The Efficacy of Zinc and Manganese in Controlling Methicillin-Resistant Staphylococcus aureus Wound Infections in vitro

The emergence of Methicillin-Resistant Stapylococcus aureus has triggered an increased interest in finding alternative natural antimicrobials to control the pathogen and combat growing antibiotic resistance. This study investigated the antimicrobial effect of two naturally occurring essential minerals, zinc (Zn) and manganese (Mn) on MRSA for potential application in wound infections. The sub inhibitory concentration (SIC) and minimum inhibitory concentration (MIC) of Zn and Mn against MRSA were determined. The effect of MIC and 2x MIC of Zn and Mn in increasing MRSA susceptibility to oxacillin, and the effect of SIC and MIC of these minerals on MRSA cell adherence and invasion of human keratinocytes were investigated. The SIC and MIC of Zn and Mn against MRSA were 0.4 mM and 2.5 mM, and 1.6 mM 4.7 mM, respectively. Both metals in combination with oxacillin were more effective in reducing MRSA than oxacillin alone. In addition, both Zn and Mn significantly reduced MRSA adhesion and invasion of human skin cells. Results indicate that the aforementioned antimicrobials can be potentially used to control MRSA wound infections, however further studies are warranted