ABSTRACT
The use of indwelling medical devices, such as central venous catheters, in current therapeutic practice has been found to be responsible for more than 80% to 90% of hospital-acquired bloodstream and deep-tissue infections. Prolonged intensive care unit stays, immunosuppression, and surgical procedures have increased the prevalence of nosocomial, especially fungal infections. Candida species are the most commonly associated fungal organisms with such nosocomial infections, with Candida albicans being the predominant species causing systemic disease. Catheter-related bloodstream infections commonly involve colonization of microorganisms on catheter surfaces where they eventually become embedded in a biofilm. Biofilms are defined as extensive communities of sessile organisms irreversibly associated with a surface, encased within a polysaccharide-rich extracellular matrix, exhibiting enhanced resistance to antimicrobial drugs. Since C. albicans is the most common fungus associated with these infections, biofilms formed by this pathogenic fungus can be used as a model to investigate the biology and pathogenesis of biofilm-associated infections. Recent studies have provided revealing insight into the effect of different variables (including growth time, nutrients, and physiological conditions) on fungal biofilm formation, morphology, and architecture. This chapter provides an update on biofilms and discusses major recent advances achieved in the clinically relevant area of catheter-associated fungal biofilms.
