Campylobacter can survive in biofilms in the unfavourable conditions outside the host and it is suggested that Campylobacter is rather a secondary coloniser of pre-existing biofilms. However, information on mechanisms of biofilm production of Campylobacter and options of biofilm reduction as well as places containing Campylobacter biofilms in the food productions chains are still scarce. Therefore, presence and places of biofilms within the farm and commercial poultry meat production as well as transcriptomic changes during biofilm formation will be elucidated. Further, environmental isolates will be included in our studies to investigate their potential in biofilm formation compared to chicken and human-derived isolates.

Different strategies to reduce Campylobacter biofilms will be investigated: i) As biofilm formation of many bacteria is regulated by Quorum sensing processes, the impact of Quorum quencher in reducing Campylobacter of mono- and multi-species biofilms will be investigated. ii) The extracellular polymeric substance of Campylobacter biofilms also consists of extracellular DNAs (eDNA). As the C. jejuni eDNase, encoded by cje1441, is able to reduce Campylobacter mono-species biofilms their efficiency in reducing Campylobacter from multi-species biofilms will be analysed. iii) The impact of further intervention strategies e.g. bacteriocins and organic acids on biofilm formation and reduction will be analysed. The most promising strategies will be implemented in commercial production stages and efficiency determined.

In addition, the role of Quorum quenching compounds in pathogenicity will be investigated to elucidate further therapeutical approaches.

Altogether, this sub-project contributes to clarify regulation of biofilm formation in C. jejuni and possible biofilm reduction strategies at environmental conditions and in commercial poultry meat production, which could result in lower cross-contamination of food products, thereby improving human health.