title: Characterization and pathogenic role of outer membrane vesicles produced by the fish pathogen Piscirickettsia salmonis under in vitro conditions.
abstract: Piscirickettsia salmonis is one of the major fish pathogens affecting Chilean aquaculture. This Gram-negative bacterium is highly infectious and is the etiological agent of Piscirickettsiosis. Little is currently known about how the virulence factors expressed by P. salmonis are delivered to host cells. However, it is known that several Gram-negative microorganisms constitutively release outer membrane vesicles (OMVs), which have been implicated in the delivery of virulence factors to host cells. In this study, OMVs production by P. salmonis was observed during infection in CHSE-214 cells and during normal growth in liquid media. The OMVs were spherical vesicles ranging in size between 25 and 145 nm. SDS-PAGE analysis demonstrated that the protein profile of the OMVs was similar to the outer membrane protein profile of P. salmonis. Importantly, the bacterial chaperonin Hsp60 was found in the OMVs of P. salmonis by Western-blot and LC-MS/MS analyses. Finally, in vitro infection assays showed that purified OMVs generated a cytopathic effect on CHSE-214 cells, suggesting a role in pathogenesis. Therefore, OMVs might be an important vehicle for delivering effector molecules to host cells during P. salmonis infection.
authors: Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile; Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile.
authors: Cristian
authors: C
authors: Oliver
authors: Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada.
authors: Karla
authors: K
authors: Valenzuela
authors: Austral-OMICS, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.
authors: Mauricio
authors: M
authors: Hernández
authors: Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.
authors: Rodrigo
authors: R
authors: Sandoval
authors: Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.
authors: Ronie E
authors: RE
authors: Haro
authors: Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile; Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile.
authors: Ruben
authors: R
authors: Avendaño-Herrera
authors: Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Austral-OMICS, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.
authors: Juan G
authors: JG
authors: Cárcamo
authors: Department of Biochemistry and Molecular Biology, School of Medicine, University of Kansas Medical Center, Kansas City, KS, United States.
authors: Maite T
authors: MT
authors: Villar
authors: Department of Biochemistry and Molecular Biology, School of Medicine, University of Kansas Medical Center, Kansas City, KS, United States.
authors: Antonio
authors: A
authors: Artigues
authors: Department of Microbiology and Immunology, Dalhousie University, Halifax, Nova Scotia, Canada.
authors: Rafael
authors: R
authors: Garduño
authors: Instituto de Bioquímica y Microbiología, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Austral-OMICS, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile; Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile. Electronic address: ayanez@uach.cl.
authors: Alejandro J
authors: AJ
authors: Yáñez
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D002460:Cell Line; D002470:Cell Survival; D018834:Chaperonin 60 / Q000737:chemistry; D066298:In Vitro Techniques; D046529:Microscopy, Electron, Transmission; D053522:Piscirickettsia / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity; D020543:Proteome / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D018834:Chaperonin 60; D020543:Proteome; D037521:Virulence Factors
keywords: Hsp60; Outer membrane vesicles (OMV); Piscirickettsia salmonis; Piscirickettsiosis; Virulence