Preparation Of Anti-endotoxin IgY Isolated From Yolk Of Hens Immunized With LPS Of Escherichia Coli And Determination Of Its Biological Activity

Bacterial endotoxin is one of the primary factor of high mortality rate associated with gram-negative bacterial(GNB)infection.They are composed of a hydrophilic polysaccharide moiety and a hydrophobic lipid moiety(lipid A)which anchors the molecules in the outer membrance.Serious endotoxin intoxication can cause sepsis and septic shocks,leading to severe hypertension,cardiovascular collapse,multiple organ failure and death.Applied antibody block therapy to treat the human endotoximia has already had many years history,but because the anti- endotoxin blood serum preparation cost is high,on clinical it has not used in the veterinarian.This research through prepares the anti-endotoxin IgY isolated from yolk of hens immunized with endotoxin of Escherichia coli,to discuss the preventing and controlling dairy cattle mastitis and endotoximia new way.Comparison of two methods for extraction of rude LPS from E.coli in order to obtain a higher content of immunogenicity of LPS.To prepare Yolk Immunoglobulin(IgY),study the change rule of anti-endotoxin IgY and the passive protective effect of IgY against EHECO.The yolk IgY was extracted by chloroform. The antibody activity was measured by IHA.The IgY was used in the experiments of mice to test the toxity and the protective effect to it.The study showed that:1.a higher content of LPS was obtained with the "phenol-chloroform-petroleum ether" method,so it's more convenient and more applicable to the massive extraction of LPS.2.The experiment showed that in immunity initial stages the antibody level in the yolk and the blood serum has not too big difference.30 days later along with the antibody level raised rapidly, the antibody level in the yolk and the blood serum has the obvious difference.3.The titer of IgY was above 1:64 by HIA.The toxity to mice of IgY was not found.4.The passive protective experiment showed that IgY has evident protective effect to the mice diarrhea and death model.