Character Virulence Association Factors and Gene Mutation Mediating Multidrug Resistance Phenotypes in Candidozyma...

Candidiasis, traditionally dominated by Candida albicans infection, now faces a paradigm shift with the emergence of non-C. albicans infections, such as the multidrug-resistant (MDR) Candidozyma (formerly Candida) species. Critically, the emergence of multidrug resistance (MDR) Candidozyma duobushaemulonii (also known as Candida duobushaemulonii) poses critical challenges to antifungal therapy. Here, in this comparative study, we analyzed four clinical C. duobushaemulonii isolates (cd, cd1, cd2, and cd3) to establish strain-specific virulence and antifungal resistance profiles. Biofilm quantification using crystal violet (CV) and 2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) metabolic activity assays showed different biomass production levels across strains. Cellular aggregation capacity differed significantly, while cell surface hydrophobicity (CSH) showed inverse patterns. In Galleria mellonella infection models, virulence stratification was observed. Antifungal susceptibility testing revealed minimum inhibitory concentration (MIC) azole gradients. MDR in the cd1 strain extended to 5-fluorocytosine (5-FC) and anidulafungin (ANI), whereas the cd3 strain showed intermediate posaconazole (PSZ) resistance distinct to the cd2 strain. Amino acid sequence analyses indicated that Y132F substitutes in ERG11 and D139N in FUR1 genes occurred in cd and cd1 strains. Gene expression analysis recorded various regulatory situations among strains. These analyses provide a complete resistance-virulence matrix for C. duobushaemulonii, establishing baseline characteristics for epidemiological surveillance and a reference framework for future comparative studies.