Shahrekord University of Medical Sciences Future Natural Products 2783-4662 3 4 2017 10 31 Evaluation of the drug synergistic and antibacterial effects of methanol extracts of Callistemon viminalis on some urinary tract infection bacteria 13 21 EN Maryam Ramezanian Sayed Jalaladdin Ashraf Mansuri Amir Abbas Minaeifar Journal Article 2016 09 08 2016 10 29 Background and aims: Urinary tract infection is considered as one of the most common clinical problems in the world. The aim of this study was to investigate the interaction effects of pharmaceutical and antibacterial activity of methanol extracts of Callistemon viminalis on a number of bacteria that cause urinary tract infections. Methods: In this experimental research, after drying leaves, extracts were prepared using methanol. The minimum lethal activity of 500, 250 and 125 µg/ml concentrations of the extracts on the standard bacteria was tested using disk diffusion and dilution method. In order to study the synergistic and antagonistic effect, a standard strains of bacteria was cultured on the medium containing methanol extract and then antibiotic discs were put on it. Results: According to the results of disk diffusion test in Agar, the highest inhibition zone diameter in 500 µg/ml was related to Staphylococcus epidermidis and the minimum diameter in this concentration was related to E. coli. Study MIC results was showed that the extract of Callistemon viminalis has the highest inhibitory effect on Staphylococcus saprophyticus and epidermidis. The extracts of Callistemon viminalis showed synergistic effects with vancomycine and ciprofloxacin on Staphylococcus aureus and epidermidis, Proteus vulgaris and Klebsiella pneumoniae. Conclusion: The results of this study indicate that extracts of Callistemon viminalis , alone or in combination with antibacterial agents may be useful in treatment of urinary tract infections. Additionally, this component can enhance the effect of some antibiotics; this implies its application, especially in drug resistance cases.