Pathogen displacement during intermittent catheter insertion: a novel in vitro urethra model

Aim: To develop a novel in vitro urethra model and use it to determine if insertion of an intermittent urinary catheter (IC) displaces pathogenic bacteria from the urethral meatus along the urethra.

Methods: Displacement of microbial growth after catheter insertion was assessed using a novel in vitro urethra model. The in vitro urethra model utilized chromogenic agar and was inoculated with bacteria at one side of the artificial urethra channel, to act as a contaminated urethral meatus, before an IC was inserted into the channel. Three ICs types were used to validate the in vitro urethra model and methodology.

Results: When compared to the bacterial growth control, a significant difference in bacterial growth was found after insertion of the uncoated (P ≤ 0·001) and hydrophilic coated (P ≤ 0·009) catheters; no significant difference when a prototype catheter was inserted into the in vitro urethra model with either bacterial species tested (P ≥ 0·423).

Conclusion: The results presented support the hypothesis that a single catheter insertion can initiate a catheter-associated urinary tract infection.

Significance and impact of the study: The in vitro urethra model and associated methodology were found to be reliable and reproducible (P ≥ 0·265) providing new research tool for the development and validation of emerging technologies in urological healthcare.