Streptococcus facts for kids

Quick facts for kids Streptococcus
Scientific classification
Kingdom:	Bacteria
Phylum:	Firmicutes
Class:	Bacilli
Order:	Lactobacillales
Family:	Streptococcaceae
Genus:	Streptococcus Rosenbach, 1884
Species
S. agalactiae S. anginosus S. bovis S. canis S. constellatus S. dysgalactiae S. equi S. equinus S. iniae S. intermedius S. mitis S. mutans S. oralis S. parasanguinis S. peroris S. pneumoniae S. pyogenes S. ratti S. salivarius S. salivarius ssp. thermophilus S. sanguinis S. sobrinus S. suis S. uberis S. vestibularis S. viridans S. zooepidemicus

Streptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group. They are cocci, meaning that they are shaped like spheres or circles. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name from Greek στρεπτος streptos, meaning easily bent or twisted, like a chain (twisted chain). Contrast this with staphylococci, which divide along multiple axes and generate grape-like clusters of cells. Streptococci are oxidase and catalase-negative, and many are facultative anaerobes.

Images for kids

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  Alpha-hemolytic S. viridans (right) and beta-hemolytic S. pyogenes (left) streptococci growing on blood agar

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  Phylogenetic tree of Streptococcus species, based on data from PATRIC. 16S groups are indicated by brackets and their key members are highlighted in red.

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  Common and species-specific genes among Streptococcus sanguinis, S. mutans, and S. pneumoniae. Modified after Xu et al. (2007)

See also

In Spanish: Estreptococos para niños