LAUSR

Origanum majorana, Melissa officinalis, Anthemis cotula and Avena sativa were extracted by using 65% ethanol to isolate their active constituents. The antimicrobial activities of extracts were investigated against 15 microorganisms by using the disk diffusion method, MIC (Minimum Inhibitory Concentration), MBC (Minimum Bactericidal Concentration) and MFC (Minimal Fungicidal Concentration) tests. Furthermore, the presence of some flavonoids were analyzed by using HPLC. It was determined flavonoids in the extracts of O. majorana, M. officinalis, A. cotula and A. sativa. As a results it was observed that O. majorana was active against Staphylococcus aureus, Enterococcus faecium, Enterococcus faecalis, Salmonella typhimurium and Pseudomonas aeruginosa, where M. officinalis was active against Enterococcus faecium and Enterococcus faecalis. On the other hand, both A. cotula and A. sativa were observed to be active against Enterococcus faecium. The extracts of plant samples showed antibacterial activity against tested microorganisms at different levels.