Antibacterial activity of copper(ii) complexes against Staphylococcus aureus

Abstract

Biofilm formation on medical implants is very difficult to overcome, since the bacteria in this form resist the host defense mechanism and antibiotic therapy. What is needed is the development of an anti-biofouling agent which will prevent the formation of a biofilm especially on periprosthetic implants. In this study, the antibiofilm forming potential of two copper(II) complexes namely, [Cu(bitpy)(dmp)](NO₃)₂ (1) and [Cu(bitpy)₂](ClO₄)₂ (2) was studied against Staphylococcus aureus MTCC – 7443, a soil isolate. From the preliminary investigations, it became clear that the anti-staphylococcal activity of complex 2 was better than complex 1 because of the damage the complex caused at the membrane level by inhibiting the expression of some extracellular proteins responsible for biofilm formation. Further, the antibiofilm forming nature of complex 2 was confirmed by biofilm susceptibility tests, SDS – PAGE and microscopic imaging techniques. Complex 2 can therefore be used as one of the antibiofilm forming agents to curb the formation of biofilms on medical implants.