title: Differential Role of the T6SS in Acinetobacter baumannii Virulence.
abstract: Gram-negative bacteria, such as Acinetobacter baumannii, are an increasing burden in hospitals worldwide with an alarming spread of multi-drug resistant (MDR) strains. Herein, we compared a type strain (ATCC17978), a non-clinical isolate (DSM30011) and MDR strains of A. baumannii implicated in hospital outbreaks (Ab242, Ab244 and Ab825), revealing distinct patterns of type VI secretion system (T6SS) functionality. The T6SS genomic locus is present and was actively transcribed in all of the above strains. However, only the A. baumannii DSM30011 strain was capable of killing Escherichia coli in a T6SS-dependent manner, unlike the clinical isolates, which failed to display an active T6SS in vitro. In addition, DSM30011 was able to outcompete ATCC17978 as well as Pseudomonas aeruginosa and Klebsiella pneumoniae, bacterial pathogens relevant in mixed nosocomial infections. Finally, we found that the T6SS of DSM30011 is required for host colonization of the model organism Galleria mellonella suggesting that this system could play an important role in A. baumannii virulence in a strain-specific manner.
authors.affiliation: Bases Moléculaires et Structurales des Systèmes Infectieux, CNRS UMR 5086, Université Lyon 1, Institut de Biologie et Chimie des Protéines, Lyon, France.
authors.forename: Guillermo D
authors.initials: GD
authors.lastname: Repizo
authors.affiliation: Bases Moléculaires et Structurales des Systèmes Infectieux, CNRS UMR 5086, Université Lyon 1, Institut de Biologie et Chimie des Protéines, Lyon, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Gagné
authors.affiliation: Unité de Microbiologie, Adaptation et Pathogénie, CNRS UMR 5240, Université Lyon 1, Villeurbanne, France.
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Foucault-Grunenwald
authors.affiliation: Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal.
authors.forename: Vitor
authors.initials: V
authors.lastname: Borges
authors.affiliation: Unité de Microbiologie, Adaptation et Pathogénie, CNRS UMR 5240, Université Lyon 1, Villeurbanne, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Charpentier
authors.affiliation: Instituto de Biologia Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiologia, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, Rosario, Argentina.
authors.forename: Adriana S
authors.initials: AS
authors.lastname: Limansky
authors.affiliation: Bioinformatics Unit, Department of Infectious Diseases, National Institute of Health, Lisbon, Portugal.
authors.forename: João Paulo
authors.initials: JP
authors.lastname: Gomes
authors.affiliation: Instituto de Biologia Molecular y Celular de Rosario (IBR, CONICET), Departamento de Microbiologia, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, Rosario, Argentina.
authors.forename: Alejandro M
authors.initials: AM
authors.lastname: Viale
authors.affiliation: Bases Moléculaires et Structurales des Systèmes Infectieux, CNRS UMR 5086, Université Lyon 1, Institut de Biologie et Chimie des Protéines, Lyon, France.
authors.forename: Suzana P
authors.initials: SP
authors.lastname: Salcedo
mesh_terms: D000151:Acinetobacter Infections / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000472:pathogenicity* / Q000502:physiology*; D000818:Animals; D018441:Biofilms; D018533:Biomass; D015964:Gene Expression Regulation, Bacterial; D023061:Gene Order; D005816:Genetic Complementation Test; D056426:Genetic Loci; D006801:Humans; D056265:Microbial Interactions; D008969:Molecular Sequence Data; D009036:Moths / Q000382:microbiology; D009154:Mutation; D010641:Phenotype; D000069376:Type VI Secretion Systems / Q000235:genetics*; D014774:Virulence / Q000235:genetics
chemical_list: D000069376:Type VI Secretion Systems