Controlo bacteriano em superfícies hospitalares com desinfetantes baseados em produtos fitoquímicos

The introduction of optimised disinfection products is crucial to prevent and control the spread of pathogens and antimicrobial resistant microorganisms. A significant example of bacterial resistance is the ability to grow as part of a sessile community, commonly referred to as biofilm, a microbial phenotype disregarded in the EU Normative for the evaluation of the bactericidal activity of chemical disinfectants and antiseptics [14]. Therefore, it is easy to comprehend why none of the currently available disinfectants is effective for biofilm control. In addition to the resistance mechanisms found in planktonic cells, the resistance of biofilms to antimicrobials is a multifactorial process generated by the community of microorganisms [15-17]. The HCAI_Disinfect project aims to evaluate the potential of phytochemical products (PP) to be used in the disinfection of healthcare settings, as single products and in combination with in-use disinfectants. The complementary expertise of the team members in applied microbiology, antimicrobial therapy, medicinal chemistry, toxicology, epidemiology and public health will allow the discovery of effective and environmentally friendly disinfectants, contributing to prevent the spread of infectious pathogens, reduce healthcare-associated infections, and mitigate the risk of pandemics. This will be achieved under the establishment of a cutting-edge approach to accomplish the following scientific objectives: I) Assess for the first time the antimicrobial activity of a minimum of 50 structurally diverse PP based on their ability to inhibit the growth of hospital-isolated bacteria, to identify the PP with the highest antimicrobial activity for disinfection. II) Evaluate the synergy of PP with in-use disinfectants for which antimicrobial resistance is widely reported, allowing us to assess the potential of PP as resistance modifying agents and for the recycling of these old disinfectants. III) Characterize the bacterial physiological changes induced by PP against planktonic microorganisms and their biofilms to understand their mechanisms of antimicrobial action and resistance. IV) Determine the potential of PP to control dry and wet biofilms formed on different surface materials used in healthcare settings. In addition to the determination of biofilm control effects of PP, the ability of biofilm cells to recover from the antimicrobial treatment will be characterized as well as the existence of persister cells following treatment. The action of PP will be benchmarked with the in-use disinfectants. V) Characterize the ecotoxicity and genotoxicity of PP to confirm their environmentally friendly status and low cutaneous cytotoxicity. It is not a correct assumption to believe that every phytochemical has no negative environmental and/or public health impact just because it is a natural product. Like most of the current disinfectants, phytochemicals can have a range of activities including potentially adverse ones. Hence, we will study the environmental and public health safety of the PP demonstrating antimicrobial action. PP can be an attractive source of environmentally friendly, relatively inexpensive and widely available new disinfectants with low cutaneous cytotoxicity and low corrosion levels. Final project outputs will provide innovative information on the potential of PP for disinfection and their structure-activity relationships and involve actively the scientific community and relevant stakeholders.