Viridans streptococci

Viridans streptococci
Scientific classificationEdit this classification
Domain: Bacteria
Phylum: Bacillota
Class: Bacilli
Order: Lactobacillales
Family: Streptococcaceae
Genus: Streptococcus

The viridans streptococci are a large group of commensal streptococcal Gram-positive bacteria species that are α-hemolytic, producing a green coloration on blood agar plates (hence the name "viridans", from Latin "vĭrĭdis", green), although some species in this group are actually γ-hemolytic, meaning they produce no change on blood agar.[1] The pseudo-taxonomic term "Streptococcus viridans" is often used to refer to this group of species, but writers who do not like to use the pseudotaxonomic term (which treats a group of species as if they were one species) prefer the terms viridans streptococci,[2] viridans group streptococci (VGS), or viridans streptococcal species.

These species possess no Lancefield antigens.[3] In general, pathogenicity is low.[4]

  1. ^ Sinner, Scott W.; Tunkel, Allan R. (2015-01-01), Bennett, John E.; Dolin, Raphael; Blaser, Martin J. (eds.), "204 - Viridans Streptococci, Nutritionally Variant Streptococci, Groups C and G Streptococci, and Other Related Organisms", Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases (Eighth Edition), Philadelphia: W.B. Saunders, pp. 2349–2361.e2, doi:10.1016/b978-1-4557-4801-3.00204-6, ISBN 978-1-4557-4801-3, retrieved 2022-04-01
  2. ^ Dorland's Illustrated Medical Dictionary, headword "streptococcus", subentry "viridans streptococci".
  3. ^ Ryan KJ, Ray CG, eds. (2004). Sherris Medical Microbiology (4th ed.). McGraw Hill. pp. 293–4. ISBN 978-0-8385-8529-0.
  4. ^ Viridans+Streptococci at the U.S. National Library of Medicine Medical Subject Headings (MeSH)