Final answer:
Patients with problems in cell-mediated immunity, such as those with SCID or HIV, are prone to opportunistic infections by pathogens normally controlled by T cells, including viruses, certain bacteria, and fungi.
Step-by-step explanation:
If a patient had a problem with cell-mediated immunity, they would be prone to infections by pathogens that are normally controlled by T cells, such as viruses and certain types of bacteria and fungi. One type of immunodeficiency that affects cell-mediated immunity is Severe Combined Immunodeficiency (SCID), where both B-cell and T-cell responses are impaired. As such, patients with SCID can suffer from severe opportunistic infections due to organisms like Candida spp., Pneumocystis jirovecii, or pathogenic strains of E. coli because their immune systems are not able to effectively respond to these pathogens.Furthermore, another group of immunodeficiencies is known as secondary immunodeficiencies, which can develop after birth due to various factors such as HIV infection, which targets helper T cells. This leads to a weakened immune system that can be exploited by opportunistic infections, exemplified when such infection progress to AIDS. It's also worth mentioning that individuals lacking sufficient TH17 cells may become more susceptible to chronic mucocutaneous infections as well as bacteremia and gastrointestinal infections.