Pulmonary nocardiosis with probable pulmonary aspergillosis in an elderly patient with COPD and T-cell lymphopenia.

Recovery of multiple microorganisms from respiratory specimens complicates pathogen attribution in patients with chronic lung disease. A 71-year-old woman with COPD and bronchiectasis presented with severe pneumonia and respiratory failure. She had T-cell lymphopenia (CD3+, CD4+, and CD8+ counts: 189, 147, and 41 cells/μL) and negative HIV testing. BALF Gram staining showed branching Gram-positive rods suspicious for Nocardia spp., and cultures yielded a Nocardia isolate, Aspergillus fumigatus, and Candida albicans. The isolate was presumptively identified as N. terpenica by MALDI-TOF MS (score, 9.534); molecular confirmation and susceptibility testing were unavailable. BALF galactomannan (index, 3.528) supported probable pulmonary aspergillosis. Influenza A virus RNA was detected by qualitative PCR, while C. albicans was considered airway colonization. The patient improved during hospitalization. This case highlights integrated pathogen attribution in complex respiratory microbiology.