The arrangement of dual-species biofilms of Candida albicans and Issatchenkia orientalis can be modified by the medium: effect of Voriconazole.

Both Candida albicans and Issatchenkia orientalis have been isolated from different types of infections over the years. They have the ability to form communities of microorganisms known as biofilms. It has been demonstrated that the medium employed in studies may affect the biofilm development. The aim of this study was to investigate the arrangement of dual-species biofilms of C. albicans and I. orientalis cultivated on either RPMI-1640 or Sabouraud Dextrose Broth (SDB), as well as the inhibitory effect of Voriconazole (VRC). For the experiments performed, ATCC strains were used, and yeast-mixed suspensions were inoculated in 96-well plates with either RPMI-1640 or SDB, in the presence or absence of VRC. The results were observed by counting the number of CFU obtained from scraping off the biofilms produced and plating the content on CHROMagar Candida medium. It was observed that for all conditions tested the medium chosen affected the arrangement of dual-species biofilms: when RPMI-1640 was used, there was a prevalence of C. albicans, while the opposite was noted when SDB was used. It could be suggested that the medium and environment could regulate interactions between both yeast species, including the response to different antifungal drugs.