Rothia aeria pneumonia in an immunocompetent patient: A novel case study.

An 80-year-old woman with no lung disease or autoimmune disease presented with a productive cough, lasting for 2 months. Chest computed tomography revealed a transbronchial dispersal shadow in the left upper lobe, and sputum culture showed Gram-positive rods. The identified causative organism was Rothia aeria, and thus, she was treated with oral trimethoprim/sulfamethoxazole (TMP-SMX). Eleven days after initiating TMP-SMX treatment, she returned with a complaint of dyspnoea. While the sputum culture revealed normal flora, the patient's condition was diagnosed as bronchitis during R. aeria pneumonia treatment; therefore, she was hospitalized. Five days after admission, her laboratory findings revealed agranulocytosis, caused by an adverse event of TMP-SMX. Her neutrophil count increased after discontinuing TMP-SMX treatment. Bronchitis was alleviated with intravenous antibiotic administration, and she was discharged on Day 8. We report a rare case of R. aeria pneumonia in an immunocompetent patient.