CHARACTERIZATION OF BIOFILM AND ENCRUSTATION ON URETERAL STENTS IN-VIVO

Objective To examine the relationship between encrustation and microbi al biofilm formation on indwelling ureteric stents. Patients and metho ds Ureteric stents from 40 patients were examined for the presence of a microbial biofilm and encrustations. Bacteria in stent biofilms were isolated and identified. Results A profuse biofilm (> 10(4) c.f.u. cm (-3)) was identified on 11 (28%) stents. Enterococcus faecalis was the most common biofilm organism identified and Proteus spp. were not pre sent. Encrustation was seen in 23 (58%) of stents and was not associat ed with the level of urinary calcium. The major risk factor for stent encrustation was the presence of urolithiasis. Importantly, there was no causative link between stent biofilm formation and encrustation. Bo th biofilm formation and encrustation increased with the duration of s tenting. Conclusion The results indicate that polyurethane is readily encrusted and colonized by bacteria in vivo despite antibiotic prophyl axis. Newer materials must be sought if effective long-term stenting i s to be achieved.