Postantibiotic effects of florfenicol in vitro against three marine pathogenic Vibrios

The postantibiotic effects(PAEs)of florfenicol against Vibrio alginolyticus, V.harveyi and V.splendidus were determined by colony counting.The results showed that the greater the drug concentration,the stronger the inhibition of bacterial growth and reproduction; and the slower the rate of recovery growth of bacteria after the drug was withdrawn.The ranking of recovery growth rate of the bacteria were:V.alginolyticusV.harveyiV.splendidus. It was found that,at concentrations of 1×MIC,2×MIC and 4×MIC,the PAE of florfenicol against V.alginolyticus,V.harveyi and V.splendidus was 0.39,0.46 and 1.07h;0.48,0.70 and 1.12h;0.63,1.03 and 1.19h,respectively.This indicated that PAE of florfenicol against V. alginolyticus,V.harveyi and V.splendidus was very significant,and the PAE increased with the increasing drug concentration.It is suggested that when formulate a prescription,the medicine withdrawal time can be prolonged,and the number of administration times can be reduced while the antibiotic effect is still maintained.