特异性卵黄抗体(IgY)对小鼠大肠杆菌败血症的保护作用

目的:研究特异性IgY对小鼠大肠杆菌败血症的保护作用.方法:以灭活的E.coli O111免疫产蛋母鸡,抗体经水稀释及盐析分离纯化.ELISA法检测大肠杆菌特异性IgY对大肠杆菌及LPS的结合活性.腹腔注射E.coli O111(1011cfu/mL)建立小鼠败血症模型,攻毒剂量为0.1mL/10g体重.小鼠随机分为5组,分别给药保护:空白组(生理盐水)、阴性对照组(非特异性IgY,20mg/mL)、阳性对照组(头孢哌酮20mg/mL)、高剂量组(特异性IgY,40mg/mL),低剂量组(特异性IgY,20mg/mL).给药剂量为:攻毒前,0.15mL/10g体重,每天一次,共两天;攻毒后,0.25mL/10g体重,每天一次,共七天.观察小鼠临床表现、体重变化、白细胞(WBC)和血小板(PLT)数变化及各组小鼠的死亡率.结果:特异性IgY与E.coli O111和LPS均有体外结合活性.大肠杆菌攻毒后,小鼠体重下降,各组小鼠外周血中WBC和PLT数均有不同程度的下降.特异性IgY保护组各项指标较快恢复到正常水平,其他组恢复缓慢.各组小鼠七天内的死亡率分别为:空白组与阴性对照组都为100%;阳性对照组60%;低剂量IgY组30%;高剂量IgY组10%.结论:特异性IgY对小鼠大肠杆菌败血症有保护作用.

Protection of Specific Egg Yolk Immunoglobulin(IgY)for Mice with Septicemia Caused by Escherichia coli

Objective:To evaluate the protection of specific egg yolk immunoglobulin(IgY)against septicemia of mice caused by Escherichia coli.Methods:Specific IgY was produced by immunizing hens with formaldehyde killed E.coli O111 and purified by water dilution and salt precipitation.Enzyme linked immunosorbent assay(ELISA)was applied to detect the binding activity of IgY against E.coli O111 and LPS.Mice septicemia was induced by celiac injection of 1011 cfu/mL E.coli O111 at a dose of 0.1mL/10g weight.One hundred mice were divided into 5 groups and protected differently:blank group(normal saline),negative group(non-specific IgY, 20mg/mL),positive group(cefoperazone,20mg/mL),high dose group(specific IgY,40mg/mL)and low dose group(specific IgY, 20mg/mL).Protective agents were given daily at doses of 0.15mL/10g weight(before challenge,total 2 days)and 0.25mL/10g weight (after challenge,total 7 days).Clinical manifestations,changes of weight,death rates,WBC and PLT were estimated.Results:IgY against E.coli O111 was specific to E.coli O111 and LPS.After injection of E.coli O111,WBC and PLT in blood and body weight of mice decreased obviously in each group.WBC and PLT of mice given specific IgY recovered to normal level rapidly while other groups were still in low level.Death rates of blank,negative,positive,low dose and high dose group were 100%,100%,60%,30% and10% re- spectively.Conclusion:E.coli O111 specific IgY was protective against septicemia of mice caused by E.coli O111.