title: Analysis of a ferric uptake regulator (Fur) knockout mutant in Aeromonas salmonicida subsp. salmonicida.
abstract: Aeromonas salmonicida subsp. salmonicida is the etiological agent of furunculosis; a serious infectious disease in aquaculture raised salmonids. Iron acquisition has been shown to be critical for the survival of pathogenic bacteria during the course of infection. Previous work has demonstrated that A. salmonicida expresses iron-repressible IROMP proteins, suggesting the presence of iron acquisition systems that are under the control of a ferric uptake regulator (Fur). In this study, the A. salmonicida fur has been sequenced and a fur deletion strain generated. The A. salmonicida fur gene has an open reading frame of 428 bp, coding for a protein of 143 amino acids, and with high homology to previously described Fur proteins. The Fur protein product had a 94% sequence identity and 96% sequence similarity to the Aeromonas hydrophila Fur protein product. Transcription of the A. salmonicida fur gene was not regulated by the iron status of the bacterium and is not autoregulated, as in Escherichia coli. Proteomic analysis of the A. salmonicida fur mutant, fails to repress iron-regulated outer membrane proteins in the presence of iron. The A. salmonicida fur::KO mutant shows significantly reduced pathogenicity compared to the wild-type parental strain. In addition, the A. salmonicida fur mutant provides an important tool for further investigation of the iron acquisition mechanisms utilized by A. salmonicida.
authors.affiliation: National Research Council Canada - Institute for Marine Biosciences, 1411 Oxford Street, Halifax, NS, Canada B3H 3Z1. Electronic address: roger.ebanks@gmail.com.
authors.forename: Roger O
authors.initials: RO
authors.lastname: Ebanks
authors.affiliation: National Research Council Canada - Institute for Marine Biosciences, 1411 Oxford Street, Halifax, NS, Canada B3H 3Z1; Fisheries and Ocean Canada, 343 University Avenue, Moncton, NB, Canada B3H 3Z1.
authors.forename: Michel
authors.initials: M
authors.lastname: Goguen
authors.affiliation: National Research Council Canada - Institute for Marine Biosciences, 1411 Oxford Street, Halifax, NS, Canada B3H 3Z1.
authors.forename: Leah
authors.initials: L
authors.lastname: Knickle
authors.affiliation: National Research Council Canada - Institute for Marine Biosciences, 1411 Oxford Street, Halifax, NS, Canada B3H 3Z1.
authors.forename: Andrew
authors.initials: A
authors.lastname: Dacanay
authors.affiliation: National Research Council Canada - Institute for Marine Biosciences, 1411 Oxford Street, Halifax, NS, Canada B3H 3Z1.
authors.forename: Andrew
authors.initials: A
authors.lastname: Leslie
authors.affiliation: National Research Council Canada - Institute for Marine Biosciences, 1411 Oxford Street, Halifax, NS, Canada B3H 3Z1.
authors.forename: Neil W
authors.initials: NW
authors.lastname: Ross
authors.affiliation: National Research Council Canada - Institute for Marine Biosciences, 1411 Oxford Street, Halifax, NS, Canada B3H 3Z1.
authors.forename: Devanand M
authors.initials: DM
authors.lastname: Pinto
mesh_terms: D048409:Aeromonas salmonicida / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005290:Ferric Compounds / Q000378:metabolism*; D005393:Fish Diseases / Q000382:microbiology*; D055786:Gene Knockout Techniques; D016905:Gram-Negative Bacterial Infections / Q000378:metabolism / Q000382:microbiology / Q000662:veterinary*; D040901:Proteomics; D014337:Trout
chemical_list: D001426:Bacterial Proteins; D005290:Ferric Compounds