Ballem, AndressaFernandes, ConceiçãoZenão, S.Gaspar, JoãoCarvalho, E.Carvalho, J.A.Aires, AlfredoRosa, EduardoSaavedra, Maria José2018-02-212018-02-212017Ballem, A.; Fernandes, Conceição; Zenão, S.; Gaspar, J.; Carvalho, E.; Carvalho, J.A.; Aires, A.; Rosa, E.; Saavedra, M.J. (2017). Antimicrobial activity against Staphylococcus aureus (MRSA and MSSA): bioactive compounds potencial. In 11as Jornadas de Biologia. Vila Realhttp://hdl.handle.net/10198/15892Hospital infections in diabetic patients are associated with Staphylococcus aureus, including S. aureus resistant to methicillin (MRSA). Besides their increase incidence, MRSA is considered one of the main pathogens causing nosocomial infections and, furthermore, many of these MRSA isolates are becoming multidrug resistant, constituting a public health problem. As a consequence, there is an increase for the search of alternatives to antibiotics, either by synthesis of new compounds or by the research for natural products with antibacterial properties. In this context, this work investigated the antibacterial effect of natural compounds present in plants (Urtica dioica L. and Lavandula angustifolia Mill) in several Gram-positive isolates, collected from diabetic foot ulcers, namely Staphylococcus aureus (MRSA and MSSA). Different plant extracts (extraction in ethanol, acetone and water) were tested and the antibacterial activity was evaluated by disk diffusion assay method, minimum inhibitory concentration (MICs), minimum bactericide concentration (MBC) and growth rate (µ). Spectrophotometry methods were used to assess the total phenolic content and HPLC-DAD/VIS method was used to identify and quantify the phytochemicals present in the plant extracts. Best antibacterial activity against both MRSA and MSSA was observed with the ethanolic extracts, reaching an effectiveness of 100%, in relation to the antibiotic gentamicin. For both plant extracts, the effect on bacterial growth rate was predominantly bacteriostatic. These findings indicate a potential of these plant extracts as a natural product with antimicrobial activity. Their use in formulations, alone or with synergistic effect with conventional antibiotics could be an alternative to limit the infections of these bacteria.engPhytochemicalsMultidrug resistantDiabeticconference object