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Investigating alternative materials to EPDM for automatic taps in the context of Pseudomonas aeruginosa and biofilm control

Published:September 15, 2020DOI:https://doi.org/10.1016/j.jhin.2020.09.013

      Summary

      Background

      Automatic taps use solenoid valves (SVs) which incorporate a rubber (typically EPDM) diaphragm to control water flow. Contaminated SVs can be reservoirs of opportunistic pathogens such as Pseudomonas aeruginosa; an important cause of healthcare-associated infection.

      Aims

      To investigate the attachment and biofilm formation of P. aeruginosa on EPDM and relevant alternative rubbers to assess the impact on water hygiene in a laboratory model.

      Methods

      Biofilm formation on EPDM, silicone and nitrile rubber coupons was investigated using a CDC biofilm reactor. SVs incorporating EPDM or nitrile rubber diaphragms were installed on to an experimental water distribution system (EWDS) and inoculated with P. aeruginosa. P. aeruginosa water levels were monitored for 12-weeks. SVs incorporating diaphragms (EPDM, silicone or silver ion-impregnated silicone rubber), pre-colonized with P. aeruginosa, were installed and the effect of flushing as a control measure was investigated. The concentration of P. aeruginosa in the water was assessed by culture and biofilm assessed by culture and microscopy.

      Findings

      Bacterial attachment was significantly higher on nitrile (6.2 × 105 cfu/coupon) and silicone (5.4 × 105 cfu/coupon) rubber than on EPDM (2.9 ×105 cfu/coupon) (P<0.05, N = 17). Results obtained in vitro did not translate to the EWDS where, after 12-weeks in situ, there was no significant difference in P. aeruginosa water levels or biofilm levels. Flushing caused a superficial reduction in bacterial counts after <5 min of stagnation.

      Conclusion

      This study did not provide evidence to support replacement of EPDM with (currently available) alternative rubbers and indicated the first sample of water dispensed from a tap should be avoided for use in healthcare settings.

      Keywords

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      References

        • Tacconelli E.
        • Magrini N.
        Global priority list of antibiotic-resistant bacteria to guide research, discovery and developement of new antibiotics.
        World Health Organization, 2017
        • Reuter S.
        • Sigge A.
        • Wiedeck H.
        • Trautmann M.
        Analysis of transmission pathways of Pseudomonas aeruginosa between patients and tap water outlets.
        Crit Care Med. 2002; 30: 2222-2228
        • Quick J.
        • Cumley N.
        • Wearn C.M.
        • Niebel M.
        • Constantinidou C.
        • Thomas C.M.
        • et al.
        Seeking the source of Pseudomonas aeruginosa infections in a recently opened hospital: an observational study using whole-genome sequencing.
        BMJ Open. 2014; 4e006278
        • Moore G.
        • Stevenson D.
        • Thompson K.-A.
        • Parks S.
        • Ngabo D.
        • Bennett A.M.
        • et al.
        Biofilm formation in an experimental water distribution system: the contamination of non-touch sensor taps and the implication for healthcare.
        Biofouling. 2015; 31: 677-687
        • Hutchins C.F.
        • Moore G.
        • Thompson K.A.
        • Webb J.
        • Walker J.T.
        Contamination of hospital tap water: the survival and persistence of Pseudomonas aeruginosa on conventional and ‘antimicrobial’ outlet fittings.
        J Hosp Infect. 2017; 97: 156-161
        • Walker J.
        • Jhutty A.
        • Parks S.
        • Willis C.
        • Copley V.
        • Turton J.
        • et al.
        Investigation of healthcare-acquired infections associated with Pseudomonas aeruginosa biofilms in taps in neonatal units in Northern Ireland.
        J Hosp Infect. 2014; 86: 16-23
        • Yapicioglu H.
        • Gokmen T.G.
        • Yildizdas D.
        • Koksal F.
        • Ozlu F.
        • Kale-Cekinmez E.
        • et al.
        Pseudomonas aeruginosa infections due to electronic faucets in a neonatal intensive care unit.
        J Paediatr Child Health. 2012; 48: 430-434
        • Hargreaves J.
        • Shireley L.
        • Hansen S.
        • Bren V.
        • Fillipi G.
        • Lacher C.
        • et al.
        Bacterial contamination associated with electronic faucets: a new risk for healthcare facilities.
        Infect Control Hosp Epidemiol. 2001; 22: 202-205
        • Sydnor E.R.
        • Bova G.
        • Gimburg A.
        • Cosgrove S.E.
        • Perl T.M.
        • Maragakis L.L.
        Electronic-eye faucets: Legionella species contamination in healthcare settings.
        Infect Control Hosp Epidemiol. 2012; 33: 235-240
        • Halabi M.
        • Wiesholzer-Pittl M.
        • Schöberl J.
        • Mittermayer H.
        Non-touch fittings in hospitals: a possible source of Pseudomonas aeruginosa and Legionella spp.
        J Hosp Infect. 2001; 49: 117-121
        • Department of Health
        Health technical memorandum 07-04: water management and water efficiency – best practice advice for the healthcare sector.
        2013
        • Clear C.
        • Hardi J.
        • Thorne A.
        Sustainable strategies for healthcare estates – lessons from university college london hospitals.
        Watford: Building Research Establishment, 2012 (Contract No.: IP 24/12)
        • British Standards Institution
        Suitability of non-metallic materials and products for use in contact with water intended for human consumption with regard to their effect on the quality of the water — Part 2: methods of test — section 2.1: samples for testing.
        2014
        • Moritz M.M.
        • Flemming H.-C.
        • Wingender J.
        Integration of Pseudomonas aeruginosa and Legionella pneumophila in drinking water biofilms grown on domestic plumbing materials.
        Int J Hyg Environ Health. 2010; 213: 190-197
        • Department of Health
        Health technical memorandum 04-01: supplement – performance specification D 08: thermostatic mixing valves (healthcare premises).
        2017
        • Gardiner C.
        • Ferreira Y.J.
        • Dragovic R.A.
        • Redman C.W.G.
        • Sargent I.L.
        Extracellular vesicle sizing and enumeration by nanoparticle tracking analysis.
        J Extracell Vesicles. 2013; 2https://doi.org/10.3402/jev.v2i0.19671
        • Kilb B.
        • Lange B.
        • Schaule G.
        • Flemming H.-C.
        • Wingender J.
        Contamination of drinking water by coliforms from biofilms grown on rubber-coated valves.
        Int J Hyg Environ Health. 2003; 206: 563-573
        • Department of Health
        Health technical memorandum 04-01: addendum: Pseudomonas aeruginosa – advice for augmented care units.
        2013
        • Garvey M.I.
        • Wilkinson M.A.C.
        • Holden K.
        • Martin T.
        • Parkes J.
        • Holden E.
        Tap out: reducing waterborne Pseudomonas aeruginosa transmission in an intensive care unit.
        J Hosp Infect. 2019; 102: 75-81
        • Department of Health
        Health Technical Memorandum 04-01: safe water in healthcare premises–part C: pseudomonas aeruginosa – advice for augmented care units.
        2016
        • Bédard E.
        • Laferrière C.
        • Déziel E.
        • Prévost M.
        Impact of stagnation and sampling volume on water microbial quality monitoring in large buildings.
        PloS One. 2018; 13e0199429
        • Michels H.
        • Noyce J.
        • Keevil C.W.
        Effects of temperature and humidity on the efficacy of methicillin-resistant Staphylococcus aureus challenged antimicrobial materials containing silver and copper.
        Lett Appl Microbiol. 2009; 49: 191-195