Chondroitin AC lyase activity is related to virulence of fish pathogenic Flavobacterium columnare.
The virulence of eight Flavobacterium columnare strains was studied to find correlations between several virulence-related factors and virulence. Virulence was tested in vivo using rainbow trout, Oncorhynchus mykiss (Walbaum). Suggested virulence-related factors such as production of the degradative enzyme chondroitin lyase, plasmid occurrence and adhesion capability were studied in vitro. Infection with the four most virulent strains resulted in 95-100% mortality within 114 h. Chondroitin lyase activity was found to be significantly related to the virulence of the strains at 25 degrees C and it was also shown to be temperature-dependent, being higher at 25 degrees C than at 20 degrees C. Virulence was not plasmid associated. The adhesion capability of the strains in vitro varied substantially when tested on crude mucus-coated slides and no statistical relationship between adhesion and virulence was found using this method.
Suomalainen
L-R
LR
Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland. lottari@bytl.jyu.fi
Tiirola
M
M
Valtonen
E T
ET
D000818:Animals; D001422:Bacterial Adhesion; D002808:Chondroitin Lyases / Q000378:metabolism*; D005387:Finland; D005393:Fish Diseases / Q000382:microbiology*; D045826:Flavobacteriaceae Infections / Q000382:microbiology / Q000401:mortality / Q000662:veterinary*; D005417:Flavobacterium / Q000201:enzymology / Q000472:pathogenicity*; D017686:Oncorhynchus mykiss; D010957:Plasmids; D014774:Virulence
D002808:Chondroitin Lyases