Dr. Roselynn M. W. Stevenson

Dr. Roselynn M. W. Roselynn M. W.
Professor Emerita
Department of Molecular and Cellular Biology
Phone number: 
53577 / 54385 / 52517
SSC 3255
SSC 3206/3207


  • B.Sc. Manitoba
  • Ph.D. Manitoba


Understanding fish diseases that occur in freshwater systems is significant for protection of aquatic resources, developing and sustaining aquaculture, and making informed biosecurity decisions.   Our laboratory carries out surveillance testing for bacterial and viral pathogens of fish, and research on diagnostic methods and pathogen diversity.   We have studied several major pathogens of salmonid fish, including Yersinia ruckeri enteric redmouth disease), Renibacterium salmoninarum (bacterial kidney disease), Aeromonas salmonicida (furunculosis) and infectious pancreatic necrosis virus (IPNV), in order to understand the virulence strategies used by these pathogens, and the cellular and humoral immune responses of fish to them.   Current work focuses on Yersinia ruckeri and the bacterial gill disease bacterium, Flavobacterium branchiophilum, and molecular tools for detection and differentiation of fish pathogens.

Selected Publications

  • Dahiya, I. and RMW Stevenson. 2010.   Yersinia ruckeri genes that attenuate survival in rainbow trout (Oncorhynchus mykiss) are identified using signature-tagged mutants. Veterinary Microbiology 144: 399-407.
  • Dahiya, I. and RMW Stevenson. 2010.   The UvrY response regulator of the BarA-UvrY two-component system contributes to Yersinia ruckeri infection of rainbow trout (Oncorhynchus mykiss). Arch. Microbiol. 192: 541-7.
  • Dahiya, I. and RMW Stevenson. 2010.   The ZnuABC operon is important for Yersinia ruckeri infection of rainbow trout, Oncorhynchus mykiss (Walbaum). J. Fish Diseases 33: 331-340.
  • Good, CM, MA Thorburn, CS Ribble and RMW Stevenson. 2010.   A prospective matched nested case-control study of bacterial gill disease outbreaks in Ontario, Canada government salmonid hatcheries.   Preventive Veterinary Medicine 95: 152-7.
  • Stevenson, R.M.W. 1997.   Immunization with bacterial antigens: Yersiniosis (Review) in: R. Gudding, A. Lillehaug and P.J. Midtlyng (eds), Fish Vaccinology. Developments in Biological Standardization vol. 90: 117-124. Karger, Basel.
  • Bootland, L.M., P. Dobos and R.M.W. Stevenson. 1995.  Immunization of adult brook trout, Salvelinus fontinalis (Mitchill), fails to prevent the infectious pancreatic necrosis virus (IPNV) carrier state. Journal of Fish Diseases 18:449-458.
  • Daly, J.G. and R.M.W. Stevenson. 1993.   Nutrient requirements of Renibacterium salmoninarum on agar and in broth media. Appl. Environ. Microbiol. 59: 2178-2183.
  • Leung, K.Y. and R.M.W. Stevenson.  1988.  Tn5-induced protease-deficient strains of Aeromonas hydrophila with reduced virulence for fish. Infection and Immunity. 56: 2639-2644.


  • BIOL*3050 Mycology I
  • MICR*3120 Systematic Bacteriology