Final answer:
The most common yeast responsible for oral thrush is Candida albicans, a unicellular fungus that can cause infections when the body's natural balance is disturbed.
Step-by-step explanation:
Candida albicans is a unicellular fungus that significantly contributes to microbial infections in humans, such as oral thrush. Oral thrush is characterized by white patches and pseudomembranes in the mouth, often associated with bleeding. This yeast infection is particularly common in infants or those with compromised immune systems, including patients with AIDS.
The yeast Candida, including C. albicans, normally exists as part of the human microbiota, living harmlessly as it's kept in check by the body's normal flora and immune system. However, when there's an imbalance due to factors like pH changes, weakened immune defenses, or alterations in the normal bacterial population, Candida albicans can grow uncontrollably, leading to infections such as oral thrush. Treatments for oral thrush include topical antifungals like nystatin and clotrimazole or, in more severe cases, systemic antifungal medication.