Experimental Study on Inhibiting Bacteriain Vitro and Acute Toxicity of Florfenicol to Pseudosciaena crocea

The checkerboard microdilution method was applied to study the effect of florfenicol on inhibiting bacteriain in vitro isolated from diseased Pseudosiaena crocea with disk-diffusion method. It is studied that the effect of florfenicol combined with 3 Chinese herbal medicines and florfenicol with Pseudosciaena crocea. The results showed that MIC values of florfenicol against eight strains of vibrios were in the range 0. 39-0. 78 μg/mL ,and the minimal bactericidal concentrations(MBC) was equal or doubled to minimal inhibitory concentrations(MIC). Compared with the single text,the MIC values of combination were slightly lower,and the fractional inhibitory concentration (FIC) index was between 1 and 0. 75. The synergic action of Rhus punjabensis Stew and florfenicol were obviously observed ; It was found that its LD50(96 h) for Pseudosciaena crocea was higher than 1 000 mg/kg body weight, and the safe concentration of florfenicol was over 100 mg/kg body weight.