Medication Regimen Of Neomycin Sulphate Against Grass Carp Bacterial Enteritis And Effect On Crucian Carp Of Immunity

Due to the short development time of aquaculture industry,the use of fishery drugs are lack of scientific and reasonable guidance,leading to drug residues,bacterial resistance,fish body damage and other problems continue to emerge.In order to rationally guide the use of antibiotics in aquaculture,this study used neomycin sulfate as the research object,the Aeromonas hydrophila caused by grass carp bacterial enteritis disease enact Medication Regimen;Crucian Carp(Carassius auratus gibelio)as the experimental object,To study effect of Neomycin Sulfate on Immunity in the Crucian Carp and Viral Titer of Cyprinid Herpesvirus 2.1 Medication regimen of Neomycin Sulphate against Grass Carp Esoenteritis Caused by Aeromonas Hydrophila.In order to enact medication regimen of neomycin sulphate against grass carp esoenteritis caused by Aeromonas hydrophila.at water temperature of(25 ± 2)℃,A single oral neomycin sulphate gavage at a dose of 10,20,30,40 mg per kg body weight into grass carp foregut with body weight of 150~200 g,to determine the concentration of drug in the blood,intestine and muscle at different time points by HPLC.study on in vitro pharmacodynamics against pathogenic bacterium Aeromonas hydrophila and in vivo pharmacokinetics of neomycin sulphate in grass carp.The in vitro pharmacodynamic results showed that MIC of neomycin sulphate on Aeromonas hydroplia was 6μg/mL,AUC24 of intestine/MIC respectively was 52.467,72.963,109.907 and 136.489.Cmax of intestine/MIC respectively was 10.93,15.24,23.20 and 28.98.Oral dosing of neomycin sulphate 40 mg per kg body weigh,The maximum concentration of the drug is 3.833μg/mL in the blood.Considering AUC24/MIC and Cmax/ MIC,the recommendation of the dosing regimen is 40 mg/kg,Once a day,Continuous administration for 3 to 5 days,the rest period is 8 days.2 Effect of Neomycin Sulfate on Immunity in the Crucian Carp(Carassius auratus gibelio)The aim of this study was to investigate the effect of neomycin sulfate on immunity in the crucian carp(Carassius auratus gibelio).First,the acute toxicity test of neomycin sulfate on crucian carp was carried out,the 96-h LD50 value of neomycin sulfate was determined to be 1029.307 mg/kg,based on which the safe concentration was calculated to be 102.9 mg/kg.The fish were then divided into four groups: control,10 mg/kg dose,20 mg/kg dose,and 40 mg/kg dose.The values of certain important immune indexes and antioxidant enzymes were examined at specific time points.The WBC count and C3 content significantly increased(P < 0.01)after treatment,but no significant changes were observed in antibacterial activity or lysozyme content.The SOD and CAT content first increased,then declined and then increased again,and in the 40 mg/kg group,in particular,it significantly increased after 96 h(P < 0.05).The MDA content first declined,then increased and then declined again,and it showed a significant decrease after 96 h(P < 0.05).The protein carbonyl content showed similar trends as MDA,with a significant decrease observed in the 10 and 20 mg/kg groups after 96 h(P < 0.05).To determine the in vitro cytotoxicity of neomycin sulfate,crucian carp fin cells were cultured with 1000,500,100,and 0 μmol/L of neomycin sulfate,and the number of viable cells was determined.No in vitro cytotoxicity was observed.The present findings indicate that administration of the appropriate dose of neomycin sulfate can increase immune function in the crucian carp and reduce oxidative damage.3 Effect of Neomycin Sulfate on Viral Titer of Cyprinid Herpesvirus 2To determine the effects of neomycin sulfate on the mortality rate and viral titer after infection with cyprinid herpesvirus 2,the fish were divided into the 0,20,and 40 mg/kg neomycin sulfate groups and control group.After 24 h,fish were intraperitoneally administered a crude extract containing the virus to induce infection(except the control group).The mortality rate of the control group,40 mg/kg group,20 mg/kg group,and untreated group was 0%,60%,80% 100%,respectively.No significant increase in the blood viral titer was observed on days 1–4,but the viral titer in the untreated group significantly increased on days 5–8(P < 0.05).The present findings indicate that administration of the appropriate dose of neomycin sulfate can reduce the mortality rate and inhibit viral proliferation in infected carp.