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C. glabrata Fluconazole Resistance — SCE Infectious Diseases MCQ

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ModerateFungal InfectionsC. glabrata Fluconazole ResistanceSCE Infectious Diseases

A 55-year-old man develops a catheter-related bloodstream infection with Candida glabrata. Susceptibility testing shows Fluconazole MIC 16 mg/L (resistant) and Caspofungin MIC 0.25 mg/L (susceptible). The catheter is removed. Why is Fluconazole resistance common in C. glabrata?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — C. glabrata has intrinsically reduced susceptibility to Fluconazole (due to enhanced efflux pump activity — CDR1/CDR2 upregulation) and develops resistance more readily than C. albicans during azole exposure

D. glabrata is the second most common Candida species in invasive disease. It has intrinsically REDUCED susceptibility to Fluconazole (MICs are higher than C. albicans) due to: (1) upregulation of CDR1/CDR2 efflux pumps (ATP-binding cassette transporters that pump azoles out of the cell), (2) point mutations in ERG11 (the azole target). Fluconazole should NOT be used empirically when C. glabrata is suspected or confirmed — echinocandins are the treatment of choice. Importantly, C. glabrata can also develop echinocandin resistance (FKS mutations) during treatment — a dangerous scenario leaving very few options.

Reference: ESCMID 2024 – Candida; IDSA 2016 – Candidiasis; EUCAST 2024