An in vitro comparison of bacterial touch contamination prevention between a novel APD cycler connector and existing APD connectors.

Abstract

BackgroundPeritoneal dialysis (PD)-associated peritonitis remains a leading cause of hospitalization, technique failure, and transfer to in-center hemodialysis, with touch contamination during connections accounting for many episodes. Although shrouded connectors and "flush before fill" mechanisms reduce contamination risk, most automated peritoneal dialysis (APD) systems incorporate recessed fluid paths on only one side of the tubing-bag interface, potentially allowing bacterial transfer. We evaluated whether bilateral shrouded connectors with recessed fluid paths reduce bacterial contamination during simulated APD therapy.MethodsIn vitro microbiological testing was performed using three APD systems: Vantive/Baxter Claria™ (System A), Fresenius Liberty™ (System C), and Simergent Archimedes™ (System B). Connectors were deliberately contaminated with Staphylococcus aureus to simulate touch contamination, followed by a simulated APD treatment. Bacterial growth was quantified from pre-therapy flush fluid and the first patient fill ("mock peritoneum"). Agar imprinting was used to assess bacterial distribution relative to connector geometry.ResultsBacterial growth adjacent to the fluid path was observed with contaminated System A connectors but not with System B or System C, where growth was confined to the shroud. Quantitative cultures demonstrated markedly higher bacterial transfer with System A compared with System B and System C across both flush and mock peritoneal samples. Systems B and C employing bilateral shrouded, recessed connectors showed bacterial counts several orders of magnitude lower. All aseptic controls were sterile.ConclusionBilateral shrouded connectors with recessed fluid paths substantially reduce transfer of touch contaminants during simulated APD therapy. This design may mitigate a major mechanism of PD-related peritonitis, warranting clinical evaluation.