Potential pathogenic properties of members of the "Streptococcus milleri" group in relation to the production of endocarditis and abscesses

J Med Microbiol. 1995 Dec;43(6):405-10. doi: 10.1099/00222615-43-6-405.


The "Streptococcus milleri" (SMG) group have been shown to possess factors in vitro that may be involved in pathogenesis. All SMG strains are able to bind fibronectin via a cell-surface protein; the binding ranged from 12 to 198 mol/cell. Strains also bound to platelet-fibrin or fibrin clots and fibrinogen, giving maximum adhesion values of 16.5%, 21.8% and 151 mol/cell respectively. Members of the species S. constellatus produced thrombin-like activity. Lancefield group C SMG aggregated rat platelets, a bacterial cell-surface protein acting as mediator in the reaction. Most of the in-vitro factors did not correlate with each other, an indication that SMG strains possess a wide variety of pathogenic properties that may be involved in the production of abscesses or endocarditis. However, there was a correlation between the binding of large amounts of fibrinogen ( > 100 mol/cell) and the ability to aggregate platelets. This suggests that fibrinogen binding may aid in platelet aggregation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abscess / microbiology*
  • Animals
  • Bacterial Adhesion
  • Blood Platelets / metabolism
  • Endocarditis, Bacterial / microbiology*
  • Fibrin / metabolism
  • Fibrinogen / metabolism
  • Fibronectins / metabolism
  • Platelet Aggregation
  • Rats
  • Serotyping
  • Streptococcal Infections / microbiology*
  • Streptococcus / classification
  • Streptococcus / pathogenicity*
  • Streptococcus / physiology*
  • Surface Properties


  • Fibronectins
  • Fibrin
  • Fibrinogen