[Greek streptos, twisted, from strephein, to turn.]
A streptococcus (Greek kokkos, berry; plural streptococci) is a bacterium of a genus that includes pathogens causing various infections such as scarlet fever and pneumonia. The bacteria form chains, and the genus was named in 1877 by the German pathologist Billroth, who took the Greek word to mean ‘chain’. The genus Streptomyces (Greek mukēs, mukēt-, fungus), another bacterial genus, was similarly named; they occur chiefly in soil as aerobic saprophytes resembling moulds and several of them are important sources of antibiotics, such as streptomycin and streptozotocin. The enzyme streptokinase, produced by some streptococci, is used to treat inflammation and blood clots; another active substance from streptococci, streptolysin (Greek lusis, loosening), removes haemoglobin from red blood cells.