Acquisition and vanishing rate of drug resistance of Aeromonas hydrophila in Pelteobagrus fulvidraco against sarafloxacin hydrochloride.

【Objective】Drug resistance of Aeromonas hydrophila in Pelteobagrus fulvidraco against Sarafloxacin hydrochloride was determined to provide references for setting drug-use procedure of Sarafloxacin hydrochloride in aquatic animal disease treatment. 【Method】Minimal inhibitory concentration(MIC) was detected using double dilution method. Acquisition and vanishing rate of drug resistance were detected using passaging method. 【Result】MIC of WZAh-01,WZAh-02,WZAh-03 and YFAh-04 against Sarafloxacin hydrochloride was 0.625,0.3125,0.3125 and 0.15625 μg/mL. After eight serial passages in Sarafloxacin hydrochloride media, MIC of four strains rose by 64-512 times. The obtained mutant strains with strong drug resistance were kept at 4℃ for 30 days. It was found that MIC of WZAh-02, WZAh-03 and YFAh-04dropped by 50%, while MIC of WZAh-01 remained the same. 【Conclusion】Aeromonas hydrophila in Pelteobagrus fulvidraco under eight serial passages had strong drug resistance against Sarafloxacin hydrochloride. The obtained mutant strains maintained stable heredity. Sarafloxacin hydrochloride should not be overused in production because drug-resistance could not be eliminated in a short time.