PRE-INOCULATION OF URINARY CATHETERS WITH ESCHERICHIA COLI 83972 INHIBITS CATHETER COLONIZATION BY ENTEROCOCCUS FAECALIS

TRAUTNER, BARBARA W.
DAROUICHE, RABIH O.
HULL, RICHARD A.
HULL, SHEILA
THORNBY, JOHN I.

From the Departments of Medicine (Infectious Diseases Section), Physical Medicine and Rehabilitation (Center for Prostheses Infection) and Molecular Virology and Microbiology, Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas

Accepted for publication July 13, 2001.

Supported by the Veterans Administration, Paralyzed Veterans of America and Spinal Cord Society.

Journal of Urology 167(1):p 375-379, January 2002.

Purpose

The capacity of a preexisting coating of Escherichia coli 83972 to reduce catheter colonization by Enterococcus faecalis 210 was investigated. Enterococcus was chosen for these trials since it is a common urinary pathogen in patients with an indwelling urinary catheter.

Materials and Methods

Each experiment tested 3 growth conditions. Group 1 or E. coli plus Enterococcus catheters were exposed to E. coli 83972 for 24 hours and then to Enterococcus for 30 minutes. Group 2 or E. coli alone catheters were incubated in E. coli for 24 hours and then in sterile broth for 30 minutes. Group 3 or Enterococcus alone catheters did not undergo the initial incubation with E. coli before the 30-minute incubation with Enterococcus: All catheters were then incubated in sterile human urine for 24 hours. Catheters were washed with saline and cut into 5, 1 cm. segments. Each segment was sonicated and the sonication fluid was diluted and plated. The results of each of the 5 segments were averaged and the set of experiments was repeated 7 times.

Results

A preexisting coating of E. coli 83972 reduced catheter colonization by E. faecalis 210 more than 10-fold. Enterococcus alone catheters had a median of 9.7 × 10⁵ enterococci per cm., whereas E. coli plus Enterococcus catheters had a median of 0.38 × 10⁵ enterococci per cm. (p = 0.016).

Conclusions

Pre-inoculating urinary catheters with E. coli 83972 significantly impedes catheter colonization by Enterococcus: These promising in vitro results prompt the clinical investigation of this particular application of bacterial interference.