Biofilms on Indwelling Urologic Devices: Microbes and Antimicrobial Management Prospect

Background: Biofilms (BFs) are a potential source of highly resistant infections, frequently formed on devicesand pose problems for management. Aim: This study was to develop rational approach for prevention of indwelling urologic device associated biofilm colonization. Subjects and Methods: From randomly selected patients visiting Department of Urology of a tertiary hospital in India 150 uro catheters and 31 used ureteric stents, in-situ for > 30, were collected aseptically. The organisms were isolated and identified from washed devices dipped in broth. Evidence of bacteriuria in each case was checked by semi-quantitative method of urine culture, on day 0 and 14 of device use. The BF statuses of the device-adhered organisms were confirmed by modified method of Christensen. The antibiotic susceptibility was determined by disc diffusion method. Data were analyzed using the Graphpad Prism version 5 statistical software. Results: Both single and multi-species BFs were formed on catheters, whereas mono-bacterial BFs were exclusive on stents. Predominant organisms were Pseudomonas aeruginosa (30.67%,69/225,) followed by Staphylococcus aureus (15.11%, 34/225), Escherichia coli (13.78%, 31/225), Klebsiella pneumoniae (12%, 27/225), Staphylococcus epidermidis (8.44%, 19/225). Of all strains, (89.33%, 201/225) were found to be BF positive and their colonizations were early indicated by the presence of insignificant bacteriuria in follow-up urine samples. All BF isolates were resistant to at least three antibiotics. Conclusions: BF colonization was almost inevitable in prolonged used urinary devices and the most frequent organisms were Pseudomonas, Staphylococcus, and Escherichia spp. Their colonizations usually were indicated by insignificant bacteriuria from follow-up samples. Such BF dislodged organisms were multidrug resistant and could be a source of disseminated infection, yet were in-vitro preventable by many drugs.