Transplanting gut microbes from chickens more resistant to Campylobacter into birds that are susceptible does not improve resistance, according to researchers.

To determine the types and numbers of microbes present, scientists from the Roslin Institute at the University of Edinburgh in Scotland analyzed the genetic makeup of gut microbiota from chicken lines with different resistance to the bacteria.

Transplanted gut bacteria only survived in the susceptible chickens for a limited time and those chickens became even more susceptible to Campylobacter.

Campylobacter burden
Researchers said the findings were unexpected and contradict results from previous studies in mice. Scientists used the poultry lines held by the National Avian Research Facility at the Roslin Institute.

based on 2018 figures of foodborne cases per year, the economic and societal burden for the U.K. from Campylobacter spp. was £712.6 million ($890 million). Campylobacter accounted for almost 300,000 infections in that year.

The annual healthcare cost for Campylobacter infections in Scotland is £3 million ($3.9 million), according to Health Protection Scotland. Public health authorities estimated there are 6,000 cases reported per year. Public Health Scotland, which launched this month, brings together Health Protection Scotland, Information Services Division and NHS Health Scotland.

Dr. Cosmin Chintoan-Uta, of the Roslin Institute, said: “Given the results of previous studies in mice, we thought that inherited differences in resistance to gut pathogens might be transferable by transplanting gut microbiota from chickens that are resistant to chickens that are susceptible.”

Results of the study, funded by the Biotechnology and Biological Sciences Research Council and Scottish Government via the Rural and Environmental Science and Analytical Services program, were published in the journal Applied and Environmental Microbiology.

Control options
Campylobacter is one of the main causes of food poisoning globally and is commonly found in chickens. Current control strategies are stringent on-farm biosecurity and carcass treatments.

One control option may be to alter the composition of microbial communities in chicken intestines by introducing beneficial bacteria and excluding harmful ones.

In mouse models, differences in resistance to bacterial infections can be partially transferred between lines by transplantation of gut microbiota. Recent studies have also indicated a protective role of the microbiota against colonization by the pathogen in chickens.

Researchers had previously described two inbred chicken lines which differ in resistance to intestinal colonization by Campylobacter. In the latest study they investigated composition of the microbial communities in the gut of these lines and whether transferring gut bacteria between the resistant and susceptible lines alters their resistance to Campylobacter.

No major differences in microbial populations were found, and resistance or susceptibility to colonization was not conferred by transferring gut bacteria between lines suggesting gut microbiota did not play a role in resistance to Campylobacter colonization.