title: Deletion of a dehydratase important for intracellular growth and cording renders rough Mycobacterium abscessus avirulent.
abstract: Mycobacterium abscessus (Mabs) is a rapidly growing Mycobacterium and an emerging pathogen in humans. Transitioning from a smooth (S) high-glycopeptidolipid (GPL) producer to a rough (R) low-GPL producer is associated with increased virulence in zebrafish, which involves the formation of massive serpentine cords, abscesses, and rapid larval death. Generating a cord-deficient Mabs mutant would allow us to address the contribution of cording in the physiopathological signs of the R variant. Herein, a deletion mutant of MAB_4780, encoding a dehydratase, distinct from the β-hydroxyacyl-ACP dehydratase HadABC complex, was constructed in the R morphotype. This mutant exhibited an alteration of the mycolic acid composition and a pronounced defect in cording. This correlated with an extremely attenuated phenotype not only in wild-type but also in immunocompromised zebrafish embryos lacking either macrophages or neutrophils. The abolition of granuloma formation in embryos infected with the dehydratase mutant was associated with a failure to replicate in macrophages, presumably due to limited inhibition of the phagolysosomal fusion. Overall, these results indicate that MAB_4780 is required for Mabs to successfully establish acute and lethal infections. Therefore, targeting MAB_4780 may represent an attractive antivirulence strategy to control Mabs infections, refractory to most standard chemotherapeutic interventions. The combination of a dehydratase assay with a high-resolution crystal structure of MAB_4780 opens the way to identify such specific inhibitors.
authors.affiliation: Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), CNRS Formation de Recherche en Evolution 3689, 34293 Montpellier, France;
authors.forename: Iman
authors.initials: I
authors.lastname: Halloum
authors.affiliation: INSERM U1058, Université de Montpellier, Montpellier 34095, France; Department of Bacteriology-Virology, Centre Hospitalo-Universitaire de Montpellier, Montpellier 34095, France;
authors.forename: Séverine
authors.initials: S
authors.lastname: Carrère-Kremer
authors.affiliation: Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), CNRS Formation de Recherche en Evolution 3689, 34293 Montpellier, France;
authors.forename: Mickael
authors.initials: M
authors.lastname: Blaise
authors.affiliation: Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), CNRS Formation de Recherche en Evolution 3689, 34293 Montpellier, France;
authors.forename: Albertus
authors.initials: A
authors.lastname: Viljoen
authors.affiliation: Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), CNRS Formation de Recherche en Evolution 3689, 34293 Montpellier, France;
authors.forename: Audrey
authors.initials: A
authors.lastname: Bernut
authors.affiliation: UMR1173, INSERM, Université de Versailles St. Quentin, 78180 Montigny le Bretonneux, France;
authors.forename: Vincent
authors.initials: V
authors.lastname: Le Moigne
authors.affiliation: Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461; Howard Hughes Medical Institute, Albert Einstein College of Medicine, Bronx, NY 10461;
authors.forename: Catherine
authors.initials: C
authors.lastname: Vilchèze
authors.affiliation: University of Lille, CNRS, UMR 8576, Unité de Glycobiologie Structurale et Fonctionnelle (UGSF), 59000 Lille, France;
authors.forename: Yann
authors.initials: Y
authors.lastname: Guérardel
authors.affiliation: Laboratoire de Dynamique des Interactions Membranaires Normales et Pathologiques, CNRS UMR5235, Université Montpellier, 34293 Montpellier, France;
authors.forename: Georges
authors.initials: G
authors.lastname: Lutfalla
authors.affiliation: UMR1173, INSERM, Université de Versailles St. Quentin, 78180 Montigny le Bretonneux, France;
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Herrmann
authors.affiliation: Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461; Howard Hughes Medical Institute, Albert Einstein College of Medicine, Bronx, NY 10461; laurent.kremer@cpbs.cnrs.fr jacobsw@hhmi.org.
authors.forename: William R
authors.initials: WR
authors.lastname: Jacobs
authors.affiliation: Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), CNRS Formation de Recherche en Evolution 3689, 34293 Montpellier, France; INSERM, CPBS, 34293 Montpellier, France laurent.kremer@cpbs.cnrs.fr jacobsw@hhmi.org.
authors.forename: Laurent
authors.initials: L
authors.lastname: Kremer
mesh_terms: D000818:Animals; D002460:Cell Line; D004625:Embryo, Nonmammalian / Q000201:enzymology / Q000276:immunology / Q000382:microbiology; D006836:Hydro-Lyases / Q000502:physiology*; D008264:Macrophages / Q000276:immunology / Q000382:microbiology; D051379:Mice; D009161:Mycobacterium / Q000472:pathogenicity*; D009164:Mycobacterium Infections / Q000201:enzymology* / Q000382:microbiology; D009504:Neutrophils / Q000276:immunology; D014774:Virulence; D015027:Zebrafish / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D029961:Zebrafish Proteins / Q000502:physiology*
chemical_list: D029961:Zebrafish Proteins; D006836:Hydro-Lyases
keywords: M. abscessus; cording; dehydratase; virulence; zebrafish