatments to combat the pathogen on the “major vehicle for Campylobacter” - poultry products.
Food additive potential
“This compound has been identified before to show an antimicrobial effect against some bacteria. But our study shows for the first time an antimicrobial effect against Campylobacter biofilm,” said Lu.
When protected by a biofilm, Campylobacter bacterium is 1000 times more resistant to antibiotics.
“The garlic ingredient is 100 times more powerful than two commonly used antibiotics at fighting Campylobacter associated foodborne illnesses.”
“It has the potential to be used as a food additive.”
Lu added that it also has the potential to extend the shelf life of poultry products, but that “more studies are needed to continuously validate it.”
“This work is very exciting to me because it shows that this compound has the potential to reduce disease-causing bacteria in the environment and in our food supply,” said Lu.
Although the current findings focus on Campylobacter, Lu suggested that research could be extended to include other foodborne pathogen.
“Our two publications last year demonstrated that diallyl sulphide also shows antimicrobial effect against different foodborne pathogens, such as E.coli 0157:H7 and Listeria monocytogenes.”
Suitable antimicrobial agent
Campylobacter biofilms and planktonic cells were treated with antibiotics including ciprofloxacin, erythromycin as well as the garlic-derived compound diallyl sulphide before examination and analysis.
The diallyl sulphite compounds were combined with a sulphur-containing enzyme, which changed the enzyme’s function and effectively shuts down the pathogen’s metabolism.
The WSU researchers found that diallyl sulphite easily penetrated the protective biofilm and killed bacterial cells.
“Diallyl sulphide treatment totally inactivated the cells within the biofilm with 5 hours compared with 24 hours for ciprofloxacin and erythromycin, as determined by the number of viable bacteria recovered following treatment,” said the WSU report.
“This is the first time diallyl sulphide has been shown to have a significantly higher antimicrobial effect against bacterial biofilms compared with commonly used antibiotics.”
“Based on our data, diallyl sulphide may be a suitable antimicrobial agency and useful as a natural food preservative,” the research document added.