【作者】 方文山；

【导师】 陈立志； 李国江；

【作者基本信息】 中国农业科学院 ， 兽医， 2007， 硕士

【摘要】 自Shanks(1938)首次报道猪水肿病后,目前已确认所有养猪国家均有发生。断奶1～2周仔猪最易发病,发病率达10%～30%,致死率高达90%。常发生在发育良好仔猪。据初步统计,吉林地区每年仔猪水肿病发病5000头左右,死亡近1300头,严重制约养猪业发展。因此,很有必要对仔猪水肿病的流行病学进行较为深入细致的调查,找出仔猪水肿病的发病规律,结合实际,制定出切实可行的综合防治方案,使养猪业健康发展。本文对吉林地区2006年各乡镇猪水肿病的发病和死亡情况进行了流行病学调查,发现猪水肿病在吉林地区呈零星散发性发生,发病率为0.29～1.36%,死亡率为0.08～0.35%,病死率为16.0～35.0%。水肿病主要侵害仔猪,育成猪也偶有发生。4～7月和9～10月份发病较多。同时从疑似猪水肿病的病死猪体内分离到8株细菌,根据其形态、培养特性和生长特性鉴定为大肠杆菌,动物致病性实验表明,8株均为致病性大肠杆菌,能致死小鼠。血清学鉴定出O8,O139,O141, O2共4种血清型,其中O8,O139,O141为优势血清型。用分离的猪水肿病大肠杆菌优势血清型制备出多价灭活疫苗。免疫剂量试验表明,易感仔猪肌肉注射6亿CFU/只,可获得坚强的免疫。将分离菌株用甲醛灭活,制成油乳剂灭活疫苗。疫苗无菌,性质稳定。疫苗免疫仔猪后肌肉进行攻毒试验,结果免疫组仔猪无异常临床表现。疫苗田间实验表明,对病料取样猪场的仔猪,免疫保护率达97%以上;对社会散养的仔猪,免疫保护率达92%以上。区域实验表明,在吉林部分地区免疫5000头,疫苗注射后保护率在90%以上。在生产实践中充分证明该疫苗的保护作用,为区域试验和大面积推广应用提供了依据,对有效防治猪水肿病具有参考价值。更多还原

【Abstract】 Since the first report of edema disease (ED) of piglets (Shanks, 1938), it had been assured that this disease now had taken place in nearly all porcine breeding countries around the world. This disease frequently happens to well-developed piglets in one or two weeks after weaning. Usually, it suddenly breaks out and has an incidence as high as ten to thirty percents, and the mortality is as high as ninety percents. According to the primary statistic, about 5,000 piglets would be subject to this disease and about 1,300 piglets would die of this disease in Jilin region every year. Therefore, in order to decrease the economic loss and effectively control the disease, it is necessary to investigate the epidemiology of piglet edema disease. And this work will benefit the control of piglet edema disease.In this paper, we investigated the incidence of the disease and the mortality of piglet edema in several towns of Jilin in 2006. The results demonstrated that piglet edema took place sporadically in Jilin region. The incidence of the disease in Jilin country was about 0.29-1.36 percents; the mortality was about 0.08-0.35 percents; the mortality in infected piglets was about 16.0-35.0 percents. This disease mainly happened to post-weaning piglets, occasionally to growing pig and often happened in April、May、September and October every year. 8 strains of Escherichia coli had been isolated from sick or dead piglets. They were identified as Escherichia coli by its morphology, culture and biochemical characteristics. The pathogenicity trial in mouses showed that they were all pathogenic bacteria. 8 strains were classified into 4 serotypes: O8, O139, O141, and O2. Among them, O8, O139 and O141 were the predominant sterotypes. Polyvalent inactivated vaccine was prepared with predominant-serotype E. coli. Piglets were inoculated with different dose of inactivated vaccine. The results showed that when susceptible piglets were inoculated with 6×108 CFU per piglet, these piglets would have stronger immunity. The separated bacteria were inactivated with formaldehyde and prepared into an inactivated, oil emulsion adjuvant vaccine. This vaccine had steady characteristics, without infection of bacteria. The piglets were challenged with live Escherichia coli strains through muscle after inoculation with the inactivated vaccine. The results showed that the vaccinated piglets had no abnormal clinical presentation. Evidences from clinic trials showed that the immune protective rate of the piglet edema disease reached to 97 percents for piglets in pig farm where the samples were collected, 92 percents for piglets sporadically reared in society. Regional trial showed that among 5000 piglets which were vaccinated in some parts of Jilin, the immune protective rate was over 92 percents. Those results proved the protective effect of this vaccine in practical production sufficiently, provided a basis for regional trial and application of the vaccine in large area and had important value for preventing piglet edema effectively.更多还原