Breakthrough Pulmonary Nocardiosis Due to Nocardia cyriacigeorgica in a Lung Transplant Recipient in Brazil: A Case Report Highlighting Management Without Susceptibility Testing

Background Nocardia infection is an emerging concern in solid organ recipients due to prolonged immunosuppression. Case Presentation We report the case of a 45‐year‐old woman with a history of cystic fibrosis who underwent bilateral lung transplantation. Eight years posttransplant, she developed progressive respiratory symptoms. Imaging revealed cavitary nodular lesions, and Nocardia cyriacigeorgica was isolated from bronchoalveolar lavage and sputum cultures. Treatment with meropenem and trimethoprim‐sulfamethoxazole led to clinical and radiological improvement. Conclusion This case highlights the diagnostic challenges of Nocardia infections, the importance of microbiological interpretation, and the potential for late‐onset disease in transplant recipients despite prophylaxis. Awareness of Nocardia as an opportunistic pathogen is crucial for timely diagnosis and management. Our findings underscore the need for continued vigilance in solid organ transplant recipients, particularly in cases of persistent pulmonary infections and high immunosuppressive therapy.