Biofilm-Mediated Urinary Tract Infections

Abstract

Biofilm-forming bacteria may involve approximately in 80% of all infections with urinary tract being one of the main areas where biofilm can become a serious threat. Biofilm plays a major role in causing catheter-associated UTIs and recurrent UTIs. Recurrent UTIs can be categorized as relapse (if all episodes of infections are caused by the same microorganism) and reinfection (if the episodes are caused by different microorganisms). Relapses may be due to biofilm-forming capacity of the microorganisms and involve protected, intracellular bacterial reservoir in bladder mucosa. Urinary catheters allow entry of microorganism, usually the commensal perineal flora into the urinary tract, causing catheter-associated UTI (CAUTIs). CAUTIs account for 40% of all nosocomial infections. Biofilms not only play an important role in CAUTIs but also cause blockage of catheter. Urinary catheter encrustation is another problem of concern as it can cause blockage of catheter, leading to urine retention, which is a painful medical emergency. The organisms most often contaminating these devices and developing biofilms are Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus epidermidis, Enterococcus faecalis, etc. Biofilms provide high resistance to antibiotics. Several studies have recommended for combination therapy rather than using single antibiotics, with macrolides being the first choice. Another way to use antimicrobials is to impregnate catheters with these antimicrobials agents. This may restrict bacteria to attach themselves to catheter surface and further development of biofilm. Another approach is to find out new therapeutic options in a way that either biofilm does not form and if forms then it could be treated easily. Some of them are coating of catheter with hydrogels, using nanoparticle or iontophoresis to disrupt biofilm, to use non-pathogenic bacteria so that they can competitively impede with pathogens to establish quorum sensing inhibitors, etc.