Secreted Subtilisin Sub3 from Microsporum Canis Is Required for Adherence to but Not for Invasion of the Epidermis

The study concluded that the protease Sub3 from *Microsporum canis* was crucial for the fungus's adherence to feline epidermis but not for its invasion. Researchers used an RNA-silenced strain of *M. canis* and found a significant reduction in adherence to feline corneocytes, while invasion capabilities remained unaffected. This indicated that Sub3 was essential for the initial attachment phase of infection. The study utilized both ex vivo adherence models and in vivo guinea pig models, confirming the stability of the RNA-silenced strain and the specific role of Sub3 in pathogenicity.