title: Differential proteomic analysis of Aeromonas salmonicida outer membrane proteins in response to low iron and in vivo growth conditions.
abstract: Aeromonas salmonicida subsp. salmonicida is the etiological agent of furunculosis, a serious infectious disease of salmonids. Bacterial phenotypes are known to change in vivo compared to the in vitro state. Proteomic analysis of in vivo phenotypes is usually not possible due to insufficient biomass. Using an in vivo growth chamber model, the pathogenic fish bacterium A. salmonicida was cultured in pure culture in vivo in its host, the Atlantic salmon, to obtain sufficient biomass to allow proteomic analysis. Growth of A. salmonicida under in vitro iron-restricted conditions resulted in the expression of outer membrane proteins of 73, 76 and 85 kDa, which were not present when grown under in vitro iron-replete conditions. Mass spectrometry analysis identified the 73 kDa protein as a colicin receptor, the 76 kDa protein as an outer membrane heme receptor, and the 85 kDa protein as a ferric siderophore receptor. When cultured in vivo, A. salmonicida up-regulated the identical 73, 76 and 85 kDa proteins. The results of this study also suggest, at least with respect to the outer membrane proteins, that the in vitro iron-restricted growth model largely reproduces the results obtained from growth of A. salmonicida within the peritoneal cavity of salmon.
authors.affiliation: National Research Council Canada, Institute for Marine Biosciences, Halifax, NS, Canada. roger.ebanks@nrc-cnrc.gc.ca
authors.forename: Roger O
authors.initials: RO
authors.lastname: Ebanks
authors.forename: Andrew
authors.initials: A
authors.lastname: Dacanay
authors.forename: Michel
authors.initials: M
authors.lastname: Goguen
authors.forename: Devanand M
authors.initials: DM
authors.lastname: Pinto
authors.forename: Neil W
authors.initials: NW
authors.lastname: Ross
mesh_terms: D000333:Aeromonas / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism; D005393:Fish Diseases / Q000378:metabolism / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D016905:Gram-Negative Bacterial Infections / Q000378:metabolism*; D007501:Iron / Q000378:metabolism*; D008969:Molecular Sequence Data; D011956:Receptors, Cell Surface / Q000378:metabolism; D012487:Salmonidae / Q000382:microbiology
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D011956:Receptors, Cell Surface; C028593:colicin receptor, E coli; C028027:heme receptor; C035902:siderophore receptors; D007501:Iron