Spondylodiscitis Caused by Streptococcus dysgalactiae Subspecies Equisimilis: A Case Report of an Increasingly Recognized Pathogenic Organism

Streptococcus dysgalactiae subspecies equisimilis (SDSE) is a β-hemolytic Streptococcus that possesses genetic and clinical similarities to Streptococcus pyogenes. It is increasingly recognized as the etiological microorganism of invasive diseases. We report a case of a 74-year-old male who was admitted to this hospital with lower back and neck pain and infected with leg ulcer. The diagnosis of spondylodiscitis C2-C3 and L1-L3 caused by Streptococcus dysgalactiae subsp. equisimilis was made. The present case demonstrates the risk of older patients of developing invasive disease upon skin infection with Streptococcus dysgalactiae subsp. equisimilis, even when risk factors are absent or well controlled (as was diabetes mellitus in this case), suggesting that the pathogenic potential of SDSE should not be underestimated.