Answer:
Michael is a compromised host. Yeast is an opportunistic pathogen in this case.
Step-by-step explanation:
The term compromised host refers to the individual who has a poor immune system and is therefore susceptible to many infections, as his defense system is unable to prevent foreign bodies from entering his body and causing disease. Michael is a compromised host because HIV has left his immune system weak and inefficient, so much so that Michael's immune system has not been able to fight off a candidiasis infection.
The yeast responsible for candidiasis, in this case, is an opportunistic pathogen. Opportunistic pathogen is one that can normally be found in the body but causes no harm in healthy individuals. The body will only become infected and have the disease when low immune defenses occur.