Streptococcus is an organism.
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 , thus they grow in chains or pairs , hence the name -- from Greek στρεπτός streptos , meaning easily bent or twisted , like a chain ( twisted chain ) . This genus has been found to be part of the salivary microbiome .