NEW RESEARCH has identified regions in the genetic make-up of chickens linked to resistance to Campylobacter ̶ the leading bacterial cause of food-borne gastroenteritis worldwide.
It found that genetic factors play a minor role in campylobacter colonisation, and that focusing on non-genetic and environmental factors would be most effective in reducing campylobacter levels in poultry.
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The study informs the extent to which parts of the chicken genetic code can be linked to the prevalence of campylobacter in the chicken gut.
Researchers from the Roslin Institute led the study, in collaboration with the poultry breeding company Aviagen.
It investigated the genetic make-up of 3,000 broilers, 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 campylobacter numbers in the birds’ gut.
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, mimicking how chickens are exposed on a commercial farm.
Campylobacter infections are common in humans 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 £50m.
Mark Stevens, personal chair of microbial pathogenesis at the Roslin Institute, said: “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.”
Aviagen’s Richard Bailey added: “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.”
Quantitative trait loci and transcriptome signatures associated with avian heritable resistance to campylobacter was published in the journal Nature.