Molecular markers for discriminating Streptococcus pyogenes and S. dysgalactiae subspecies equisimilis

Eur J Clin Microbiol Infect Dis. 2010 May;29(5):585-9. doi: 10.1007/s10096-010-0899-x. Epub 2010 Mar 12.


Given the increasing aetiological importance of Streptococcus dysgalactiae subspecies equisimilis in diseases which are primarily attributed to S. pyogenes, molecular markers are essential to distinguish these species and delineate their epidemiology more precisely. Many clinical microbiology laboratories rely on agglutination reactivity and biochemical tests to distinguish them. These methods have limitations which are particularly exacerbated when isolates with mixed properties are encountered. In order to provide additional distinguishing parameters that could be used to unequivocally discriminate these two common pathogens, we assess here three molecular targets: the speB gene, intergenic region upstream of the scpG gene (IRSG) and virPCR. Of these, the former two respectively gave positive and negative results for S. pyogenes, and negative and positive results for S. dysgalactiae subsp. equisimilis. Thus, a concerted use of these nucleic acid-based methods is particularly helpful in epidemiological surveillance to accurately assess the relative contribution of these species to streptococcal infections and diseases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics*
  • Cysteine Endopeptidases / genetics
  • Diagnosis, Differential
  • Genetic Markers
  • Humans
  • Polymerase Chain Reaction / methods*
  • Species Specificity
  • Streptococcal Infections / microbiology
  • Streptococcus / classification*
  • Streptococcus / genetics
  • Streptococcus pyogenes / classification
  • Streptococcus pyogenes / genetics


  • Bacterial Proteins
  • Genetic Markers
  • Cysteine Endopeptidases
  • streptopain