Morphology: Yeast with pseudohyphae; biofilm-former on indwelling devices.
Yeast
Typical drugs
- #1Fluconazole— Preferred — better in vitro and clinical activity than echinocandins.
- #2Amphotericin B (liposomal)— If azole resistance or unstable host.
- #3Micafungin— Higher MICs than other species; reserve when fluconazole not an option.
Empiric therapy when resistant
If patient improving on echinocandin, no need to switch (per IDSA). Otherwise step down to fluconazole when susceptible.
Resistance mechanisms
Target alteration
Naturally elevated FKS1 hot-spot variants reduce echinocandin affinity
Example: Higher echinocandin MICs (clinical relevance debated).
Resistance notes
Elevated echinocandin MICs by design — don't reflexively switch if doing well clinically. Azole resistance has emerged in outbreak strains (Brazil, southern Europe).
Pearls
Especially common in neonates and patients with central lines / TPN. Skin / nail commensal. Biofilm on prosthetics — line removal essential. Step down to fluconazole when stable.
References
- IDSA Candidiasis Guidelines (2016)