A 32-year-old woman with poorly controlled type 2 diabetes mellitus (HbA1c 10.2%) presents with vulvovaginal itching, erythema, and thick white vaginal discharge for 2 weeks. Wet mount microscopy shows budding yeast cells and pseudohyphae. Culture on Sabouraud dextrose agar at 37°C grows white, creamy colonies. The isolate ferments glucose and maltose but not trehalose. What is the most likely causative organism?

## Identification of Candida albicans ### Clinical Presentation **Key Point:** Vulvovaginal candidiasis in a hyperglycemic patient is a classic presentation. Hyperglycemia increases vaginal glucose, creating an ideal environment for Candida overgrowth. ### Diagnostic Features | Feature | Candida albicans | Candida glabrata | Candida auris | Candida tropicalis | |---------|-----------------|-----------------|---------------|-------------------| | **Morphology** | Budding yeast + pseudohyphae | Small budding yeast only | Budding yeast | Budding yeast + pseudohyphae | | **Glucose fermentation** | Positive | Positive | Positive | Positive | | **Maltose fermentation** | Positive | Positive | Negative | Positive | | **Trehalose fermentation** | Positive | Positive | Negative | Negative | | **Germ tube test** | Positive (37°C, serum) | Negative | Negative | Positive | | **CHROMagar appearance** | Green | Pink/magenta | Pink/magenta | Pink/magenta | ### Biochemical Interpretation **High-Yield:** The fermentation pattern (glucose+, maltose+, trehalose−) is consistent with *Candida tropicalis* or *Candida albicans*. However, the presence of **pseudohyphae on wet mount** is the critical differentiator — *C. albicans* produces true pseudohyphae and germ tubes, while *C. tropicalis* produces only budding yeast in most clinical specimens. **Clinical Pearl:** *Candida albicans* accounts for ~80–90% of vulvovaginal candidiasis cases. The combination of pseudohyphae morphology and fermentation profile (glucose+, maltose+) points definitively to *C. albicans*. ### Pathophysiology **Mnemonic: CHAMP** — *Candida albicans* Host factors: - **C**arbohydrate metabolism (hyperglycemia) - **H**ormonal changes (estrogen, pregnancy) - **A**ntibiotics (disrupted normal flora) - **M**ucosal barrier disruption - **P**hagocytic dysfunction (diabetes) ### Risk Factors in This Case - Poorly controlled diabetes (HbA1c 10.2%) - Female gender - Intact immune system (non-immunocompromised presentation)