Assessment of Candida attributes under in vitro repeated exposure to hydrogen peroxide

Abstract Fungal infections have emerged as a significant concern in healthcare, due to the development of antifungal resistance and the limited availability of diagnostic and therapeutic options. The Candida species represent a category of particular importance with regard to fungi. Therefore, the implementation of infection prevention and control measures, such as hydrogen peroxide (H 2 O 2 ) disinfection, is imperative in healthcare settings. In consideration of the existing literature, which demonstrates that repeated exposure to H 2 O 2 does not compromise microbial tolerance to the disinfectant, the expression of virulence attributes may be altered under the influence of external selective pressure. The present study aims to evaluate the effect of repeated exposure to H 2 O 2 on antifungal susceptibility profiles, catalase production, and biofilm formation on Candida strains in a phenotypic assessment of the microbial behaviour. In previous studies, strains of C. albicans , C. parapsilosis , and C. auris were repeatedly exposed to different H 2 O 2 concentrations and evaluated for their susceptibility to the disinfectant over 30 days. The present study demonstrated that repeated exposure to H₂O₂ resulted only in minor fluctuations of the antifungal susceptibility of C. albicans and C. parapsilosis , but not of C. auris . Repeated exposure to H₂O₂ demonstrated no variation in catalase production or alteration in biofilm formation for the evaluated species. In conclusion, repeated exposure to H₂O₂ resulted in only minor fluctuations in antifungal susceptibility in C. albicans and C. parapsilosis strains, demonstrating that utilization of H 2 O 2 as a daily disinfectant is safe in relation to microbial adaptation. However, environmental surveillance is advised to prevent the inadvertent development of antifungal resistance.