Biofilm formation and drug susceptibility of biofilm Candida spp. clinically isolated from nasopharyngeal cancer patients in Vietnam

Background and Objectives: The biofilm formation has been widely recognized as one of the main mechanisms of antimicrobial resistance development in microorganisms. However, few studies are focusing on this phenomenon in Candida spp. in clinical settings, especially on immuno-compromised patients. Materials and Methods: In this study, both the rate of biofilm formation in those patients and its drug susceptibility in initial and mature biofilm were assessed using crystal violet assay and dilution method. Results: The results demonstrated that the biofilm formation rate was similar between albicans and non-albicans Candida. However, the biofilm formation capacity was more pronounced in non-albicans Candida, especially, C. glabrata. As expected, there was a significant relationship between biofilm formation and drug resistance. In addition, our study reconfirmed that the age of high concentration of antifungal agents only affected Candida before its biofilm formation regardless of its biofilm formation capacity. In the contrary, once the biofilm was formed even elevated drug concentrations did not show sufficient efficacy, highlighting a need for high dosage at the early stage of treatment for those patients. Conclusion: The results of this study highlighted the importance of using appropriate antifungal agents for Candida treatment before the formation of biofilm.