Preliminary Study On The Control Of Aquatic Animal Stress Syndrome

The aquatic animal stress syndrome, caused by poor water quality stress characterizedwith high ammonia, nitrite, COD in intensive aquaculture, and secondary bacterialinfection after stress, is more common.In order to improve water quality, and inhibit pathogens in water or aquatic animal,we preliminarily study the prevention and control of aquatic animal stress syndrome withchemical and biological methods. The results were as follows:Ferrate can kill Aeromonas sorbia, Aeromonas schubert, Vibrio ordalii and Vibriometschnikovii, with the minimum inhibitory (MIC) of0.20mg/L、0.25mg/L、0.25mg/L和0.22mg/L, respectively. The ferrate have scavenging effect on nitrite with the concentrationof10、20、30、40、50mg/L at pH6.3、7.6and9in artificial water. The ferrate havescavenging effect on COD with the concentration of6、12、24mg/L in aquaculture water.The ferrate can promote the growth of chlorella with the concentration of0.4～1.6mg/L,but inhibit the growth of chlorella with concentration of3.2mg/L. The ferrate is safe forgrass goldfish with concentration of1620mg/L.The bacillus (KC) is Bacillus subtilis according to the characteristics of physiology,biochemistry, and16S rDNA. The Bacillus subtilis can antagonistic multi-resistant bacteriawhich separated from the human, fish, livestock, and chicken manure， especially forpathogens for aquatic animal. The secreted protein of approximate35KD may beinvolved in the antibacterial activity of Bacillus subtilis KC strain. The Bacillus subtiliskc with the concentration of103、104、105cfu/mL, have a weak scavenging effect on theammonia and nitrite, but have a obvious elimination effect with a dose-responserelationship.The MIC of enrofloxacin and norfloxacin was respectively0.08、0.32、0.16mg/L and0.16、0.32、0.16mg/L to Aeromonas hydrophila, Vibrio hollisae, and Vibrio vulnificus formrice-felid eel (Monopterus albus). The concentration of drugs in serum, muscle and viscera,reached pick at3h after immerse with concentration of10mg/L for2h, then enter theelimination period. The enrofloxacin in serum can kill three above pathogens at168h afterimmerse; but The norfloxacin in serum cannot kill Vibrio hollisae at12h after immerse.Therefore, in clinical medicine, firstly, we can use ferrate to reduce COD and nitrite nitrogen, and to kill pathogen, then use Bacilluse subtilis to reduce COD and to inhibitpathogen. During vote seeding of Monopterus albus, enrofloxacin immerse withconcentration of10mg/L for2h, can effectively inhibit pathogens.Therefore, in clinical medicine, firstly, we can use ferrate to reduce COD and nitritenitrogen, and to kill pathogen, then use Bacilluse subtilis to reduce COD and to inhibitpathogen. During vote seeding of Monopterus albus, enrofloxacin immerse withconcentration of10mg/L for2h, can effectively inhibit pathogens.