The catheterized urinary tract selects for MRR1-mediated efflux and fluconazole resistance in Candida albicans biofilms.

Urinary tract environment promotes fluconazole resistance in Candida albicans biofilms via MRR1-mediated efflux, with many isolates shifting from susceptible to resistant in urine-like conditions.

• Why it matters: Understanding the molecular basis of Candida CAUTIs is crucial because current clinical tests may underestimate resistance, leading to ineffective treatments and persistent infections.
• What they did: Researchers developed a physiologically relevant artificial urine medium and performed transcriptomic and genomic analyses on clinical isolates, revealing environment-dependent resistance mechanisms involving MRR1.
• The result: The urinary environment induces efflux and detoxification pathways, increasing drug resistance and suggesting that standard susceptibility tests may not accurately predict fluconazole efficacy in urinary tract infections.