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Omics-based characterization of chlorotonil-, myxopyronin- and chelocardin-stress in Clostridioides difficile
- Clostridioides difficile is the leading cause of antibiotic-associated diarrhea referring to infections of the gastrointestinal tract in the course of (broad-spectrum)antibiotic therapy. While antibiotic therapy, preferentially with fidaxomicin or vancomycin, often stops the acute infection, recurrence events due to remaining spores and biofilm-associated cells are observed in up to 20% of cases. Therefore, new antibiotics, which spare the intestinal microbiota and eventually clear infections with C. difficile are urgently required. In this light, the presented work aimed at the evaluation and characterization of three natural product classes, namely chlorotonils, myxopyronins and chelocardins, with respect to their antimicrobial activity spectrum under anaerobic conditions and their potential for the therapy of C. difficile infections. Briefly, compounds of all three classes were screened for their activity against a panel of anaerobic bacteria. Subsequently, the systemic effects of selected derivatives of each compound class were analyzed in C. difficile using a proteomics approach. Finally, appropriate downstream experiments were performed to follow up on hypotheses drawn from the proteomics datasets. Thereby, all three compound classes demonstrated significant activity against C. difficile. However, chelocardins similarly inhibited the growth of other anaerobes excluding chelocardins as antibiotic candidates for C. difficile infection therapy. In contrast, chlorotonils demonstrated significantly higher in vitro activity against C. difficile and close relatives compared to a small panel of other anaerobes. In addition, it could be shown that chlorotonils affect intracellular metal homeostasis as demonstrated in a multi-omics approach. The data led to speculate that chlorotonils eventually affect cobalt and selenate availability in particular. Moreover, a metaproteomics approach verified that oral chlorotonil treatment only marginally affected the intestinal microbiota of piglets on taxonomic and functional level. Furthermore, the proteome stress response of C. difficile 630 to myxopyronin B, which similarly showed elevated activity against C. difficile compared to a few other anaerobes, indicated that the antibiotic inhibited early toxin synthesis comparatively to fidaxomicin. Finally, evidence is provided that C. difficile 630 responds to dissipation of its membrane potential by production and accumulation of aromatic metabolites.
Author: | Madita Brauer |
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URN: | urn:nbn:de:gbv:9-opus-75833 |
Title Additional (English): | Omics-basierte Charakterisierung von Chlorotonil-, Myxopyronin- und Chelocardin-Stress in Clostridioides difficile |
Referee: | Prof. Dr. Katharina Riedel, Prof. Dr. Isabelle Martin-Verstraete, Prof. Dr. Franziska Faber |
Advisor: | Prof. Dr. Katharina Riedel |
Document Type: | Doctoral Thesis |
Language: | English |
Year of Completion: | 2022 |
Granting Institution: | Universität Greifswald, Mathematisch-Naturwissenschaftliche Fakultät |
Date of final exam: | 2022/10/19 |
Release Date: | 2022/11/01 |
Tag: | Antibiotics; Clostridioides difficile; Metallomics; Metaproteomics; Proteomics |
GND Keyword: | Antibiotikum , Proteom , Clostridium difficile , In vivo , In vitro |
Faculties: | Mathematisch-Naturwissenschaftliche Fakultät / Abteilung für Mikrobiologie und Molekularbiologie |
DDC class: | 500 Naturwissenschaften und Mathematik / 570 Biowissenschaften; Biologie |