犬瘟热病毒的静水压灭活

以250MPa的静水压力对犬瘟热病毒（CDV）处理30min之后，CDV被灭活，由其制成的灭活疫苗诱导犬产生中和抗体的能力明显优于传统的福尔马林灭活疫苗，免疫保护率达90％。电镜观察显示，经不同程度静水压力处理后的CDV粒子均发生变形，表面呈现凸起，但CDV H基因部分片段的RT－PCR扩增结果揭示，高达510MPa的静水压力作用30min也未能使其基因片段受到破坏。     

Antibody titers in domestic ferret jills and their kits to canine distemper virus vaccine

Antibody titers were measured in domestic or European ferret (Mustela putorius furo) jills vaccinated with modified-live canine distemper virus (CDV) vaccine and in their kits. The half-life of maternal antibody to CDV in ferrets was 9.43 days. Ferret kits should be vaccinated against CDV at 6, 10, and 14 weeks of age.     

犬瘟热病毒弱毒和野毒的全基因组扩增及序列测定

分析比对了GenBank中已公布的23株犬瘟热病毒全基因组序列,针对保守区设计了11对特异性通用引物,用于扩增犬瘟热病毒野毒株和疫苗株全基因组。通过优化11对引物的工作浓度及退火温度等条件,对保存的3株疫苗毒CDV3株、OR12株、CDV/R-20/8株和2株野毒HBF-1株和SD(14)07株进行了全基因组扩增。取5μL扩增产物进行1%琼脂糖凝胶电泳,结果显示11对通用引物对以上5株犬瘟热病毒扩增后,均获得11个特异性目的片段,条带大小与预期相符。选取疫苗毒OR12株和野毒HBF-1株的进行全基因组序列测定,与GenBank中已公布的序列进行比对,同源性均大于99.0%,证实这11对特异性通用引物能够实现对犬瘟热病毒野毒和弱毒全基因组的准确扩增,并获得准确的全基因组序列。     

犬瘟热病毒感染的研究现状

犬瘟热（Canine distemper）是由犬瘟热病毒（Canine distemper virus,CDV）引起犬的一种急性、高度接触性传染病。早期表现以双相热、急性鼻卡他、卡他性肺炎和胃肠炎为特征,后期出现神经症状,少数病犬出现鼻和足垫过度角化现象。CDV感染是犬科动物最常见的、最主要的病毒性疾病之一,发病率高、治愈率低,是食肉动物病毒病的典型代表。笔者就近年来我国CDV感染的研究现状简述如下。     

Polioencephalomalacia associated with canine distemper virus infection

Eight dogs with severe neurologic signs, including seizures, had polioencephalomalacia of the pyriform cortex, Ammon's horn and deep structures in the temporal lobe. The polioencephalomalacia was considered to be a consequence of canine distemper virus infection based on clinical signs, typical inclusions, the demonstration of viral antigens in the lesions and of characteristic paramyxovirus nucleocapsids by electron microscopy. Little evidence for neuronal destruction by direct viral activity was found. Selective nerve cell necrosis was attributed to ischemia (vascular lesions and seizure induced consumptive anoxia) and immune mechanisms. The selective involvement of the rhinencephalic structures was thought to be related to the mode of entry and spread of the virus.     

Immunoperoxidase study of canine distemper virus pneumonia

Forty-two cases of canine pneumonia were examined for the presence of canine distemper virus. For that purpose canine distemper virus inclusion bodies were located. The histopathological lesions were related to the presence of canine distemper antigen, as demonstrated with an immunoperoxidase technique. This technique was more sensitive for detecting canine distemper infection in lung tissue than was the study of inclusion bodies. Attention was also paid to combined infection with canine adenovirus and Bordetella bronchiseptica.     

Neurological manifestations of canine distemper virus infection

Canine distemper virus causes a multi systemic disease in dogs often with severe neurological signs. These signs are the result of viral replication in neurons and glial cells leading to grey matter lesions and demyelination. Inflammation leads to further destruction of the tissue. As extraneural signs are often lacking and only one localisation may be found on neurological examination, distemper may be difficult to diagnose. Myoclonus is almost pathognomonic for this disease but occurs in less than half of the cases. The inflammation of the central nervous system that occurs during the chronic stage of the disease can be detected on examination of the cerebrospinal fluid, in particular by determination of the IgG index. Viral antigen can be demonstrated in cerebrospinal fluid cells by fluorescent antibody techniques. The prognosis of nervous distemper is generally poor although dogs can recover from this disease. Treatment is largely supportive and symptomatic. The importance of regular vaccination is stressed.     

Three-year duration of immunity in dogs vaccinated with a canarypox-vectored recombinant canine distemper virus vaccine

Two studies evaluated the duration of serologic response to the recombinant, canarypox-vectored canine distemper virus vaccine (Recombitek, Merial). Serologic duration of immunity was shown to be at least 36 months. Thus, Recombitek provides protection when administered less frequently than the manufacturer's label. After the initial vaccination protocol of two or more doses administered approximately 4 weeks apart, with the last dose given at 12 to 16 weeks of age or older, and re-vaccination at 1 year of age, Recombitek can confidently be readministered every 3 years with assurance of protection in immunocompetent dogs. This allows the vaccine to be administered in accordance with the recommendations of the American Animal Hospital Association Canine Vaccine Task Force and others.     

Effect of vaccination with recombinant canine distemper virus vaccine immediately before exposure under shelter-like conditions

Vaccination with modified-live virus (MLV) canine distemper virus (CDV) vaccine has historically been recommended for animals in high-risk environments because of the rapid onset of immunity following vaccination. Recombinant CDV (rCDV) vaccine was deemed a suitable alternative to MLV-CDV vaccination in pet dogs, but insufficient data precluded its use where CDV was a serious threat to puppies, such as in shelters, kennels, and pet stores. In this study, dogs experimentally challenged hours after a single dose of rCDV or MLV vaccine became sick but recovered, whereas unvaccinated dogs became sick and died. Dogs vaccinated with a single dose of rCDV or MLV vaccine 1 week before being experimentally challenged remained healthy and showed no clinical signs. Dogs given one dose of rCDV vaccine hours before being placed in a CDV-contaminated environment did not become sick. These findings support the hypothesis that rCDV vaccine has a similar time-to-immunity as MLV-CDV vaccines and can likewise protect dogs in high-risk environments after one dose.     

国内流行犬瘟热病毒DNA重组疫苗的初步研究

为了探究H蛋白的免疫原性以及抗体效价,构建了1株犬瘟热病毒(CDV)ZH-10株H基因的真核表达载体pCI-H,对表达产物的免疫原性进行了初步研究,并进行了小鼠的DNA免疫试验。结果显示,pCI-H免疫组血清可与感染病毒的MDCK细胞发生特异性IPMA反应呈现特异的棕红色;ELISA血清抗体滴度可达1:28~1:79;病毒中和抗体可达1:11~1:32。研究结果表明,H蛋白具有免疫原性,但诱导抗体效价不足,需进一步完善。     

Measles vaccine in dogs: efficacy against aerosol challenge with virulent canine distemper virus.

Fifty young Beagle pups were used in studies on the efficacy of measles virus vaccine in providing protection against virulent canine distemper (CD) virus given intranasally. Among 29 dogs vaccinated with measles virus vaccine and subsequently exposed to virulent CD virus, 1 died, 7 developed relatively severe signs of CD, 15 had mild signs of distemper, and 6 remained clinically normal. Of 15 unvaccinated dogs similarly exposed to virulent CD virus, 11 succumbed to distemper. Six pups vaccinated with modified live-virus (MLV) CD virus vaccine remained clinically normal following immunity challenge.