1. iFlavobacterium columnare/iferric iron uptake systems are required for virulence
- Author
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Rachel A. Conrad, Jason P. Evenhuis, Ryan S. Lipscomb, David Pérez-Pascual, Rebecca J. Stevick, Clayton Birkett, Jean-Marc Ghigo, Mark J. McBride, University of Wisconsin - Milwaukee, National Center for Cool and Cold Water Aquaculture, ARS-USDA, USDA-ARS : Agricultural Research Service, Génétique des Biofilms - Genetics of Biofilms, Université Paris Cité (UPCité)-Microbiologie Intégrative et Moléculaire (UMR6047), Institut Pasteur [Paris] (IP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut Pasteur [Paris] (IP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), This work was funded in part by United States Department of Agriculture-ARS CRIS projects 8082-32000-006-00-D and 5090-31320-004-00D and by cooperative agreements 5090-31320-004-03S and 58-5090-1-022, and by grant NA18OAR4170097, project R/SFA-20 from the University of Wisconsin Sea Grant Institute under grants from the National Sea Grant College Program, National Oceanic and Atmospheric Administration, U.S. Department of Commerce, and the State of Wisconsin. J-MG, D-PP and RS were funded by the French government’s Investissement d’Avenir Program, Laboratoire d’Excellence 'Integrative Biology of Emerging Infectious Diseases' (grant ANR-10-LABX-62-IBEID) and by an Institut Carnot Pasteur MS fellowship., and ANR-10-LABX-0062,IBEID,Integrative Biology of Emerging Infectious Diseases(2010)
- Subjects
Microbiology (medical) ,Virulence ,Iron ,Immunology ,outer membrane siderophore receptor ,Siderophores ,Microbiology ,[SDV.MP.BAC]Life Sciences [q-bio]/Microbiology and Parasitology/Bacteriology ,Flavobacterium ,Flavobacterium columnare ,Fish Diseases ,Infectious Diseases ,Flavobacteriaceae Infections ,Oncorhynchus mykiss ,Animals ,ATP-Binding Cassette Transporters ,heme binding protein ,Zebrafish ,iron acquisition - Abstract
Flavobacterium columnare, which causes columnaris disease, is one of the costliest pathogens in the freshwater fish-farming industry. The virulence mechanisms of F. columnare are not well understood and current methods to control columnaris outbreaks are inadequate. Iron is an essential nutrient needed for metabolic processes and is often required for bacterial virulence. F. columnare produces siderophores that bind ferric iron for transport into the cell. The genes needed for siderophore production have been identified, but other components involved in F. columnare iron uptake have not been studied in detail. We identified the genes encoding the predicted secreted heme-binding protein HmuY, the outer membrane iron receptors FhuA, FhuE, and FecA, and components of an ATP binding cassette (ABC) transporter predicted to transport ferric iron across the cytoplasmic membrane. Deletion mutants were constructed and examined for growth defects under iron-limited conditions and for virulence against zebrafish and rainbow trout. Mutants with deletions in genes encoding outer membrane receptors, and ABC transporter components exhibited growth defects under iron-limited conditions. Mutants lacking multiple outer membrane receptors, the ABC transporter, or HmuY retained virulence against zebrafish and rainbow trout mirroring that exhibited by the wild type. Some mutants predicted to be deficient in multiple steps of iron uptake exhibited decreased virulence. Survivors of exposure to such mutants were partially protected against later infection by wild-type F. columnare.
- Published
- 2022