title: Iron acquisition and siderophore production in the fish pathogen Renibacterium salmoninarum.
abstract: Renibacterium salmoninarum is the causative agent of bacterial kidney disease, which significantly affects salmonid farming worldwide. Despite this impact, there is scarce data on its iron uptake ability, a factor of pathogenesis. This study investigated the iron acquisition mechanisms of R. salmoninarum and its capacity to uptake iron from different sources. Thirty-two Chilean isolates and the DSM20767Ttype strain grew in the presence of 2,2'-Dipyridyl at varying concentrations (250-330 μm), and all isolates positively reacted on chrome azurol S agar. Subsequently, inocula of four Chilean isolates and the type strain were prepared with or without 200 μm of 2,2'-Dipyridyl for uptake assays. Assay results revealed differences between the isolates in terms of iron acquisition. While a prior iron-limited environment was, for most isolates, not required to activate the uptake of iron (II) sulphate, ammonium iron (III) citrate or iron (III) chloride at higher concentrations (100 μm), it did facilitate growth at lower iron concentrations (10 μm and 1 μm). An exception was the H-2 isolate, which only grew with 100 μm of iron sulphide. In turn, 100 μm of haemin was toxic when isolates were grown in normal KDM-2. In silico R. salmoninarumATCC 33209Tgenome analysis detected various genes coding iron uptake-related proteins. This is the first study indicating two iron acquisition systems in R. salmoninarum: one involving siderophores and another involving haem group utilization. These data represent a first step towards fully elucidating this virulence factor in the pathogenic R. salmoninarum.
authors.affiliation: Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Viña del Mar, Chile.|Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile.
authors.forename: J
authors.initials: J
authors.lastname: Bethke
authors.affiliation: Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Viña del Mar, Chile.|Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile.
authors.forename: M
authors.initials: M
authors.lastname: Poblete-Morales
authors.affiliation: Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Viña del Mar, Chile.|Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile.
authors.forename: R
authors.initials: R
authors.lastname: Irgang
authors.affiliation: Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile.|Facultad de Ciencias, Instituto de Bioquímica y Microbiología, Universidad Austral de Chile, Valdivia, Chile.
authors.forename: A
authors.initials: A
authors.lastname: Yáñez
authors.affiliation: Laboratorio de Patología de Organismos Acuáticos y Biotecnología Acuícola, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Viña del Mar, Chile. ravendano@unab.cl.|Interdisciplinary Center for Aquaculture Research (INCAR), Concepción, Chile. ravendano@unab.cl.
authors.forename: R
authors.initials: R
authors.lastname: Avendaño-Herrera
mesh_terms: D000193:Actinomycetales Infections / Q000378:metabolism / Q000382:microbiology / Q000662:veterinary*; D000818:Animals; D002677:Chile; D005393:Fish Diseases / Q000378:metabolism / Q000382:microbiology*; D007501:Iron / Q000378:metabolism*; D007668:Kidney / Q000382:microbiology; D007674:Kidney Diseases / Q000378:metabolism / Q000382:microbiology / Q000662:veterinary; D008835:Micrococcaceae / Q000378:metabolism*; D020317:Salmo salar; D017262:Siderophores / Q000378:metabolism*
chemical_list: D017262:Siderophores; D007501:Iron
keywords: 
  Renibacterium salmoninarum
  ; Gram-positive; bacterial kidney disease; chrome azurol S; iron uptake; virulence