Rothia dentocariosa pneumonia in an immunocompromised patient.

An 84-year-old woman with acute myelocytic leukemia presented with fever and a left upper lobe infiltrate on chest x-ray. She failed to respond to initial broad spectrum antibiotic therapy. Bronchoalveolar lavage fluid and a transthoracic needle aspirate subsequently both grew Rothia dentocariosa, a gram-positive branching rod. The pneumonia resolved after prolonged treatment with Clindamycin. Rothia dentocariosa must be considered a cause of opportunistic pulmonary infection.