Long-time survival and morphological stability of preserved Sporothrix schenckii strains.

The survival and stability of morphological traits of 33 Sporothrix schenckii strains were evaluated. Strain subcultures were maintained under mineral oil for different periods of time lasting as long as 41 years, or in sterile distilled water for as long as 23 years. Of the 33 strains preserved under mineral oil, 28 (85%) maintained viability and unchanged macro- and microscopic characteristics. All of the 4 strains maintained in distilled water also remained viable, with no morphological changes. The results confirm the efficiency of the methods used to preserve strains of the pathogenous and anamorphous fungus Sp. schenckii, especially in laboratories of limited resources.