Hospital Acquired Infections With Multiresistant Microorganisms: UN Interagency Coordination Group on Antimicrobial Resistance Demands Immediate, Ambitious and Innovative Action
Copyright (c) 2020 S Guggenbichler, Fey T, Guggenbichler JP
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The present review is mostly focused on decontamination of solid air interfaces in health-care units, such as hospital furniture, door-handles, computer keyboards, textiles etc., although solid liquid surfaces are also of great concern in hospitals such as faucets, showers, pipes and drains, where biofilms occur frequently. New methods, in addition to or as an alternative to appropriate use of disinfectants and antibiotics are required to reduce microbial associated infections and to reverse the dramatic increase in antimicrobial resistance. The requirements for such surfaces mandatory for prevention of hospital acquired infections and the emergence of multi-resistant microorganisms however are high. Many different chemical strategies and technologies for coatings intended to eradicate microorganisms from surfaces are described in the literature. None of these technologies meets the expectations for prevention of hospital acquired infections by formation of self-sanitizing surfaces except the in situ generated biocides on the basis of transition metal oxides embedded into surfaces. Surfaces decorated with metal oxide Lewis acids such as MoO3, WO3 and Zinc Molybdate show a broad-band and strong antimicrobial activity resulting in a reduction of the number of colony forming units by 6 – 7 log 10 within 1-3 hours. Their mechanism of action is based on the in-situ generation of H3O+ ions through the reaction with moisture from the air, inspired by the body’s own defense mechanism imitating e.g. the acid coating of the skin. The resulting acidified surfaces have a pH of 4.5 and the H3O+ ions are able to diffuse through the cell membrane of microorganisms where they can distort the pH-equilibrium and transport systems of the cell. In addition by these mechanism also free radicals e.g. oxygen radicals and hydroxyl radicals are formed which result in a synergistic mode of action including a positive zeta potential. This is reflected by an extraordinary fast eradication of microorganisms i.e. a reduction of 5 log 10 within 10 minutes.