The interaction between biofilm formation in candida species and materials used in central venous catheters

Objective: Among catheter related bloodstream infections, candida species are in forth line within the pathogens isolated form blood cultures. The aim of this study is to determine the biofilm formation of candida species which cause candidemia in-vitro on the surface of central venous catheters made with different materials and to determine the role of surface diversity.Method: In our study slime factor presence in C. albicans, C. tropicalis, C. parapsilosis and C. glabrata species isolated from blood cultures were examined with glycolised liquid saboraud medium in petri dish. From each candida species, one slime factor positive sample were collected randomly. Catheters made of silicone, carbotane, polyurethane were cut 0,5 cm long and were put into wells, containing 96 wells in one plate. Fungus suspension which contained 107 colonies in 1 mL added to the wells and incubated in 370 C for 72 hours. After incubation, plates were washed and MTT reduction reactivator was used and the plate was read in 540nm absorbans in spectrophotometer to determine the quantity of colonies in biofilm. The fungus adhered to catheter surface were fixed with 2,5% gluteraldehide and 1% Osmium tetra-oxide solution and were dried in the incubator. After this procedure, the plate was covered with gold and the images were analyzed with scanning electron microscope.Results: In this study, it is determined that C. parapsilosis species produced more slime factor than other candida species (%83.4). It is found that there is a significant difference between C. albicans and non-albicans species in producing slime factor (p=0.0001). Although C. albicans, C. parapsilosis and C. glabrata adhered to all three types of catheter without any difference, C. tropicalis fixed to carbotane catheter at least (p=0.011) and also less to silicone catheter (p=0.024).Conclusion: Except C. tropicalis species there was no superiority determined betweenthe catheters we used. Altough carbotane catheter was resistant to the biofilms produced by C.tropicalis, it was easily colonized with other candida species. As it is determined in this study,when planing to purchase catheters, units of candidemia is common the cost-effectivenesssholud be considered more than the carbotane materials used for catheter.Keywords: Biofilm, Candida, Catheter.