A review of GermanScedosporium prolificanscases from 1993 to 2007

Abstract

Scedosporium prolificans is one of the most life-threatening fungal opportunistic pathogens due to its high resistance to common systemic antifungal agents. While a close relative of Pseudallescheria boydii, S. prolificans has a more limited geographic range being primarily found in Australia, USA and Spain. Infections have also been reported from several other European countries and from Chile. Twenty patients with Scedosporium prolificans infection or colonization from August 1993 to May 2007 were retrospectively reviewed in Germany. They had all been identified at or reported to the Reference Laboratory for Pseudallescheria/Scedosporium spp. in Berlin. Twelve of 13 patients with haematological disorders and/or on immunosuppressive therapy developed a fatal invasive scedosporiosis. Colonization of the respiratory tract was reported for one patient after heart-lung-transplantation, all six patients with cystic fibrosis and one with chronic sinusitis. Molecular studies of the S. prolificans isolates confirmed that parts of the 18S, the Internal Transcribed Spacer (ITS) regions and the D1/D2 domain of the 28S region of rDNA are monomorphic. However, sequencing of parts of the translation elongation factor EF1-alpha (EF-1alpha) and the chitin synthase (CHS-1) genes revealed the presence of three and two distinct genotypes, respectively. Two informative mutations were found in EF-1alpha and a single nucleotide exchange in the CHS-1 gene.

Melanized Fungi in Human Disease

“…All disseminated infections were in individuals with underlying disease, primarily hematological malignancies; 70% of these had positive blood cultures, and mortality in this group was 88%. Molecular characterization by ITS, D1/D2, translation elongation factor 1␣, and the chitin synthase genes for 20 cases of S. prolificans infection occurring in Germany between 1993 and 2007 suggests the possibility of two or three distinct genotypes (747). This finding may further our understanding of the epidemiology of this organism.…”

“…The most common isolate was S. prolificans, accounting for over a third of cases. Since that review, S. prolificans remains the most frequent cause of disseminated disease, almost exclusively in immunocompromised patients (33,62,96,151,304,358,364,368,434,697,709,747,750,796). E. dermatitidis, in contrast, is commonly seen in immunocompetent patients, particularly from Asia (13,349,565).…”

“…The genus Scedosporium and its associated teleomorph Pseudallescheria were extensively reviewed by Cortez et al in 2008 (153); therefore, the information provided here will augment that previously published and/or highlight new taxonomy, distribution, and disease. Scedosporium prolificans, which is closely related but not a member of this complex, appears to occupy a more restricted geographic range, with infections occurring mainly in Australia, Spain, and the United States (747). Clinical discussion (see Clinical Syndromes and Their Management below) will be limited to S. prolificans, as related species have been extensively reviewed elsewhere (153) and may not reveal phaeoid hyphae in tissue, in contrast to the case for S. prolificans.…”

Mucormycosis, Pseudallescheriasis, and Other Uncommon Mold Infections

“…Pulmonary findings may be localized or may be part of more disseminated disease (53). Airway colonization without invasive infection has also been described (47). Symptoms of disease include high fevers, dyspnea, cough, and other nonspecific complaints (60,61).…”

“…Scedosporium prolificans, a closely related species, is also a soil saprophyte with a slightly less extensive distribution (47). Entry into the human host is often via traumatic inoculation or through inhalation into the pulmonary system; acquisition can occur in both the community-acquired and nosocomial settings (48).…”