Fungi in dialysis water and dialysate: occurrence, susceptibility to antifungal agents and biofilm production capacity

Abstract

The aim of this study was to investigate the occurrence of fungi in dialysis water and dialysate, in addition to evaluating the susceptibility to antifungals and the biofilm production capacity of isolated microorganisms. The samples were collected in three hemodialysis units in Bauru (Brazil), every 15 days (July 2017–June 2018) at post-reverse osmosis, reuse, and dialysate points. The fungi were isolated by spread plate on Sabouraud dextrose agar. Filamentous fungi were phenotypically identified and yeasts were subjected to molecular evaluation of the ITS region. Susceptibility test to antifungals was carried out by the broth microdilution method and biofilm production capacity was evaluated in microtiter plates using crystal violet staining. Fungi were isolated in 52/216 (24.1%) samples, with an average count of 16.3 (10–40) CFU/mL. Overall, 61 microorganisms were identified, with 54 (88.5%) filamentous fungi and 7 (11.5%) yeasts. The main genera included were Penicillium, Cladosporium, Scedosporium, Rhinocladiella, Fusarium, and Emmonsia. Most isolates showed high values of minimum inhibitory concentration for 5-flucytosine and fluconazole and 35/45 (77.8%) isolates were classified as strong producers of biofilm. In order to increase the safety of the dialysis process, the adoption of control measures and monitoring of fungi in hemodialysis fluids is suggested.

Alternative and Classical Processes for Disinfection of Water Polluted by Fungi: A Systematic Review

“…Particularly, Fusarium spp., Penicillium spp., Scedosporium spp., Rhinocladiella spp., Mucor spp., Rhinocladiella spp., Emmonsia spp., Scopulariopsis spp., Geotrichum spp., Trichoderma spp., Pithomyces spp., Phoma spp., Paecilomyces spp., and Candida spp. are reported in hospital water systems [39][40][41][42] (see Table S2 in the Supplementary Materials).…”

Fungal identification in the air and water of a hemodialysis unit in Brazil

“…In this therapy, water is utilized in dialysate production and dialyzer reprocessing, exposing patients through the semipermeable membrane of the dialyzer to a considerable volume of dialysis fluid, approximately 400 liters per week or 20,000 liters per year. Given this substantial exposure, the quality of water used in the process plays a pivotal role in mitigating any additional health risks for the patients (Nazemi et al, 2016;Totaro et al, 2017;Anversa et al, 2021).…”

“…Water quality guidelines for hemodialysis procedures have been established in various regions worldwide (Anversa et al, 2021). However, it is important to highlight that in Brazil, current guidelines do not include the enumeration of filamentous fungi and yeasts as part of the recommended microbiological parameters (Brasil, 2014).…”

“…It is relevant to note that infectious diseases represent the second leading cause of mortality in patients with chronic kidney disease, and the incidence of fungal infections has shown a progressive increase in individuals undergoing hemodialysis or peritoneal dialysis (Crowe et al, 2021;Heerspink et al, 2021;Gowher et al, 2022;Kanjanabuch et al, 2022). However, the knowledge regarding the epidemiology of these infections, their associated factors, and the impact they entail is still limited, underscoring the urgent need for microbiological studies to assess water quality in these facilities (Anversa et al, 2021).…”

Physical-chemical and microbiological characterization of water destined to hemodialysis

“…Despite established guidelines, studies conducted in Brazil reveal dissatisfaction levels regarding certain parameters of water quality intended for hemodialysis, such as high levels of heterotrophic bacteria, elevated concentrations of endotoxins (Almodovar et al, 2018;Hilinski et al, 2020;de Jesus et al, 2022), and the significant presence of aluminum (de Jesus et al, 2022). Additionally, some studies report the presence of fungi in these waters, posing potential risks to the health of hemodialysis patients (Montanari et al, 2018;Oliveira et al, 2018;Anversa et al, 2021;Calumby et al, 2023).…”