Projects / Programmes
Microbial interactions as a basis for bio-control of Campylobacter jejuni
| Code |
Science |
Field |
Subfield |
| 4.02.04 |
Biotechnical sciences |
Animal production |
Processing of animal raw materials |
| Code |
Science |
Field |
| 4.02 |
Agricultural and Veterinary Sciences |
Animal and Dairy science |
Campylobacter, bio-control, microbial interactions, Bacillus subtilis, food safety, health
Researchers (13)
Organisations (3)
Abstract
In the last ten years, Campylobacter jejuni is the most frequent and increasingly resistant food-borne bacterial intestinal human pathogen, with high costs for public health and economy. New methods and strategies for control of resistant C. jejuni are nedeed, not sensitive to development of new resistance mechanisms. Biological control, with specific biological molecules or live bacterial cells (probiotics) are one of the alternatives. However, interactions of C. jejuni are not understood yet. This project will tackle the gap in fundamental knowledge on C. jejuni interactions on cell-cell, inter-strain and inter-species (C. jejuni-B. subtilis) level. The first aim is to understand quorum sensing (QS) mechanisms and its inhibition by selected plant derived QS inhibitors - we continue previously established work on antimicrobially efficient plant preparations, but quantificartion of AI-2 signalling molecules will be done for the first time with direct HPLC-FLD method. The consequences of QS inhibition will be confirmed in extraintestinal conditions by quantifying adhesion and biofilm on polystyrene and glass contact surfaces and as adhesion and invasion reduction on model cell lines. Concerning inter-strain interactions of C. jejuni, this is the first project studying phylogenetic relatedness of C. jejuni strains in co-culture and impacts on C. jejuni biofilm formation and spread of antibiotic resistance determinants. We predict that more related strains (kin) of C. jejuni are engaged in cooperative behaviour, whereas less related strains (non-kin) are more antagonistic. Co-aggregation, co-adhesion and biofilm formation as well as transfer of resistance of chosen strain combinations will be examined. We will target also C. jejuni-B. subtilis interactions to gain new knowledge of molecular mechanisms behind B. subtilis antagonistic interaction in co-culture and coadhesion (biofilm) assay. Functional role of C. jejuni genes for efflux pumps and stress response as well as B. subtilis genes for antimicrobial compounds and extraintestinal matrix will be confirmed. C. jejuni fitness and biofilm formation dynamics will be determined in the presence of B. subtilis spent medium to understand the importance of direct cell-cell contacts in C. jejuni-B. subtilis interactions. Novel knowledge gained will enable new understanding of B. subtilis as probiotic antagonist of C. jejuni. This research is possible with the unique culture collections of the project team, with genetically well characterized C. jejuni and B. subtilis reference strains, mutants and environmental isolates from natural and industrial environment, and exceptionally strong expertize of project team members on bacterial (B. subtilis) interactions and physiology of C. jejuni. The project team joins specific research equipment to study bacterial interactions on population, cellular and molecular level (e.g. fluorescence confocal microscopy and electron microscopy, laboratories for microbiology, molecular biology and cell cultures). The project will be carried out in collaboration of 3 Slovenian project partners: University of Ljubljana, Biotechnical Faculty, University of Maribor, Medical Faculty and National Institute of Biology, with a good balance of five young researchers, three experienced middle-age researchers and two senior scientists-full professors. The questions opened in this project have never been addressed before, so the findings will be novel and publishable in high impact scientific journals. With specified project aims we are contributing new knowledge to fundamental science of bacterial interactions – and this is essential for development new strategies of improved bio-based control of this important food-borne and increasingly resistant bacterial pathogen - C. jejuni. The project aims are in accordance with the priorities of the national research program of the Republic of Slovenia and exposed topics of ARRS and EU calls of research project proposals.
