Central line-associated Cyberlindnera fabianii fungemia: A case report and review of diagnostic and therapeutic challenges.

Introduction: Cyberlindnera fabianii is an uncommon opportunistic yeast increasingly recognized as a cause of invasive fungal infections, particularly in immunocompromised patients and those with indwelling medical devices. Clinical experience remains limited, with most published cases involving neonates or adults with significant comorbidities.

Case presentation: We report a case of C. fabianii fungemia in a 26-year-old man with end-stage renal disease on maintenance hemodialysis via a long-term tunneled catheter. The patient presented with fever following dialysis and was found to have leukocytosis and elevated inflammatory markers. Blood cultures from both peripheral and catheter sites grew yeast after 48 hours. Empiric antibacterial therapy was initiated, and the hemodialysis catheter was removed. Antifungal treatment with anidulafungin was started, leading to clinical improvement. Species identification was achieved using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), which revealed C. fabianii. Antifungal susceptibility testing demonstrated low minimum inhibitory concentrations (MICs) for echinocandins and variable susceptibility to azoles. The patient completed a 14-day course of anidulafungin with full recovery.

Discussion: This case underscores the importance of accurate identification of rare yeasts such as C. fabianii, which may be misidentified as other less pathogenic species. MALDI-TOF MS and molecular diagnostics are critical tools for early detection. Due to its potential for azole resistance and biofilm formation, echinocandins appear to be an effective treatment option. Prompt catheter removal and appropriate antifungal therapy were pivotal to the patient's successful outcome.

Conclusion: C. fabianii should be considered in patients with fungemia and risk factors for invasive candidiasis, especially when initial identification is inconclusive. Awareness of this emerging pathogen and its management is essential to ensure timely intervention and improve clinical outcomes.