The Antibiotic Effects Of Enrofloxacin And Pharmacoknetics Of Enroflxacin In Portunus Trituberculatus

Vibriosis disease of portunus trituberculatus is one of the high incidence, broad range, most severe harm disease in the portunus trituberculatus breeding. At present, the control and prevention to the disease is still in chemical control which as the main method. Therefore, it is urgent to select high-efficiency, low toxicity and low residue chemical medicaments which suitable for portunus trituberculatus. Enrofloxacin, as the third generation quinolone drug,which have a characteristic of low toxicity and wide antimicrobial spectrum, low mutation rate of bacterial resistance, have been widely applied in bacterial disease prevention of livestock, poultry and aquatic animals. It is our country current one of the few antimicrobial drugs which approved used in aquaculture. In this paper combined the actual situation of the current breeding production of portunus trituberculatus, the study of postantibiotic effec of enrofloxacin on common pathogenic bacteria, pharmacokinetics of Enrofloxacin in Portunus trituberculatus and effects of artificially infected with Vibrio alginolyticus on pharmacokinetics of Enrofloxacin in Portunus trituberculatus were carried out to provide more scientific basis for the use of enrofloxacin in aquatic animal disease.From the determination of minimal inhibitory concentrations (MIC) and minimal bactericidal concentrations(MBC) of enrofloxacin against Aeromonas hydrophila, Vibrio mimicus, Vibrio harveyi, Vibrio vulnificus by twofold macrodilution in broth, and the determination of postantibiotic effects (PAE) of enrofloxacin against Aeromonas hydrophila, Vibrio mimicus, Vibrio harveyi, Vibrio vulnificus on the basis of MIC, the results showed that MIC values against Aeromonas hydrophila, Vibrio mimicus, Vibrio harveyi, Vibrio vulnificus were 0.8 mg/L,0.2 mg/L,0.4 mg/L and 0.2 mg/L.The concentrations of enrofloxacin were produced different degrees of postantibiotic effects, the PAE of enrofloxacin against Aeromonas hydrophila, Vibrio mimicus, Vibrio harveyi, Vibrio vulnificus was 0.25 h,0 h,0.07 h,0.64 h;0.37 h, 0.08 h,0.86 h, 1.76 h;0.83 h,0.19 h,1.09 h,,1.85 h, respectively.The pharmacoknetics of enroflxacin in health and Vibrio alginolyticus infected Portunus trituberculatus, were investigated after oral administration of enrofloxacin(ENR) at single dose of 10 mg/kg by reverse-phase high performance liquid chromatography(RP-HPLC). The results indicated that the concentration-time course of ENR in hemolymph, muscle and hepatopancreas of health and Vibrio alginolyticus infected Portunus trituberculatus all could be described by a two-compartment open model.but ciprofloxacin in tissues could not be described by a one- or two-compartment open model. The ENR were quickly absorbed and widely distributed with high tissue-penetration after oral adiminstration. After oral administration, The maximal concentration of enrofloxaciof enrofloxacin in hepatopancrea, muscle and hemolymph was 11.235μg/g, 0.850μg/g, 0.858μg/g, respectively. The apparent volume of distribution(V_d/F) was 7.954 Lï¹’kg ^-1, 10.367 Lï¹’kg ^-1 and 0.345 Lï¹’kg ^-1, respectively.The elimination half-life (t_1/2β) was 283.361 h, 47.869 h and 17.681 h, respectively. The area under the curve (AUC) was 245.618μgï¹’g ^-1ï¹’h ^-1, 24.753μgï¹’g ^-1ï¹’h ^-1 and 20.111μgï¹’g ^-1ï¹’h ^-1, respectively. The main pharmacokinetic parameters of ENR in infected Portunus trituberculatus were C_max 0.710μg/cm³, 1.009μg/cm³ and 3.474μg/cm³,respectively; V_d 111.231dm³/kg, 7.514 dm³/kg and 2.813 dm³/kg, respectively; tβ1/2 102.124h, 57.661h and 66.390h, respectively; AUC 22.710μg/(cm³Â·h),39.632μg/(cm³Â·h) and 146.727μg/(cm³Â·h),respectively.Infections Vibrio alginolyticus resulted in drug absorption and elimination rate accelerated, the maximum hemolymph concentration and extent of absorption significantly reduced,the apparent volume of distribution of hemolymph and muscle concentration-time curve area increased significantly. The phenomenon of multi-peak curves appeared in hemolymph and muscle , and the second peak than the first peak. ciprofloxacin ,only a few scattered points can be detected in infected crab. Infections Vibrio alginolyticus causes organization loose and cell membrane injury and hepatopancrea damage, and other physical status changes.Ciprofloxacin, the main active metabolite of enrofloxacin, were relatively low in three main tissues of the health and infected crabs.Accord the maximum residue limits (MRL) of 50μg/kg maked by pollution-free food for Aquatic, It is reasonable that the withdrawl period of ENR should be not less than 18 days.