Antimicrobial Activity of Aqueous and Alcoholic Extracts of Chamomile, Fleawort, Aquatic Pennyroyal and Nettle Plants on Klebsiella pneumoniae and Comparing Their Effects with Common Antibiotics

Background: In recent years, the use of medicinal plants has increased due to their lower side effects and costs compared to chemical drugs and patientschr('39') adaptation to these drugs. This study was performed to investigate the antibacterial effect of aqueous and alcoholic extract of four native medicinal plants of Gilan province against the bacterium Klebsiella pneumoniae. Materials & Methods: In this study, plant species were collected from different areas of Gilan province and extraction was performed. The antibacterial effect of the extracts was investigated by the disc diffusion method. Then, using microdilution method, the minimum inhibitory concentration of bacterial growth was determined. Results and Conclusion: The results showed that chamomile alcoholic extract with the maximum average halo diameter of 14 mm showed the best effect against K. pneumoniae. The bacterium showed resistance against the aqueous and alcoholic extracts of fleawort. Also, the ethanolic extracts of nettle and chamomile plants had the best antibacterial effect at 0.39 mg/ml. The minimum inhibitory concentration of aqueous extract of fleawort plant against Klebsiella pneumoniae was 12.5 mg/ml which was lower than other types of extracts. According to the results, these extracts can be used as antibacterial products in the pharmaceutical and food industries and in the treatment of infection symptoms.