title: Mycobacterium abscessus phospholipase C expression is induced during coculture within amoebae and enhances M. abscessus virulence in mice.
abstract: Mycobacterium abscessus is a pathogenic, rapidly growing mycobacterium involved in pulmonary and cutaneo-mucous infections worldwide, to which cystic fibrosis patients are exquisitely susceptible. The analysis of the genome sequence of M. abscessus showed that this bacterium is endowed with the metabolic pathways typically found in environmental microorganisms that come into contact with soil, plants, and aquatic environments, where free-living amoebae are frequently present. M. abscessus also contains several genes that are characteristically found only in pathogenic bacteria. One of them is MAB_0555, encoding a putative phospholipase C (PLC) that is absent from most other rapidly growing mycobacteria, including Mycobacterium chelonae and Mycobacterium smegmatis. Here, we report that purified recombinant M. abscessus PLC is highly cytotoxic to mouse macrophages, presumably due to hydrolysis of membrane phospholipids. We further showed by constructing and using an M. abscessus PLC knockout mutant that loss of PLC activity is deleterious to M. abscessus intracellular survival in amoebae. The importance of PLC is further supported by the fact that M. abscessus PLC was found to be expressed only in amoebae. Aerosol challenge of mice with M. abscessus strains that were precultured in amoebae enhanced M. abscessus lung infectivity relative to M. abscessus grown in broth culture. Our study underlines the importance of PLC for the virulence of M. abscessus. Despite the difficulties of isolating M. abscessus from environmental sources, our findings suggest that M. abscessus has evolved in close contact with environmental protozoa, which supports the argument that amoebae may contribute to the virulence of opportunistic mycobacteria.
authors.affiliation: CNRS-Aix-Marseille Université-Enzymologie Interfaciale et Physiologie de la Lipolyse UMR7282, Marseille, France.
authors.forename: Jean Claude
authors.initials: JC
authors.lastname: Bakala N'Goma
authors.affiliation: EA 3647, EPIM, UFR des Sciences de la Santé-Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines, Montigny le Bretonneux, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Le Moigne
authors.affiliation: EA 3647, EPIM, UFR des Sciences de la Santé-Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines, Montigny le Bretonneux, France Service de Microbiologie, Hôpital Raymond Poincaré, Assistance Publique Hôpitaux de Paris, Garches, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Soismier
authors.affiliation: EA 3647, EPIM, UFR des Sciences de la Santé-Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines, Montigny le Bretonneux, France.
authors.forename: Laura
authors.initials: L
authors.lastname: Laencina
authors.affiliation: Institut Pasteur, Unit for Integrated Mycobacterial Pathogenomics, Paris, France Université Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, Paris, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Le Chevalier
authors.affiliation: EA 3647, EPIM, UFR des Sciences de la Santé-Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines, Montigny le Bretonneux, France Service de Microbiologie, Hôpital Raymond Poincaré, Assistance Publique Hôpitaux de Paris, Garches, France.
authors.forename: Anne-Laure
authors.initials: AL
authors.lastname: Roux
authors.affiliation: CNRS-Aix-Marseille Université-Enzymologie Interfaciale et Physiologie de la Lipolyse UMR7282, Marseille, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Poncin
authors.affiliation: CNRS-Aix-Marseille Université-Enzymologie Interfaciale et Physiologie de la Lipolyse UMR7282, Marseille, France.
authors.forename: Carole
authors.initials: C
authors.lastname: Serveau-Avesque
authors.affiliation: EA 3647, EPIM, UFR des Sciences de la Santé-Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines, Montigny le Bretonneux, France Service de Microbiologie, Hôpital Raymond Poincaré, Assistance Publique Hôpitaux de Paris, Garches, France.
authors.forename: Martin
authors.initials: M
authors.lastname: Rottman
authors.affiliation: EA 3647, EPIM, UFR des Sciences de la Santé-Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines, Montigny le Bretonneux, France Service de Microbiologie, Hôpital Raymond Poincaré, Assistance Publique Hôpitaux de Paris, Garches, France.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Gaillard
authors.affiliation: Centre National de la Recherche Scientifique, Institut de Pharmacologie et de Biologie Structurale (Unité Mixte de Recherche 5089), Département Tuberculose Biologie des Infections, Toulouse, France Université de Toulouse (Université Paul Sabatier, Toulouse III), Institut de Pharmacologie et de Biologie Structurale, Toulouse, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Etienne
authors.affiliation: Institut Pasteur, Unit for Integrated Mycobacterial Pathogenomics, Paris, France.
authors.forename: Roland
authors.initials: R
authors.lastname: Brosch
authors.affiliation: EA 3647, EPIM, UFR des Sciences de la Santé-Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines, Montigny le Bretonneux, France Service de Microbiologie, Hôpital Raymond Poincaré, Assistance Publique Hôpitaux de Paris, Garches, France jean-louis.herrmann@rpc.aphp.fr fabienne.girard-misguich@uvsq.fr.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Herrmann
authors.affiliation: CNRS-Aix-Marseille Université-Enzymologie Interfaciale et Physiologie de la Lipolyse UMR7282, Marseille, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Canaan
authors.affiliation: EA 3647, EPIM, UFR des Sciences de la Santé-Simone Veil, Université de Versailles Saint-Quentin-en-Yvelines, Montigny le Bretonneux, France jean-louis.herrmann@rpc.aphp.fr fabienne.girard-misguich@uvsq.fr.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Girard-Misguich
mesh_terms: D000656:Amoeba / Q000382:microbiology / Q000502:physiology*; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D018920:Coculture Techniques; D003550:Cystic Fibrosis / Q000382:microbiology; D055786:Gene Knockout Techniques; D016680:Genome, Bacterial / Q000235:genetics; D008264:Macrophages / Q000276:immunology; D008563:Membrane Lipids / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009161:Mycobacterium / Q000201:enzymology / Q000235:genetics / Q000472:pathogenicity*; D009165:Mycobacterium Infections, Nontuberculous / Q000276:immunology* / Q000382:microbiology; D011994:Recombinant Proteins; D017422:Sequence Analysis, DNA; D010738:Type C Phospholipases / Q000235:genetics / Q000502:physiology*; D037521:Virulence Factors / Q000235:genetics
chemical_list: D008563:Membrane Lipids; D011994:Recombinant Proteins; D037521:Virulence Factors; D010738:Type C Phospholipases