Molecular epidemiology of Aspergillus collected from cystic fibrosis patients

Background - Aspergillus respiratory infection is a common complication in cystic fibrosis (CF) and is associated with loss of pulmonary function and allergic disease. Methods - Fifty-three Aspergillus isolates recovered from CF patients were identified to species by Internal Transcribed Spacer Region (ITS), β-tubulin, and calmodulin sequencing. Results - Three species complexes (Terrei, Nigri, and Fumigati) were found. Identification to species level gave a single Aspergillus terreus sensu stricto, one Aspergillus niger sensu stricto and 51 Aspergillus fumigatus sensu stricto isolates. No cryptic species were found. Conclusions - To our knowledge, this is the first prospective study of Aspergillus species in CF using molecular methods. The paucity of non-A. fumigatus and of cryptic species of A. fumigatus suggests a special association of A. fumigatus sensu stricto with CF airways, indicating it likely displays unique characteristics making it suitable for chronic residence in that milieu. These findings could refine an epidemiologic and therapeutic approach geared to this pathogen.