Using Bacteriophages To Reduce Formation of Catheter-Associated Biofilms by Staphylococcus epidermidis

Abstract

ABSTRACT Use of indwelling catheters is often compromised as a result of biofilm formation. This study investigated if hydrogel-coated catheters pretreated with a coagulase-negative bacteriophage would reduce Staphylococcus epidermidis biofilm formation. Biofilms were developed on hydrogel-coated silicone catheters installed in a modified drip flow reactor. Catheter segments were pretreated with the lytic S. epidermidis bacteriophage 456 by exposing the catheter lumen to a 10-log-PFU/ml culture of the bacteriophage for 1 h at 37°C prior to biofilm formation. The untreated mean biofilm cell count was 7.01 ± 0.47 log CFU/cm 2 of catheter. Bacteriophage treatment with and without supplemental divalent cations resulted in log-CFU/cm 2 reductions of 4.47 ( P < 0.0001) and 2.34 ( P = 0.001), respectively. Divalent cation supplementation without bacteriophage treatment provided a 0.67-log-CFU/cm 2 reduction ( P = 0.053). Treatment of hydrogel-coated silicone catheters with an S. epidermidis bacteriophage in an in vitro model system significantly reduced viable biofilm formation by S. epidermidis over a 24-h exposure period, suggesting the potential of bacteriophage for mitigating biofilm formation on indwelling catheters and reducing the incidence of catheter-related infections.