Evaluation of the potential of colicins to prevent extraluminal contamination of urinary catheters by Escherichia coli.

The feasibility of using colicins to create an antimicrobial lubricant to prevent extraluminal catheter contamination during urinary catheter insertion was assessed. Levels of resistance of uropathogenic Escherichia coli to antibiotics and colicins were compared. The results showed that antibiotics and colicins possess similar frequencies of resistance to a single drug, whereas colicins exhibit significantly lower levels of multidrug resistance (22%) than antibiotics (42%). Colicins and antibiotics showed complementary inhibitory activity, with each targeting different subsets of pathogenic isolates. The collateral impact of these two antimicrobials on genera that are members of the fecal/vaginal/urinary microbiome was assessed, with colicins showing significantly less collateral damage than antibiotics. Using a novel colicin, SR4, minimum inhibitory concentrations (MICs) for a panel of 30 uropathogenic isolates were determined and showed that SR4 achieved the same antimicrobial efficacy as gentamicin using 20-30% less drug. An SR4-impregnated catheter lubricant was created and its ability to prevent extraluminal urinary catheter contamination in vitro was demonstrated. These data indicate that a colicin-impregnated lubricant may provide a viable prophylactic option for preventing catheter-associated urinary tract infections.