Bronchoscopic lavage cultured on sheep blood agar , gram-positive, aerobic, weekly acid-fast branching filaments
A young boy comes with a history of fever and cough for two weeks. He has reduced appetite and weight loss. He is also a known case of congenital heart disease. He has taken penicillin prophylaxis. Sputum examination is normal, however bronchoscopic lavage cultured on sheep blood agar showed evidence of gram-positive, aerobic, weekly acid-fast branching filaments. What is likely diagnosis?