新型仔猪腹泻病的流行特点与免疫学研究

发布时间：2018-04-23 18:52

本文选题：新型仔猪腹泻病 + PEDV　；参考：《聊城大学》2015年硕士论文

【摘要】：猪腹泻是由多种病因引起以腹泻为主要症状的一种综合征,为猪养殖过程中最为常见的疾病之一。自2010年起,在我国全国范围内,中大规模的猪场、小型猪场以及散养户均发生不同程度的腹泻。由于其流行特点与以往传统的腹泻不同,称之为新型仔猪腹泻病。本研究对新型仔猪腹泻病的流行病学特点进行了调查,检测了疑似新型仔猪腹泻病仔猪的PEDV阳性率。研究了腹泻仔猪的心脏、肝脏、肾脏、脾脏和小肠的病理组织学变化。并对新型仔猪腹泻病免疫学方面进行探索,测定了病猪猪瘟病毒(CSFV)抗体和圆环-2型病毒(PCV-2)抗体的含量,细胞因子IL-1、IL-2及IFN-γ的水平以及分泌型免疫球蛋白A(SIg A)的含量,除此之外,探索了应用干扰素对新型仔猪腹泻病进行治疗,初步评估了其治疗效果。1.新型仔猪腹泻病流行病学调查新型仔猪腹泻病病猪的主要症状为呕吐、腹泻,严重的病猪会发生脱水,该病主要侵害7日龄内仔猪,猪场内仔猪的死亡率可达到70%和100%之间,中大型的猪场多发,持续时间久可流行数月,其流行时间集中在一年的12月份到下一年的4月份之间,其余时间也有流行。159份的病料检测出100份PEDV阳性样品,阳性率为62.5%。提示我国自2010年以来爆发的新型仔猪腹泻病主要病原体为PEDV。2.新型仔猪腹泻病病理组织学变化制备患病仔猪心脏、肝脏、肾脏、脾脏和小肠石蜡切片,用HE染色发现心脏心肌纤维间隙增宽,心肌纤维多处发生断裂;肝组织普遍发生坏死或出血,肝小叶结构不明显,肝细胞索结构消失,细胞核浓缩、溶解消失,细胞核破碎表现为蓝紫色深染的碎片,肝组织淤血,中央静脉扩张、里面充满红细胞,肝索之间、静脉充满红细胞,肝索之间有少量的含铁血黄素沉积;肾小管上皮细胞肿胀,管状结构破坏,肾小管管腔有浆液和少量细胞,在油镜下观察管内细胞为为肾小管内皮细胞脱落,肾脏组织充血;脾小体结构不明显且数量减少,脾动脉周围淋巴鞘淋巴细胞减少;小肠绒毛脱落严重。表明各组织器官存在功能障碍,提示患病机体存在严重的血液循环障碍及免疫功能障碍。3.新型仔猪腹泻病的免疫学研究腹泻仔猪CSFV抗体水平低于健康对照猪(P0.01),腹泻组仔猪PCV-2抗体水平高于健康对照组(P0.01)。腹泻仔猪血清中IL-2和IFN-γ的浓度明显低于健康仔猪(P0.05);腹泻仔猪血清中IL-1的浓度与健康对照组(P㧐0.05)无明显差别。新型仔猪腹泻病仔猪粪便的SIg A水平低于健康对照仔猪(P0.01)。经过干扰素治疗后的腹泻仔猪症状得到了有效的缓解,且IL-2和IFN-γ的含量显著提高。本试验结果表明患病猪机体存在免疫功能障碍,体液免疫、细胞免疫以及小肠黏膜免疫功能均有所降低。而经过干扰素治疗的腹泻仔猪,病症得到了有效的缓解。表明干扰素可以提高患病仔猪机体的免疫功能并可以有效的缓解仔猪新型仔猪腹泻病的症状。
[Abstract]:Pig diarrhea is one of the most common diseases in pig breeding. Since 2010, diarrhea has occurred in large-scale pig farms, small pig farms and free-range farmers in China. Because its epidemic characteristic is different from the traditional diarrhea, it is called the new type piglet diarrhea disease. In this study, the epidemiological characteristics of new type piglets diarrhea disease were investigated, and the positive rate of PEDV in piglets suspected to be new type piglets diarrhea disease was detected. The pathological changes of heart, liver, kidney, spleen and small intestine in diarrhea piglets were studied. In addition, the contents of CSFV antibody and PCV-2 antibody, the levels of IL-1IL-2 and IFN- 纬, and the content of secretory immunoglobulin A (sig A) were determined. To explore the application of interferon in the treatment of a new type of piglet diarrhea disease, the preliminary evaluation of its therapeutic effect. 1. Epidemiological investigation of new type piglets diarrhea disease the main symptoms of new type piglets diarrhea disease pigs are vomiting, diarrhea, serious disease pigs will be dehydrated, the disease mainly affects the piglets within 7 days of age, the mortality of piglets in the pig farm can reach 70% and 100%. Large and medium pig farms have more PEDV positive samples, lasting a long time for several months. The epidemic time is concentrated between December of one year and April of the following year. In the remaining time, 100 samples of PEDV positive were detected in the other time, the positive rate was 62.5%. It is suggested that the main pathogen of the new type of piglet diarrhea disease in China since 2010 is PEV. 2. Preparation of paraffin sections of heart, liver, kidney, spleen and small intestine of piglets with new type of diarrhea disease. Necrosis or haemorrhage was common in liver tissue, hepatic lobular structure was not obvious, the structure of hepatic cell cord disappeared, the nucleus was concentrated and dissolved, the nucleus was broken into pieces with blue and purple staining, the liver tissue was clotted and the central vein was dilated. It is filled with red blood cells, between the hepatic cord, between the veins, and between the hepatic cords with a small amount of hemosiderin deposition; the tubular epithelial cells are swollen, the tubular structure is destroyed, and the renal tubule lumen has serous fluid and a small number of cells. Under the oil microscope, the cells in the tube were the renal tubular endothelial cells, the renal tissue was congested, the structure of the splenic body was not obvious and the number of the splenic body was decreased, the lymphocyte around the splenic artery was decreased, and the villi of the small intestine were shedded seriously. The results indicated that there were serious blood circulation disorders and immune dysfunction. 3. Immunological study on the new type of piglets diarrhea the level of CSFV antibody in diarrhea piglets was lower than that in healthy control pigs and the PCV-2 antibody level in diarrhea group was higher than that in healthy control group. The concentrations of IL-2 and IFN- 纬 in serum of diarrhea piglets were significantly lower than those of healthy piglets (P 0.05), but the concentrations of IL-1 in serum of diarrhea piglets were not significantly different from those of the healthy control group (P 0.05). The level of SIg A in feces of new type piglets with diarrhea disease was lower than that of healthy control piglets (P 0.01). The symptoms of diarrhea piglets treated with interferon were effectively alleviated, and the levels of IL-2 and IFN- 纬 were significantly increased. The results showed that there were immune dysfunction, humoral immunity, cellular immunity and intestinal mucosal immunity. In piglets treated with interferon, the disease was effectively alleviated. The results showed that interferon could improve the immune function of sick piglets and relieve the symptoms of new type piglets diarrhea.
【学位授予单位】：聊城大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S858.28

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