Test on antibiotic resistence of E.coli isolated from ducks

The resistence of 14 strains of E.coli isolated from ducks to 10 antibacterial drugs was detected by method of B-K. Results showed that 14 strains were 100% sensitive to cefazolin, cefotaxime, amikacin. The next was gentamicin,the sensitive rate was 78.6%. The isolates were resistant to other drugs in different degree, highly resistent to tetracycline, TMP/SMZ and doxycycline with the rates of 92.9%, 85.7%and 78.6% respectively. Resistant rates to amoxicillin, chloramphenicol and ciprofloxacin were 57.1%, 50.0% and 64.3% respectively. 78.6% strains were multipleresistant to 10 antibacterial drugs. Strains that resistant to amoxicillin can produce β-lactamase and the minimal inhibitory concentration of amoxicillin against them ranged from 256 to 1 024 mg/L .