Nocardia Isolation in People with Cystic Fibrosis and Non-CF Bronchiectasis: A Multicenter Italian Study

<b>Background:</b><i>Nocardia</i> species are an emergent pathogen in people with CF (pwCF) or bronchiectasis. Their clinical role and management remain unclear, and their isolation is a challenge. In this paper, we describe four cases of Nocardia detection, in two pwCF and two patients with non-CF bronchiectasis or primary ciliary dyskinesia (PCD). <b>Methods:</b> We conducted a multicenter retrospective study, involving pwCF and non-CF people with bronchiectasis who presented with a <i>Nocardia</i> detection and were followed at three CF Italian centers (Florence, Verona, and Cerignola). <b>Results:</b><i>Nocardia</i> detection was associated with clinical and radiological respiratory exacerbation and decline in lung function. In one CF patient, <i>Nocardia</i> was not detected in sputum cultures after starting Elexacaftor-Tezacaftor-Ivacaftor therapy. <b>Conclusions:</b> Managing <i>Nocardia</i> detection in patients with underlying lung diseases such as CF, PCD, or bronchiectasis presents significant challenges for clinicians.