Pre-inoculation of urinary catheters with Escherichia coli 83972 inhibits catheter colonization by Enterococcus faecalis.
OBJECTIVE
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.


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 x 10(5) enterococci per cm., whereas E. coli plus Enterococcus catheters had a median of 0.38 x 10(5) 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.
Trautner
Barbara W
BW
Department of Medicine (Infectious Diseases Section), Veterans Affairs Medical Center, Houston, TX, USA.
Darouiche
Rabih O
RO
Hull
Richard A
RA
Hull
Sheila
S
Thornby
John I
JI
D000898:Antibiosis / Q000502:physiology*; D002408:Catheters, Indwelling / Q000382:microbiology*; D013293:Enterococcus faecalis / Q000254:growth & development*; D004926:Escherichia coli / Q000254:growth & development*; D006801:Humans; D066298:In Vitro Techniques; D014546:Urinary Catheterization / Q000295:instrumentation*; D014556:Urine