福建省部分地区鹦鹉喙羽病的分子流行病学调查及其病原Cap蛋白抗原表位预测

为了解2017-2018年鹦鹉喙羽病在福建省某些地区鹦鹉中的流行情况,收集了福建省部分地区298份鹦鹉粪便样品,采用PCR方法进行粪便样品检测,对其中鹦鹉喙羽病病毒检测呈阳性的5个地区的样品进行衣壳蛋白(Cap)基因测序后比较其同源性,绘制系统进化树,分析氨基酸序列,并通过生物信息学及序列分析软件预测Cap蛋白二级结构...     

我国大陆地区首例鹦鹉喙羽病的诊断及其致病病毒C1基因的序列分析

2008年7月末,我国青岛即墨地区患病的虎皮鹦鹉幼雏出现体重下降、脱羽和羽毛变形萎缩、鸟喙变形及胸腺结构变异等症状,怀疑为鹦鹉喙羽病(PBFD)。利用PCR对濒死鹦鹉进行鹦鹉喙羽病病毒(PBFDV)的检测,并对扩增的C1基因进行了测序与分析。结果表明,有两只检测为PBFDV阳性,B last分析发现,QD-CN08株与GenBank中已发表的PBFDV分离株C1基因同源性为82%~93%,进化树分析表明与日本的毒株有比较近的亲缘关系。结合临床症状、流行病学特征和实验室诊断,确诊为鹦鹉喙羽病,此病为中国大陆首次报道。     

新型鹅细小病毒感染鸭的肝、胸腺、回肠转录组差异表达分析

旨在探究新型鹅细小病毒(novel goose parvovirus,NGPV)与宿主细胞相互作用的分子致病机制.本研究采用转录组测序技术对感染NGPV SD株14 d雏鸭的肝、胸腺和回肠进行分析.结果 显示:感染组回肠上调基因有78个,下调基因有31个;感染组胸腺上调基因有111个,下调基因有78个;感染组肝中上调基...     

黄羽父母代种鸡混合感染禽白血病病毒与马立克病病毒的鉴定

广西某养殖场130日龄父母代种鸡发生临床肿瘤样病变和死亡,对病鸡采用病理解剖、组织病理学观察、PCR检测、病毒分离以及分离株重要基因的序列测定和病原鉴定。结果显示:病鸡的心脏、肝脏、脾脏等部位表现有肿瘤样病变; PCR检测及病毒分离培养有J亚群禽白血病病毒(avian leukosis virus subgroup J,ALV-J)和马立克病病毒(Marek's disease virus,MDV)的感染; ALV-J分离株env基因的序列与10株ALV-J参考株的核苷酸相似性为87. 2%～97. 7%,与ALV A-E亚型参考株的相似性为53. 5%～54. 7%;与ALV-J英国原型株HPRS-103的env基因糖基化位点进行分析比较,部分糖基化位点发生了改变; MDV分离株meq基因序列与8株MDV参考株的核苷酸相似性为98. 7%～99. 4%,分离株在第71～80位氨基酸发生突变,符合国内强毒分离株的特征。结果说明:该鸡群为ALV-J和MDV的混合感染。     

猪繁殖与呼吸综合征病毒(PRRSV)协同感染细菌性疾病的分析研究

为了解湖北某养殖场猪繁殖与呼吸综合征病毒（porcine reproductive and respiratory syndrome virus,PRRSV）流行毒株的遗传变异和临床感染情况,试验采集10份疑似PRRS发病仔猪的肺脏、淋巴结等临床样品,应用RT-PCR方法扩增PRRSV的Nsp2部分基因用于定性检测分析,并对扩增的其中2份PRRSV阳性样品进行ORF5基因核苷酸序列测定,结合不同疫苗毒株开展同源性比对分析。为进一步揭示病因,通过多重PCR方法对10份发病猪的肺脏和12份鼻拭子样品进行了相关致病菌的鉴定,并对其中的2株不同病原菌开展药敏试验。结果显示,10份临床样品中有5份检测到美洲型变异PRRSV,病原阳性率为50%。ORF5全基因序列分析表明,2个流行毒株间的核苷酸同源性为99.7%,与以TJM-F92、JXA1-R、HuN4-F112等为代表的高致病性致弱疫苗毒株核苷酸同源性最高,为96.7%~97.0%;与美洲型标准毒株VR2332的同源性分别为87.6%和87.9%;与国内较早分离的经典毒株（CH-1R和R98株）的核苷酸同源性分别为92.9%和87.4%、87.7%。患病猪临床常见感染模式为PRRSV+PM+SS、PRRSV+PM或PRRSV+HPS,2株主要致病菌药敏试验表明,多杀性巴氏杆菌对头孢曲松、阿莫西林等药物高度敏感,猪链球菌对阿莫西林、氨苄西林、阿奇霉素等药物高度敏感。本研究揭示了该场保育猪的发病病原,并从分子水平明确了临床PRRSV与不同疫苗毒株的亲缘关系,为弱毒疫苗的合理选择使用和综合防控PRRS提供了实践依据。     

Porcine reproductive and respiratory syndrome virus whole-genome sequencing efficacy with field clinical samples using a poly(A)-tail viral genome purification method

The genomic surveillance of porcine reproductive and respiratory syndrome virus (PRRSV) is based on sequencing of the ORF5 gene of the virus, which covers only 4% of the entire viral genome. It is expected that PRRSV whole-genome sequencing (WGS) will improve PRRSV genomic data and allow better understanding of clinical discrepancies observed in the field when using ORF5 sequencing. Our main objective was to implement an efficient method for WGS of PRRSV from clinical samples. The viral genome was purified using a poly(A)-tail viral genome purification method and sequenced using Illumina technology. We tested 149 PRRSV-positive samples: 80 sera, 33 lungs, 33 pools of tissues, 2 oral fluids, and 1 processing fluid (i.e., castration liquid). Overall, WGS of 67.1% of PRRSV-positive cases was successful. The viral load, in particular for tissues, had a major impact on the PRRSV WGS success rate. Serum was the most efficient type of sample to conduct PRRSV WGS poly(A)-tail assays, with a success rate of 76.3%, and this result can be explained by improved sequencing reads dispersion matching throughout the entire viral genome. WGS was unsuccessful for all pools of tissue and lung samples with Cq values > 26.5, whereas it could still be successful with sera at Cq ≤ 34.1. Evaluation of results of highly qualified personnel confirmed that laboratory skills could affect PRRSV WGS efficiency. Oral fluid samples seem very promising and merit further investigation because, with only 2 samples of low viral load (Cq = 28.8, 32.8), PRRSV WGS was successful.     

鸡新城疫-禽流感(H9亚型)二联灭活疫苗(La Sota株+HP株)的灭活试验

为了研究鸡新城疫-禽流感(H9亚型)二联灭活疫苗(La Sota株+HP株)中两种病毒的最佳甲醛灭活浓度和灭活时间,试验选取四种甲醛最终浓度0.1%、0.2%、0.4%、0.8%,分别对两种抗原进行灭活,在灭活10 h、12 h、14 h、16 h、18 h、24 h、30 h、36h、42 h分别取样,对每个样品进行灭活检验和血凝价测定。从试验结果得出,新城疫病毒(La Sota株)最适合的甲醛浓度为0.1%,灭活时间为16 h;禽流感病毒(H9亚型HP株)最适合甲醛浓度为0.1%,灭活时间为18 h。     

整合进禽反转录病毒长末端重复序列的马立克氏病病毒的分离鉴定

应用鸭胚成纤维细胞(DEF)从曾免疫过CVI988/Rispens株疫苗的患马立克氏病(MD)肿瘤的三黄鸡中分离到一株马立克氏病病毒(MDV,命名为GXY2株。用禽肿瘤病聚合酶链式反应(PCR)鉴别诊断技术对患鸡的肿瘤组织病料及克隆纯化毒株的DEF培养物进行检测,结果均扩增到MDV-1强毒株的132-bpr特异性带和网状内皮组织增殖病病毒(REV)的长末端重复序列(LTR)。用基于抗MDV-1的gB蛋白单克隆抗体BA4、MEQ蛋白单克隆抗体3G12E6和抗REV的单克隆抗体11B118分别对毒株的培养物进行间接免疫荧光试验(IFA),结果样品只与抗MDV-1的单克隆抗体呈现阳性反应,而与抗REV的单克隆抗体呈现阴性反应。应用PCR技术扩增并测定了毒株的致瘤相关基因meq的核苷酸序列,并与其他MDV-1参考毒株的序列进行比较分析,结果发现其序列与我们之前分离鉴定的MDV-1野强毒株G2和YL040920高度同源。研究的结果表明,分离株GXY2为整合有REVLTR片段的重组MDV强毒株。     

H5N1流感病毒感染恒河猴短期和恢复期病理学观察

为观察恒河猴在感染H5N1流感病毒后短期和恢复期的病理学变化,利用1株鹅源H5N1流感病毒环甲膜穿刺接种恒河猴。感染后短期内恒河猴产生了典型的肺炎和肺外器官不同程度的损伤,3个月后,恒河猴从病理上表现恢复。病理检查结果表明,H5N1流感病毒对恒河猴的感染是一种急性的呼吸道综合征,并伴有多器官功能不全的症状,随着感染时间的延长,可通过自身免疫调节恢复正常。     

荧光RT-PCR检测活禽和禽产品中新城疫病毒中强毒株的研究

本研究中，采用TaqMan方法，根据新城疫病毒F基因核苷酸序列，设计合成多对引物，在上游引物和下游引物之间设计多条探针，通过对引物、探针的筛选，反应条件的选择和优化，建立了检测活禽和禽产品中中强毒力新城疫病毒的荧光RT-PCR方法。经对10株倍比稀释的中强毒力新城疫病毒的尿囊液进行检测后，表明所建立的荧光RT-PCR方法的检测极限在10^-5～10^-7”之间，略低于鸡胚病毒分离方法（10^-8～10^-9）；对收集到的所有新城疫病毒株和常见禽类病毒（包括禽流感病毒H5、H9亚型、IBDV、IBV、KIBV、CAAV、鸭瘟病毒、鸭肝炎病毒）进行检测，结果表明建立的方法不能检出其他的常见禽类病毒，特异性良好。进一步用建立的荧光RT-PCR检测人工感染SPF肉鸡的组织脏器、咽喉及泄殖腔拭子及临床样品中的中强毒力的新城疫病毒，并同鸡胚分离结果比较，结果表明荧光RT-PCR的敏感性同鸡胚分离试验基本一致。由于荧光RT-PCR方法快速，从处理样品开始到出结果只需不到4小时，而且检测样品量大，这就充分显示了其快速、敏感、特异的优势。在强调口岸快速通关的今天，该方法的建立无疑为活禽或禽产品的快速检验检疫提供了有效的手段。     

Haematology and serum chemistry of Pyrenean chamois (Rupicapra pyrenaica) naturally infected with a border disease virus

In 2005 and 2006 an outbreak of disease associated with border disease virus (BDV) infection caused high mortality in the Pyrenean chamois (Rupicapra pyrenaica) in the Catalan Pyrenees (NE Spain). The aim of this study was to determine values for different haematological and serum biochemical analytes in 32 free-ranging Pyrenean chamois affected by the disease and to compare them with those obtained from healthy chamois.In the affected chamois red blood cell counts, haemoglobin concentrations, packed cell volumes, mean corpuscular volumes and lymphocyte counts were all lower, while the neutrophil and platelet counts were higher. Glucose, lactate, triglycerides, creatinine, total protein concentrations and alkaline phosphatase activity were also lower, in contrast to the concentrations of total bilirubin, urea and aspartate aminotransferase activity, which were higher.Most of the observed changes could be associated with cachexia and inflammation in the affected chamois. Lymphopenia could be directly related to the BDV, which would lead to immunosuppression and explain the high rate of secondary infection observed in these animals.     

Characterisation of genotype VII Newcastle disease virus (NDV) isolated from NDV vaccinated chickens,and the efficacy of LaSota and recombinant genotype VII vaccines against challenge with velogenic NDV

A Newcastle disease virus (NDV) isolate designated IBS002 was isolated from a commercial broiler farm in Malaysia. The virus was characterised as a virulent strain based on the multiple basic amino acid motif of the fusion (F) cleavage site ¹¹²RRRKGF¹¹⁷ and length of the C-terminus extension of the hemagglutinin-neuraminidase (HN) gene. Furthermore, IBS002 was classified as a velogenic NDV with mean death time (MDT) of 51.2 h and intracerebral pathogenicity index (ICPI) of 1.76. A genetic distance analysis based on the full-length F and HN genes showed that both velogenic viruses used in this study, genotype VII NDV isolate IBS002 and genotype VIII NDV isolate AF2240-I, had high genetic variations with genotype II LaSota vaccine. In this study, the protection efficacy of the recombinant genotype VII NDV inactivated vaccine was also evaluated when added to an existing commercial vaccination program against challenge with velogenic NDV IBS002 and NDV AF2240-I in commercial broilers. The results indicated that both LaSota and recombinant genotype VII vaccines offered full protection against challenge with AF2240-I. However, the LaSota vaccine only conferred partial protection against IBS002. In addition, significantly reduced viral shedding was observed in the recombinant genotype VII-vaccinated chickens compared to LaSota-vaccinated chickens.     

The duration of the foot-and-mouth disease virus carrier state in African buffalo (i) in the individual animal and (ii) in a free-living herd

The maintenance of a virus depends on a number of factors, including the duration of infectivity and the size of the available host population. In this work, foot-and-mouth disease virus was shown to persist in individual African buffalo (Syncerus caffer) for up to at least five years; thus, the duration of infectivity is more than adequate to cover the normal periods between calving peaks. In a small isolated free-living population which varied from 30 to 100 buffalo, two immunological types of foot-and-mouth disease virus were maintained for at least 24 years and through several generations.