The incidence of airway colonization by Scedosporium apiospermum and of related sensitization was investigated prospectively in 128 patients with cystic fibrosis over a 5-year period, and results were compared with clinical data. Scedosporium apio-spermum, recovered from sputum samples in 11 of 128 (8.6%) patients, was the most frequent filamentous fungus after Aspergillus fumigatus. Counterimmuno-electrophoresis, used to detect scedosporiosis serologically, was positive in 27 of 128 (21.1%) patients. The discrepancy between the mycological and serological results may be related to immune cross-reactions between Scedosporium apiospermum and Aspergillus fumigatus. However, symptoms of allergic bronchopulmonary disease were observed in two patients chronically colonized by Scedosporium apiospermum. The results clearly demonstrate that the frequency of this fungus is largely underestimated and that it may trigger an inflammatory response, thus suggesting a pathogenic role in patients with cystic fibrosis.

Cystic fibrosis (CF) is the most common inherited genetic disease in Caucasian populations. Besides bacteria, many species of fungi may colonize the respiratory tract of these patients, sometimes leading to true respiratory infections. In this study, an oligonucleotide array capable of identifying 20 fungal species was developed to directly detect fungi in the sputum samples of CF patients. Species-specific oligonucleotide probes were designed from the internal transcribed spacer (ITS) regions of the rRNA operon and immobilized on a nylon membrane. The fungal ITS regions were amplified by PCR and hybridized to the array for species identification. The array was validated by testing 182 target strains (strains which we aimed to identify) and 141 nontarget strains (135 species), and a sensitivity of 100% and a specificity of 99.2% were obtained. The validated array was then used for direct detection of fungi in 57 sputum samples from 39 CF patients, and the results were compared to those obtained by culture. For 16 sputum samples, the results obtained by the array corresponded with those obtained by culture. For 33 samples, the array detected more fungal species than culture did, while the reverse was found for eight samples. The accuracy of the array for fungal detection in sputum samples was confirmed (or partially confirmed) in some samples by cloning and resequencing the amplified ITS fragments. The present array is a useful tool for both the simultaneous detection of multiple fungal species present in the sputa of CF patients and the identification of fungi isolated from these patients.

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