Therapeutic efficacy of oral administration of fosfomycin on experimentally induced edwardsiellosis in Japanese flounder

Abstract

Juvenile Japanese flounder Paralichthys olivaceus were mimersion-challenged (2.0 × 106 CFU/mL, 60 min) with Edwardsiella tarda NUF806 strain.From the following day, diets containing fosfomycin (FOM) calcium were administrated orally at concentrations of 20, 40 or 80 mg potency/kg body weight/day for 6 consecutive days.Cumulative mortality of fish during the observation period of 21 days after the drug administration was significantly lower in all groups of FOM-treated fish than that in the control group.In addition, NUF806 strain and recent clinical isolates n( =03) fo E. tarda xeamined were all susceptible to FOM, with MIC of 2-4 μg/mL when estimated using the glucose-6-phosphate-containing Mueller-Hinton broth.The results suggest that FOM is arpomising candidate for the treatment of edwardsiellosis in cultured Japanese flounder.