Development Of Compound Egg Yolk Powder For Prevention And Curing Bacteriosis Of Pisces

As the sharp development of fishery industry these years,bacteriosis of pisces has become one of the most serious infectious diseases and it has caused great damage and economical losses.Chemoprophylaxis,immunize prevention and cure,breeding for disease resistance are the main measures taken to solve these problems.Compared with the infectious diseases of animals',the reasearch of pisces disease in our country is fall far behind.In theory,breeding for disease resistance species has the effect once for all,but the breeding process is long and to obtain specieses that resistance several diseases is almost impossiable.There is neither effective strategy of the water body environment control nor effective vaccine available at preasent,so chemicals and antibiotics were over dependented,they were used unreasonabaly and were used too much for a long time.The abuse of chemicals and antibiotics not only induced the drug resistance bacterium but also polluted the water,furthermore,the noxious residue in the fishery product are threatening people's health seriously.So we should make great effort to develope medicine specialised for aquatic products and use these medicine properly,only by doing this can we control aquatic animal's diseases effectively and protect the health of human beings.Yolk antibody(IgY),a kind of immune globulin,have the similar function as IgG.The cost of IgY is relatively low and is much easier for mass production,besides,IgY will not cause a series of problrms as chemicals and antibiotics did,so IgY may become the next generation of biologic product to substitute for antibiotics.After the main pathogenic bacterium and their pathogenicity of several kind of fishes were confirmed,cross-reaction experiment was done among all kinds of bacterium antigen.Four kind of method IgY abstraction were compared,ELISA and MA methods were used for IgY detection.The best method for IgY extracton was chosen and it was shown that MA method was better for IgY detection.As the result,each strain almost can't generate valid cross-reaction.Based on these results,potency curve of IgY,which were obtained from different immune programme,was drawn.As we can see,there are immune competition and inhibition phenomenon among some antigenes.Using trigeminy vaccine four times can get the best effect.To study the biologic activity of dried egg yolk,dried egg yolk was made according to the technology of spray drying.Agglutinate potency of IgY,the trials of bacteriostasis experiment shown that drying spray will do little influence on the potency and biologic activity of IgY.Dried egg yolk of high level IgY can restrain the growth and multiplication of corresponding bacterium.effectively.Agglutination titer of 24containing specific antibody water-soluble components of the yolk (WSF) makes 625 times of dilution can still have 50 percent of the corresponding pathogenic bacteria inhibitory effect.The spray drying technology can deactivate bacterium effectively.For animal experiment,crucian were fed with high potency dried egg yolk for a period of time,and it was verified that dried egg yolk has clinical application prospect in preventing and curing bacteriosis of pisces. Yolk powder agglutination titer of 26 can produce 90 percent and 75 percent of the protective effect to 1 times and 2 times the minimum lethal dose of the corresponding pathogenic bacteria.To redeem the flaw that there is almost no effective cross-reaction among different straines and reinforce the effect of IgY,toxin of Aer and ECPase were extracted from Aeromonas hydrophila and their biologic activity were reaserched.As the potency curve showes that the toxin of Aer or ECPase of different straines can have cross-reaction but won't restrain the generation of IgY.The discovery have established the foundation to manufacture compound and enhanced whole egg powder.