Electron microscopic study of an infected Foley catheter.

A scanning and transmission electron microscopic study was made of material from the surface of a Foley catheter removed from an 87-year-old woman with antibiotic-resistant bacteriuria. A thick, adherent bacterial biofilm was found. The sessile adherent bacteria were surrounded by an extensive exopolysaccharide glycocalyx that appears to be fundamental in the pathogenesis of catheter-associated urinary tract infections and their resistance to systemic antibiotic therapy.