Candida nivariensis, an emerging fungus causing peritonitis in a patient receiving peritoneal dialysis

Area of Science:

• Medical Mycology
• Infectious Diseases
• Nephrology

Background:

• Fungal peritonitis (FP) is a serious complication in patients undergoing peritoneal dialysis (PD), often linked to poor prognoses.
• Non-albicans Candida species are frequently implicated in FP, necessitating precise etiological identification.

Observation:

• A case of FP caused by Candida nivariensis in a 68-year-old woman with end-stage kidney disease on PD is described.
• Initial biochemical profiling failed to identify the yeast, requiring advanced techniques like molecular phylogeny and MALDI-TOF mass spectrometry.
• The patient received standard treatment including PD catheter removal and fluconazole, but showed only partial response.

Findings:

• Candida nivariensis was definitively identified as the causative agent using molecular and mass spectrometry methods.
• Antifungal susceptibility testing revealed resistance to certain triazoles, while susceptibility to amphotericin B and voriconazole was noted.
• Despite treatment, the patient experienced a partial clinical response and ultimately succumbed to the infection.

Implications:

• This case highlights the importance of accurate identification of rare Candida species in FP for appropriate treatment selection.
• Understanding the drug susceptibility profile of the causative organism is critical for optimizing antifungal therapy in PD-associated peritonitis.
• The findings underscore the challenges in managing invasive fungal infections in immunocompromised patients, even with guideline-directed care.