MICROBIAL COLONIZATION OF IMPLANTED SILICONE AND POLYURETHANE CATHETERS

Catheters explanted from nephropathic children were tested for microbial colonization, biofilm formation and surface defects chargeable to the implantation into the organism.; Infection symptoms were detected in 13.6% of cases, versus 16% of colonization detected in the absence of clinical signs of infection. PU catheters showed slightly higher colonization/ infection rates, perhaps due to the implant location. Biofilm was observed on both silicone and PU catheters, independently of the duration of catheterization; a lower amount of organic deposits was observed on the external catheter surfaces. Surface morphology of the catheters seemed to affect biofilm deposition, cavities and scratches present on both unused and explanted catheters providing preferential sites of deposit formation. Surface characteristics as well as biofilm possibly affected bacterial attachment in an in vitro adherence test. The presence of antibiotic molecules trapped in the biofilm was hypothesized to explain partial inhibition of S. epidermidis and S. aureus adhesion to catheter implanted in patients who underwent antibiotic therapy.