Abstract: Objective To evaluate the morphology and conversion rate of mycelial phase to yeast phase of Sporothrix schenckii isolates after successive passages.Methods Ninety-five clinical isolates of Sporothrix schenckii were incubated on BHIA until yeast phase.Morphology and proportion of mycelium to spore were observed.Result Twenty-three of tatal 95 isolates of Sporothrix schenckii converted to yeast phase after the first passage,with 14 isolates after the second passage,10 isolates after the third passage,6 isolates after the fourth passage.After four passages,55.8% of all isolates converted to yeast phase.Conclusion Several successive passages were needed for part of Sporothrix schenckii converting from mycelia phase to yeast phase and helpful for conversion improvement.

Key words: Sporothrix, Sporothrix schenckii, yeast phase