Campylobacter is a major cause of acute bacterial enteritis in humans and causes a high economic burden in industrialized nations worldwide. In addition, immunological complications of infections such as various inflammatory bowel syndromes, the Guillain-Barré-Syndrome or chronic arthritis account for serious suffering. The increasing number of officially registered human cases creates the urgent need for development of novel strategies for prevention, control and treatment of Campylobacter infections. To achieve this, we are proposing several coordinated lines of research within this closely linked One Health consortium represented by veterinarians, food microbiologists, physicians, epidemiologists, microbiologists, and public health experts.
Contaminated environment plays an important role in the transmission of Campylobacter, directly to humans or indirectly via farm animals. Emission from broiler farms could play an important role in environmental contamination. However, systematic investigations about different emission routes from broiler farms and their impact are still scarce. Moreover, the role of viable but nonculturable (VBNC) state in environmental transmission is not studied up to now.
Therefore, in this study broiler farms will intensively be investigated over a time. Samples from animals and their environment inside the barn will be collected simultaneously to different samples in the farms´ surrounding with focus on as well as a direct entry/immission and a direct emission. These processes will be recorded over a longer time period. Besides the cultivation and quantification of Campylobacter also VBNC state will be detected and quantified.
Isolates from the barn will be compared to isolates from the farms´ environment via NGS and epidemiological relationships will be evaluated. Moreover, the tenacity and pathogenic potential of isolated environmental Campylobacter including their VBNC state will be analysed in a laboratory approach.
In the end, the relevance of emissions from broiler farms for a direct transmission to humans as well as a recurring contamination of broiler flocks from the environment will be evaluated.
Established control strategies against Campylobacter spp. infections in livestock are focusing mainly on improved biosecurity measures, vaccination trials and non-specific nutritional approaches.
However, these measures alone result so far only in an insufficient reduction of Campylobacter infections both of the farm animals and subsequently the consumers. Therefore, in this individual project (IP) various non biosecurity-based measures of keeping and housing conditions and their combinations will be evaluated for their impact on Campylobacter reduction on herd level and on individual animal level. Initially, these management factors will be evaluated in experimental Campylobacter infection experiments of chickens. Investigated factors will be: i) different stocking densities, ii) two slowly growing genetics/breeds compared to fast growing breeds, each combined with tailored diet, iii) continuous decontamination of the air and the barn surfaces due to vaporisation of essential oils, iv) litter with decontaminating characteristics and with a reduced humidity. For this purpose, an experimental animal model with broilers will be established in the Toolbox (Z) as the in vivo platform Z1. This model is based on “Seeder Birds” which are orally infected with either one (for monovalent infection) or three (for trivalent infection) well-characterised C. jejuni strains (and in the trivalent infection beside two C. jejuni strains also one C. coli strain). Effects were evaluated quantitatively and qualitatively on group and animal levels. Induced VBNC state will be also monitored in some trials. Successful measures, combinations of that and combinations of measures successfully evaluated in the experimental infections and measures already known to be able to effectively reduce Campylobacter will be later implemented and evaluated under practical conditions in poultry farms.