仔猪黄、白痢高免卵黄抗体的试制

[摘要]为了解决临床上应用抗生素治疗仔猪黄、白痢病治愈率低、细菌易产生耐药性的缺点,采用把适当数量的K88、K99、987P抗原按一定比例混合后免疫健康鸡,制备高免的卵黄抗体治疗发病仔猪,结果表明该方法是可行的。它的推广和应用给临床上治疗该病提供了一种治愈率高、不产生耐药性、安全、有效的方法。     

猪K88、K99、987P、F41埃希氏大肠杆菌高密度发酵培养技术的初步探讨

采用高密度发酵和普通深层通气两种方法培养含K88、K99、987P、F41菌毛抗原的四株猪埃希氏大肠杆菌,对其培养液进行活菌数、OD值、pH值、效价的测定。实验结果表明,运用高密度发酵方法培养,各菌活菌数可达4.1×1010~4.9×1010CFU/mL,效价为211~213;运用普通深层通气方法培养,各菌活菌数为0.51×1010~0.59×1010CFU/mL,效价为24~25,可选择高密度发酵方法替代普通深层通气方法培养,用于制备猪埃希氏大肠杆菌K88、K99、987P、F41四价菌毛提纯苗。     

K88,K99,987P基因工程三价苗的免疫效力试验

对六个批次的K_(88)、K_(99)、987P基因工程三价苗作免疫效力测定。第一次试验,对用三个批次基因工程三价苗被动免疫(通过初乳)的仔猪,以三种强毒菌进行攻击,死亡率上均获得100%保护,黄痢腹泻发病率上获得98%保护;而对照仔猪,对三种强毒菌的攻击,发病率均达100%,死亡率分别是K_(88)为96%、K_(99)为72.7%、987P为80%,平均83.3%。第二试验的另外三个批次的基因工程三价苗的被动免疫(通过初乳)仔猪,虽然三种强毒菌的攻击剂量各增加三分之一,但保护率仍达到与第一次试验一致的结果;而对照仔猪,黄痢腹泻发病率均达100%,死亡率分别为K_(88)100%、K_(99)95%、987P91%,平均95%。     

抗幽门螺旋杆菌卵黄抗体的制备及其体外抑菌试验

试验以幽门螺旋杆菌(helicobacter pylori，HP)全菌灭活抗原对150日龄伊沙褐壳母鸡进行首免，165日龄二免，180日龄三免，于首免后即开始收集鸡蛋，利用凝集实验测定卵黄中的抗体效价。结果表明：每间隔15天，采取两次加强免疫方法，可有效地引起免疫应答。母鸡在初免45d后，抗体效价可达到1：1024，同批样品在此水平可维持达60d以上(效价大于1：128)，然后抗体效价呈缓慢下降趋势，经130d后，抗体效价下降至1：8。体外抑菌实验表明，高免卵黄具有明显的抑制HP生长的活性。     

The food contaminant fumonisin B1 reduces the maturation of porcine CD11R1+ intestinal antigen presenting cells and antigen-specific immune responses, leading to a prolonged intestinal ETEC infection

Consumption of food or feed contaminated with fumonisin B₁ (FB₁), a mycotoxin produced by Fusarium verticillioides, can lead to disease in humans and animals. The present study was conducted to examine the effect of FB₁ intake on the intestinal immune system. Piglets were used as a target and as a model species for humans since their gastro-intestinal tract is very similar. The animals were orally exposed to a low dose of FB₁ (1 mg/kg body weight FB₁) for 10 days which did not result in clinical signs. However, when compared to non-exposed animals, FB₁-exposed animals showed a longer shedding of F4⁺ enterotoxigenic Escherichia coli (ETEC) following infection and a lower induction of the antigen-specific immune response following oral immunization. Further analyses to elucidate the mechanisms behind these observations revealed a reduced intestinal expression of IL-12p40, an impaired function of intestinal antigen presenting cells (APC), with decreased upregulation of Major Histocompatibility Complex Class II molecule (MHC-II) and reduced T cell stimulatory capacity upon stimulation. Taken together, these results indicate an FB₁-mediated reduction of in vivo APC maturation.     

种茧育桑园氮磷钾施肥最佳配方的试验1．春季不同施肥比例对桑叶产、质量的影响

试验在其它桑园管理措施一致的前提下,改变其N、P2O5、K2O肥的施用比例,并对桑叶产、质量进行了调查。结果是N：P2O5：K2O=10：5：5的施肥比例,能显著提高生长芽生长量,极显著提高春叶产量;适当提高种茧4龄起蚕结茧率和虫蛹统～生命率。显著提高全茧量及茧层量。极显著提高卵质成绩及下代孵化率。