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

Fungal peritonitis (FP) is usually associated with poor patient outcomes and is mostly caused by non-albicans Candida species. We present a Candida nivariensis-associated peritonitis in a 68-year-old woman with end-stage kidney disease on peritoneal dialysis (PD). Biochemical profiling of the cultured yeast of the effluent sample did not adequately identify the yeast. Hence, molecular phylogeny and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) mass spectroscopy were employed which correctly identified the causative species, C. nivariensis. PD catheter was removed and oral fluconazole was promptly started according to the 2022 International Society for PD (ISPD) Peritonitis Guidelines. However, the patient achieved only a partial clinical response and eventually died. The susceptibility test showed that the pathogen was susceptible to amphotericin B and voriconazole but resistant to other triazoles. This report underlines the importance of identifying the species, though rarely reported, and the drug susceptibility of the organism.