Low success rate of recovery of Sporothrix spp. from a fungal collection using storage through mineral oil technique

Subject: We aimed to evaluate the recovery rate of Sporothrix spp. isolates maintained for years through the mineral oil technique. Methods: Two hundred and seventeen isolates of Sporothrix spp. from the fungal collection of the Mycology Laboratory of Faculdade de Medicina - Universidade Federal do Rio Grande (FAMED-FURG), Southern Brazil, with a mean period of storage of five years, were included in the study. Isolates were subcultured in duplicate on Sabouraud dextrose agar and on brain heart infusion agar. Results: Of the 217 isolates, only 16.6% (n = 36) were recovered. The median period of storage was similar between the viable (n = 36) and non-viable (n = 181) isolates, being 5.8 years and 4.7 years, respectively (p ˃ 0.05). Conclusion: Considering the low rate of Sporothrix spp. recovery using mineral oil, we reject to use this methodology and strongly recommend another storage methods to guarantee the maintenance of viable Sporothrix spp. isolates in fungal cultures.