Streptococcus dysgalactiae subspecies equisimilis bacteraemia in an HIV-1 patient with HBV/HCV co-infections: case report and literature review.

Streptococcus dysgalactiae subspecies equisimilis (SDSE) is a common pathogen in animals and generally considered a rare cause of infection in humans. Recently, epidemiological studies demonstrated an increasing number of severe infections, including bacteraemia and endocarditis, caused by SDSE, mainly in predisposed hosts, immunocompromised by underlying conditions. Even though the immune status seems to play an important role in the appearance of SDSE infections, this microorganism has been rarely described as a pathogen in HIV-1 infected subjects. An extensive review of the literature on this pathogen is reported, with a description of a case of SDSE bacteraemia associated to septic arthritis with soft tissue infection in a patient with HIV-1 disease and chronic hepatitis due to HCV and HBV co-infections.