UK research explains role of selenium in spread of common foodborne pathogen in chicken products

Posted by AFN Staff Writers on 23rd May 2012

Researchers at the Institute of Food Research, in the UK, say they have discovered why the micronutrient selenium is important to the survival of Campylobacter bacteria.

In Australia, Campylobacter is one of the most common causes of bacterial gastroenteritis and is frequently associated with the consumption of contaminated poultry. Knowing how and why Campylobacter uses selenium could help develop ways of controlling it, benefiting public health and the food industry.

Previous research has found that Campylobacter needs selenium, but it is has not been known how selenium is acquired or metabolised by Campylobacter.

The new research, by Dr Arnoud van Vliet at the Institute of Food Research, identified two Campylobacter genes required for the formation of the formate dehydrogenase enzyme – which is essential for the bacteria’s survival.

Inactivation of these two genes blocked the formation of the formate dehydrogenase enzyme, but when the bacteria were supplemented with extra selenium, they were able to synthesize the enzyme again, suggesting that the two Campylobacter genes are involved in selenium metabolism.

As it was previously shown that the lack of formate dehydrogenase affects the ability of Campylobacter to colonise the chicken gut, the new findings may open up possibilities to target this pathway for antimicrobial purposes.

New findings a step forward in reducing impact of Campylobacter in the food industry

Commenting on the new findings, Dr van Vliet said, “Selenium metabolism is still poorly understood in bacteria, and its role in important foodborne pathogens like Campylobacter is not yet appreciated fully.

“With the identification of these two genes essential for formate respiration, we now hope to have a tool to generate knowledge that helps us get a better understanding of what makes Campylobacter so good in colonising the chicken gut and cause disease in humans. Such knowledge is essential if we want to achieve the ultimate goal of reducing the impact of Campylobacter in the food industry,” Dr van Vliet said.

Dr van Vliet also said that, as the same selenium metabolism genes and the formate dehydrogenase enzyme are also present in other important foodborne pathogens like Salmonella and E. coli, it may be possible to extend investigations to other areas of food safety.