4. The yeast cells of P. brasiliensis, H. capsulatum and B. dermatitidis are internalized by macrophages of their human hosts, but they have a remarkable ability to survive and even reproduce inside the lytic vacuoles by raising the intravacuolar pH and withstanding the attack of the lytic enzymes and the ‘oxidative burst’
created by the macrophages.
Yeast cells inside macrophages represent latent inoculum which can cause relapses many years after the initial infection, especially when the host’s immune system becomes weakened by other causes. Thus, these three species have been likened, in terms of their pathology, to the bacterium Mycobacterium tuberculosis.