摘要
为制备抗大肠杆菌O157:H7卵黄中的免疫球蛋白Y(IgY),并研究其对人工感染大肠杆菌的昆明乳鼠是否具有预防和治疗效果,本研究将O157:H7大肠杆菌菌液经甲醛灭活后加弗氏佐剂和弗氏不完全佐剂制备灭活疫苗,以其免疫蛋鸡后每间隔1个月用灭活菌液加强免疫并收集鸡蛋,从蛋黄中分离纯化浓缩IgY,采用微量凝集试验检测卵黄抗体效价。采用Eudragit~?L100-55包被精制IgY制成骨架型肠溶片,以未包被的IgY抗体作为对照。在体外模拟胃/肠环境对未包被IgY及包被后的IgY通过微量凝集试验进行活性检测,同时对小鼠口服肠溶片并检测包被的IgY在动物消化道内的活性变化。结果显示,在模拟胃/肠液耐受性和体内释放试验中,未包被的IgY在胃模拟液内活性迅速丧失,在肠模拟液内活性逐渐丧失,并在10 h后活性完全丧失;而包被肠溶片IgY的生物活性可以保持较高水平。小鼠实验结果显示,IgY肠溶片的活性基本未受小鼠胃环境的影响,肠溶片IgY可到达动物肠道释放IgY且其活性可以保持较长时间。利用大肠杆菌O157:H7的6倍半数致死量(6LD_(50)),即1.5×10^(10)cfu/mL感染小鼠建立小鼠感染模型,通过小鼠实验验证口服IgY肠溶片的预防和治疗效果,以口服未包被IgY的小鼠作为对照组。治疗试验结果显示,对感染大肠杆菌后小鼠每日饲喂含0.4 mL IgY的肠溶片时,可以达到100%的存活率;预防试验结果显示;每日饲喂含0.05 mLIgY的肠溶片,并用6LD_(50)剂量的细菌感染,饲喂7 d后对小鼠的保护率达100%,保护试验与预防试验中IgY肠溶片组小鼠的存活率均远高于未包被IgY组。本研究结果表明口服IgY肠溶片可以有效预防和治疗大肠杆菌血清型O157:H7对昆明乳鼠的感染,为治疗和预防特定肠道的传染性疾病抗体制剂的研究奠定了基础。
This study aimed to evaluate the effectiveness of egg-yolk antibody IgY in preventing and treating artificially infected Kunming mice with E.coli O157:H7.Laying hens were immunized with formaldehyde-inactivated E.coli O157:H7,followed by further immunization with inactivated bacteria solution every month.IgY antibodies were isolated and purified from yolk,and the titer of yolk antibody was detected by trace agglutination.Enteric-coated tablets were prepared using Eudragit®L100-55,coated with*Corresponding author purified IgY,while uncoated IgY served as controls.The activity of uncoated IgY and coated IgY was detected by microagglutination test in a simulated gastric/intestinal environment in vitro.Additionally,mice were orally administered the enteric-coated tablets,and changes in IgY activity in their digestive tracts were detected.The results showed that the activity of uncoated IgY in simulated gastroenteric fluid was rapidly lost in simulated gastric fluid and gradually lost in simulated intestinal fluid.The activity was completely lost after 10 hours.In contrast,enteric-coated IgY maintained high biological activity.In vivo experiments demonstrated that gastric environment had no impact on IgY activity,and the antibodies were released and remained active in the intestinal region for an extended period.Mice fed enteric-coated tablets containing 0.4mL IgY daily showed 100%survival rate when infected with 6LD_(50)(1.5×10^(10)cfu/mL)of E.coli O157:H7.Moreover,a 100%protection rate was achieved after 7 days of feeding with enteric-coated tablets containing 0.05mL IgY,compared to the control group.The survival rate of infected mice treated with enteric-coated IgY tablets was significantly higher than those treated with uncoated IgY.In conclusion,oral IgY enteric-coated tablets can effectively prevent and treat the protective effect of E.coli serotype O157:H7 on Kunming suckling mice,laying a foundation for the study of antibody preparations for the treatment and prevention of specific intestinal infectious dise
作者
曹章
陈欣婷
赵静
刘德凯
张彦龙
CAO Zhang;CHEN Xin-ting;ZHAO Jing;LIU De-kai;ZHANG Yan-long(College of Wildlife and ProtectedArea,Northeast Forestry University,Harbin 150040,China;Liaoning Yikang Biological Corporation Limited,Liaoyang 111005,China)
出处
《中国预防兽医学报》
CAS
CSCD
北大核心
2024年第8期832-836,共5页
Chinese Journal of Preventive Veterinary Medicine
基金
应用抗体对产志贺毒素大肠杆菌的保护效果研究(43219024)。
关键词
口服
包被
卵黄抗体
大肠杆菌
take orally
encrustation
yolk antibody
E.coli
