肉鸭中黄病毒的分离与鉴定

为探索2011年年底在广东阳江地区某肉鸭场出现的病鸭和死鸭的发病原因,对其中2个发病鸭场的病死鸭进行了解剖,对病变组织的样品应用RT-PCR的方法进行了病原鉴定。经剖检,发现鸭心脏表面形成小结节,伴有少量心包积液;肝脏和胆囊肿大;脾脏有花斑;胰腺和直肠有出血点。利用病料研磨上清和病料接种后的鸡胚尿囊液进行RT-PCR检测,结果显示鸭黄病毒阳性。序列分析显示,该病毒的核苷酸序列与坦布苏病毒Fengxian株的相似性为99%。试验结果表明,该病毒为黄病毒,是引起此次鸭场发病的病原。     

鸭圆环病毒与鹅细小病毒混合感染病例的实验室诊断

为确诊贵州省三穗县某规模化养鸭场40日龄花边鸭出现发病死亡的原因,剖检4只病死鸭并采集心脏、肝脏、脾脏病料,根据发病情况、临床症状、病理变化、细菌分离培养和相关病毒核酸检测进行诊断。结果:(1)病鸭主要以神经症状为主,鸭群发病4 d死亡率为17.24%;典型病理变化为腹膜呈灰白色、心脏有坏死灶、肝脏不同程度受损。(2)病料在不同营养琼脂培养基上培养24 h后均未见菌落生长。(3)病料中检测出鸭圆环病毒、鹅细小病毒特异性核酸片段,未检出禽流感病毒、新城疫病毒、鸭瘟病毒特异性核酸片段。结论:综合诊断养鸭场病例为鸭圆环病毒与鹅细小病毒混合感染。     

一例雏番鸭感染鸭1型甲肝病毒的诊断

2016年3月,广东茂名某鸭场雏番鸭出现大量死亡,死亡雏番鸭多呈运动失调、角弓反张症状。解剖死亡雏鸭可见肝脏点状出血、肾脏肿大出血。初步诊断疑似鸭病毒性肝炎。采集病死鸭肝脏、脾脏等组织,分别进行细菌分离鉴定及病毒RT-PCR检测。结果显示,送检样品能扩增出约321 bp大小的鸭甲型肝炎病毒特异性引物条带,细菌分离为阴性。结合临床剖检症状和实验室检测结果,确诊该群雏番鸭发病的病原为鸭1型甲肝病毒。     

探针检测鸭黄病毒的地高辛标记DNA的制备与应用

利用RT-PCR方法扩增鸭黄病毒的NS3基因406bp的特异性片段,回收并纯化PCR产物,用地高辛标记,制备核酸探针。特异性试验结果表明,该探针仅与鸭黄病毒的核酸特异性杂交,而与鸭瘟病毒、H9N2禽流感病毒、新城疫病毒、传染性法氏囊病病毒、减蛋综合征病毒的核酸杂交均为阴性。敏感性试验表明,该探针对鸭黄病毒的RNA最低检出限量为100μg/L。对疑似黄病毒感染鸭的肝脏、肺脏、脾脏、输卵管、卵泡膜和泄殖腔棉拭子进行检测,以卵泡膜的检出率最高。该研究为鸭黄病毒感染的诊断和流行病学调查提供了一种可靠的方法。     

一例鸭疫里默氏杆菌病的诊断及病原分离鉴定

河南商丘一肉鸭养殖场疑似发生鸭疫里默氏杆菌病,为确定其病原,无菌采集病死鸭的大脑、肝脏、脾脏、肺脏等组织,依据常规PCR检测方法进行低致病性禽流感H9(AIV-H9)、鸭坦布苏病毒(DTMUV)、鸭呼肠孤病毒(DRV)、新城疫病毒(NDV)等鸭群常见病毒病的核酸检测,利用血清琼脂平板进行细菌分离鉴定,玻片凝集鉴定分离菌株血清型,PCR检测鉴定后进行动物回归试验。并进行31种抗菌药物的敏感试验。结果显示,AIV-H9、TMUV、DRV及NDV核酸检测全部为阴性,初步排除这4种病毒的感染。无菌挑取发病鸭肝脏及脑组织于血清营养琼脂培养基中培养,发现培养基中呈现针尖大小、半透明的菌落。取纯化培养的菌液进行PCR扩增显示,扩增出338 bp的鸭疫里默氏杆菌(RA)特异性条带,血清型鉴定结果为RA血清7型。动物回归试验结果显示,该分离菌株可在临床上被成功复制,能够表现出明显的传染性浆膜炎临床感染症状。药物敏感性试验显示,该血清型RA对头孢克肟、头孢唑林、头孢拉定、头孢曲松、大观霉素、多西环素、左氧氟沙星、氟苯尼考、林可霉素、氨苄西林(舒巴坦)高度敏感。综上所述,造成该肉鸭场疾病感染的病原为血清7型RA,建议使用头孢菌素类等高敏药物进行治疗。     

鹅大肠杆菌病的实验室诊断

为确诊某养鹅场雏鹅发病死亡的病因,采集4日龄发病雏鹅的肝脏组织,采用细菌分离鉴定和相关病毒核酸PCR检测方法进行病原学诊断。结果:(1)在肝脏样本中分离出细菌,经染色镜检、生化鉴定、动物感染试验,鉴定为致病性大肠杆菌;(2)鹅细小病毒PCR检测试剂盒检测未发现鹅细小病毒特异性DNA片段。综合诊断为鹅大肠杆菌病。     

一例鸭疫里默氏杆菌病的诊断及病原分离鉴定

河南商丘一肉鸭养殖场疑似发生鸭疫里默氏杆菌病,为确定其病原,无菌采集病死鸭的大脑、肝脏、脾脏、肺脏等组织,依据常规PCR检测方法进行低致病性禽流感H9(AIV-H9)、鸭坦布苏病毒(DTMUV)、鸭呼肠孤病毒(DRV)、新城疫病毒(NDV)等鸭群常见病毒病的核酸检测,利用血清琼脂平板进行细菌分离鉴定,玻片凝集鉴定分离菌株血清型,PCR检测鉴定后进行动物回归试验。并进行31种抗菌药物的敏感试验。结果显示,AIV-H9、TMUV、DRV及NDV核酸检测全部为阴性,初步排除这4种病毒的感染。无菌挑取发病鸭肝脏及脑组织于血清营养琼脂培养基中培养,发现培养基中呈现针尖大小、半透明的菌落。取纯化培养的菌液进行PCR扩增显示,扩增出338 bp的鸭疫里默氏杆菌(RA)特异性条带,血清型鉴定结果为RA血清7型。动物回归试验结果显示,该分离菌株可在临床上被成功复制,能够表现出明显的传染性浆膜炎临床感染症状。药物敏感性试验显示,该血清型RA对头孢克肟、头孢唑林、头孢拉定、头孢曲松、大观霉素、多西环素、左氧氟沙星、氟苯尼考、林可霉素、氨苄西林(舒巴坦)高度敏感。综上所述,造成该肉鸭场疾病感染的病原为血清7型RA,建议使用头孢菌素类等高敏药物进行治疗。     

鸭圆环病毒套式PCR检测方法的建立

根据GenBank发布的鸭圆环病毒(duck circovirus,DuCV)序列(AY228555),运用Primer Premier 5.0设计2对引物,建立了适合DuCV快速检测的套式PCR方法,采用该方法对从安徽省望江县采集的发病鸭肝脏、胸腺、法氏囊、肾脏和脾脏等内脏病料进行DuCV检测。结果显示,套式PCR对所有内脏病料均能扩增出340 bp的条带,而正常鸭胚、健康鸭肝脏、鸭瘟病毒、禽流感病毒(H9亚型)、新城疫病毒、传染性法氏囊病病毒、网状内皮组织增生病毒、鸡传染性贫血病毒、鸭源大肠杆菌和鸭疫里氏杆菌的扩增结果均为阴性;该方法第1次扩增的敏感性是1 ng,第2次扩增的敏感性是1 fg,第2次比第1次扩增的敏感性高106倍;表明本试验所建立的套式PCR方法可用于鸭圆环病毒(DuCV)感染的临床诊断和流行病学调查。     

广东新兴Ⅰ型鸭病毒性肝炎病原分离与鉴定

从广东新兴某鸭场大批发病和死亡的10日龄雏鸭肝、脾脏中分离到1株病毒，该病毒无血凝性，攻毒1日龄雏鸭能引起100％发病死亡，利用Ⅰ型鸭病毒性肝炎病毒标准血清进行中和试验、血清被动免疫保护试验、RT—PCR鉴定及序列分析表明该毒株为Ⅰ型鸭病毒性肝炎病毒。     

散养淮南王土鸡J亚群禽白血病的诊断

对湖北省某农户散养的12周龄淮南王土鸡病鸡进行剖检,发现病鸡肝脏有白色肿瘤;心肌增厚,有疑似肿瘤赘生物;脾脏萎缩,切面呈暗色。用J亚群禽白血病病毒（ALV-J）特异性引物进行PCR检测,扩增出了约545 bp的条带,病鸡组织内含有ALV-J病毒核酸序列,表明该病例为ALV-J感染。     

鸭坦布苏病毒江苏XZ株的分离和鉴定

从江苏徐州地区分离到的以引起樱桃谷鸭产蛋下降和死亡为特征的1株病毒,命名为XZ株。对该病毒进行电镜观察、血凝试验、ELD₅₀测定、RT-PCR扩增特异性目的基因、序列比对分析和动物回归试验。结果显示,分离毒株能致死鸭胚和鸡胚,电镜下观察到球形病毒粒子,不具有血凝性,对病料和接毒鸭胚尿囊液进行RT-PCR,均可扩增出基因片段,其核苷酸序列与坦布苏病毒奉贤株的相似性最高,为98.7%,与其他坦布苏病毒的毒株也具较高同源性,为86%~98%。用鸭胚分离毒株接种健康产蛋鸭,能复制出同样的疾病。结果表明分离病毒为鸭黄病毒属的坦布苏病毒。     

一株新型鸭源呼肠孤病毒(TH11株)的分离与鉴定

本文从太湖流域某养鸭场分离到一株呼肠孤病毒(Duck reovirus,DRV)TH11株,该病毒感染的病鸭主要表现软脚和拉稀等主要症状,剖检病变以肝脏出血和脾脏坏死为主要特征。电镜鉴定结果显示,该病原具有呼肠孤病毒的典型形态学特征。动物回归试验和RT-PCR扩增结果证明,该株病毒无论是在致病性方面,还是在基因序列方面都不同于以往的番鸭呼肠孤病毒,而是一株对多品种鸭具有较高致病性和病死率的新型鸭呼肠孤病毒。     

鸭副粘病毒强毒株的分离和鉴定

采用鸡胚接种法从安徽凤阳某患病肉鸭群中分离到一株病毒。该素株对鸡红细胞具有凝集性，并可被康复鸭鸭血清和NDV阳性抗血清所抑制，而不能被禽流感标准阳性血清抑制，结合血清中和鸡胚接种试验，病毒回归试验和免疫防治效果的研究结果，确认为鸭副粘病毒。参照国际上规定的新城疫病毒毒力判定的标准及其方法，测定该分离株的鸡胚最小致死量平均死亡时间（MDT），1日龄鸡及脑内接种致病指数（ICPI）和6周龄鸡静脉内接种致病指数（IVPI）分别为48.9h,1.80和2．45。表明该鸭副粘病天线离株具有新城疫病毒（NDV）速发型相类似的毒力，属强毒力毒株，并定名为WF00D株。     

Isolation from ducks of a hypervirulent strain of duck plague virus and an avian type 6 paramyxovirus

This paper describes the isolation and identification of a duck plague virus (DP) and a paramyxovirus (PMV₆), from the livers and intestines collected in 4-month old mule ducks, under fattening, exhibiting 75% mortality and necrotic-haemorrhagic gross lesions. These viruses were isolated in specific pathogen free (SPF) muscovy duck eggs and SPF chicken eggs respectively. Then the DP virus was adapted to duck and chicken fibroblasts. The disease was reproduced in 2-week old SPF muscovy ducklings, intramuscularly inoculated with the previous organs, as well as in contact ducks. From them, only the DP virus was isolated again. Experimentally the intramuscular inoculation of the duck plague French vaccinal strain, 4 h post contact, did not prevent the disease and did not decrease its severity.

Regarding the DP virus, the typical signs and lesions observed in experimentally infected muscovy ducks as well as the presence of intranuclear inclusions of the epithelial cells of their oesophagus, intestines, bursa of Fabricus and liver on the one hand, and on the other hand, of the epithelial cells of the duck egg chorio-allantoïc membrane and fibroblasts inoculated with the samples first defined, allowed the characterization of the virus. Direct electron microscopy, as well as the results of seroneutralization tests with different specific avian Herpes virus antisera confirmed the DP virus identification. Moreover the DP isolate was not antigenically different from the serotype actually known.

The haemagglutinating virus (PMV₆) was characterized by direct electron microscopy as well as with 18 specific avian Myxovirus antisera; its identification was confirmed too by the specific seroconversion observed 4 weeks post-inoculation of this virus, in 11 weeks old SPF muscovy ducklings.

Finally an assay was carried out to appreciate the pathogenicity of theses viruses inoculated either separately or associated. It showed the high pathogenicity of the DP strain. The PMV₆ was apathogenic and no synergic effect with the DP virus was demonstrated. It appears to be the first isolation of PMV₆ in France, to our knowledge. The epidemiological circumstances related to theses isolations are discussed. The failure of the emergency vaccination in contact ducks, might be attributed to the high virulence of the DP strain.     

鸭黄病毒感染病例的病理组织学观察

为了探明湖北省肉种鸭和蛋鸭产蛋下降的原因,对引起产蛋下降的病鸭的卵巢中分离的病毒的目的基因进行测序,对3代接种的SPF鸡胚尿囊液进行电镜观察,对脑等组织进行组织病理学观察。序列分析结果表明,扩增的序列属于黄病毒的NS5基因,且与恩塔亚病毒群有相近的遗传进化关系。电镜可观察到40nm～60nm的有囊膜的病毒粒子。组织病理学观察发现输卵管出现严重的充血、出血和炎性反应,脑充血、炎性反应,心脏中有大量变性坏死的炎性细胞。     

Evaluation of nutrient content,physicochemical and functional properties of desalted duck egg white by ultrafiltration as desalination

In this study, the effects of ultrafiltration technique on the desalination efficiency, nutrient content, physicochemical properties, functional properties, texture profile, and microstructure of salted duck egg white were evaluated. The results showed that ultrafiltration can remove 92.93% salt from salted duck egg white (SDEW) and final salt% of desalted duck egg white (DDEW) was 0.65%. The analysis of nutrient content and amino acid of SDEW and desalted duck egg white powder (DDEWP) sample was significantly lower than those of fresh duck egg white (FDEW). Although emulsifying capacity of SDEW, DDEW, and DDEWP exhibited significantly lower than that of FDEW, an excellent foaming ability was found in those samples. Moreover, the texture profiles (gel strength, hardness and elasticity) of SDEW, DDEW, and DDEWP samples presented lower value than FDEW. The observation of microstructure, DDEWP possessed smooth surface of protein globules with deep hole liked donuts and distribution of a few of salt crystals. While salted duck egg white powder (SDEWP) had a raisin‐like surface formation with salt formed cubic crystals. Overall, both liquid and dried material of desalted duck egg could be used as a good ingredient in baking food due to their excellent foaming capacity.     

Factors limiting traditional household duck production in Bangladesh

A cross sectional survey of duck production was carried out in 2002 on 771 traditional, semiscavenging household duck farms on the coastal Island of Hatia. We determined the socioeconomic characteristics of duck farmers and their management systems, identified the factors associated with egg production, and measured the level of selected duck diseases and current preventive strategies. Household family size varied from 1 to 14 individuals and women were the main caretakers of ducks. Around 34% of keepers were illiterate. Most duck products (eggs and meat; 85%) were sold at the local market. Duck houses were poorly ventilated and a variety of bedding materials were used. Feed was available in nearby scavenging areas; however, additional feed was frequently supplied by farmers. Almost all farmers (96%) ranked the rainy season as the best time for rearing ducks due to greater feed availability. The annual egg production was 79 eggs per layer with a weight of 48 g and a hatchability rate of 87%. Egg production varied by zone (p < 0.05). The odds of suboptimal egg production was 0.5 times lower in educated farmers (p = 0.001). The odds of suboptimal egg production was 2.5 times more likely in ducks that attained sexual maturity at >22 weeks (p<0.001). Most farmers ranked duck plague as the most important disease, followed by duck cholera, botulism, and duck viral hepatitis. Preventive vaccination was sporadic and used by few farmers (28%). There are significant opportunities for improved duck production on the Island of Hatia and in Bangladesh generally.     

鸭传染性法氏囊病病原分离鉴定及防治试验

从疑似鸭传染性法氏囊病的病例中分离到 １ 株鸭传染性法氏囊病毒,该病毒可使 ７ 日龄健康鸭 １００％ 发病,发病鸭具有鸭传染性法氏囊病的典型病变,用鸡传染性法氏囊高免卵黄抗体预防和治疗鸭传染性法氏囊病取得了满意效果。     

广东地区鸭黄病毒JM株的分离和初步鉴定

2010年4月以来,我国部分地区陆续发生以产蛋鸭产蛋急剧下降为特点的疾病。从广东省江门地区某鸭场的发病鸭群采集样品,接种鸭胚后分离到一株病毒,并命名为JM株,经RT-PCR检测为黄病毒核酸阳性。序列测定后分析显示,该分离株JM株与黄病毒属Tembusu病毒的对应序列相似性最高,其中与Tembusu病毒JS804株相似性最高达98%。结果表明,JM株为黄病毒,与该病鸭产蛋急剧下降有关。     

樱桃谷鸭大肠杆菌病的诊治

鸭大肠杆菌病是由致病性大肠杆菌引起的多病型疾病的总称。临床病型众多,其中以雏鸭或小鸭败血症和产蛋母鸭的卵黄性腹膜炎(蛋子瘟)危害最为严重,该病是目前对养鸭业危害较大的传染病。2012年3月,盘锦市某大型养鸭场饲养2000多只樱桃谷鸭,从186日龄开始陆续发病,主要表现为产蛋率迅速下降,病鸭精神萎顿,食欲减退,下痢,发病后期病鸭的腹部膨大、下垂,病死率约为4%。通过临床观察、病理剖检及实验室检查,确诊为鸭大肠杆菌病。根据药敏试验结果,选用极度敏感的丁胺卡那霉素治疗并采取综合性措施,迅速控制了病情。