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1.
Replication of a waterfowl-origin influenza virus in the kidney and intestine of chickens 总被引：1，自引：0，他引：1
Intravenous inoculation of chickens with a waterfowl-origin type A influenza virus resulted in high titers of virus in kidney tissues and viral nucleoprotein in renal tubular epithelial cells and in intestinal mucosal epithelial cells. Virus titers in kidneys of four of eight clinically normal chickens sampled on days 3 and 5 postinoculation (PI), one dead chicken on day 3 PI, and one dead chicken on day 7 PI exceeded 10(6) mean embryo infectious dose per gram of tissue. Using immunofluorescent and immunoperoxidase staining, viral nucleoprotein was identified in the cytoplasm and nucleus of tubular epithelial cells in kidneys and in nucleus of mucosal epithelial cells lining villi in the lower small intestine. Based on the low intravenous pathogenicity index for this virus (0.3) along with the high virus titers in kidney tissues and localization of viral antigen in kidney important site for replication of avian influenza (AI) virus of low pathogenicity. Recovery of type A influenza viruses from cloacal swabs could result from viral replication in kidneys as well as in the lower intestine and/or the bursa of Fabricius. 相似文献
2.
One-day-old chickens were inoculated intravenously with one of three low-pathogenicity avian-origin influenza isolates. On day 5 postinoculation (PI), the frequency of influenza virus isolation from cloacal swabs following challenge with each isolate ranged from 83% to 100% for clinically normal euthanatized chickens. Influenza virus was also frequently isolated from kidneys of these chickens (47%) and from chickens that died (100%). Kidneys positive for virus isolation had lesions of nephrosis and/or acute nephritis, and influenza viral nucleoprotein was demonstrated in nuclei and cytoplasm of necrotic renal tubule epithelium. On sampling days 28 and 45/60 PI, influenza virus was neither isolated from nor immunohistochemically demonstrated in kidneys (0/125); however, the kidneys (47%) did have chronic histologic lesions that suggested previous influenza virus infection of the kidneys. Influenza virus was isolated from cloacal swabs of two of 44 chickens on day 28 PI, but all cloacal swabs were negative for virus recovery on sampling day 45/60 PI (0/81). These results indicate that replication of influenza virus in renal tubule epithelial cells did not result in persistence of type A influenza virus in this immunologically privileged site. 相似文献
3.
Tanimura N Tsukamoto K Okamatsu M Mase M Imada T Nakamura K Kubo M Yamaguchi S Irishio W Hayashi M Nakai T Yamauchi A Nishimura M Imai K 《Veterinary pathology》2006,43(4):500-509
Highly pathogenic H5N1 avian influenza viruses were isolated in 9 large-billed crows that died in Kyoto and Osaka prefectures in Japan from March to April in 2004. We studied 3 of the 9 crows using standard histologic methods, immunohistochemistry, and virus isolation. The most prominent lesions were gross patchy areas of reddish discoloration in the pancreas. The consistent histologic lesions included severe multifocal necrotizing pancreatitis, focal degeneration and necrosis of neuron and glial cells in the central nervous system, and focal degeneration of cardiac myocytes. All of these tissues contained immunohistochemically positive influenza viral antigens. The virus was isolated from the brain, lung, heart, liver, spleen, and kidney of the crows examined. Thus we concluded that highly pathogenic avian influenza virus was associated with clinical disease, severe pathologic changes, and death in the 3 crows. 相似文献
4.
Risza Hartawan Dwi Ari Pujianto Ni Luh Putu Indi Dharmayanti Amin Soebandrio 《Journal of veterinary science (Suw?n-si, Korea)》2022,23(2)
BackgroundSmall interfering RNA technology has been considered a prospective alternative antiviral treatment using gene silencing against influenza viruses with high mutations rates. On the other hand, there are no reports on its effectiveness against the highly pathogenic avian influenza H5N1 virus isolated from Indonesia.ObjectivesThe main objective of this study was to improve the siRNA design based on the nucleoprotein gene (siRNA-NP) for the Indonesian H5N1 virus.MethodsThe effectiveness of these siRNA-NPs (NP672, NP1433, and NP1469) was analyzed in vitro in Marbin-Darby canine kidney cells.ResultsThe siRNA-NP672 caused the largest decrease in viral production and gene expression at 24, 48, and 72 h post-infection compared to the other siRNA-NPs. Moreover, three serial passages of the H5N1 virus in the presence of siRNA-NP672 did not induce any mutations within the nucleoprotein gene.ConclusionsThese findings suggest that siRNA-NP672 can provide better protection against the Indonesian strain of the H5N1 virus. 相似文献
5.
Neil A. Bryant Adam S. Rash Alana L. Woodward Elizabeth Medcalf Maud Helwegen Franziska Wohlfender Fatima Cruz Claudia Herrmann Kerstin Borchers Ashish Tiwari Thomas M. Chambers J. Richard Newton Jennifer A. Mumford Debra M. Elton 《Veterinary microbiology》2011,147(1-2):19-27
Like other influenza A viruses, equine influenza virus undergoes antigenic drift. It is therefore essential that surveillance is carried out to ensure that recommended strains for inclusion in vaccines are kept up to date. Here we report antigenic and genetic characterisation carried out on equine influenza virus strains isolated in North America and Europe over a 2-year period from 2008 to 2009. Nasopharyngeal swabs were taken from equines showing acute clinical signs and submitted to diagnostic laboratories for testing and virus isolation in eggs. The sequence of the HA1 portion of the viral haemagglutinin was determined for each strain. Where possible, sequence was determined directly from swab material as well as from virus isolated in eggs. In Europe, 20 viruses were isolated from 15 sporadic outbreaks and 5 viruses were isolated from North America. All of the European and North American viruses were characterised as members of the Florida sublineage, with similarity to A/eq/Lincolnshire/1/07 (clade 1) or A/eq/Richmond/1/07 (clade 2). Antigenic characterisation by haemagglutination inhibition assay indicated that the two clades could be readily distinguished and there were also at least seven amino acid differences between them. The selection of vaccine strains for 2010 by the expert surveillance panel have taken these differences into account and it is now recommended that representatives of both Florida clade 1 and clade 2 are included in vaccines. 相似文献
6.
Equine herpes virus 2 (EHV-2), a gamma(2)-herpesvirus, is common in horses of all ages. Its role as a primary pathogen is unclear but there is an association between EHV-2, respiratory disease and keratoconjunctivitis. The purpose of this study was to gain more information on the prevalence of EHV-2 DNA in conjunctival swabs from horses with and without ocular disease and to define the anatomical site and cell type harbouring viral genome or antigen. By polymerase chain reaction (PCR) 22 out of 77 (28.6%) ocular swabs of clinically healthy and only 4 out of 48 (8.3%) samples from diseased horses were positive. To define the main virus reservoir ocular tissue from 13 randomly selected horses without pathological evidence of ocular disease were analysed by nested PCR. In two horses optic nerve, lacrimal gland and conjunctiva, in further two cases lacrimal gland and conjunctiva and in four horses the conjunctiva only were EHV-2 PCR positive. For specifying the target cell we focused on conjunctivae and selected 3 out of 15 clinically healthy slaughterhouse horses positive for EHV-2 by PCR. In situ hybridisation on sections of these paraffin embedded conjunctivae localized viral genome in histiocyte-like cells of the submucosa. Immunohistochemical staining with an EHV-2 or S100 specific polyclonal antiserum demonstrated that Langerhans cells were co-localized in the same region of the sample section where virus positive cells were detected. Furthermore, we concluded that detection of viral antigen revealed a productive virus infection. 相似文献
7.
Study of the duration and distribution of equine influenza virus subtype 2 (H3N8) antigens in experimentally infected ponies in vivo. 总被引：2，自引：1，他引：1
The purpose of this experiment was to study the duration and distribution of equine influenza virus in actively infected ponies over a 3 wk period. Pony foals (6-8 mo old) were infected experimentally by nebulizing equine influenza subtype-2 virus ultrasonically through a face mask. Successful infection was clinically apparent as each of the foals (n = 6) had a febrile response, a deep hacking cough and mucopurulent nasal discharge for 7 to 10 d. The virus was isolated from nasopharyngeal swabs of all the ponies 3 and 5 d after infection and all the ponies seroconverted to the virus. Samples were taken from the nasopharynx, mid-trachea and the mainstem bronchus with cytology brushes through an endoscope as well as from bronchoalveolar lavage fluid. On days 3 to 7 post-infection, ciliacytophtorea (the presence of cilia and ciliated plates separated from columnar epithelial cells) was recognized on routine cytological stain. Indirect immunoperoxidase staining utilizing polyclonal antibodies demonstrated viral antigen in intact and fragmented ciliated epithelial cells and in fragments of ciliated plates. The infected cells and cell fragments were particularly evident on days 3 and 5 post-infection in the nasopharynx, mid-trachea and mainstem bronchus and on days 3 to 7 post-infection in the bronchoalveolar lavage samples. On days 7 and 21 post-infection, viral antigen was identified in vacuoles of alveolar macrophage-like cells collected by bronchoalveolar lavage. It can be concluded from this study that equine influenza virus can infect not only the upper airways but also the bronchial epithelium and that viral antigen can persist up to 21 d post-infection. 相似文献
8.
To determine histopathological damage in the respiratory tract, ducks were inoculated with five different influenza A viruses, including viruses virulent for other avian hosts. Lungs were collected for detection of virus and histopathological examination. Small amounts of infectious virus were recovered from lungs, and viral antigens were demonstrated by immunoperoxidase staining with monoclonal antibodies to the viral nucleoprotein. Although clinical signs were not detected, lungs of ducks infected with both virulent and avirulent viruses had mild pneumonia characterized by infiltrates of lymphocytes and macrophages. These findings show that although clinical signs are not evident, ducks may have damage to the respiratory tract during influenza. 相似文献
9.
10.
Tissue tropism properties of A/chicken/Alabama/75 (H4N8) were examined after intravenous inoculation of 5-week-old specific-pathogen-free chickens. From 14 clinically normal chickens euthanatized on days 1-20 postinoculation, the frequencies of virus recovery were highest for cloacal swabs (86%), bursal swabs (64%), and kidney tissues (64%) and lowest for tracheal swabs (14%), thymus tissues (14%), bone-marrow swabs (7%), and brain tissues (0%). Evidence that the high frequency of virus recovery from kidney tissues was associated with virus replication in the kidney tissues was provided by high virus titers, ranging up to 10(9.5) mean embryo infectious dose per gram of kidney tissue, and by identification of intranuclear and intracytoplasmic type A influenza nucleoprotein in kidney cells using immunohistochemistry. Virus-recovery and virus titer results from three chickens that died on days 4 and 5 postinoculation paralleled the results from the clinically normal chickens. These findings indicate that A/chicken/Alabama/75 has nephrotropic properties similar to nephrotropic properties previously reported for waterfowl-origin type A influenza viruses and provide evidence that kidney lesions could be manifestations of systemic influenza infections in commercial laying chickens. 相似文献
11.
12.
Bertran K Pérez-Ramírez E Busquets N Dolz R Ramis A Darji A Abad FX Valle R Chaves A Vergara-Alert J Barral M Höfle U Majó N 《Veterinary research》2011,42(1):24
ABSTRACT: An experimental infection with highly pathogenic avian influenza virus (HPAIV) and low pathogenic avian influenza virus (LPAIV) was carried out in red-legged partridges (Alectoris rufa) in order to study clinical signs, gross and microscopic lesions, and viral distribution in tissues and viral shedding. Birds were infected with a HPAIV subtype H7N1 (A/Chicken/Italy/5093/1999) and a LPAIV subtype H7N9 (A/Anas crecca/Spain/1460/2008). Uninoculated birds were included as contacts in both groups. In HPAIV infected birds, the first clinical signs were observed at 3 dpi, and mortality started at 4 dpi, reaching 100% at 8 dpi. The presence of viral antigen in tissues and viral shedding were confirmed by immunohistochemistry and quantitative real time RT-PCR (qRRT-PCR), respectively, in all birds infected with HPAIV. However, neither clinical signs nor histopathological findings were observed in LPAIV infected partridges. In addition, only short-term viral shedding together with seroconversion was detected in some LPAIV inoculated animals. The present study demonstrates that the red-legged partridge is highly susceptible to the H7N1 HPAIV strain, causing severe disease, mortality and abundant viral shedding and thus contributing to the spread of a potential local outbreak of this virus. In contrast, our results concerning H7N9 LPAIV suggest that the red-legged partridge is not a reservoir species for this virus. 相似文献
13.
Outbreaks of influenza were diagnosed in two turkey breeder flocks on the same premises in eastern North Carolina during the "dark-out" period of recycling for a second lay. Clinical history included increased mortality from acute death with no apparent predisposing illness. Mortality attributed to the disease was 4.5% in one flock and 3.3% in the other. Necropsy findings included severe diffuse congestion and edema of both lungs, with little or no pleural exudate. Spleens were moderately to markedly enlarged and mottled, and kidneys were swollen and congested. Microscopic lesions included moderate to severe serofibrinous pneumonia with severe pulmonary congestion. Splenic changes included fibrin deposition and severe congestion, and severe congestion was noted in kidneys. Influenza virus (H1N1) was isolated from pools of tissues including lung, spleen, liver, and kidney, and both flocks seroconverted to influenza (H1N1) virus. 相似文献
14.
Teifke JP Klopfleisch R Globig A Starick E Hoffmann B Wolf PU Beer M Mettenleiter TC Harder TC 《Veterinary pathology》2007,44(2):137-143
Mortality in wild aquatic birds due to infection with highly pathogenic avian influenza viruses (HPAIV) is a rare event. During the recent outbreak of highly pathogenic avian influenza in Germany, mortality due to H5N1 HPAIV was observed among mute and whooper swans as part of a rapid spread of this virus. In contrast to earlier reports, swans appeared to be highly susceptible and represented the mainly affected species. We report gross and histopathology and distribution of influenza virus antigen in mute and whooper swans that died after natural infection with H5N1 HPAIV. At necropsy, the most reliable lesions were multifocal hemorrhagic necrosis in the pancreas, pulmonary congestion and edema, and subepicardial hemorrhages. Major histologic lesions were acute pancreatic necrosis, multifocal necrotizing hepatitis, and lymphoplasmacytic encephalitis with neuronal necrosis. Adrenals displayed consistently scattered cortical and medullary necrosis. In spleen and Peyer's patches, mild lymphocyte necrosis was present. Immunohistochemical demonstration of HPAIV nucleoprotein in pancreas, adrenals, liver, and brain was strongly consistent with histologic lesions. In the brain, a large number of neurons and glial cells, especially Purkinje cells, showed immunostaining. Occasionally, ependymal cells of the spinal cord were also positive. In the lungs, influenza virus antigen was identified in a few endothelial cells but not within pneumocytes. The infection of the central nervous system supports the view that the neurotropism of H5N1 HPAIV leads to nervous disturbances with loss of orientation. More investigations are necessary to clarify the mechanisms of the final circulatory failure, lung edema, and rapid death of the swans. 相似文献
15.
Replication and transmission of live attenuated infectious laryngotracheitis virus (ILTV) vaccines 总被引：1，自引：0，他引：1
The aim of this study was to evaluate the replication of live attenuated infectious laryngotracheitis virus vaccines in selected tissues and their ability to transmit to contact-exposed birds. Four-week-old specific-pathogen-free chickens were eye drop-inoculated with tissue culture origin (TCO) and chicken embryo origin (CEO) vaccines. Contact-exposed chickens were housed in direct contact with eye drop-inoculated chickens from the first day postinoculation. Virus isolation and real-time polymerase chain reaction were used to detect the presence of live virus and viral DNA, respectively, in the trachea, trigeminal ganglia, eye conjunctiva, cecal tonsils, and cloaca from eye drop-inoculated and contact-exposed birds at days 2, 4, 5 to 10, 14, 18, 21, 24, and 28 postinoculation. No differences were observed in the ability of the TCO and CEO vaccines to replicate in the examined tissues. Both vaccines presented a localized replication in the eye conjunctiva and the trachea. Both vaccines were capable of transmitting to contact-exposed birds, attaining peaks of viral DNA as elevated as those observed in inoculated birds. The CEO vaccine replicated faster and reached higher viral genome copy number than the TCO vaccine in the conjunctiva and trachea of eye drop-inoculated and contact-exposed birds. The viral DNA from both vaccines migrated to the trigeminal ganglia during early stages of infection. Although the CEO and TCO vaccines were not recovered from the cecal tonsils and the cloaca, low levels of viral DNA were detected at these sites during the peak of viral replication in the upper respiratory tract. 相似文献
16.
G D Wallace 《American journal of veterinary research》1979,40(8):1159-1164
To obtain more information on mechanisms by which influenza virus is perpetuated in swine, retrospective and prospective seroepizootiologic observations were made in swine herds in Hawaii, beginning in 1974. An epizootic of swine influenza (Hsw1N1) virus was observed in November and December 1976, involving 31 of 41 herds. Features of the epizootic included (1) infection of all herds within one geographic location, during a short period; (2) no obvious introduction of virus from the outside in most herds; (3) epizootics mainly in herds with serologic history of infection; (4) no evidence that lungworms were involved; and (5) little clinical disease associated with infection. There was evidence of viral activity in some herds before the epizootic period and afterward in two of three herds monitored. Evidence of viral transmission by feral animals was not obtained. Data indicated that swine influenza virus persists through latently or chronically infected swine, with epizootics occurring when herd immunity reaches a critically low degree. 相似文献
17.
This investigation detailed the clinical disease, gross and histologic lesions, and distribution of viral antigen in juvenile laughing gulls (Larus atricilla) intranasally inoculated with either the A/tern/South Africa/61 (H5N3) (tern/SA) influenza virus or the A/chicken/Hong Kong/220/97 (H5N1) (chicken/HK) influenza virus, which are both highly pathogenic for chickens. Neither morbidity nor mortality was observed in gulls inoculated with either virus within the 14-day investigative period. Gross lesions resultant from infection with either virus were only mild, with the tern/SA virus causing decreased lucency of the air sacs (2/6), splenomegaly (2/6), and pancreatic mottling (1/6) and the chicken/HK virus causing only decreased lucency of the air sacs (2/8) and conjunctival edema (2/8). Histologic lesions in the tern/SA-inoculated gulls included a mild to moderate heterophilic to lymphoplasmacytic airsacculitis (6/6), mild to moderate interstitial pneumonia (3/6), and moderate necrotizing pancreatitis and hepatitis at 14 days postinoculation (DPI) (2/6). Immunohistochemical demonstration of viral antigen occurred only in association with lesions in the liver and pancreas. In contrast, viral antigen was not demonstrated in any tissues from the chicken/HK-inoculated gulls, and inflammatory lesions were confined to the air sac (3/8) and lungs (3/8). Both viruses were isolated at low titers (<10(1.68) mean embryo lethal dose) from oropharyngeal and cloacal swabs up to 7 days postinoculation (DPI), from the lung and kidney of one of two tern/SA-inoculated gulls at 14 DPI, and from the lung of one of two chicken/HK-inoculated gulls at 7 DPI. Antibodies to influenza viruses as determined with the agar gel precipitin test at 14 DPI were detected only in the two tern/SA-inoculated gulls and not in the two chicken/HK-inoculated gulls. 相似文献
18.
旨在调查野鸟中存在的禽流感病毒,并为禽流感的防制提供依据。采集新疆艾比湖自然保护区野鸟的粪便棉拭子进行禽流感病毒的分离与鉴定,将PCR产物进行纯化后用T载体连接并转化到DH5α细胞中;菌液PCR鉴定后将目的菌液送至上海生工测序并比对测序结果,在NCBI上进行基因序列分析。结果显示,从新疆艾比湖自然保护区野鸟的粪便棉拭子分离得到1株H1N2亚型禽流感病毒;经序列分析得知,该毒株为1株低致病性禽流感病毒,且存在与多种亚型病毒的重配现象。 相似文献
19.
Englund L 《Veterinary microbiology》2000,74(1-2):101-107
An influenza A virus, A/mink/Sweden/84 (H10N4), was isolated from farmed mink during an outbreak of respiratory disease, histopathologically characterised by severe interstitial pneumonia. The virus was shown to be of recent avian origin and closely related to concomitantly circulating avian influenza virus. Serological investigations were used to link the isolated virus to the herds involved in the disease outbreak. Experimental infection of adult mink with the virus isolate from the disease outbreak reproduced the disease signs and pathological lesions observed in the field cases. The mink influenza virus also induced an antibody response and spread between mink by contact. The same pathogenesis in mink was observed for two avian influenza viruses of the H10N4 subtype, circulating in the avian population. When mink were infected with the prototype avian H10 influenza virus, A/chicken/Germany/N/49, H10N7, the animals responded with antibody production and mild pulmonary lesions but neither disease signs nor contact infections were observed. Detailed studies, including demonstration of viral antigen in situ by immunohistochemistry, of the sequential development of pathological lesions in the mink airways after aerosol exposure to H10N4 or H10N7 revealed that the infections progress very similarly during the first 24h, but are distinctly different at later stages. The conclusion drawn is that A/mink/Sweden/84, but not A/chicken/Germany/N/49, produces a multiple-cycle replication in mink airways. Since the viral distribution and pathological lesions are very similar during the initial stages of infection we suggest that the two viruses differ in their abilities to replicate and spread within the mink tissues, but that their capacities for viral adherence and entry into mink epithelial cells are comparable. 相似文献
20.
Development and evaluation of a DAS-ELISA for rapid detection of avian influenza viruses 总被引：4，自引：0，他引：4
Rapid detection of avian influenza virus (AIV) infection is critical for control of avian influenza (AI) and for reducing the risk of pandemic human influenza. A double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) was developed for this purpose. The method employed a monoclonal antibody (MAb) as the capture antibody and rabbit polyclonal IgG labeled with horseradish peroxidase as the detector antibody, and both antibodies were against type-specific influenza A nucleoprotein (NP). The DAS-ELISA could detect minimally 2.5 ng of influenza viral protein in virus preparations treated with Triton X-100, which is equvilent to 2.5 x 10(2) EID50 virus particles. This DAS-ELISA could detect all 15n AIV subtypes (H1-H15) and did not cross react with other avian pathogens tested. The DAS-ELISA were directly compared with virus isolation (VI) in embryonated chicken eggs, the current standard of influenza virus detection, for 805 chicken samples. The DAS-ELISA results correlated with VI results for 98.6% of these samples, indicating a sensitivity of 97.4% and specificity of 100%. The method was further tested with H5N1 and H9N2 AIV experimentally infected chickens, ducks, and pigeons, as well as field samples obtained from central China in 2005. The DAS-ELISA method has demonstrated application potential as an AIV screening tool and as a supplement for virus isolation in Asia. 相似文献