The Streptococcus anginosus group was first discovered in the 1950s and over time has
evolved to consist of three species designated S. anginosus, S. constellatus, and S.
intermedius. Investigation of these bacteria over the last few decades has revealed that
infections caused by these gram-positive cocci have significant variability in their clinical
presentations. In addition, studies have shown that hemolysis, Lancefield group reaction,
and other laboratory techniques commonly used to identify bacteria are inconsistent …