Prevalence of fungal colonization in cystic fibrosis: a retrospective study over 3 years in Buenos Aires, Argentina

BRITO DEVOTO T; POLA SJ; FINQUELIEVICH JL; RUBEGLIO E; GAMARRA S; GARCIA-EFFRON G; CUESTAS ML

Congreso; 18th ICID; 2018

Background: Fungal colonization of the respiratory tract isfrequently found in cystic fibrosis patients (CF). However, theknowledge on prevalence of moulds and yeasts lung colonization in patients with this genetic disorder in Argentina is scarce.The aim of this work is to overview the epidemiology of fungalcolonization in CF patients. Over a 3-year period, 121 fungal strains280 Abstracts / International Journal of Infectious Diseases 73S (2018) 3?398isolated from respiratory samples of 32 CF patients from BuenosAires were studied.Methods & Materials: Isolates were identified by morphological criteria according to standard macroscopic and microscopiccriteria. In order to identify species to subspecies level and uncovercryptic species, sequence analysis of the fungal ITS regions ofthe ribosomal DNA, beta-tubulin and calmodulin genes were performed. For identification of Scedosporium spp. in respiratory tractspecimens, a multiplex PCR assay was also carried out targeting ITSregion.Results: Overall, about 65.6% of CF patients were colonized byAspergillus spp. of the Fumigati section, 18.8% by Aspergillus sectionFlavi, 15.3% by Penicillium/Talaromyces sp., 12.5% by Aspergillus section Nigri, Scedosporium sp., Exophiala sp., and 3.1% by Alternariasp., Paecilomyces sp. and Geotrichum sp. The occurrence of rarefungi in CF patients like Ramsamsonia argillacea, Cephalotheca foveolata, Phoma haematocycla and Rhodothorula spp. was sporadicallyobserved. Among Aspergillus spp., Aspergillus fumigatus was themost prevalent species, followed by Aspergillus terreus, Aspergilluspseudeoterreus, Aspergillus oryzae, Aspergillus flavus, Aspergillusniger, Aspergillus ustus, Aspergillus calidoustus, Aspergillus lentulusand Aspergillus parasiticus. Among the genera Scedoporium, themost common species were Scedosporium apiospermum and Scedosporium aurantiacum. In some cases, fungal coinfections weredetected (eg, A. fumigatus and Exophiala dermatitidis; A. terreus/A.fumigatus and S. auarantiacum).Conclusion: The pathogenic role of fungal isolates has to beevaluated in accordance with clinical data, immune status of thepatient and available data regarding the pathogenicity of each particular fungal species. Further studies are needed to evaluate theclinical implications of fungal coinfections and their contributionto inflammation and clinical deterioration in CF patients.