Spectrum of Fungal Infections in Continuous Ambulatory Peritoneal Dialysis: A 20-Year Retrospective Study From a Tertiary Care Center

Introduction Fungal peritonitis (FP) is a rare but severe complication in patients on continuous ambulatory peritoneal dialysis (CAPD), leading to high mortality. Globally, FP ranges from 1% to 12%, while in India it reaches up to 24%. In the past decades, rare fungi have been identified as the causative agents of FP. The treatment varies depending on the fungi isolated, and it is important to know the species causing infection. The aim of the present study is to analyze the spectrum of fungal pathogens causing CAPD peritonitis. This study highlights a diverse spectrum of fungal pathogens isolated from CAPD patients over 20 years, emphasizing emerging and rare fungi and underscoring the necessity for species-specific antifungal susceptibility data to guide clinical management. Methods This was a retrospective observational study of 20 years (January 2004-December 2023) conducted at a tertiary care center in India. The CAPD fluid samples received in the Microbiology Department were inoculated into Sabouraud Dextrose Agar with chloramphenicol and incubated at 30°C and 37°C for 5-7 days. The yeast isolates were identified by the VITEK-2C system (bioMérieux, Marcy-l'Étoile, France). Identification of the molds was done by slide culture of the colony. Antifungal susceptibility testing (AFST) for yeasts was performed as per Clinical and Laboratory Standards Institute (CLSI) guidelines M27. Rare pathogens were identified by sequencing the internal transcribed spacer (ITS) region of the rDNA. Results A total of 139 CAPD samples were received from 110 patients. Repeat samples were obtained in 29 patients. Yeast was isolated in 65 (59%) of the samples, whereas mold was isolated in 45 (41%) of the cases. Among the yeasts, <i>Candida tropicalis (C. tropicalis)</i> was isolated in 20 (30.7%) cases. Among the molds, <i>Aspergillus flavus</i> was isolated in 26 (57.7%) cases. AFST data could be retrieved for only 33/65 (50.7%) yeast isolates. A total of 27/33 (81.8%) isolates were susceptible to the antifungals tested, and 3/4 (75%) <i>Trichosporon asahii</i> (<i>T. asahii) </i>isolates were found resistant to amphotericin B. Moreover, 2/20 (10%) <i>C. tropicalis</i> isolateswere found resistant to fluconazole and voriconazole. One rare yeast, <i>Fereydounia khargensis (F. khargensis)</i>, was resistant to amphotericin B and echinocandins. Conclusion <i>Candida</i> spp. was the most common pathogen isolated. The spectrum of fungi causing FP and their AFST is important for the appropriate management of patients.