title: Selective growth-inhibitory effect of 8-hydroxyquinoline towards Clostridium difficile and Bifidobacterium longum subsp. longum in co-culture analysed by flow cytometry.
abstract: The major risk factor for Clostridium difficile infection (CDI) is the use of antibiotics owing to the disruption of the equilibrium of the host gut microbiota. To preserve the beneficial resident probiotic bacteria during infection treatment, the use of molecules with selective antibacterial activity enhances the efficacy by selectively removing C. difficile. One of them is the plant alkaloid 8-hydroxyquinoline (8HQ), which has been shown to selectively inhibit clostridia without repressing bifidobacteria. Selective antimicrobial activity is generally tested by culture techniques of individual bacterial strains. However, the main limitation of these techniques is the inability to describe differential growth dynamics of more bacterial strains in co-culture within the same experiment. In the present study, we combined fluorescent in situ hybridization and flow cytometry to describe the changes in active and non-active cells of a mixed culture formed by the opportunistic pathogen C. difficile CECT 531 and the beneficial Bifidobacterium longum subsp. longum CCMDMND BL1 after exposure to 8HQ. It was observed that without 8HQ, the proportion of both strains was almost equal, oscillating between 22.7 and 77.9 % during a time lapse of 12 h, whereas with 8HQ the proportion of active C. difficile decreased after 4 h, and persisted only between 8.8 and 17.5 %. In contrast, bifidobacterial growth was not disturbed by 8HQ. The results of this study showed the selective inhibitory effect of 8HQ on clostridial and bifidobacterial growth dynamics, and the potential of this compound for the development of selective agents to control CDIs.
authors.affiliation: Department of Crop Sciences and Agroforestry, Faculty of Tropical AgriSciences, Czech University of Life Sciences Prague, Kamycka 129, 165 21 Prague 6-Suchdol, Czech Republic.
authors.forename: Jitka
authors.initials: J
authors.lastname: Novakova
authors.affiliation: Joint Unit of Research in Genomics and Health, Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunidad Valenciana (FISABIO)-Salud Pública, Avenida de Catalunya 21, Valencia 46020, Spain.|Centro de Investigación en Red en Epidemiología y Salud Pública (CIBEResp), Melchor Fernández Almagro 3-5, 28029 Madrid, Spain.|Instituto Cavanilles de Biodiversidad y Biología Evolutiva, University of Valencia, c/Catedrático José Beltrán 2, 46980 Paterna, Valencia, Spain.
authors.forename: Mária
authors.initials: M
authors.lastname: Džunková
authors.affiliation: Department of Microbiology, Nutrition and Dietetics, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, 165 21 Prague 6-Suchdol, Czech Republic.
authors.forename: Sarka
authors.initials: S
authors.lastname: Musilova
authors.affiliation: Department of Microbiology, Nutrition and Dietetics, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Kamycka 129, 165 21 Prague 6-Suchdol, Czech Republic.
authors.forename: Eva
authors.initials: E
authors.lastname: Vlkova
authors.affiliation: Department of Crop Sciences and Agroforestry, Faculty of Tropical AgriSciences, Czech University of Life Sciences Prague, Kamycka 129, 165 21 Prague 6-Suchdol, Czech Republic.
authors.forename: Ladislav
authors.initials: L
authors.lastname: Kokoska
authors.affiliation: Centro de Investigación en Red en Epidemiología y Salud Pública (CIBEResp), Melchor Fernández Almagro 3-5, 28029 Madrid, Spain.|Instituto Cavanilles de Biodiversidad y Biología Evolutiva, University of Valencia, c/Catedrático José Beltrán 2, 46980 Paterna, Valencia, Spain.|Joint Unit of Research in Genomics and Health, Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunidad Valenciana (FISABIO)-Salud Pública, Avenida de Catalunya 21, Valencia 46020, Spain.
authors.forename: Andrés
authors.initials: A
authors.lastname: Moya
authors.affiliation: Centro de Investigación en Red en Epidemiología y Salud Pública (CIBEResp), Melchor Fernández Almagro 3-5, 28029 Madrid, Spain.|Instituto Cavanilles de Biodiversidad y Biología Evolutiva, University of Valencia, c/Catedrático José Beltrán 2, 46980 Paterna, Valencia, Spain.|Joint Unit of Research in Genomics and Health, Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunidad Valenciana (FISABIO)-Salud Pública, Avenida de Catalunya 21, Valencia 46020, Spain.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: D'Auria
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001644:Bifidobacterium / Q000187:drug effects* / Q000254:growth & development*; D016360:Clostridioides difficile / Q000187:drug effects* / Q000254:growth & development*; D005434:Flow Cytometry; D017404:In Situ Hybridization, Fluorescence; D056265:Microbial Interactions; D015125:Oxyquinoline / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D015125:Oxyquinoline