title: Mycobacterium llatzerense, a waterborne Mycobacterium, that resists phagocytosis by Acanthamoeba castellanii.
abstract: Nontuberculous mycobacteria (NTM) are environmental bacteria increasingly associated to public health problems. In water systems, free-living amoebae (FLA) feed on bacteria by phagocytosis, but several bacteria, including many NTM, are resistant to this predation. Thus, FLA can be seen as a training ground for pathogenic bacteria. Mycobacterium llatzerense was previously described as frequently associated with FLA in a drinking water network. The present study aimed to characterize the interactions between M. llatzerense and FLA. M. llatzerense was internalised by phagocytosis and featured lipid inclusions, suggesting a subversion of host resources. Moreover, M. llatzerense survived and even multiplied in presence of A. castellanii. Using a genomic-based comparative approach, twelve genes involved in phagocytosis interference, described in M. tuberculosis, were identified in the M. llatzerense genome sequenced in this study. Transcriptomic analyses showed that ten genes were significantly upregulated during the first hours of the infection, which could partly explain M. llatzerense resistance. Additionally, M. llatzerense was shown to actively inhibit phagosome acidification. In conclusion, M. llatzerense presents a high degree of resistance to phagocytosis, likely explaining its frequent occurrence within FLA in drinking water networks. It underscores that NTM should be carefully monitored in water networks to prevent human health concerns.
authors.affiliation: Laboratoire Ecologie et Biologie des Interactions, Equipes « Microbiologie de l'Eau » et « Ecologie, Evolution, Symbiose», Université de Poitiers, UMR CNRS 7267, F-86073 Poitiers, France.|Eau de Paris, Direction de la Recherche et du Développement pour la Qualité de l'Eau, R&D Biologie, 33, Avenue Jean Jaurès, F-94200 Ivry sur Seine, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Delafont
authors.affiliation: Laboratoire Ecologie et Biologie des Interactions, Equipes « Microbiologie de l'Eau » et « Ecologie, Evolution, Symbiose», Université de Poitiers, UMR CNRS 7267, F-86073 Poitiers, France.
authors.forename: Ascel
authors.initials: A
authors.lastname: Samba-Louaka
authors.affiliation: APHP Groupe Hospitalier Saint-Louis Lariboisière-Fernand-Widal, Centre National de Référence des Mycobactéries et de la Résistance aux Antituberculeux; UMR1137 IAME, Inserm, Université Paris Diderot, F-75010 Paris, France.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Cambau
authors.affiliation: Laboratoire Ecologie et Biologie des Interactions, Equipes « Microbiologie de l'Eau » et « Ecologie, Evolution, Symbiose», Université de Poitiers, UMR CNRS 7267, F-86073 Poitiers, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Bouchon
authors.affiliation: Eau de Paris, Direction de la Recherche et du Développement pour la Qualité de l'Eau, R&D Biologie, 33, Avenue Jean Jaurès, F-94200 Ivry sur Seine, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Moulin
authors.affiliation: Laboratoire Ecologie et Biologie des Interactions, Equipes « Microbiologie de l'Eau » et « Ecologie, Evolution, Symbiose», Université de Poitiers, UMR CNRS 7267, F-86073 Poitiers, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Héchard
mesh_terms: D048248:Acanthamoeba castellanii / Q000382:microbiology* / Q000502:physiology* / Q000648:ultrastructure; D018920:Coculture Techniques; D054884:Host-Pathogen Interactions; D006801:Humans; D009161:Mycobacterium / Q000276:immunology* / Q000648:ultrastructure; D010587:Phagocytosis / Q000276:immunology*; D010588:Phagosomes