Necrotizing Pneumonia due to Nocardia farcinica in an Immunocompetent Host

Abstract

Nocardiosis is a rare, serious infection caused by Nocardia species, primarily affecting immunocompromised individuals. It commonly presents as pulmonary disease, often mimicking tuberculosis or bacterial pneumonia. Nocardia farcinica , although less common than Nocardia asteroides , is notably aggressive, multidrug-resistant, and linked to disseminated disease and high morbidity. We report necrotizing pneumonia caused by N. farcinica in a 74-year-old woman without major immunosuppression, with only controlled diabetes and hypertension as comorbidities. She presented with a 20-day history of fever and productive cough, progressing to moderate obtundation (GCS 9 to 12). Diagnosis was established through endotracheal aspirate culture with Matrix-Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF) identification after 6 to 7 days of admission. Targeted combination therapy with intravenous imipenem-cilastatin, intravenous amikacin, and oral trimethoprim-sulfamethoxazole (TMP-SMX) led to complete clinical, neurological, and radiological resolution at 6 months.