PRODUCTION OF VIRULENCE-RELATED PROTEINS BY CANADIAN STRAINS OF STREPTOCOCCUS-SUIS CAPSULAR TYPE-2

The production of muramidase-released protein (MRP), extracellular pro tein factor (EF) and hemolysin (suilysin) by 101 Canadian field strain s of Streptococcus suis capsular type 2 is described, Most strains (72 %) isolated from diseased pigs were MRP-EF- and only 1 strain was MRPEF+. This strain was also the only 1 to produce the hemolysin. Thirtee n strains (15%) were MRP+ EF- and only 3 strains were MRP EF-. All th e strains isolated from clinically healthy pigs as well as a bovine an d 2 human isolates had a MRP-EF- phenotype. In addition, 7 strains (8% ) had a MRPs phenotype, which had so far been described for S. suis ca psular type 1, In conclusion, most Canadian field isolates of S. suis capsular type 2 tested in this study do not produce the virulence-rela ted proteins described so far for this bacterial pathogen.