In-vitro Inhibition of Biofilm Formation in Candida albicans and Candida tropicalis by Heat Stable Compounds in Culture Filtrate of Aspergillus flavus

Abstract

Background: Invasive candidiasis, caused mostly by Candida albicans and C. tropicalis is one of the most common causes of bloodstream infection with a substantial attributable mortality. This disease is associated with formation of structured, multilayered microbial communities known as biofilms over indwelling devices. Treatment is rendered difficult owing to factors like poor drug penetration through biofilms and high cost of the available antifungal drugs. Hence there is imminent need of developing low-cost natural compounds inhibiting Candidal biofilm formation in vitro. Organohalgen compounds derived from crude culture filtrate of Aspergillus flavus have been documented to impair in vitro Candidal survival. Aim: We aimed to detect the effect of preheated and unheated crude culture filtrate of Aspergillus flavus on biofilm formation of Candida albicans and C. tropicalis in vitro. Setting and Designs: Ours was a laboratory-based observational study with clinical isolates of the microorganisms selected randomly. Material and Methods: In this study, we showed for the first time by microtitre plate method that heat stable compounds which were present in preheated and unheated culture filtrates of Aspergillus flavus inhibited biofilm formation of Candida albicans and C. tropicalis and also lipase activities of these pathogens, and filtrate was non-toxic on human cell line as checked microscopically. Statistical Analysis used: Z-test of significance was used to calculate significant difference between Candidal biofilm formation in normal liquid medium and culture filtrate, respectively. Results and Conclusion: Heat stable compounds present in culture filtrate of Aspergillus flavus inhibit biofilm formation of Candida albicans and C. tropicalis and also in-vitro lipase activity of these pathogens and could pave the way for development of low-cost alternatives to treat invasive candidiasis.

Keywords

• invasive candidiasis
• biofilm
• candida spp
• aspergillus flavus