ABSTRACT
Streptococcus constellatus (S. constellatus) is a commensal microorganism belonging to the "Streptococcus milleri" group, but may cause infections in different locations in immunocompromised patients. The infection of S. constellatus has high mortality and morbidity due to its tendency to cause abscesses in infected patients, which require immediate surgical drainage for effective treatment. We report on a 72-year-old woman with end stage renal disease, who suffered from dyspnea and general weakness that had developed over 7 days. Chest CT showed loculated pleural effusion. S. constellatus was cultured from exudative pleural effusions and confirmed by an analysis of 16S rRNA sequence. The patient was treated with drainage of pleural effusion and piperacillin/tazobactam for 5 weeks.