Study on some anti E. coli characteristics of some medicinal plants hydro alcoholic extracts

Because low complication of medical plants, and very high drug resistance strains of bacteria, in this study was analyzed the anti-Escherichia coli (E.coli) property of three native medical plants of Iran comprising Scrophularia deserti, Quercus brantii, and Achilea spp. The E.coli strains were isolated from cases suspected to colibacillosis. The anti-bacterial effect of these extracts was analyzed by disc diffusion and micro broth dilution methods. In dilution method, fosfomycine and florfenicol were selected as standard and mentioned extracts were compared with Erythromycin, Doxycycline, Ampicillin, Tetracycline, Streptomycine, Sulfadiazin-trimethoprime. Results showed from 9 studied antibiotics, only Ampicilline, Erythromycine and fosfomycine were formed inhibitory zone. Other antibiotics solely and in combined with extracts were not formed inhibitory zone. The minimum inhibitory concentration was 0.52. The study showed the E.coli isolates from broiler chickens have resistance to antibiotics and the studied medical plants have no anti-bacterial effect on E.coli isolates.