title: Comparative Analysis of Membrane Vesicles from Three Piscirickettsia salmonis Isolates Reveals Differences in Vesicle Characteristics.
abstract: Membrane vesicles (MVs) are spherical particles naturally released from the membrane of Gram-negative bacteria. Bacterial MV production is associated with a range of phenotypes including biofilm formation, horizontal gene transfer, toxin delivery, modulation of host immune responses and virulence. This study reports comparative profiling of MVs from bacterial strains isolated from three widely disperse geographical areas. Mass spectrometry identified 119, 159 and 142 proteins in MVs from three different strains of Piscirickettsia salmonis isolated from salmonids in Chile (LF-89), Norway (NVI 5692) and Canada (NVI 5892), respectively. MV comparison revealed several strain-specific differences related to higher virulence capability for LF-89 MVs, both in vivo and in vitro, and stronger similarities between the NVI 5692 and NVI 5892 MV proteome. The MVs were similar in size and appearance as analyzed by electron microscopy and dynamic light scattering. The MVs from all three strains were internalized by both commercial and primary immune cell cultures, which suggest a potential role of the MVs in the bacterium's utilization of leukocytes. When MVs were injected into an adult zebrafish infection model, an upregulation of several pro-inflammatory genes were observed in spleen and kidney, indicating a modulating effect on the immune system. The present study is the first comparative analysis of P. salmonis derived MVs, highlighting strain-specific vesicle characteristics. The results further illustrate that the MV proteome from one bacterial strain is not representative of all bacterial strains within one species.
authors.affiliation: Center of Integrative Microbiology and Evolution, University of Oslo, Oslo, Norway.|Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway.
authors.forename: Julia I
authors.initials: JI
authors.lastname: Tandberg
authors.affiliation: Center of Integrative Microbiology and Evolution, University of Oslo, Oslo, Norway.|Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway.
authors.forename: Leidy X
authors.initials: LX
authors.lastname: Lagos
authors.affiliation: Center of Integrative Microbiology and Evolution, University of Oslo, Oslo, Norway.|Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway.
authors.forename: Petter
authors.initials: P
authors.lastname: Langlete
authors.affiliation: Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway.|Department of Biosciences, University of Oslo, Oslo, Norway.
authors.forename: Eva
authors.initials: E
authors.lastname: Berger
authors.affiliation: Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway.
authors.forename: Anne-Lise
authors.initials: AL
authors.lastname: Rishovd
authors.affiliation: Department of Biosciences, University of Oslo, Oslo, Norway.
authors.forename: Norbert
authors.initials: N
authors.lastname: Roos
authors.affiliation: Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, New South Wales, Australia.
authors.forename: Deepa
authors.initials: D
authors.lastname: Varkey
authors.affiliation: Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, New South Wales, Australia.
authors.forename: Ian T
authors.initials: IT
authors.lastname: Paulsen
authors.affiliation: Center of Integrative Microbiology and Evolution, University of Oslo, Oslo, Norway.|Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway.
authors.forename: Hanne C
authors.initials: HC
authors.lastname: Winther-Larsen
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D002170:Canada; D002677:Chile; D022162:Cytoplasmic Vesicles / Q000276:immunology / Q000378:metabolism*; D013058:Mass Spectrometry / Q000379:methods; D009664:Norway; D053522:Piscirickettsia / Q000302:isolation & purification* / Q000378:metabolism; D044225:Piscirickettsiaceae Infections / Q000276:immunology*; D040901:Proteomics / Q000379:methods*; D012487:Salmonidae / Q000382:microbiology; D037521:Virulence Factors / Q000378:metabolism; D015027:Zebrafish / Q000276:immunology / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors