The Active Efflux of Riemerella Anatipestifer for Fluoroquinolone Antibiotics

To study the active efflux mechanism of Riemerella anatipestifer for fluoroquinolone antibiotics (FQNS) such as norfloxacin, enrofloxacin, ciprofloxacin, ofloxacin and levofloxacin, the minimum inhibitory concentration (MIC) of 25 Riemerella anatipestifer isolates for FQNS was tested, and simultaneously the MIC was detected after adding carbonylcyanide-m-chlorophenylhydrazone (CCCP) .The ratios of the FQNS-resistant strains were 84%, 72%, 76%, 68%and 36%;76%of strains were resistant to two or more drugs.CCCP increased the sensitivity of the drug-resistant bacteria to FQNS (except levofloxacin) , indicating that active efflux mechanism played an important role in resistance mechanisms to FQNS in Riemerella anatipestifer.