Descending necrotizing mediastinitis caused by group A streptococcus (serotype M1T1).

We present a fatal case of descending necrotizing mediastinitis secondary to group A Streptococcus (serotype M1T1). Group A Streptococcus is a well-described cause of necrotizing fasciitis, but there have only been 4 previous cases documenting its involvement in descending necrotizing mediastinitis. This is the first case report to describe involvement of the M1 serotype in this condition.