Development of a bioelectric device for disinfection of hospital sink biofilms

Hospital sinks are reservoirs for biofilm-forming multi-drug-resistant organisms (MDROs) which cause healthcare-associated infections (HAIs). Conventional mitigation methods, such as chlorine disinfection and sink trap replacement, often fail due to persistent biofilm regrowth.

Bioshield Pro (BPro), a bioelectric disinfection prototype, was evaluated to determine its ability to enhance chlorine efficacy against biofilms and reduce microbial spread from contaminated sink traps, through laboratory testing and a real-world paediatric clinic trial.

In-vitro testing assessed the effectiveness of BPro, alone and with 1000 parts per million (ppm) chlorine, against Enterococcus faecalis, a common and resilient HAI organism. A three-month field trial was also conducted. Biofilm formation in sink bottle traps was assessed using crystal violet staining. Bacterial splashback was quantified using colony counts from agar plates placed near the sink strainer, simulating hand contamination from water droplets.

Laboratory tests showed that applying 1.0 V reduced E. faecalis to 39.9% (P≤0.001) relative to the control. BPro also augmented chlorine disinfection, lowering bacteria presence from 63.9% to 29.9% (P≤0.01). In the clinical setting, BPro reduced biofilm to 12.1% relative to the control (P≤0.0001), with no added benefit from combining with disinfectants. Additionally, BPro reduced the bacterial load of splashbacked water by over 80.0% (from 17.67 colony-forming units (cfu)/plate in the control sink to 2.67 cfu/plate), outperforming chlorine treatment alone (13.67 cfu/plate). The system operated continuously at low voltage, with no reported adverse effects during the trial.

These preliminary tests demonstrate that BPro is a promising alternative to conventional healthcare sink disinfection. Further validation in diverse clinical environments is needed to support broader implementation.