Candida biofilms and their less susceptibility to antifungal drugs

Candida species as opportunistic pathogens are liable to attack immunocompromised hosts and are the most common fungi isolated from nosocomial infections. Biofilms are structured microbial communities that are attached to a surface. Formation of biofilms by Candida species have been demonstrated on a number of devices، including central venous catheters، cardiovascular devices and urinary catheters. Successful management in the treatment of Candida biofilms depends on early diagnosis and treatment، the adequate choice of therapy and antifungal resistance. Biofilms formed by these organisms are associated with drastically enhanced ability to express resistance against most antifungal agents including amphotericin B and fluconazole. The expression of drug efflux pumps during the early phase of biofilm formation and alterations in membrane sterol composition contribute to resistance of these biofilms against antifungal agents. In this review، we will focus on the antifungal resistance exhibited by Candida biofilms and discuss the mechanisms underlying this resistance.