Genetic insights could help tackle food bug
Chicken study reveals the genetic basis of resistance to bacteria that cause food poisoning in people.
Scientists have identified regions in the genetic makeup of chickens that are linked to resistance to Campylobacter ̶ the leading bacterial cause of food-borne gastroenteritis worldwide.
Data obtained in the study inform the extent to which parts of the chicken genetic code can be linked to the prevalence of Campylobacter in the chicken gut.
A study led by researchers from the Roslin Institute, in collaboration with the poultry breeding company Aviagen, investigated the genetic make-up of 3,000 chickens bred for meat, to discover whether parts of their genetic code were associated with resistance to Campylobacter colonisation.
This was achieved by looking for variation at specific positions in the chickens’ genome and their association with numbers of Campylobacter in the gut of the birds.
Scientists combined this with analyses of the expression of genes in chickens that were resistant or susceptible to colonisation by the bacteria.
All the chickens were naturally exposed to Campylobacter present in their environment, which mimics how chickens are exposed on a commercial farm.
Impactful human disease
Campylobacter infections are common in people, who can develop diarrhoea and severe complications after handling or eating contaminated chicken meat.
Each year, it is estimated that more than 500,000 people in the UK are infected, costing the country approximately £50 million.
Future control strategies
Surveys have shown that over half of fresh chicken on sale in the United Kingdom is contaminated with Campylobacter.
Here, we looked for regions of the chicken genome that are associated with resistance to the bacterium. Our data indicates that there is low genetic basis for resistance to Campylobacter colonisation and also show that non-genetic factors play a more significant role in carriage of Campylobacter in chickens. In addition, the regions of the genome associated to resistance to colonisation were highly prevalent in the chicken line studied.
These results show that whilst there are genetic factors that influence Campylobacter colonisation, these factors play a minor role and therefore it is crucial to characterise and understand the role of the non-genetic and environmental factors to further reduce Campylobacter levels in poultry.
The study is published in the journal Scientific Reports and has received funding from Aviagen, the Scottish Government and the Biotechnology and Biological Sciences Research Council, as part of UK Research and Innovation.
** The Roslin Institute is part of the University of Edinburgh’s Royal (Dick) School of Veterinary Studies. **