Antibacterial effects of the extracts of rosemary (Rosmarinus officinalis L.) Leaves on three multidrug resistant bacterial isolates using nanoparticle size technique

Abstract

The present study was consisted of four simple experiments applied in the laboratories of the Department of Biology, College of Science, Salahaddin-Erbil University, and Scientific Research Center at Erbil Polytechnic University to determine the effects of methanol extract, ethyl acetate extracts and essential oils of the leaves of rosemary (Rosmarinus officinalis L.) extracts on multidrug resistant bacterial isolates such as Escherichia coli, Staphylococcus aureus and Pseudomonas aeroginosa during 2022. The results showed that the rosemary essential oil (RMEO) have antibacterial effects on E. coli and S. aureus, methanol rosemary leaf extracts (MRLE) affected on E. coli at 300 µg/ml and affected on the three bacterial isolates at conc. 300 µg/ml when used with Ag-NPs but ethyl acetate rosemary leaf extracts (EARLE) affected on S. aureus when used alone and on S. aureus and P. aeroginosa when used with Ag-NPs at conc. 50 µg/ml and affected on the three bacterial isolates at conc. 100 µg/ml. The minimal inhibition concentration (MIC) of RMEO was 300µg/ml when used alone for E. coli and 300µg/ml with Ag-NPs. The MIC of ME was 300µg/ml for E. coli alone or with Ag-NPs and 300µg/ml for the three bacterial isolates when used with Ag-NPs only, and MIC of (EARLE) was 50µg/ml for S. aureus when used without Ag-NPs, 50µg/ml for S. aureus and P. aeroginosa when used with Ag-NPs and 100µg/ml for E. coli using alone or with Ag-NPs. P. aeroginosa was resistant against Amoxicillin/clavulanic acid (AMC30).