January 18, 2021

Roslin: Chicken genetic insights could help tackle Campylobacter

A study involving chickens has revealed the genetic basis of resistance to Campylobacter which causes food poisoning, the Roslin Institute said.

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.

Led by researchers from the Roslin Institute, the study - 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.

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 United Kingdom are infected by Campylobacter, costing the country approximately £50 million (US$60.4 million).

"Surveys have shown that over half of fresh chicken on sale in the United Kingdom is contaminated with Campylobacter," said Dr Androniki Psifidi, a lecturer in Veterinary Clinical Genetics, Royal Veterinary College, and honorary scientific associate of the Roslin Institute.

"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," said Professor Mark Stevens, personal chair of Microbial Pathogenesis at the Roslin Institute.

"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," said Aviagen's Dr. Richard Bailey.

- Roslin