MP20-01 AURICLOSENE IRRIGATION SOLUTION PREVENTS ENCRUSTATION BY CRYSTALLINE BIOFILM DUE TO PROTEUS MIRABILIS IN AN IN VITRO URINARY CATHETER PATENCY MODEL

Abstract

INTRODUCTION AND OBJECTIVES: Long-term indwelling urinary catheters are susceptible to blockage due to formation of crystalline biofilms by urease-producing microorganisms such as Proteus mirabilis. An in vitro catheter biofilm model (CBM) was developed to compare current methods for maintaining urinary catheter patency. We compared various bladder irrigation solutions or antimicrobial-coated urinary catheters, versus a novel anti-microbial catheter irrigation solution containing auriclosene (N,N-dichloro-2,2-dimethyltaurine; formerly designated NVC-422). METHODS: CBM units were fed artificial urine at 0.5 mL per min. The artificial bladder chamber was inoculated with 10 8 colony forming units (CFU) of P. mirabilis and biofilm was allowed to establish for 48 hours before daily treatments commenced. A single treatment consisted of two sequential 50-mL irrigations. Each irrigation was retained in the catheter for 15 min and then drained, with a 30-min washout period between the two irrigations. Experiments were conducted for up to 10 days or until catheter blockage. The pH of the effluent, CFU counts in the bladder chamber and the time to catheter blockage were recorded. The area of catheter encrustation was measured using Stereo Zoom imaging. RESULTS: Inoculation of the CBM reactor with 10 8 CFU of P. mirabilis resulted in blockage of the urinary catheters within 5 days. The use of silver-hydrogel or nitrofurazone-coated catheters did not extend the period of catheter patency. Catheters irrigated with 0.25% acetic acid, 10 mM acetate-buffered saline or isotonic saline blocked at the same rate as untreated catheters. Catheter irrigation with a citrate-buffered formulation of 0.2% auriclosene resulted in complete eradication of P. mirabilis biofilm within one treatment day. In contrast, daily irrigations of infected catheters with 0.2% auriclosene in 10 mM acetate-buffered saline (at pH 4) or Renacidin ® Irrigation Solution had no effect on P. mirabilis colonization of the bladder chamber, even though catheter patency was maintained throughout 10-day studies. CONCLUSIONS: Irrigation with the rapidly bactericidal antimicrobial auriclosene in a buffered acidic formulation - termed Auriclosene Irrigation Solution - significantly enhanced catheter patency in vitro versus other irrigation solutions and antimicrobial- coated urinary catheters. Clinical evaluation of Auriclosene Irrigation Solution is ongoing. Results (continued) Abstract