Atigenic similarity between Ceratocystis species and Sporothrix schenckii as observed by immunofluorescence

Antigenic properties of Sporothrix schenckiii and 2 species of Ceratocystis (C. stenoceras and C. ulmi) were compared by indirect immunofluorescent staining technique. Both species of Ceratocystis and 2 strains of S. schenckii reacted equally well with the unabsorbed antisera against 2 strains of S. schenckii, indicating that these three species share common antigen. The absorption experiments showed that only S. schencki human strain demonstrated a unique antigen. These results support the hypothesis of Ceratocystis-Sporothrix complex in the point that both species have one major common antigen.