Evaluation of the ability of five Candida species to produce in vitro biofilms on the surface of teflon, polyurethane and polyvinyl chloride

Abstract number: r1911

Estivill  D., Torres-Lana  Á., Arias  Á., Arévalo  M.P.

Objectives: 

To assess the in vitro ability of five Candida species to produce adherence and biofilms on the surface of three synthetic material commonly used in Medicine: teflon, polyurethane and polyvinyl chloride (PVC).

Material and methods: 

We have studied 82 clinically relevant isolates of yeasts from genus Candida: 23 C. albicans, 23 C. parapsilosis, 17 C. glabrata, 16 C. tropicalis and 5 C. krusei. Catheters were carefully cut into 1 cm segments and sterilised with ethylene oxide. A surface of 28 mm² was estimated for polyurethane, 36 mm² for PVC and 45 mm² for teflon. The segments were incubated together with an adjusted inoculum of yeasts (optical density of 1.0 at 540 nm wavelength). The incubation was 35°C for 90 minutes to establish baseline adherence and further 72 hours to assess the biofilm production. Nonadherent organisms were removed by washing three times with 1 ml of PBS. Results are shown as logarithm (log) of viable cells in colony forming units per millilitre (CFU/ml). In both cases results are adjusted according surface size as estimated previously.

Results: 

For polyurethane C. albicans and C. parapsilosis showed the lesser adherence (6.88 log and 7.29 log respectively) and biofilms production (9.00 log and 9.31 log respectively) with this material, whereas C. tropicalis showed the similar values for adherence and higher values for biofilm production (7.22 log for adherence and 9.43 log respectively). The difference was not significant. For PVC, C. albicans and C. glabrata had the lower measures for adherence (7.20 log and 7.82 log respectively) and again C. tropicalis showed the intermediate value (7.29 log). In the case of biofilm formation on PVC the results were 9.39 log for C. albicans, 9.79 log for C. parapsilosis, 8.93 log for C. glabrata, 8.24 log for C. krusei and 9.04 log for C. tropicalis. No statistic signification was found. For teflon, we found that C. albicans had the lower result in adherence (6.56 log) and C. parapsilosis the highest (7.54 log) and it was statistically significant. In the case of biofilm production, C. parapsilosis and C. albicans had the greater growth (10.37 log and 10.17 log, respectively) and C. glabrata had the lower biofilm formation (8.93 log) and these differences were statistically significant.