spherical Gram-positive bacteria occurring in pairs or chains; cause e.g. scarlet fever and tonsillitis
"The doctor confirmed that her recurring tonsillitis was caused by a strain of streptococcus, forcing her to stay home for antibiotics."
A spherical, gram-positive bacterium of the genus Streptococcus. Although commonly found benignly in the human mouth and gut, and though many species are non-pathogenic, other species can cause diseases including strep throat and more serious conditions.
"The doctor confirmed that my sore throat was caused by a specific strain of streptococcus bacteria rather than a virus."