Analyzing specialized metabolites from Clostridioides difficile at the human-microbe interface

• Applicant: Dr. Nadya Abbood
• Subject Area: Medical Microbiology and Mycology, Hygiene, Molecular Infection Biology ; Metabolism, Biochemistry and Genetics of Microorganisms
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 544327732

The human microbiome is comprised of diverse microorganisms, including bacteria, fungi, viruses, and archaea, that reside on various body surfaces. These microorganisms are crucial to numerous metabolic processes within the human body and are often referred to as a "human organ". Maintaining a balanced microbiome is crucial for supporting the host's physiological functions, while dysbiosis has been associated with various pathologies. The genetic diversity within the human microbiome includes biosynthetic gene clusters (BGCs) responsible for producing specialized metabolites, such as non-ribosomal peptides (NRPs). These NRPs, synthesized by non-ribosomal peptide synthetases (NRPSs), possess diverse bioactivities and hold promise in pharmaceutical applications, serving as antitumor, antifungal, antiviral, and immunosuppressant agents. Investigating NRPSs from microbial organisms within the human microbiome represents crucial steps toward comprehending their biological functions and potential medical applications. One representative of the human microbiome is Clostridioides difficile, which can cause severe intestinal inflammation due to over-colonization from prolonged antibiotic use. AntiSMASH analyses of C. difficile discovered an unconventional NRPS BGC harboring the potential to unveil unusual enzymatic reactions or a novel mechanism of action. Characterizing this NRPS and its product in this research project aims to contribute to our understanding of the structure, function, and regulation of such molecules in the human microbiome and their potential importance for therapeutic approaches. The proposed research project to functionally characterize the NRPS-encoding BGC in C. difficile, involves three main objectives: Firstly, it encompasses the characterization of the produced metabolite, the functional investigation of the involved genes, and the analysis of the biosynthetic pathway by applying the computer-aided design of synthetic genetic elements (CAD-SGE) designed for cross-kingdom expression. Secondly, it aims to explore the functional and regulatory mechanisms underlying the NRPS BGC by conducting a comparative transcriptome analysis. Lastly, it involves the analysis of the biological activity and mechanism of action of the target metabolites. This includes conducting 'chemical complementation' in C. difficile, performing antimicrobial, antifungal, and cytotoxicity assays, and screenings to activate 314 human G-protein coupled receptors.

• DFG Programme: WBP Fellowship
• International Connection: USA
• Host: Professor Dr. Jason M. Crawford