B73-14 Nocardia Without Immunodeficiency: A Rare Case in a Nonagenarian

Abstract A 97 year old caucasian woman presented to the pulmonary clinic with a 3 year history of progressively worsening productive cough, intermittently producing dark or “black” sputum. She also endorsed night sweats, but denied fever, weight loss, dyspnea or hemoptysis. She has no history of smoking, COPD, asthma, alcohol use or immunosuppression. She had a history of COVID pneumonia in 2022. Her chronic cough had previously been attributed to recurrent bronchitis and treated symptomatically without improvement. High resolution chest CT revealed chronic bronchiectasis, upper and lower lobe pleural thickening and scarring. Due to persistent symptoms despite conservative therapy, induced sputum sampling was performed. Acid-fast bacilli smears were repeatedly negative. HIV testing and fungal studies were negative. However, three separate induced sputum cultures consistently isolated Nocardia cyriacigeorgica, establishing a diagnosis of chronic pulmonary nocardiosis. The patient was initiated on trimethroprom-sulfamethoxazole (TMP-SMX) with careful dosing titration in consideration of advanced age and renal function. She continues therapy with plans for a prolonged antimicrobial course to prevent relapse. Discussion Nocardia Cyriacigeorgica is an increasingly recognized pulmonary pathogen and has been reported in immunocompromised and immunocompetent older adults. The clinical course is often indolent, with nonspecific respiratory symptoms that may be misattributed to chronic airway disease or old age illness. Radiographic findings frequently mimic post-infectious bronchiectasis, chronic aspiration especially in older adults and post-infectious scarring. Diagnosis is commonly delayed as nocardia requires prolonged culture incubation and may not be detected if specimens are not specifically requested to be held for longer than routine testing. Additionally, negative AFB smears do not exclude nocardiosis, as the organism is weakly acid-fast. This case highlights the critical role of repeated and induced sputum sampling when spontaneous sputum production is limited. Induced sputum is important in evaluating patients who have bronchiectasis with chronic cough. Early recognition is essential because directed and prolonged therapy is effective and prevents relapse. References: 1. Brown-Elliott BA, Conville PS, Wallace RJ Jr. Clinical and Laboratory Features of Nocardia Species. Clin Microbiol Rev. 2006;19(2):259-282.2. McTaggart LR, Richardson SE, Witkowska M, et al. Nocardia cyriacigeorgica: An Emerging Pathogen. J Clin Microbiol. 2015;53(2):627-635.3. Rivera A, Hager DN, Debiane LG. Nocardia infections in older adults. Drugs Aging. 2021;38:927-938.4. Wilson JW. Nocardiosis: Updates and Clinical Overview. Mayo Clin Proc. 2012;87(4):403-407.5. Griffith DE, Girard WM, Wallace RJ Jr. Pulmonary nocardiosis in patients with bronchiectasis. Clin Infect Dis. 1999;28(2):373-378. This abstract is funded by: none