血清4型Ⅰ群禽腺病毒对不同日龄SPF鸡的致病性研究

发布时间：2018-03-07 14:51

  本文选题：血清4型Ⅰ群禽腺病毒　切入点：SPF鸡　出处：《山东农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：心包积水-肝炎综合征(Hydropericardium Hepatitis Syndrome,HHS),又称安哥拉(Angara)病,是由腺病毒科的Ⅰ群禽腺病毒血清4型引起的以心包积水和包涵体肝炎为特征的一种高度接触性传染病。1987年在巴基斯坦安哥拉地区爆发了一种新病,其临床症状与包涵体肝炎(Inclusion Body Hepatitis,IBH)相似却又伴有严重心包积水的“新”综合征。随后该病在印度、科威特、伊朗、日本、墨西哥等地相继发生,经研究证实,这些地区的心包积水-肝炎综合征均由Ⅰ群禽腺病毒的血清4型(Fowl Adenovirus serotype 4,FAV-4)引起。2015年6月以来,我国湖南、江苏、河南、山东、河北、辽宁、安徽、吉林等省的部分地区鸡群出现了一种可以引起鸡心包积液和包涵体肝炎为特征的血清4型Ⅰ群禽腺病毒感染。该病多呈急性经过,且多发生于3-5周龄的肉用仔鸡,发病后第4-8d为死亡高峰,病程8-15d,死亡率为20%-80%,目前,该病在杂交鸡、麻鸡、种鸡、蛋鸡和肉鸭也可发生,给我国养禽业造成了严重的威胁,并造成严重的经济损失,因此加强对该病的研究,对于保护和促进我国养禽业的发展具有重要意义。本试验将90只10日龄SPF鸡,随机分为口腔攻毒组(30只)、肌肉攻毒组(30只)和对照组(30只)3组,每组用隔离罩隔离饲养。口腔攻毒组鸡,每只口腔注射1mL(EID50=10-7.569/0.2mL)病毒液;肌肉攻毒组鸡,每只肌肉注射1mL(EID50=10-7.569/0.2mL)病毒液;对照组鸡,每只注射1mL生理盐水。攻毒后连续观察20d,记录发病情况。分别于攻毒后第4d、8d、12d、16d和20d称重、采血,并随机剖杀攻毒组和对照组鸡各5只,观察记录感染鸡的临床症状和剖检变化,HE染色观察组织病理学变化,检测血清中生化指标(ALT,AST,LDH,UREA),ELISA试验测定血清中细胞因子(IL-6,IFN-γ)与抗体效价,荧光定量PCR方法检测组织中病毒载量。20日龄和10日龄组鸡的攻毒剂量及试验方法相同。两个日龄的攻毒组鸡均表现为精神沉郁,食欲减退,体重增长缓慢,且该病发病急,死亡快,死亡率较高,10日龄肌肉攻毒组的死亡率达到50%。剖检结果显示,10日龄组的病变与20日龄组类似,但是更加严重,出现明显的心包积液和包涵体肝炎现象,脾脏肿大、出血,肺脏水肿、出血,肾脏肿大,胸腺肿大、出血,且10日龄组腺胃出血。病理组织学结果表明试验鸡的肝脏、脾脏可见明显的炎性细胞浸润,心肌间质水肿增宽,胸腺与法氏囊淋巴细胞坏死。生化指标的检测结果显示,攻毒后ALT、AST、LDH、UREA的含量均升高,且明显高于对照组。细胞因子的检测结果显示,攻毒后IL-6和IFN-γ的含量均升高。对血清中抗体的检测结果显示,攻毒组抗体一直处于上升状态,且明显高于对照组。对组织中病毒载量的检测结果显示,口腔攻毒组和肌肉攻毒组的心脏、肝脏、脾脏、肺脏、肾脏、胸腺、胰腺和法氏囊等组织器官中均检测到了病毒的存在,其中心脏和肝脏的病毒含量较高,且肌肉攻毒组各器官的病毒载量明显高于口腔攻毒组。FAV-4可侵害鸡的多个器官,导致鸡的发病,在没有母源抗体及其他病毒干扰的情况下,感染该病后小日龄鸡比大日龄鸡的病变情况更加严重。本研究表明,FAV-4对SPF鸡的致病性强弱与感染日龄和感染途径有关,小日龄比大日龄的鸡更易感,且肌肉攻毒组组比口腔攻毒组发病死亡情况更为严重,该病可侵害多个器官,病毒在组织中分布较广。
[Abstract]:Hydropericardium hepatitis syndrome (Hydropericardium Hepatitis, Syndrome, HHS), also known as Angola (Angara) is caused by disease, fowl adenovirus group serum by adenovirus type 4 with pericardial effusion and inclusion body hepatitis is a highly contagious disease of.1987 in Pakistan area of Angola broke out a new kind of disease, the clinical symptoms and inclusion body hepatitis (Inclusion Body, Hepatitis, IBH) similar but with severe pericardial effusion of the "new" syndrome. Then the disease in India, Kuwait, Iran, Japan, Mexico and other places have occurred, the study confirmed that these regions hydropericardium hepatitis syndrome serum the fowl adenovirus group type 4 (Fowl Adenovirus 4 serotype, FAV-4) has caused by.2015 in June, China's Hunan, Jiangsu, Henan, Shandong, Hebei, Liaoning, Anhui, Jilin and other parts of the province have a chicken Cause the heart-shaped effusion and inclusion body hepatitis package of serotype 4 of avian adenovirus infection. The disease was more acute after, and broiler occurred at the age of 3-5 weeks, after the onset of 4-8d death peak, duration of 8-15d, mortality rate was 20%-80%, at present, the disease in hybrid chicken, chicken. Chicken, chicken and duck can also occur, causing a serious threat to the poultry industry in China, and caused serious economic losses, so strengthen the research of the disease, it is important to protect and promote the development of China's poultry industry. The 90 10 day old SPF chickens were randomly divided into oral the challenge group (30 rats), muscle inoculation group (30 rats) and control group (30 rats) 3 groups, each group with shield isolatedfeeding. Oral challenge group chicken, each oral injection of 1mL (EID50=10-7.569/0.2mL) virus liquid; muscle challenged group chickens, each intramuscular injection of 1mL (EID50=10-7.569/0.2mL) virus solution; control group 楦，

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