Streptococcus is a
genus of
coccus (spherical)
gram-positive bacteria belonging to the phylum
Firmicutes and the order
Lactobacillales (lactic acid bacteria).
Cell division in this genus occurs along a single
axis in these bacteria, and thus they grow in chains or pairs, hence the name—from
Greek στρεπτός
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.)