Fungal colonization of the respiratory tract of cystic fibrosis patients: a first report in Argentina

RUBEGLIO E; DAN FRANCO O; CUESTAS ML; LOPEZ DANERI G; POLA S; FINQUELIEVICH JL; SPRAJER E; BRITO DEVOTO T

Congreso; 15TH INFOCUS; 2017

Cystic fibrosis (CF) is the major cause of pulmonary disease in children with an incidence of 1/2,000-1/3,500 live newborns. Chronic pulmonary infections caused by opportunistic pathogens affect more than 90% of patients suffering from CF. In addition to bacterial colonization, these patients are predisposed to fungal colonization, due to the capacity of environmental fungi to colonize the lower respiratory tract and to the prolonged therapy with antibiotics and corticosteroids, which leads to the alteration of the normal biota. Currently, the role of fungi in the course of CF is not clearly defined but there is evidence supporting that filamentous fungi may lead to the deterioration of lung function, as occurs in allergic broncho-pulmonary aspergillosis (ABPA) which is the most common fungal disease in this context. Aspergillus fumigatus, Scedosporium apiospermum and Aspergillus terreus are the main filamentous fungi associated with CF described worldwide. The prevalence of different fungi in CF patients from Argentina is unknown. Objectives: to determine the frequency of fungi in the respiratory tract of Argentinean CF patients. Methods: A total of 104 fungal strains isolated from sputa of 30 patients from Buenos Aires, Argentina were investigated. Isolates were identified by morphological and molecular criteria. Results: Aspergillus species were the most common filamentous fungi (58.7%) followed by Scedosporium sp (12.5%), Penicillium sp (6.7%), Exophiala sp (5.8%), Talaromyces sp (4.8%), Ramsansonia sp (1.0%), Geotrichum sp (1.0%) and Paecylomyces sp (1.0%). Among the Aspergillus genera, A. fumigatus was the most prevalent, followed by Aspergillus terreus, Aspergillus pseudeoterreus, Aspergillus oryzae, Aspergillus flavus, Aspergillus niger, Aspergillus ustus, Aspergillus calidoustus and Aspergillus parasiticus. Among the genera Scedoporium, the most common species were S. apiospermum and Scedosporium aurantiacum. In some cases, fungal coinfections were successively detected (eg, A. fumigatus, A. niger and E. dermatitidis; A. terreus and S. auarantiacum; A. fumigatus, A. niger and A. pseudoterreus; A. fumiagtus and Rasamsonia sp; A fumigatus and A. terreus, A. niger, A. ustus, A. calidoustus and Scedosporium sp.) in the same patients.Conclusion: this is the first report about fungal infections in patients with CF in Argentina. Although less common, and in contrast to A. fumigatus, several fungal species including A. oryzae and A. calidoustus may be isolated transiently from CF respiratory secretions, while others such as E. dermatitidis, S. apiospermum and S. aurantiacum may chronically colonize the airways. Further studies are needed to evaluate the clinical implications of fungal coinfections in the physiopathology of CF lung infection-colonization.