Author(s): European Commission
One aspect about the application of biocides that has not been fully appreciated is the induction of a selective pressure which may favour the selection of less-susceptible bacteria and the expression and dissemination of mechanisms of resistance. These aspects have not been particularly well studied, but scientific research has yielded some important information on the potential negative impact of biocides in vitro and in situ. All of the research studies suggested in this opinion are important to gain a better understanding of the interaction between biocides and bacteria and to perform an appropriate risk assessment on the use of biocides and emerging resistance and crossresistance in bacteria. One of the main objectives of these recommendations is to determine the resistance mechanisms against biocides and antibiotics following exposure to biocides. However, in order to take into account probable financial constraints, this opinion strongly suggests that two work packages should be considered in priority: - WP1: Characterisation of mechanisms involved in cross-resistance against biocides and antibiotics, and - WP2: Development of strategies to combat cross-resistance mechanisms. Although these work packages will not be able to lead to a full risk assessment of the use of biocides and emerging resistance and cross-resistance, they are essential in providing a fundamental understanding of the bacterial mechanisms involved in resistance necessary for the development of measures that can be used by biocide manufacturers to decrease the development of resistance mechanisms in bacteria.