CamChain - Campylobacter in chicken production: survival, virulence and control

Lead Research Organisation: University of Liverpool
Department Name: Institute of Infection and Global Health

Abstract

Campylobacter is a major food borne pathogen in the EU, estimated to infect 1% of people. EFSA estimates that poultry is responsible for up to 80% of cases. Chicken carcass contamination presents two threats. Surface levels can be high, posing a cross-contamination risk and extra-intestinal spread to muscle and liver increases the chance that Campylobacter survives cooking. Broilers become infected during production from the environment. Mechanisms by which Campylobacter survives in the farm and processing environments, transmits to broilers and subsequently colonises them are not well understood. We seek to identify the mechanisms by which these processes occur at the molecular level and examine survival in the farm environment and through the food chain.
Understanding of the mechanism and timing of entry of Campylobacter into broiler houses and initial colonisation of the flock is lacking. Similarly, our understanding of the within flock epidemiology of Campylobacter is poor. We will address these issues. Bird general and gut health play major roles in susceptibility to Campylobacter and we will investigate this. Our proposed field studies will also determine what strains of Campylobacter are present in the farm and surrounding environment, how these vary over time and by season and how such strains relate to those in broilers on those farms.
Campylobacter can be isolated from edible tissues of chickens. Research suggests that host stress and innate immune responses can create invasive Campylobacter phenotypes. Nothing is known about mechanisms by which Campylobacter leaves the chicken gut. We will identify these and the mechanisms for intestinal colonisation, using post-genomic techniques. We will examine methods for enhancing bird resistance to Campylobacter through the use of potentially probiotic bacteria and prebiotic diets. Past work has had mixed success but our preliminary data indicate that we have products with potential. We will determine their effects on Campylobacter carriage, bird gut health and the gut microbiome. Both play a role in susceptibility of birds to Campylobacter and also influence its in vivo behaviour. We will measure success on the basis of whether flocks are Campylobacter-positive or -negative, on levels of flock colonisation and numbers of the bacteria in caeca and on carcasses.
It is not well known how Campylobacter survives in 'hostile conditions' or whether such exposure affects virulence. Campylobacter is considered to be fragile yet survives well on farm and on chicken carcasses. In vitro studies show that C. jejuni co-cultured with other microbes can better survive adverse conditions. The role of microbial communities in Campylobacter ecology that co-occur in natural and farm environments has not been studied. We will determine levels of Campylobacter and the different strains present in farm environments and how they are affected by climate, weather and season. There is a lack of understanding of the molecular response of Campylobacter to stresses in the farm and processing environments. Past work showed that C. jejuni isolates differ in survival in hostile environments.Other work found that isolates differ in virulence. What has not been done is to establish whether there is a relationship between environmental resilience, stress responses and virulence at the molecular level. This is an important objective of the proposed work and one which leads to effective control of the pathogen in the food chain.

Technical Summary

We comprise groups in Europe, Thailand and Viet Nam. The Thai government will fund work there and that in Viet Nam will be funded by Wellcome Trust and the Dutch Government. Our work will address knowledge gaps on the behaviour of Campylobacter in the poultry chain. We need to better understand interactions between Campylobacter, chickens and the environment and how these affect food safety. We will create a holistic picture of Campylobacter behaviour in chicken production and fundamental data on survival, how environmental exposures affect virulence and on-farm population biology and on pre- and/or probiotic intervention on-farm to reduce Campylobacter levels entering the food chain. We will use modelling and risk assessment tools to identify and test the potential efficacy of different interventions that can be utilised by the international poultry industry. We will determine the role of flies as vectors of Campylobacter to broilers and develop improved surveillance tools in order to reduce the number of Campylobacter in broiler meat
We aim to better understand the behaviour of Campylobacter in poultry production to improve control. We will generate understanding of mechanisms for:
In-flock transmission and risk in production including bird to bird spread in-house and downstream in the production chain
Virulence encompassing both broiler colonisation and extra-intestinal spread
Interventions for improving host resistance based on enhancing gut health and, in so doing, finding points for control
Environmental survival and the impact of environmental exposures on virulence. During these processes will be deterine pathogen source and persistence mechanisms
Population evolution to examine how the production chain selects certain sub-types of Campylobacter and whether the selection processes change virulence potential

Planned Impact

Campylobacter is the most important food borne zoonosis in the UK and the wider EU. In the UK it is estimated that there are 700000 cases of infection each year and that chicken-associated Campylobacter infection costs the UK economy ~£1 billion per year. Chicken is overwhelmingly the most important vehicle for human infection and is believed to be responsible for up to 80% of infections. ~80% of chickens on sale in the UK are Campylobacter-positive. Contaminated chicken presents two health threats. Surface contamination levels can be very high and contamination of deep muscle and liver tissues has been reported in up to 27 and 60% of samples tested respectively. The project seeks to better understand the processes that allow Campylobacter, and principally Campylobacter jejuni, to survive in the poultry production chain in the EU and in Thailand and to determine how exposure to potentially hostile environments affects virulence and bacterial population structures. We will also provide a comprehensive understanding of the molecular mechanisms used by C. jejuni to colonise the chicken gut and to leave there and infect edible tissues. We will examine the role of chicken gut health in the processes of Campylobacter infection and explore the use of pro- and prebiotics to better protect the birds from this major zoonotic pathogen.
The project is in partnership with the EU poultry industry and that in Thailand and all major UK retailers. Thus the beneficial impacts of our work can quickly be transferred to stakeholders.

Publications

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Indikova I (2015) Survival with a Helping Hand: Campylobacter and Microbiota. in Frontiers in microbiology

 
Description 'A Twisted Bug's Life' at the Liverpool World Museum 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact A team led by Dr Elli Wright (PDRA on CamChain), led a showcase on Campylobacter research as part of a family-friendly event at Liverpool's World Museum on Saturday 20 September. The exhibit, called 'A Twisted Bug's Life', is funded by a BBSRC science communication award and will be part of the Great British Bioscience Festival. Visitors had the chance to walk through a giant inflatable human gut and learn more about Campylobacter and research being down at Liverpool including on CamChain.

Individuals were not aware of the risks of Campylobacter from poultry and reported risky activities such as washing their chickens and that this exhibit made them better aware of the risks when handling raw poultry meat.
Year(s) Of Engagement Activity 2014
 
Description 'Healthy Tums, Happy Bums' exhibition at the Liverpool World Museum. 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact The exhibit lead to discussion with those attending about whether or not you should wash your raw chicken, with members of the public not realising that this could be a risk for acquiring gastroenteritis due to Campylobacter specues.

We believe this exhibit led to greater awareness of the public to some of the risks for acquiring Campylobacter infection, including the washing of raw chicken carcasses.
Year(s) Of Engagement Activity 2013
URL http://news.liv.ac.uk/2013/06/14/food-safety-on-the-menu-at-liverpools-world-museum/
 
Description CampyUK bi-annual meeting held at Liverpool 
Form Of Engagement Activity Scientific meeting (conference/symposium etc.)
Part Of Official Scheme? No
Type Of Presentation paper presentation
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact A poster on the work being undertaken and the key findings of CamChain thus far on the poultry farm study were presented, the meeting was attended by academics, industry and other stakeholders, with interest in the finding of Campylobacter in the poultry farm environment throughout the winter environment.

NA
Year(s) Of Engagement Activity 2014
 
Description First annual meeting of the CamChain consortia, hosted by the University of Liverpool. 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact This first meeting and workshop discussed study design and sharing between partners of protocols.

None.
Year(s) Of Engagement Activity 2013
 
Description Inaugural meeting of CamChain partners 
Form Of Engagement Activity Scientific meeting (conference/symposium etc.)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Participants in your research or patient groups
Results and Impact A meeting as held in Liverpool in March 22nd 2013 for all institutions in CamChain. Representatives from each institution gave presentations.

The next meeting of this sort will be held in Italy in March 2014 Meeting rooms and meeting support

no actual impacts realised to date
Year(s) Of Engagement Activity 2013
 
Description Invitation to sit on a restatement panel on the Campylobacter hosted by the University of Oxford 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact I was invited to take part in a restatement workshop on Campylobacter which involved contributing to a restatement paper. This paper will be sent to stakeholders for further opinion and the subsequent paper published and used as a briefly document for policymakers.
Year(s) Of Engagement Activity 2017
 
Description Meet the Scientists event at Liverpool World Museum 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact 'Meet the scientists' was a free large organised event at the Liverpool World Museum featuring many different research groups presenting their work and in total 1900 visitors were recorded for the event. We had a stand called "Chicken or egg" and we highlighted all aspects of commercial chicken and egg production, accompanied by lots of interactive activities, as well as providing information on our research, including our Campylobacter work and how Campylobacter maybe transmitted on through the food chain and in the domestic kitchen.
Year(s) Of Engagement Activity 2018
 
Description Participation in a One Health EU-SE Asia workshop. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact There was interest and discussion on Campylobacter and its role in disease in developing countries and potential differences in transmission in different value chains present in SE Asia.

There is the potential for further collaboration from with other researchers in SE Asia with discussions on-going with colleagues at the workshop.
Year(s) Of Engagement Activity 2014
 
Description Presentation about Campylobacter control at the 7th Pan Commonwealth Veterinary Conference, Bangalore March 2019 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Invited talk on the infection biology and control of Campylobacter in broilers and the broiler meat chain.
~70 people attended from India and other commonwealth countries
Year(s) Of Engagement Activity 2019
 
Description Second Camchain annual meeting, held in Terramo, Italy. 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact This annual meeting involved all consortia participants presenting updates on their research and allowing discussion amongst the whole consortia on the research findings, as well as discussing future work.

Allowed discussion of further collaboration between two of the consortia participants to explore the relationship between Clostridium perfringens and Campylobacter using the M1 TraDis library, which was beyond the scope of the planned work.
Year(s) Of Engagement Activity 2014
 
Description Talk to local high school about Campylobacter and infectious disease research. 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact The talk was given to students studying BTEC Biology (year 12) at a local high school, who after the talk requested to come and visit our labs on the Leahurst Campus, which they did the following week and were shown how Campylobacter is isolated and identified within our laboratory and the pupils also got some hand on experience in the laboratory to identify Campylobacter by microscopy.

The BTEC students who were spoken to did not consider research or working within the university sector as a potential career option, some students expressed an interest exploring this avenue further.
Year(s) Of Engagement Activity 2013
 
Description Trust Me I'm A Vet, BBC programme filming 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact I took part in filming of a BBC programme 'Trust me I'm a vet' which featured our laboratory and the related work we were doing on the current trend for feeding raw meat diets to household dogs and the risks this may contribute to, in terms of contamination of the household environment with food borne enteric pathogens, such as Campylobacter and the importance of good hygiene. We also highlighted the increased risk of faecal shedding by dogs of enteric pathogens, including Campylobacter.
Year(s) Of Engagement Activity 2017
 
Description Twisted Bugs Life exhibit, British Bioscience Festival 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact NA
Year(s) Of Engagement Activity 2014
URL http://www.bbsrc.ac.uk/society/exhibitions/gb-bioscience-festival/twisted-bugs-life.aspx
 
Description Workshop on Antimicrobial use and resistance in foodborne pathogens, Bangkok, Thailand, 7-10th July. 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact NJ Williams was the UK facilitator for this Thai-UK workshop and promoted discussion on Campylobacter and the issue of antimicrobial resistance in poultry isolates.

Contacted by Thai colleagues interested in collaborating in this area.
Year(s) Of Engagement Activity 2014