Professor of Avian Infection and Immunity Paul Wigley and his team in the Institute of Infection, Veterinary and Ecological Sciences are investigating how the microbiome of new born chickens (the collection of bacteria, viruses and fungi that live in and on them) can reduce and prevent the spread bacterial infections such as Salmonella.
Salmonella is a common bacterial infection that humans can contract usually through contaminated food and water, and is the most common cause of food poisoning in the UK. Whilst most people recover from an infection after a few days, some variations of the bacteria can cause more serious diseases. As Professor Wigley describes, “whilst food borne pathogens aren’t life threatening to the majority of people, Salmonella is still a big problem with as many as 80 million cases and more than 150,000 deaths around the world each year.”
The poultry industry is a very important part of the global food supply chain, but chickens suffer from the same bacterial infections as humans, including salmonella, campylobacter and E.coli. Birds die from these infections in large numbers, and also have the potential to pass the infection on to humans. Currently, antibiotics are used to treat infections in bird populations, but this is increasing the use of antibiotics in the food chain and driving the development of antimicrobial resistant bacteria which is a major global health issue.
Microbiome transfer may hold the key for reducing infections in poultry flocks. A microbiome is the community of organisms that naturally live within a specific habitat. In humans, we have bacteria, viruses and fungi that coexist, and help our immune system to work against some diseases. Chickens have the same kind of microbiome community which can be inherited from the mother, but this is dependent on the conditions they are hatched into. “Chickens born in commercial breeding flocks, in large scale hatcheries, don’t get a microbiome transfer from the mother hen so lack the ‘good bacteria’ that can help ward off infection” outlines Professor Wigley.
Professor Wigley, who has spent over 24 years studying foodborne pathogens such as Salmonella and Campylobacter, is hoping to discover the best and most effective way to ‘transplant’ microbiomes into chickens. This increases their immune response to infections resulting in the need for less antibiotics hence reducing the levels of antibiotics entering our food chain.
“There are many ways you can transplant a microbiome from letting them eat faeces to adding products to food or spraying their skin. We carried out research in 2015/16 and gave a microbiome to 18 of 36 chickens at hatch” outlined Professor Wigley. “We then infected two of each group with campylobacter and monitored transmission. We expected them all to be infected by days six or seven but they weren’t. Post mortem examination of their intestinal content and examination of their faeces found that levels of the bacteria were not only greatly reduced in those who had had the transplant but also the other birds in the flock were less likely to become infected.”
Current follow on work will see Professor Wigley and his team explore the parameters for microbiome transfer, researching what age is the cut off point for a transfer to deliver maximum benefit, resulting in the greatest number of different ‘good’ bacteria in a chicken’s gut.
Professor Wigley, said: “Chickens in a hatchery are usually vaccinated by a spray or through drops in their drinking water, usually within the first 48-72 hours of life. We’re researching which bacteria are transferred and therefore what combination of bacteria (a microbiome) will be most effective to give to chickens to increase their immunity to common infections.”
Improving immunity in chickens will have far-reaching impacts. Professor Wigley said, “If we can improve the gut health of chickens, increasing the chance of immunity to infections then we can not only reduce the amount of antibiotics fed to poultry but also improve food security. The poultry industry globally is huge and is a vital part of our food chain. By making flocks healthier and more sustainable we can maintain a supply of poultry without compromising the health of chickens or people. If more birds survive we will have stronger food chains and will be able to reduce the levels of antibiotics used to treat ill birds, which then ultimately end up entering our human food chain.”
He added: “The benefits to the birds themselves and the poultry industry are significant. In the UK alone, we estimate around four million birds die of E. coli infections early in their life, so reductions in disease will lead to productivity gains but this research could also have huge impacts for farmers in developing countries.”
“We are carrying out research in Thailand and the Philippines on birds born and raised in different environments. Put simply, birds held in different environments, those in commercial environments and those in ‘backyards’ will have significantly different microbiomes. There are so many factors affecting microbiomes and the environment is one of them. We’ll research foodborne pathogens in birds in both environments and see how the birds respond and if they have good immune responses. We want to understand how the microbiome varies between breeds and what is the best microbiome combination to prevent Salmonella and other bacterial infections.”
Through genome sequencing the team want to map all components and work out which, if used in combination, create the strongest and most effective microbiome. They also plan to research if probiotics can be given to hens along with Salmonella vaccines to improve overall health or if it interferes with the live vaccine.
Professor Wigley added: “The benefit of our research is that it directly benefits poultry and animal nutrition suppliers and ultimately humans and biomedical research. By working with industry partners we’re able to address real problems in poultry production and provide real solutions that bring economic, social and environmental benefits.”
The team’s work on microbiomes has been supported by UK Research and Innovation (UKRI)/Biotechnology and Biological Science Research Council (BBSRC), Newton Fund and DuPont Animal Nutrition.
Anyone interested in collaborating with the Infection Biology and Microbiomes team in the Institute of Infection, Veterinary and Ecological Sciences or with the Microbiome Innovation Centre can find out more here.
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