In vitro study of antimicrobial effects of Rosmarinus officinalis and Glycyrrhiza glabra extracts against some pathogens

Background and aims: Disease causing bacteria have always been considered a major cause of morbidity and mortality in humans. The appearance of resistant microorganisms paved the way to the occurrence of infections that are only treated by a limited number of antimicrobial agents. The present study was, the antimicrobial effects of Rosmarinus officinalis and Glycyrrhiza glabra extract against some pathogens. Methods: In this study, the antibacterial activity using 9 Gram-positive and Gram-negative bacterial strains includes: Streptococcus pyogenes ATCC® 19615, Streptococcus pneumoniae ATCC 49619, S. saprophyticus ATCC®15305, Hafnia alvei ATCC 51873, Acinetobacter baumannii ATCC 19606, Enterococcus faecalis ATCC 29212, Proteus mirabilis ATCC 35659, Serratia marcescens ATCC 274 and Staphylococcus aureus ATCC® 25923 with micro dilution methods was studied. The MIC, MBC were studied also, resistance of these bacteria to standard antibiotics such as erythromycin, cefixime, ceftazidime, tetracycline, ampicillin and amikacin were compared. Results: In this study, the minimum inhibitory concentration (MIC) was used. The levels of MIC of R. officinalis were in ranges from 6.25 to 25 mg/ml. The highest MIC value was observed at 25 ppm against S. pyogenes, S. pneumoniae and P. mirabilis and the levels of MIC of G. glabra were in ranges from 6.25 to 12.5 ppm. The highest MIC value was observed at 12.5 ppm against S. pyogenes, S. pneumoniae, P. mirabilis and S. marcescens. Conclusion: In important human pathogens, drug resistance is increasing according to the results of this study, and may be proposed that this plant can be used as a drug. It can be a good way to replace herbs with chemical drugs