Pathogenicity of Ochroconis gallopava isolated from hot springs in Japan and a review of published reports.

Four strains of Ochroconis gallopava from 3 out of 15 Japanese hot springs were isolated. Colonies of the hot spring isolates were uniformly floccose and dark olive green on the surface and dark brown on their reverse side on potato dextrose agar (PDA) plates, however, they became felty, flat, and brownish-black, and produced a reddish-brown pigment after several times of subculture at room temperature. Shapes and sizes of conidia of the four strains were individual, while the D1/D2 domain of the large subunit ribosomal RNA gene sequences showed 99.7% identity in the GenBank database. The DNA pattern of the hot spring isolates amplified by species specific loop mediated isothermal amplification method were as the same pattern as that of a clinical isolate. The minimum inhibitory concentrations of antifungal agents to O. gallopava isolated from the hot springs were ranged from 0.5 to 1 microg/ml in amphotericin B, 1 to 16 microg/ml in flucytosine, 0.125 to 0.25 microg/ml in itraconazole, 1 to 4 microg/ml in miconazole, 16 to 64 microg/ml in flconazole and 0.03 to 0.5 microg/ml in micafungin. The isolates had fatal outcome in experimentally infected mice intravenously with severe invasiveness to brains and kidneys. These findings suggested that O. gallopava habitats in hot springs could be one of sources for infection.