title: Improved plaque assay identifies a novel anti-Chlamydia ceramide derivative with altered intracellular localization.
abstract: Chlamydia trachomatis is a medically important human pathogen causing different diseases, including trachoma, the leading cause of preventable blindness in developing countries, and sexually transmitted infections that can lead to infertility and ectopic pregnancies. There is no vaccine against C. trachomatis at present. Broad-spectrum antibiotics are used as standard therapy to treat the infection but have unwanted side effects, such as inducing persistent or recurring infections and affecting the host microbiome, necessitating the development of novel anti-Chlamydia therapies. Here, we describe the establishment of a robust, fast, and simple plaque assay using liquid overlay medium (LOM) for the identification of anti-Chlamydia compounds. Using the LOM plaque assay, we identified nitrobenzoxadiazole (NBD)-labeled 1-O-methyl-ceramide-C16 as a compound that efficiently inhibits C. trachomatis replication without affecting the viability of the host cell. Further detailed analyses indicate that 1-O-methyl-NBD-ceramide-C16 acts outside the inclusion. Thereby, 1-O-methyl-NBD-ceramide-C16 represents a lead compound for the development of novel anti-Chlamydia drugs and furthermore constitutes an agent to illuminate sphingolipid trafficking pathways in Chlamydia infections.
authors.affiliation: Junior Research Group "Sexually Transmitted Bacterial Pathogens" (NG 5), Robert Koch Institute, Berlin, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Banhart
authors.affiliation: Organic and Bioorganic Chemistry, Department of Chemistry, Humboldt-Universität zu Berlin, Berlin, Germany Chemistry Department, Faculty of Science, Suez Canal University, Ismailia, Egypt.
authors.forename: Essa M
authors.initials: EM
authors.lastname: Saied
authors.affiliation: Junior Research Group "Sexually Transmitted Bacterial Pathogens" (NG 5), Robert Koch Institute, Berlin, Germany.
authors.forename: Andrea
authors.initials: A
authors.lastname: Martini
authors.affiliation: Junior Research Group "Sexually Transmitted Bacterial Pathogens" (NG 5), Robert Koch Institute, Berlin, Germany.
authors.forename: Sophia
authors.initials: S
authors.lastname: Koch
authors.affiliation: Junior Research Group "Sexually Transmitted Bacterial Pathogens" (NG 5), Robert Koch Institute, Berlin, Germany Department of Molecular Biology, Max Planck Institute for Infection Biology, Berlin, Germany.
authors.forename: Lukas
authors.initials: L
authors.lastname: Aeberhard
authors.affiliation: Advanced Light and Electron Microscopy (ZBS 4), Robert Koch Institute, Berlin, Germany.
authors.forename: Kazimierz
authors.initials: K
authors.lastname: Madela
authors.affiliation: Organic and Bioorganic Chemistry, Department of Chemistry, Humboldt-Universität zu Berlin, Berlin, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Arenz
authors.affiliation: Junior Research Group "Sexually Transmitted Bacterial Pathogens" (NG 5), Robert Koch Institute, Berlin, Germany heuerd@rki.de.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Heuer
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001692:Biological Transport; D045744:Cell Line, Tumor; D002518:Ceramides / Q000494:pharmacology* / Q000627:therapeutic use; D002690:Chlamydia Infections / Q000188:drug therapy; D002692:Chlamydia trachomatis / Q000187:drug effects*; D019411:Clinical Laboratory Techniques / Q000379:methods*; D055808:Drug Discovery / Q000379:methods; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008826:Microbial Sensitivity Tests; D013107:Sphingolipids / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D002518:Ceramides; D013107:Sphingolipids