TITLE:
Effect of Human Insulin on the Formation of Catheter-Associated E. coli Biofilms
AUTHORS:
Balbina J. Plotkin, Zijian Wu, Kathleen Ward, Shaven Nadella, Jacalyn M. Green, Benny Rumnani
KEYWORDS:
Escherichia coli, Insulin, Catheters, Diabetes Mellitus, Biofilm, Electronegativity
JOURNAL NAME:
Open Journal of Urology,
Vol.4 No.5,
May
28,
2014
ABSTRACT: Biofilm formation is essential for the survival and growth of Escherichia coliin catheter-associated infections. Individuals with type 2 diabetes mellitus can excrete insulin and/or glucose in their urine. This population also has an increased incidence of urinary tract infections. The focus of this study was to determine if the composition of Foley catheter material affects biofilm formation by E. coli in a model system for type 2 diabetes mellitus. Rubber (lubricious-coated), silicon-coated, silver-coated and nitrofurazone-coated catheter segments (5 mm; n = 6) were tested. Catheter segments were added to E. coli ATCC25922 (104 CFU/ml, final concentration) in artificial urine alone, or with insulin (40 μU/ml) and/or glucose (0.1%). After incubation (18 h, 37?C, in air and anaerobically) the level of catheter-associated biofilm was determined by crystal violet staining (Abs550nm). Statistical analysis was done by ANOVA with post-hoc analysis (Tukey). Neither nitrofurazone-coated nor silver-coated catheters supported the formation of E. coli biofilm, regardless of growth condition tested. In contrast, under aerobic biofilm formation on silicon catheters was significantly higher (p E. coli controls. Biofilm formation was also significantly increased (p