Updated: 12/14/2016

Introduction to Streptococcus

Review Topic
Introduction to Streptococcus

  • There are 6 classic Gram-positive groups of bacteria that cause disease in humans
    • 2 are cocci
      • one of these is streptococcus
      • the other is staphylococcus
  • Streptococci vs staphylococcus
    • on Gram stain, strep looks like a "strip" of bacteria, while staph looks like a cluster
    • strep is catalase negative, staph is catalase positive
  • Lancefield antigens
    • strep are characterized by the antigenic properties of the C carbohydrate in the cell wall
    • so-called Lancefield antigens are given letter names (A, B, C, D, etc. through S)
    • S. pneumoniae and viridans group streptococci do not have Lancefield antigens
  • Significant human streptococci pathogens
    • S. pyogenes (group A)
    • S. agalacticae (group B)
    • S. bovis (group D)
    • enterococci (group D)
    • S. pneumoniae
    • viridans group streptococci
Topic Rating

Please rate topic.

Average 5.0 of 3 Ratings


Topic COMMENTS (4)
Private Note