[Nocardiosis and bronchiectasis. An uncommon association?]

Abstract

Objective: Nocardiosis is difficult to diagnose and infrequently associated with bronchiectasis or cystic fibrosis. This study analyzes the clinical and microbiological characteristics of 40 patients in whom microorganisms belonging to the Nocardia asteroides complex were isolated.

Methods: We studied 27 males and 13 females, with a mean age of 45 years (8-82). Nocardia spp. were isolated in 129 samples. Cultures were performed with conventional methods; additionally, when branching Gram-positive bacilli were visualized on microscopic examination, modified BCYE-alpha (m) medium was used.

Results: In 77.5% of the cases, investigation for Nocardia spp. was based on microscopy findings, in six patients it was a fortuitous finding in BCYE-alpha (m) medium, and in only three patients nocardiosis was clinically suspected. Twenty-five patients had nocardiosis (5 disseminated infection and 20 lung infection) and the remaining 15 were colonized. The most frequent risk factor in the infections, whether disseminated or not, was systemic glucocorticoid use (P 5 .001). The most frequent underlying pathology was bronchiectasis (80%), associated or not with cystic fibrosis. There were seven deaths and two patients had neurological sequelae.

Conclusions: Bronchiectasis was an important risk factor for colonization by Nocardia spp. (P 5 0.01) in all the patients studied, and for infection (P 5 0.05) in patients without cystic fibrosis. The use of BCYE-alpha (m) medium in processing respiratory secretions highly facilitated the isolation of Nocardia spp.