Experimental Study on the Phaeohyphomycosis Caused by Ochroconis gallopava / 中华皮肤科杂志

ABSTRACT

Objective To study the morphology, physiology, biochemistry and molecular biologic characteristics of Ochroconis gallopava which was firstly isolated from a pulmonary phaeohyphomycosis in China and compare it with a standard strain to assist in the clinical diagnosis and treatment. Methods The clinical isolate and standard strain were inoculated on SDA, PDA, CMA, CDA, BHIA and OA, respectively to observe the colony morphology and growth rate, and slide cultures were prepared and were examined under light microscope and electron microscope. Thermo-tolerance study, cycloheximide resistance test, API 20C, antifungal susceptibility test and PCR for the internal transcribed spacer of rDNA were also performed. Results Ochroconis gallopava grew rapidly on most media. The colonies appeared to be brown in color with smooth surface. There were aerial mycelia on SDA and PDA. Microscopic observations revealed pale brown and septate hyphae with club-shaped conidia. The growth of O. gallopava was optimal at 35 ℃ and was inhibited by cycloheximide. The two strains assimilated the same 14 glycogens, but 1 different, in API 20C AUX. MICs of fluconazole, itraconazole, amphotericin B and terbinafine were 32 ~ 64 ?g/mL, 1 ?g/mL, 2 ?g/mL and 0.25 ~ 0.5 ?g/mL, respectively. PCR results showed that the ITS segment was 743 bp with 3 bp difference in both strains. The length of 18S region was 506 bp, their sequences were the same entirely. Conclusions The clinical isolate is proved as a domestic strain of Ochroconis gallopava at the level of morphology, physiology, biochemistry and molecular biologic characteristics.