Abstract

Drug resistance is widely distributed in Escherichia coli coli, and related technology is urgently required to control its transmission. The Chinese pulsatilla extracts containing crude drug of 12.5 mg/ml was used to eliminate resistance plasmid against streptomycin in chicken E. coli. After screening and identification, plasmids were extracted from resistance-eliminated strain and electrophoresed in order to compare plasmid profiles before and after elimination. After the drug resistance was eliminated, the diameter of inhibition zone became larger and the minimum inhibitory concentration declined. These results indicated that Chinese pulsatilla extracts makes E. coli strain that was sensitive to streptomycin become resistant to this antibiotic. The alimentation rate was 15.8% (79/500). Compared with the control bacteria, the resistance-eliminated strain lost an approximately 20 kbp plasmid band, which showed that the Chinese pulsatilla extracts may convert drug resistance by eliminating plasmid against streptomycin. 

Key words: Chinese pulsatilla, Escherichia coli, streptomycin, resistance plasmid.