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1.
Newly discovered viruses of flying foxes. 总被引：3，自引：0，他引：3
Flying foxes have been the focus of research into three newly described viruses from the order Mononegavirales, namely Hendra virus (HeV), Menangle virus and Australian Bat Lyssavirus (ABL). Early investigations indicate that flying foxes are the reservoir host for these viruses. In 1994, two outbreaks of a new zoonotic disease affecting horses and humans occurred in Queensland. The virus which was found to be responsible was called equine morbillivirus (EMV) and has since been renamed HeV. Investigation into the reservoir of HeV has produced evidence that antibodies capable of neutralising HeV have only been detected in flying foxes. Over 20% of flying foxes in eastern Australia have been identified as being seropositive. Additionally six species of flying foxes in Papua New Guinea have tested positive for antibodies to HeV. In 1996 a virus from the family Paramyxoviridae was isolated from the uterine fluid of a female flying fox. Sequencing of 10000 of the 18000 base pairs (bp) has shown that the sequence is identical to the HeV sequence. As part of investigations into HeV, a virus was isolated from a juvenile flying fox which presented with neurological signs in 1996. This virus was characterised as belonging to the family Rhabdoviridae, and was named ABL. Since then four flying fox species and one insectivorous species have tested positive for ABL. The third virus to be detected in flying foxes is Menangle virus, belonging to the family Paramyxoviridae. This virus was responsible for a zoonotic disease affecting pigs and humans in New South Wales in 1997. Antibodies capable of neutralising Menangle virus, were detected in flying foxes. 相似文献
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Morbillivirus group: genome organisation and proteins 总被引：1，自引：0，他引：1
A Diallo 《Veterinary microbiology》1990,23(1-4):155-163
The Paramyxoviridae family is divided into three genera: Paramyxovirus, Pneumovirus and Morbillivirus. In the last group, there are four closely related viruses which are seriously pathogenic for man and animals, and usually cause acute diseases. At least two of them (measles and canine distemper viruses) can cause a persistent infection which leads to a chronic disease of the nervous system that, in the end, is fatal. For a long time, the biochemical analysis of morbilliviruses was hampered by the high susceptibility of some of their proteins to proteolysis. With cloning and sequencing technology, more data on the biology of those viruses are now available. 相似文献
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Isolation and genetic characterization of avian origin H9N2 influenza viruses from pigs in China 总被引：7，自引：1，他引：6
Yu H Hua RH Wei TC Zhou YJ Tian ZJ Li GX Liu TQ Tong GZ 《Veterinary microbiology》2008,131(1-2):82-92
As pigs are susceptible to infection with both avian and human influenza A viruses, they have been proposed to be an intermediate host for the adaptation of avian influenza viruses to humans. In April 2006, a disease caused by highly pathogenic porcine reproductive and respiratory syndrome virus (PRRSV) occurred in several pig farms and subsequently overwhelmed almost half of China with more than 2,000,000 cases of pig infection. Here we report a case in which four swine H9N2 influenza viruses were isolated from pigs infected by highly pathogenic PRRSVs in Guangxi province in China. All the eight gene segments of the four swine H9N2 viruses are highly homologous to A/Pigeon/Nanchang/2-0461/00 (H9N2) or A/Wild Duck/Nanchang/2-0480/00 (H9N2). Phylogenetic analyses of eight genes show that the swine H9N2 influenza viruses are of avian origin and may be the descendants of A/Duck/Hong Kong/Y280/97-like viruses. Molecular analysis of the HA gene indicates that our H9N2 isolates might have high-affinity binding to the alpha2,6-NeuAcGal receptor found in human cells. In conclusion, our finding provides further evidence about the interspecies transmission of avian influenza viruses to pigs and emphasizes the importance of reinforcing swine influenza virus (SIV) surveillance, especially after the emergence of highly pathogenic PRRSVs in pigs in China. 相似文献
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The propagation of avian viruses in a continuous cell line (QT35) of Japanese quail origin 总被引：1，自引：0，他引：1
Seven of nine avian virus families tested (Birnaviridae, Coronaviridae, Herpesviridae, Paramyxoviridae, Poxviridae, Reoviridae, and Retroviridae) were found to replicate in a quail fibroblast cell line, designated QT35, resulting in a cytopathic effect (CPE) visible with the naked eye or by low-power microscopy. In comparison, only one (Paramyxoviridae) of seven mammalian virus families tested produced an observable CPE. Cytopathic changes induced by examined viruses were round cell, syncytial, and focus formation. Trypsin did not promote cytopathic changes by selected CPE-negative avian and mammalian viruses in QT35 cells. Several avian viruses (infectious bursal disease virus, Newcastle disease virus, Canary pox virus, and reovirus) formed plaques under agar. Avian reovirus and infectious bursal disease virus produced similar titers in chicken embryo fibroblast (CEF) and QT35 cell cultures. Chicken-egg-yolk neutralizing-antibody titers to IBDV were comparable in CEF and QT35 cell-culture systems. 相似文献
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Raj Kumar Singh Ruchi Tiwari Senthilkumar Natesan Rekha Khandia 《The Veterinary quarterly》2019,39(1):26-55
Nipah (Nee-pa) viral disease is a zoonotic infection caused by Nipah virus (NiV), a paramyxovirus belonging to the genus Henipavirus of the family Paramyxoviridae. It is a biosafety level-4 pathogen, which is transmitted by specific types of fruit bats, mainly Pteropus spp. which are natural reservoir host. The disease was reported for the first time from the Kampung Sungai Nipah village of Malaysia in 1998. Human-to-human transmission also occurs. Outbreaks have been reported also from other countries in South and Southeast Asia. Phylogenetic analysis affirmed the circulation of two major clades of NiV as based on currently available complete N and G gene sequences. NiV isolates from Malaysia and Cambodia clustered together in NiV-MY clade, whereas isolates from Bangladesh and India clusterered within NiV-BD clade. NiV isolates from Thailand harboured mixed population of sequences. In humans, the virus is responsible for causing rapidly progressing severe illness which might be characterized by severe respiratory illness and/or deadly encephalitis. In pigs below six months of age, respiratory illness along with nervous symptoms may develop. Different types of enzyme-linked immunosorbent assays along with molecular methods based on polymerase chain reaction have been developed for diagnostic purposes. Due to the expensive nature of the antibody drugs, identification of broad-spectrum antivirals is essential along with focusing on small interfering RNAs (siRNAs). High pathogenicity of NiV in humans, and lack of vaccines or therapeutics to counter this disease have attracted attention of researchers worldwide for developing effective NiV vaccine and treatment regimens. 相似文献
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Nomura N Sakoda Y Soda K Okamatsu M Kida H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2012,74(4):441-447
H9N2 influenza viruses circulate in wild birds and poultry in Eurasian countries, and have been isolated from pigs and humans in China. H9N2 viruses isolated from birds, pigs and humans have been classified into three sublineages based on antigenic and genetic features. Chicken antisera to H9N2 viruses of the Korean sublineage reacted with viruses of different sublineages by the hemagglutination-inhibition test. A test vaccine prepared from a non-pathogenic A/duck/Hokkaido/49/1998 (H9N2) strain of the Korean sublineage, obtained from our influenza virus library, induced immunity in mice to reduce the impact of disease caused by the challenge with A/Hong Kong/1073/1999 (H9N2), which is of a different sublineage. The present results indicate that an inactivated whole virus vaccine prepared from a non-pathogenic influenza virus from the library could be used as an emergency vaccine during the early stage of a pandemic caused by H9N2 infection. 相似文献
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The characteristics of four United Kingdom isolates of swine vesicular disease (SVD) virus from 1981 to 1982 have been compared with those of an isolate obtained from the first outbreak of swine vesicular disease diagnosed in the United Kingdom in 1972. When the virus structural proteins were examined by polyacrylamide gel electrophoresis the four isolates from 1981-82 all had the same polypeptide pattern, which was different from that of the 1972 isolate. Immunodiffusion tests with the 1972 isolate and one 1982 isolate did not reveal any antigenic difference between the viruses but minor antigenic differences were shown by cross-neutralisation tests between the 1972 isolate and the four isolates from 1981-82. In experimentally infected pigs the 1972 isolate produced typical SVD lesions whereas the four more recent SVD viruses produced only very mild clinical disease. Clinical lesions scored numerically were four- to 10- and five- to 11-fold higher at seven and 14 days after infection for pigs infected with the 1972 isolate than with the four isolates from 1981-82. The serum of pigs infected with the 1972 isolate contained significantly higher levels of neutralising antibody than those of pigs infected with more recent isolates. The antibody titres of pigs with only primary lesions ranged from log10 1.9 to 2.8 and one clinically normal pig had a titre of log10 2.4 at 14 days after infection. Attention is drawn to the implication of these findings for SVD control policies based only on the recognition and reporting of clinical disease. 相似文献
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Sait M Clark EM Wheelhouse N Spalding L Livingstone M Sachse K Markey BK Magnino S Siarkou VI Vretou E Caro MR Yaga R Lainson FA Smith DG Wright F Longbottom D 《Veterinary microbiology》2011,152(3-4):284-290
Torque teno viruses (TTVs) are vertebrate infecting, small viruses with circular single stranded DNA, classified in the Anelloviridae family. In pigs, two different TTV species have been described so far, Torque teno sus virus 1 (TTSuV1) and 2 (TTSuV2). TTSuVs have lately been linked to postweaning multisystemic wasting syndrome (PMWS). In the present study, TTSuV1 and TTSuV2 prevalence and DNA loads in longitudinally collected serum samples of healthy and PMWS affected pigs from Spanish conventional, multi-site farms were analyzed. Serum samples were taken at 1, 3, 7, 11 and around 15 weeks of age (age of PMWS outbreak) and viral DNA loads determined by quantitative PCR. For both TTSuV species, percentage of viremic pigs increased progressively over time, with the highest prevalence in animals of about 15 weeks of age. TTSuV1 and TTSuV2 viral DNA loads in healthy and TTSuV1 loads in PMWS affected animals increased until 11 weeks of age declining afterwards. On the contrary, TTSuV2 DNA loads in PMWS affected pigs increased throughout the sampling period. It seems that TTSuV species differ in the in vivo infection dynamics in PMWS affected animals. 相似文献
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D J Alexander 《Veterinary microbiology》1990,23(1-4):103-114
This paper reviews the recent developments related to members of the Paramyxoviridae family which infect avian species. These developments include: (1) The identification of the virus responsible for the diseases turkey rhinotracheitis and swollen head syndrome in chickens as a member of the Pneumovirus genus, the first of this type to be isolated from birds. (2) The use of monoclonal antibodies prepared against Newcastle disease virus (NDV) and other avian paramyxoviruses which has enabled more exact and rapid diagnosis and greater understanding of the epizootiology of these viruses. (3) The nucleotide sequencing of the genome of NDV and subsequent amino acid sequencing of the major virus proteins have resulted in greater understanding of the pathogenicity of this economically important virus. 相似文献
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The surface exposed capsid proteins, VP1, VP2 and VP3, of foot-and-mouth disease virus (FMDV) determine its antigenicity and the ability of the virus to interact with host-cell receptors. Hence, modification of these structural proteins may alter the properties of the virus.In the present study we compared the pathogenicity of different FMDVs in young pigs. In total 32 pigs, 7-weeks-old, were exposed to virus, either by direct inoculation or through contact with inoculated pigs, using cell culture adapted (O1K B64), chimeric (O1K/A-TUR and O1K/O-UKG) or field strain (O-UKG/34/2001) viruses. The O1K B64 virus and the two chimeric viruses are identical to each other except for the capsid coding region.Animals exposed to O1K B64 did not exhibit signs of disease, while pigs exposed to each of the other viruses showed typical clinical signs of foot-and-mouth disease (FMD). All pigs infected with the O1K/O-UKG chimera or the field strain (O-UKG/34/2001) developed fulminant disease. Furthermore, 3 of 4 in-contact pigs exposed to the O1K/O-UKG virus died in the acute phase of infection, likely from myocardial infection. However, in the group exposed to the O1K/A-TUR chimeric virus, only 1 pig showed symptoms of disease within the time frame of the experiment (10 days). All pigs that developed clinical disease showed a high level of viral RNA in serum and infected pigs that survived the acute phase of infection developed a serotype specific antibody response. It is concluded that the capsid coding sequences are determinants of FMDV pathogenicity in pigs. 相似文献
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Survey of infectious agents involved in acute respiratory disease in finishing pigs. 总被引：4，自引：0，他引：4
W L Loeffen E M Kamp N Stockhofe-Zurwieden A P van Nieuwstadt J H Bongers W A Hunneman A R Elbers J Baars T Nell F G van Zijderveld 《The Veterinary record》1999,145(5):123-129
Outbreaks of respiratory disease constitute a major health problem in herds of finishing pigs and their aetiology often remains unclear. In this study, 16 outbreaks of respiratory disease with acute clinical signs in finishing pigs were investigated to determine which infectious agents were involved. From each herd four diseased and two clinically healthy pigs were examined pathologically and for the presence of viruses, bacteria and mycoplasmas. In addition, paired blood samples from 10 groupmates of the diseased pigs were tested for antibodies against commonly known causal agents of respiratory disease. A clear diagnosis was possible in 12 of the 16 outbreaks. Seven were due to an infection with influenza virus and five were due to an infection with Actinobacillus pleuropneumoniae. A combination of influenza virus and A pleuropneumoniae may have caused one other outbreak, but no clear cause could be established for the other three outbreaks. 相似文献
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A型塞尼卡病毒（Senecavirus A,SVA）也称为塞尼卡谷病毒（Seneca Valley virus,SVV）,属于小RNA病毒科塞尼卡病毒属成员。SVA主要引起猪的水泡性疾病,与口蹄疫、水泡性口炎、猪水泡病等临床症状相似,可导致新生仔猪急性死亡,严重影响养猪业发展。自2015年广东省发生SVA感染以来,中国多省份陆续有该病发生的报道。当前,中国因猪群缺乏针对SVA的免疫屏障,加之该病传染性较强,存在大范围暴发的潜在风险。如何有效防控SVA感染是迫切需要解决的问题。目前已开发出多种SVA诊断方法用于进行实验室及现场条件下早期的鉴别诊断。SVA的分离鉴定、原位杂交和免疫组化可用于检测病原体的存在及其与组织内形态学变化关系;血清学诊断方法包括基于不同结构蛋白的间接ELISA方法、竞争ELISA方法、均相光激化学发光免疫技术和病毒中和试验,用免疫学方法检测抗体有助于了解SVA感染进程,是临床诊断的主要手段;病毒核酸检测方法主要有PCR技术、等温扩增技术、基因组测序等分子生物学技术,在病毒感染的早期快速检测及检测新发病毒中具有重要作用。目前仍无商品化疫苗预防SVA感染,但科研人员已研发出了灭活疫苗、弱毒疫苗、核酸疫苗和亚单位疫苗等多种具有潜力的候选疫苗。笔者系统总结了SVA检测方法及疫苗研发的最新进展,以期为SVA感染的防控提供参考依据。 相似文献
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尼帕病毒(Ni V)和亨德拉病毒(HeV)属于副黏病毒亚科的亨尼帕病毒属的成员。Ni V和HeV感染引起新的两种重要的人兽共患传染病。有关APMV-1(NDV)的发病和流行以及病原学研究认为APMV-1不断发生演化,新的基因型不断产生,对不同宿主的致病力不断变化,病毒感染的宿主谱不断扩大。本文简要介绍两种新的人兽共患传染病和APMV-1对鹅、鸭、猪的感染研究现状,就APMV-1宿主感染谱与演化加以分析,思考新的动物副黏病毒病防控对策。 相似文献
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In early 1991, the Dutch pig industry was struck by the so-called mystery swine disease. Large-scale laboratory investigations were undertaken to search for the aetiological agent. We focused on isolating viruses and mycoplasmas, and we tested paired sera of affected sows for antibodies against ten known pig viruses. The mycoplasmas M. hysonoviae, M. hyopneumoniae, and Acheloplasma laidlawii, and the viruses encephalomyocarditis virus and porcine enterovirus types 2 and 7 were isolated from individual pigs. An unknown agent however, was isolated from 16 of 20 piglets and from 41 of 63 sows. This agent was characterized as a virus and designated Lelystad virus. No relationship between this virus and other viruses has yet been established. Of 165 sows reportedly affected by the disease, 123 (75 per cent) seroconverted to Lelystad virus, whereas less than 10 per cent seroconverted to any of the other virus isolates or to known viral pathogens. Antibodies directed against Lelystad virus were also found in pigs with mystery swine disease in England, Germany, and the United States. We conclude that infection with Lelystad virus is the likely cause of mystery swine disease. 相似文献
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The isolation and attenuation of a virus causing rhinotracheitis in turkeys in South Africa 总被引：4，自引：0，他引：4
In March 1978, a number of turkeys with severe respiratory symptoms affecting over 80% of the flock were investigated for a possible causative agent. With the standard techniques used for the isolation of bacteriae, mycoplasmae and viruses, only Mycoplasma gallisepticum, Mycoplasma meleagridis and Newcastle disease virus were isolated. Tracheal organ cultures were subsequently prepared from 27-day-old turkey embryos and inoculated with sinus exudate from affected turkeys. After an incubation period of 4 days a virus was isolated with which the typical symptoms, as observed in the field, could be reproduced in susceptible turkeys after 3-5 days. Following primary isolation in tracheal organ cultures, the virus grew readily in embryonated eggs and Vero cells. With the electron microscope, virus-like particles, varying in size from 40 nm-500 nm, were observed, having a pleomorphic shape and studded with fine surface projections. The virus seems to fall into the family Paramyxoviridae. A vaccine produced from attenuated virus in embryonated eggs afforded good protection against mortalities due to airsacculitis that normally follows on to turkey rhinotracheitis infection. The serological and clinical effects of the virus on chickens are also reported on. 相似文献
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Van Reeth K 《Veterinary research》2007,38(2):243-260
The introduction of swine or avian influenza (AI) viruses in the human population can set the stage for a pandemic, and many fear that the Asian H5N1 AI virus will become the next pandemic virus. This article first compares the pathogenesis of avian, swine and human influenza viruses in their natural hosts. The major aim was to evaluate the zoonotic potential of swine and avian viruses, and the possible role of pigs in the transmission of AI viruses to humans. Cross-species transfers of swine and avian influenza to humans have been documented on several occasions, but all these viruses lacked the critical capacity to spread from human-to-human. The extreme virulence of H5N1 in humans has been associated with excessive virus replication in the lungs and a prolonged overproduction of cytokines by the host, but there remain many questions about the exact viral cell and tissue tropism. Though pigs are susceptible to several AI subtypes, including H5N1, there is clearly a serious barrier to infection of pigs with such viruses. AI viruses frequently undergo reassortment in pigs, but there is no proof for a role of pigs in the generation of the 1957 or 1968 pandemic reassortants, or in the transmission of H5N1 or other wholly avian viruses to humans. The major conclusion is that cross-species transmission of influenza viruses per se is insufficient to start a human influenza pandemic and that animal influenza viruses must undergo dramatic but largely unknown genetic changes to become established in the human population. 相似文献