Chitinase-functionalized UiO-66 framework nanoparticles active against multidrug-resistant Candida Auris

Abstract

Candida auris (C. auris) is a yeast that has caused several outbreaks in the last decade. Cell wall chitin plays a primary role in the antifungal resistance of C. auris. Herein, we investigated the potential of chitinase immobilized with UiO-66 to act as a potent antifungal agent against C. auris. Chitinase was produced from Talaromyces varians SSW3 in a yield of 8.97 U/g dry substrate (ds). The yield was statistically enhanced to 120.41 U/g ds by using Plackett–Burman and Box–Behnken design. We synthesized a UiO-66 framework that was characterized by SEM, TEM, XRD, FTIR, a particle size analyzer, and a zeta sizer. The produced framework had a size of 70.42 ± 8.43 nm with a uniform cubic shape and smooth surface. The produced chitinase was immobilized on UiO-66 with an immobilization yield of 65% achieved after a 6 h loading period. The immobilization of UiO-66 increased the enzyme activity and stability, as indicated by the obtained Kd and T1/2 values. Furthermore, the hydrolytic activity of chitinase was enhanced after immobilization on UiO-66, with an increase in the Vmax and a decrease in the Km of 2- and 38-fold, respectively. Interestingly, the antifungal activity of the produced chitinase was boosted against C. auris by loading the enzyme on UiO-66, with an MIC50 of 0.89 ± 0.056 U/mL, compared to 5.582 ± 0.57 U/mL for the free enzyme. This study offers a novel promising alternative approach to combat the new emerging pathogen C. auris.