A new study published in the Scientific Reports journal, led by RVC lecturer and Roslin scientific associate Dr Androniki Psifidi, has revealed how genes influence chickens’ resistance to Campylobacter, a genus of bacteria that causes food poisoning in thousands of people ever year. Significantly, the study identified that control strategies for the bacteria should take non-genetic factors into account when being designed.
Campylobacter is the leading bacterial cause of food-borne gastroenteritis worldwide. Symptoms of infection include diarrhoea, fever, vomiting and stomach cramps. In the UK alone, it is estimated that more than 500,000 people are infected each year, costing the country approximately £50 million.
The study, undertaken by researchers from the RVC and the Roslin Institute, in collaboration with the poultry breeding company Aviagen, investigated the genetic make-up of 3,000 chickens bred for meat. The aim of the study was to identify if elements of the chickens’ genetic code were linked to resistance to colonisation by Campylobacter bacteria.
The researchers explored variation at specific positions in the chickens’ genome and their association with numbers of Campylobacter in the gut of the birds. The study also analysed the expression of genes in chickens that were resistant or susceptible to colonisation by the bacteria.
The study concluded that, although there are genetic factors that influence Campylobacter colonisation, these factors play a minor role, meaning it is crucial to characterise and understand the role of the non-genetic and environmental factors to further reduce Campylobacter
levels in poultry.
All the chickens were naturally exposed to Campylobacter present in their environment, which mimics how chickens are exposed on a commercial farm.
Dr Androniki Psifidi, Lecturer in Veterinary Clinical Genetics at the RVC, said
“Although we identified a genetic component to resistance of chickens to Campylobacter, this was relatively small, and the majority of the chickens we studied already carried regions of the genome associated with resistance to gut colonisation. According to our results, other non-genetic factors play a greater role and will need to be considered in the design of control strategies.”
