Phenotypic and molecular identification of Sporothrix isolates of clinical origin in Northeast China

Sporotrichosis is the most common deep mycosis in Northeast China which is an area of high epidemicity due to contact with reeds or cornstalks. In this study, we have characterized a total of 74 clinical isolates from fixed cutaneous, lymphocutaneous and disseminated clinical forms and from Heilongjiang, Jilin, and Liaoning provinces, respectively. All isolates (previously as Sporothrix schenckii) were identified as Sporothrix globosa according to their phenotypic characteristics and calmodulin gene sequences analysis. They were subdivided into two sub-clades (S. globosa I and S. globosa II). Most of our isolates (71/74) presented restricted growth at 37 °C, which differed from a previous report. Up to now, S. globosa is the only pathogenic species in Northeast China, no matter what kind of clinical form and which region it is isolated from. Most of our clinical isolates (68/74) were clustered with three Chinese environmental isolates reported in the literature. The new findings of S. globosa isolates on division and thermotolerance at 37 °C described in this study will help us gain a better understanding of S. globosa.