In which form are dimorphic molds found in infected tissue?

Dimorphic molds are unique fungi that can exist in two different forms depending on the environmental conditions. In particular, when they infect a host, these organisms typically switch to the yeast phase. This conversion is crucial for their pathogenicity because the yeast form is often more suited to survive within the host's body, where temperature, nutrient availability, and immune responses differ significantly from the external environment where the mold form thrives.

The yeast phase allows these fungi to evade the immune system more effectively and to inhabit tissues, as it can adapt to the warmer temperatures found in the human body. The yeast cells can also reproduce through budding, which is a mechanism well-suited for survival and growth within tissues.

Understanding this transformation from a mold to a yeast form is essential in microbiology, especially in the context of infections caused by dimorphic fungi, such as Histoplasma capsulatum or Coccidioides immitis. These pathogens can lead to serious diseases, and recognizing their form in infected tissues helps inform diagnosis and treatment strategies.