Abstract
Adhesion to medical devices and biofilm formation are considered important virulence factors of Candida tropicalis. This work aimed to use artificial urine (AU) and urinary catheters, under flow conditions, for studying C. tropicalis biofilms. Adhesion and biofilm formation on silicone and latex urinary catheters were quantified by crystal violet staining and determination of colony forming units. Candida surface hydrophobicity was also evaluated, as well as the biofilms’ matrix content in terms of proteins and carbohydrates. Candida tropicalis was able to adhere and to form biofilms along the entire length of the catheters under flow conditions. It was found that the isolate U69 adhered significantly more to both types of catheters than did the reference strain. However, U69 biofilms contained significantly less cultivable cells and higher biofilm biomass than those of the reference strain. Detachment of cells from biofilms on latex catheter was lower compared to silicone catheter. This model using AU appeared to be suitable for studies mimicking the real body conditions. Additionally, C. tropicalis was in fact able to colonize urinary catheters in the presence of AU and to detach from these catheters, demonstrating their capacity to colonize distal sites.
Acknowledgments
The authors acknowledge Cordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brazil, for supporting Melyssa Negri work through grant BEX 4642/06-6. Moreover the authors would like to thank Fabio Luiz Grassi the design of .
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
This paper was first published online on Early Online on 7 March 2011.