Research Projects

Abstract

One of the greatest challenges of the modern world is the increasing threat of antibiotic-resistant pathogens, to which the use of antibiotics as growth promoters in animal feed has also contributed. For this reason, EU legislation has prohibited this strategy since 2006, and livestock producers urgently need alternative and sustainable solutions.

Probiotics—live microorganisms that confer beneficial effects on the host’s health—are considered a sustainable and environmentally friendly approach to combating antibiotic resistance. However, our understanding of microbial interactions among probiotics, pathogens, and the host remains very limited. These studies are particularly important given the growing demand for probiotics in human nutrition and animal husbandry, while the consequences of their consumption are still poorly understood.

The project, with the acronym COMPATPROBs (competition between a pathogen and the probiotic Bacillus subtilis), is based on our recent findings that a patented strain of Bacillus subtilis inhibits the growth of foodborne pathogens and positively affects growth and immune status in broiler chickens in vivo.

These findings, together with unpublished data described in the project proposal, form the foundation of this project. The main objective is to further define the mechanisms driving interactions between B. subtilis and Salmonella Typhimurium in vitro, and to extend the research to an in vivo mouse model. Since the habitat of Salmonella is broad—encompassing not only the animal gastrointestinal tract but also natural soil and aquatic environments where nutrients are limited—the project also aims to expand our understanding of how nutrient availability influences interactions between the pathogen and the probiotic.

For the implementation of the COMPATPROB project tasks, we bring together the expertise of three research groups from UL-BF and the expertise of the National Institute of Biology:

The MICRO group (BF) contributes expertise in microbial interactions, comparative genomics, and the construction of recombinant bacterial strains (mutants and reporter strains), as well as experience in experimental evolution and high-resolution confocal microscopy.

The BioNANO-BF group provides expertise in intestinal epithelial barrier models, immune responses, and scanning electron microscopy.

The Center for Laboratory Animals and Genomics (BF) offers expertise in mouse models, host responses, and the detection of fluorescently labeled microbes in vivo.

The BioTEHSystem group (National Institute of Biology) contributes expertise in transcriptomics.

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The phases of the project and their realization

The project is organized into six work packages, each with several tasks and milestones:

WP1: Preparation of specific mutants and recombinant strains, together with the optimization of selected in vitro and in vivo model systems (M1–18).

WP2: Characterization of competition-sensing mechanisms in nutrient-limited environments (M1–24).

WP3: Investigation of the mechanisms and role of the probiotic in modulating pathogen sensitivity to antibiotics (M6–36).

WP4: Assessment of the stability of the probiotic’s antagonistic effects against Salmonella during experimental evolution (M3–36).

WP5: Analysis of pathogen–probiotic interactions and their consequences for the host using an intestinal epithelial barrier model and a mouse infection model (M1–36).

WP6: Project management and dissemination of results: communication, exploitation, and data management (M1–36).

Project partners

• NIB - National institute Of Biology