Chronic airway colonization by Scedosporium apiospermum with a fatal outcome in a patient with cystic fibrosis

Abnormally viscous bronchial secretions, a characteristic feature of cystic fibrosis (CF), may trap bacteria and fungi, allowing transient or chronic lung colonization. We report here a case of persistent Scedosporium apiospermum colonization in a patient with CF, who subsequently developed a lung mycetoma, and died with neurological symptoms suggestive of cerebral fungal involvement. Six isolates from consecutive sputum samples were molecularly typed by random amplification of polymorphic DNA (RAPD) using primers UBC701, UBC703, and GC70. Moreover, in vitro susceptibility of these isolates to current antifungals (amphotericin B, itraconazole, voriconazole, posaconazole, caspofungin and anidulafungin) was investigated by means of both E-test and CLSI methods. Antifungal susceptibility testing showed low minimum inhibitory concentration values only for triazole drugs. However, a unique genotype was isolated over a 12-month period, despite antifungal treatment with voriconazole for three months. This case report illustrates the therapy-refractory feature of this fungus, and provides new evidence that, as already reported, once a genotype of S. apiospermum has established colonization, it seems not to be replaced by others.