An-Najah Staff

Ethanolic extracts of fifty four plant species used in folk medicine in Palestine for treatment of several infections and diseases were investigated for their antimicrobial activities against 10 strains of Propionibacterium acnes, and five strains of aerobic bacteria, Echerichia coli, Klebsiella pneumonic', Protects vulgaris, Pseuclomonas eruginosa, and Staphylococcus aureate. Two susceptibility tests were used in this work: the disk diffusion method for measuring the antimicrobial activity, and broth method for the determination of MIC, and MBC for the active plant extracts. The results demonstrated that the studied plants differ significantly in their activity against the studied microorganisms. The IX most active plants against bacterial strains were Rhus coriaria, Ricinus communes, and Sarcopoterium spinosuin. Test microorganisms differed significantly in relation to their susceptibility to different plant extracts used. The most susceptible test microorganism was Propionibacterium acnes (anaerobic bacteria), whereas the least susceptible microorganism was Klebsiella pneumonia. Generally, anaerobic bacteria were more susceptible to plant extract than aerobic bacteria. This was attributed to differences in modes of actions of plant extracts against both groups.