Characterization of biofilms produced by Candida species isolated from tertiary care hospitals, Rawalpindi, Pakistan

Biofilm formation is one of the important virulence factors of Candida species. Candida species are able to form biofilm on any biotic or abiotic surface. These biofilms can cause recurrent infections as they overtake the immune responses and are resistant to most of the available antifungals. The present study was conducted to characterize the biofilm formation by clinical isolates of Candida obtained from a tertiary care hospital, Rawalpindi, Pakistan. The biofilms were quantified using quantification methods such as dry weight measurement and XTT reduction assays. Candida albicans strain SC 5314 was used as a control in each experiment. The structural organization 3D was studied by confocal laser microscopy. Additionally a well-established 96 well plate method was used to study the antifungal susceptibility of the biofilms. It was observed that all the Candida sp. form biofilm and was highly resistant to fluconazole. Caspofungin was effective against all species of the Candida included in the study but Candida glabrata showed reduced suceptibilty towards it. We also showed that biofilms formed by the Candida glabrata are significantly different probably due to the inability to form hyphae.