Infections Caused byScedosporiumspp

Abstract

SUMMARY Scedosporium spp. are increasingly recognized as causes of resistant life-threatening infections in immunocompromised patients. Scedosporium spp. also cause a wide spectrum of conditions, including mycetoma, saprobic involvement and colonization of the airways, sinopulmonary infections, extrapulmonary localized infections, and disseminated infections. Invasive scedosporium infections are also associated with central nervous infection following near-drowning accidents. The most common sites of infection are the lungs, sinuses, bones, joints, eyes, and brain. Scedosporium apiospermum and Scedosporium prolificans are the two principal medically important species of this genus. Pseudallescheria boydii, the teleomorph of S. apiospermum, is recognized by the presence of cleistothecia. Recent advances in molecular taxonomy have advanced the understanding of the genus Scedosporium and have demonstrated a wider range of species than heretofore recognized. Studies of the pathogenesis of and immune response to Scedosporium spp. underscore the importance of innate host defenses in protection against these organisms. Microbiological diagnosis of Scedosporium spp. currently depends upon culture and morphological characterization. Molecular tools for clinical microbiological detection of Scedosporium spp. are currently investigational. Infections caused by S. apiospermum and P. boydii in patients and animals may respond to antifungal triazoles. By comparison, infections caused by S. prolificans seldom respond to medical therapy alone. Surgery and reversal of immunosuppression may be the only effective therapeutic options for infections caused by S. prolificans.

Diagnosis of invasive fungal infections by a real-time panfungal PCR assay in immunocompromised pediatric patients

“…The vast majority of IFD events are still caused by Candida and Aspergillus species; however, changes in the epidemiology have occurred over the past decades. [1][2][3][4][5] Recent studies from North American and European centers indicate an increasing incidence of previously uncommon fungal genera, such as Cryptococcus, Trichosporon, Malassezia, 6,7 Fusarium, 8,9 Scedosporium, Pseudallescheria, 10,11 and, very importantly, different members of the class Zygomycetes, such as Rhizopus and Mucor. 12 Timely detection of the fungal pathogens is a prerequisite for successful therapy and the clinical outcome in patients with IFD.…”

Freshwater Fungal Infections

“…28,49 Scedosporium apiospermum (Figure 4) also may cause colonization and infection of the respiratory tract in persons with predisposing conditions, systemic invasive disease (usually in immunocompromised hosts) and keratitis, and has rarely been associated with otitis externa. 28,50 Common superficial fungal infections also may rarely result from freshwater exposure. Dermatophytes and other keratinophilic fungi have been reported in freshwater and sources of drinking water.…”

“…26 Other agents include dematiaceous (dark-pigmented) fungi, Scedosporium apiospermum (discussed in more detail on page 36) and other molds. 28 In the United States, Candida species were the predominant causes of fungal keratitis in a New York series and were much more common than Fusarium or Aspergillus. 27 29 perhaps in association with an outbreak associated with a particular contact lens solution.…”

“…45 Causative agents include fungi in the family Mucoraceae, Cladophialophora, Fusarium, Aspergillus, Pseudallescheria and Scedosporium. 28,[45][46][47][48] The latter, while primarily found in soil, may be found in muddy water, sewage, and polluted, brackish and other freshwater. 28,49 Scedosporium apiospermum (Figure 4) also may cause colonization and infection of the respiratory tract in persons with predisposing conditions, systemic invasive disease (usually in immunocompromised hosts) and keratitis, and has rarely been associated with otitis externa.…”

“…28,[45][46][47][48] The latter, while primarily found in soil, may be found in muddy water, sewage, and polluted, brackish and other freshwater. 28,49 Scedosporium apiospermum (Figure 4) also may cause colonization and infection of the respiratory tract in persons with predisposing conditions, systemic invasive disease (usually in immunocompromised hosts) and keratitis, and has rarely been associated with otitis externa. 28,50 Common superficial fungal infections also may rarely result from freshwater exposure.…”