Schizophyllum commune is a widely distributed fungus, often found on dead and decaying organic matter, especially rotten wood of trees. Recently, it has been increasingly reported as one of the etiologic agents of allergic broncho-pulmonary mycosis (ABPM) or other allergy-related bronchopulmonary diseases and sinusitis. Besides, invasive infections of the lung, brain and palate in immunocompetent and immunocompromised patients have been described. We report S. commune as the etiologic agent of one case each of ABPM and pulmonary fungal ball, and present a literature review. In addition we performed in vitro antifungal susceptibility profiles (CLSI microbroth dilution), AFLP and ITS sequencing of 22 isolates of S. commune isolated from respiratory tract specimens of patients suspected of bronchopulmonary mycoses. In ABPM and pulmonary fungal ball cases the diagnosis was based on mycological, immunological, clinical and roentgenographic criteria. The isolates from both of the patients were characterized by clamp connections, hyphal spicules, and the ability to form basidiocarps and basidiospores. The phenotypic identification of all the isolates was confirmed by sequencing of the ITS region. Of the azoles, posaconazole exhibited the highest activity (GM, 0.09 lg ml)1), followed by Isavuconazole (GM, 0.109 lg ml)1), itraconazole (GM, 0.137 lg ml)1), voriconazole (GM, 0.22 lg ml)1) and amphotericin B (GM, 0.31 lg ml)1). AFLP generated five distinct banding patterns suggestive of a species complex. To-date, ABPM and pulmonary fungal ball due to S. commune have been only reported from Japan. Of the 71 global cases due to S. commune we reviewed, 45 (63%)were bronchopulmonary, 22 (31%) sinusitis and 4 extrapulmonary. Taken together, cases of bronchopulmonary disease and sinusitis numbered 67 (94%), indicating the respiratory tract as the primary target of disease. The preponderance of the disease in Japan may be attributed to its greater awareness and acquaintance with the diagnostic morphological characters of S. commune vis-a`-vis that in other countries rather than to any geographic/ climatic factors. We believe that the burden of S. commune-incited disease is currently underestimated, warranting comprehensive prospective studies to determine its prevalence. The present study is the largest series of susceptibility results reported so far.
- ISHAM 18th (2012)