Microbial Transfer by Intermittent Catheters: An In Vitro Evaluation of Microbial Transfer in Catheter With Variable Protective Features.

Purpose: The purpose of this study was to evaluate the effects of various protective features (eg, catheter cap, introducer tip, and catheter sleeve) of hydrophilic intermittent catheters against contamination with urinary tract infection-associated microorganisms using an in vitro model.

Design: An in vitro study of microbial transfer.

Materials and methods: Gloves were contaminated with uropathogenic microorganisms and used to simulate intermittent catheterization of male anatomical models with and without the protective features present in 5 commercially available hydrophilic catheters. Using this contaminated touch transfer method, both the meatus of the sterile male anatomical models and sterile surgical gloves of an operator were inoculated with a high level of microorganisms (107 and 109 colony-forming units [CFU], respectively). The operator then performed catheterization of the anatomical model. The most relevant segments of the catheter were sampled, and the level of microbial transfer and catheter contamination was quantified. Results from experimental and sample replicates from the 3 microbial species and 5 catheters (sleeved and unsleeved) were analyzed by pair-wise t tests and analysis of variance.

Results: Of the 5 commercially available sleeved intermittent catheters evaluated in this study, use of catheters with multiple protective components (ring cap, introducer tip, and catheter sleeve) resulted in significant improvement in protection against contamination with a 25- to 2500-fold lower level of microbial contamination (C1 segment) across all species as compared to catheters protected with only sleeves or un-sleeved catheters.

Conclusions: The combination of a ring cap, protective introducer tip, and protective sleeve provides additional protection when compared to sleeve alone from transferring microbial contamination from the meatus to the advancing catheter. Additional research is needed to determine whether these design features result in fewer urinary tract infections among intermittent catheter users.