Investigating the Effect of Intermittent Catheter Lubricant Type on the Transfer of Urinary Tract-Related Bacteria Using an In Vitro Bacterial Displacement Test

Aims Whilst intermittent catheters (ICs) are the gold standard for managing bladder voiding difficulties, they are still linked with catheter-associated urinary tract infections (CAUTI). There are two main types of catheters: uncoated catheters, which require lubrication with a gel, and hydrophilic catheters, which are lubricated with water-based wetting solutions. Using a previously validated bacterial displacement <i>in vitro</i> model, we evaluated whether gel-based catheter lubricating products reduce bacterial displacement compared to water-based catheter lubricating products. Methods and results Simulated urethra agar channels (UACs) were prepared with catheter-specific-sized channels in selective media specific to the challenge organisms. Before insertion of ICs into the UACs, <i>Escherichia coli</i> and <i>Enterococcus faecalis</i> were separately inoculated in the first 1 cm of the UACs to represent the naturally contaminated distal urethra (meatus). Following insertion of the test catheter, UACs were processed for total viable counts (TVCs) or visual displacement images. Four ICs were evaluated: two gel-based ICs, Cure Twist^® (Gel-based female (GBF); Cure Medical, Henderson, NV, USA) and Cure Ultra^®(Gel-based male (GBM); Cure Medical, Henderson, NV, USA), and two water-based ICs, SpeediCath^® Compact Eve (Water-based female (WBF); Coloplast Ltd., Orton, Peterborough, UK) and SpeediCath^® Flex (Water-based male (WBM); Coloplast Ltd., Orton, Peterborough, UK). Both the microscopy results and TVCs showed that ICs lubricated with gel carried fewer bacteria along the length of the UAC and catheter in comparison to ICs lubricated with water. Conclusions The previously validated bacterial displacement method demonstrated that ICs with gel-based lubricants displaced fewer bacteria from the distal urethra to the proximal bladder, compared to ICs with water-based lubricants.