The Natural History and Composition of Urinary Catheter Biofilms: Early Uropathogen Colonization with Intraluminal and Distal Predominance

Purpose:We sought to determine the composition and initiation site of bacterial biofilm on indwelling urinary catheters and to track biofilm progression with time.Materials and Methods:Indwelling urinary catheters were collected from 2 tertiary care centers following removal from patients. Indwelling time was noted and catheters were de-identified. Catheters were sectioned, stained for biofilms and analyzed by spectrophotometry and visualization. Biofilm colonization patterns were analyzed using descriptive statistical analysis and bacterial composition was determined using next generation sequencing.Results:We collected and analyzed a total of 33 catheters from 26 males and 7 females with indwelling time ranging from 15 minutes to 43 days. Biofilm colonization was consistently high on the region of the balloon for all indwelling times. After week 1 the distal third of the catheter had higher biofilm colonization than the proximal third (week 2 p=0.034). At all indwelling times the intraluminal surface of the catheter had greater biofilm colonization than the outer surface. Next generation sequencing detected potential uropathogenic bacteria in all 10 analyzed samples.Conclusions:The catheter balloon, its distal aspect and its lumen were the predominant locations of biofilm comprising uropathogenic bacteria. Strategies to prevent or treat biofilm should be targeted to these areas.