Presence of the Streptococcus suis suilysin gene and expression of MRP and EF correlates with high virulence in Streptococcus suis type 2 isolates

Vet Microbiol. 1999 Dec;70(3-4):201-11. doi: 10.1016/s0378-1135(99)00147-9.


Nineteen Streptococccus suis type 2 isolates that had been analyzed previously for hemolysin production, ribotype, and virulence in pigs were examined for presence of the gene coding for suilysin by PCR amplification, and southern blot and hybridization techniques. Based on southern blot and hybridization analysis, all isolates tested contained at least a portion of the suilysin gene. PCR amplification of the entire gene resulted in gene fragments from five of the seven highly virulent isolates and none of the moderately virulent or avirulent isolates. Additional PCR analysis showed that mutation or deletions at the 5' end of the suilysin gene in the less virulent isolates prevented amplification of the sly gene fragment from those isolates. The MRP+ (muramidase-released protein) EF+ (extracellular protein) phenotype was also expressed by the same five highly virulent/sly+ isolates.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacterial Proteins / biosynthesis*
  • Bacterial Proteins / genetics
  • Blotting, Western / veterinary
  • Electrophoresis, Polyacrylamide Gel / veterinary
  • Gene Expression Regulation, Bacterial*
  • Hemolysin Proteins / genetics*
  • Muramidase / metabolism*
  • Organic Chemicals
  • Polymerase Chain Reaction / veterinary
  • Streptococcal Infections / microbiology
  • Streptococcal Infections / veterinary
  • Streptococcus suis / genetics*
  • Streptococcus suis / pathogenicity*
  • Swine
  • Swine Diseases / microbiology


  • Bacterial Proteins
  • Epf protein, Streptococcus suis
  • Hemolysin Proteins
  • Organic Chemicals
  • suilysin
  • Muramidase