Oral candidiasis is caused by which genus?

• A. Candida
• B. Aspergillus
• C. Cryptococcus
• D. Saccharomyces

Answer: (A)

Oral candidiasis is a fungal infection of the mouth caused by organisms in the genus Candida, most commonly Candida albicans. Candida muscles normally live in the mouth without causing harm, but they can overgrow when the balance of microbes is disrupted—such as after antibiotic use, with immune suppression, diabetes, dry mouth, or use of inhaled steroids—leading to the white, curd-like plaques and red, irritated mucosa of thrush. The other fungi listed are associated with different diseases: Aspergillus causes aspergillosis, Cryptococcus with cryptococcosis (often meningitis or lung infection), and Saccharomyces is primarily a harmless or kitchen yeast, occasionally problematic only in certain immune-compromised cases. So the genus responsible for oral candidiasis is Candida.