Comparison of single bacteria and a bacterial reference community in a test against coated surfaces of varying copper content.

Introduction: Pathogens can easily transmit via surfaces and objects. In light of the ongoing pandemic of antimicrobial resistance, silently threatening millions worldwide, this is of particular concern in clinical and public environments. Thus, it is crucial to understand how antimicrobial materials influence surface-associated microbes and microbial communities. Copper, known for its antimicrobial activity, has demonstrated effectiveness against numerous clinically relevant pathogens. However, these Methods: Hence, in this study we not only tested the antibacterial effectivity of different copper concentrations against single species, but also against a reference bacterial community representing the most abundant bacterial genera in public transport. This allowed a comparison of the antibacterial efficacy of copper against a bacterial community and against single species. Coatings on glass, which were composed of full copper (100 at.% Cu) and copper-aluminum alloys with different Cu contents (79 at.%, 53 at.% and 24 at.%) were tested with two selected single species ( Results: In general, the survival of the two species within the bacterial community was higher compared to their respective survival as a single species, significantly for Discussion: Our results highlight the benefits of additional testing of microbial communities rather than pure cultures. These experiments allow for enhanced evaluation of antimicrobial surfaces since they also take complex and diverse interactions within a surface microbiota into account. Therefore, community testing might be the more holistic approach for the testing of antibacterial materials.