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1.
Ecco R Brown C Susta L Cagle C Cornax I Pantin-Jackwood M Miller PJ Afonso CL 《Veterinary immunology and immunopathology》2011,141(3-4):221-229
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A I Khalafalla M A Fadol O A Hameid Y A Hussein M el Nur 《Acta veterinaria Hungarica》1992,40(4):329-333
Six Newcastle disease virus (NDV) isolates were obtained from disease outbreaks on different poultry farms in the Sudan between 1988 and 1991. The pathogenic properties of these isolates were studied in comparison to those of strain Herts 33/56. All the isolates were similar in that they killed chicken embryos quickly, in mean death time (MDT) and embryo lethal dose 50 per cent (ELD50), had higher intracerebral pathogenicity indices (ICPI), and produced viscerotropic lesions in the infected chickens. The field isolates had the characteristics of the velogenic viscerotopic strains of NDV. The pathogenesis of infection caused by one of the isolates was studied. The virus was first detected in different organs and in oral and cloacal swabs on the third day after infection. 相似文献
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The pathogenesis of five different Newcastle disease virus (NDV) isolates representing all pathotypes was examined in commercial and specific pathogen-free (SPF) turkeys. Experimentally-infected birds were monitored clinically and euthanatized, with subsequent tissue collection, for examination by histopathology, by immunohistochemistry for the presence of NDV nucleoprotein, and by in situ hybridization for the presence of replicating virus. Clinically, the lentogenic pathotype did not cause overt clinical signs in either commercial or SPF turkeys. Mesogenic viruses caused depression in some birds. Turkeys infected with velogenic neurotropic and velogenic viscerotropic isolates showed severe depression, and neurologic signs. Histologic appearances for all strains had many similarities to lesions observed in chickens inoculated with the various isolates; that is, lesions were present predominantly in lymphoid, intestinal, and central nervous tissues. However, in general, disease among turkeys was less severe than in chickens, and turkeys could be considered a subclinical carrier for some of the isolates. 相似文献
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P.B. Spradbrow A. L. Ibrahim † Ungku Chulan† G. Milliken † R. Shapcott † D. Kingston † 《Australian veterinary journal》1980,56(12):580-584
SUMMARY Sixty-eight breeder chickens, 4 to 12 months of age, were taken from Australian flocks that had been naturally infected with avirulent Newcastle disease virus (NDV) and transported by air to Malaysia. Nearly all the breeders had haemagglutination inhibition antibodies to NDV, at titres of from 2 to 128. Thirty-two were inoculated intranasally with an Asian, velogenic, viscerotropic strain of NDV and all survived this challenge. Thirty-six were exposed to contact infection with the same velogenic NDV and 2 died of Newcastle disease within 14 days. The levels of haemagglutination inhibition antibodies against NDV increased in the surviving breeders after challenge, reaching 2048 or greater in a few birds. Velogenic NDV was isolated from a cloacal swab from one clinically normal breeder 10 days after challenge by contact. Cloacal swabs taken 7 to 10 days after challenge from another 23 breeders yielded no NDV. Twenty-four broilers, 7 weeks of age, were also transported from Australia to Malaysia. All lacked detectable haemagglutination inhibition antibody to NDV and they were from a flock with no detectable antibody to NDV. Twelve were challenged with velogenic NDV intranasally and 12 were subjected to contact challenge. All broilers died of Newcastle disease within 13 days. 相似文献
6.
Roy P Venugopalan AT 《Comparative immunology, microbiology and infectious diseases》2005,28(4):277-285
Newcastle disease virus (NDV) specific antigen in the gut contents and NDV specific antibody in blood circulation were seen in day old chicks belonging to nine different commercial hatcheries of Tamil Nadu, India. Antigen disappeared by 4th week and antibody by 6th week of age. Fourteen NDV isolates obtained from the gut contents of day old chicks of different commercial hatcheries, one NDV isolate from dead in shell eggs and one NDV isolate from breeder hen were characterized and grouped under velogenic, mesogenic and lentogenic pathotypes. Four isolates were grouped under F and another four isolates were grouped under E based on reaction with monoclonal antibodies (Mabs) but found to be velogenic based on pathogenicity tests. In one particular flock velogenie NDV was isolated from breeder hen, dead in shell embryos and day old chicks and they all belong to Mabs group E. Vertical transmission of velogenic, mesogenic and lentogenic NDVs and role of NDVs in the gut contents have been discussed. 相似文献
7.
Interactions between viscerotropic velogenic Newcastle disease virus and pet birds of six species. II. Viral evolution through bird passage 总被引：1，自引：0，他引：1
Following in vivo studies in pet birds of 6 species, 279 Newcastle disease virus (NDV) reisolates were selected for characterization by the embryonated-chicken-egg mean-death-time, plaque-assay, hemagglutination-elution, and hemagglutinin-thermostability techniques. Initially, the 279 isolates were screened by the mean-death-time and plaque-assay techniques, and 5 sequential isolates were chosen for each of 3 budgerigars and 2 parrots for characterization by the other 2 in vitro assays to determine whether the Colorado Psittacine Isolate of viscerotropic velogenic (VV) NDV (COPI-VVNDV) had evolved during passage through pet birds. Nineteen isolates were then selected for chicken back-passage studies. Fifteen of the 19 isolates were chosen for potential avirulence for 8-week-old domestic chickens. The 4 remaining isolates produced large red plaques when assayed and were therefore used as virulent virus controls likely to be VVNDV. Subsequent in vitro characterization of selected back-passage chicken NDV isolates demonstrated little change in the 4 parameters originally evaluated for the pet-bird isolates used for the back-passage studies. Although the psittacine isolate slowly evolved to relatively avirulent strains of NDV by passage in pet birds, reversion did not occur during the chicken back-passage studies. 相似文献
8.
The purified RNA from three velogenic strains of Newcastle disease virus (Ca-1083 [Fontana], Largo, and Texas GB) was analyzed by oligonucleotide fingerprinting. An image-processing system used to manipulate and rescale autoradiographs to uniform dimensions assisted the manual comparison of RNA fingerprints. Based on this analysis, the fingerprints of the Largo and Ca-1083 viscerotropic strains were more similar to each other than either virus was to the Texas GB neurotropic strain. By contrast, the Largo and Texas GB strains displayed more differences in the pattern of RNA fragment migration than other strain comparisons. Fingerprint comparisons were also performed between velogenic and previously reported lentogenic strains of NDV. No large RNA fragments were identified as NDV-specific or virulence-specific. This study evaluates the relationships among these NDV strains. 相似文献
9.
Humorally deficient, in ovo-bursectomized (Bx) and sham-Bx chickens were vaccinated twice, 1 month apart, with Newcastle disease virus (NDV) Roakin strain and challenged with a velogenic viscerotropic NDV strain via the oronasal route. Hemagglutination-inhibition and seroneutralization tests showed that Bx chickens had reduced antibody-mediated immunity to virus infection. In contrast, they had significantly higher cell-mediated immunity (CMI) before challenge, as estimated simultaneously by determination of blastogenic capacity of peripheral blood lymphocytes induced by phytohemagglutinin and by specific antigen stimulation. After virus challenge, there was transitory inhibition of CMI based on marked reductions in levels of stimulation indices, and this impairment in CMI was supported by persistence of virus in Bx chickens for longer periods. Bx chickens resisted challenge, even though antibody titers were well below those considered predictive of resistance to challenge, suggesting that CMI provides a degree of resistance to velogenic NDV. 相似文献
10.
To expand the epidemiological understanding of Newcastle disease virus (NDV) found in domestic ducks in Korea, 14 NDV isolates from apparently healthy domestic ducks were biologically and genetically characterized. Thirteen and 1 isolates of NDV were categorized into lentogenic and velogenic viruses, respectively, based on in vivo pathogenicity tests. Twelve lentogenic viruses showed HA activity to horse RBCs, while 1 lentogenic virus and the velogenic virus were negative. Lentogenic viruses (n=13) had sequence motifs of (112)ERQERL(117) (n=1) or (112)GRQGRL(117) (n=12) at the F0 cleavage site, while the velogenic virus (n=1) had a sequence motif of (112)RRQKRF(117) at the same site. Phylogenetic analysis revealed that at least three distinct genotypes may exist in domestic ducks in Korea; one class I genotype (genotype 2), and two class II (genotypes I and VII) genotypes. The class I virus was most closely related to strains of genotype 2 which were isolated in birds from the USA, Germany and Denmark. Twelve lentogenic class II viruses were grouped together in genotype I, and were then divided into at least three clusters, namely Aomori-like, Ulster2C-like, and V4-like. The velogenic class II virus was assigned to genotype VII which represents viruses responsible for recent epidemics in many Asian countries including Korea. The epidemiological importance of domestic duck isolates of NDV in Korea is discussed. 相似文献
11.
Roy P. Venugopalan A.T. Selvarangam R. Ramaswamy V. 《Tropical animal health and production》1998,30(5):299-303
Newcastle disease virus (NDV) was isolated from the faeces of seven different species of clinically healthy captive wild birds. All seven NDV isolates were characterized as velogenic, based on the mean death time in embryonated hens' eggs and the intracerebral pathogenicity index in day-old chicks. Three of the isolates were placed in group C1 based on the reactions with monoclonal antibodies. The role of captive wild birds in the epidemiology of Newcastle disease is briefly discussed. 相似文献
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The virulence of six pigeon-origin isolates of Newcastle disease virus (NDV) was evaluated before and after passage in white leghorn chickens. Four isolates were defined as pigeon paramyxovirus-1 (PPMV-1) and two isolates were classified as avian paramyxovirus-1 (APMV-1) with NDV monoclonal antibodies. The four PPMV-1 isolates were passaged four times in chickens, and the APMV-1 isolates were passaged only once. Infected birds were monitored clinically and euthanatized. Tissues were collected for histopathology, in situ hybridization with a NDV matrix gene digoxigenin-labeled riboprobe, and immunohistochemistry with an anti-peptide antibody to the nucleoprotein. Mean death time, intracerebral pathogenicity index, and intravenous pathogenicity index tests performed before and after passage in chickens demonstrated increased virulence of the passaged PPMV-1 isolates and high virulence of the original isolates of APMV-1. Sequence analysis of the fusion protein cleavage site of all six isolates demonstrated a sequence typical of the virulent pathotype. Although the pathotyping results indicated a virulence increase of all passaged PPMV-1 isolates, clinical disease was limited to depression and some nervous signs in only some of the 4-wk-old specific-pathogen-free white leghorns inoculated intraconjunctivally. However, an increased frequency of clinical signs and some mortality occurred in 2 wk olds inoculated intraconjunctivally with passaged virus. Histologically, prominent lesions in heart and brain were observed in birds among all four groups inoculated with the PPMV-1 isolates. The behavior of the two pigeon-origin APMV-1 isolates when inoculated into chickens was characteristic of velogenic viscerotropic NDVs and included necro-hemorrhagic lesions in the gastrointestinal tract. 相似文献
14.
Youn-Jeong Lee Haan-Woo Sung Jun-Gu Choi Eun-Kyoung Lee Hachung Yoon Jae-Hong Kim Chang-Seon Song 《Journal of veterinary science (Suw?n-si, Korea)》2008,9(3):301-308
Recombinant baculoviruses containing the fusion (F) and hemagglutinin-neuraminidase (HN) glycoprotein gene of the viscerotropic velogenic (vv) Newcastle disease virus (NDV) isolate, Kr-005/00, and a lentogenic La Sota strain of the NDV were constructed in an attempt to develop an effective subunit vaccine to the recent epizootic vvNDV. The level of protection was determined by evaluating the clinical signs, mortality, and virus shedding from the oropharynx and cloaca of chickens after a challenge with vvNDV Kr-005/00. The recombinant ND F (rND F) and recombinant HN (rND HN) glycoproteins derived from the velogenic strain provided good protection against the clinical signs and mortality, showing a 0.00 PI value and 100% protection after a booster immunization. On the other hand, the combined rND F + HN glycoprotein derived from the velogenic strain induced complete protection (0.00 PI value and 100% protection) and significantly reduced the amount of virus shedding even after a single immunization. The rND F and rND HN glycoproteins derived from the velogenic strain had a slightly, but not significantly, greater protective effect than the lentogenic strain. These results suggest that the combined rND F + HN glycoprotein derived from vvNDV can be an ideal subunit marker vaccine candidate in chickens in a future ND eradication program. 相似文献
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《Research in veterinary science》2009,86(3):612-616
Seventy-nine velogenic Newcastle disease virus (NDV) isolates were obtained from infected chicken flocks during the outbreaks of Newcastle disease (ND) in various regions of the mainland of China in 2006. The F gene fragment (535 bp, from nt 47 to 581 of the F gene) which codes the main functional region of the F protein was obtained by RT-PCR and sequenced. All sequences obtained in this study have been submitted to GenBank. All the isolates have the motif 112R-R-Q/R-K/R-R-F117 at the cleavage site of the fusion protein, which is typical of velogenic NDV isolates. For genotyping, a phylogenetic tree based on nucleotides 47–435 of the F gene was constructed, and the 79 isolates could be divided into two genotypes, namely VIId and III. Most of the isolates proved to be of genotype VIId; only two isolates were of genotype III. Genotype VIId NDV has been the predominant pathogen responsible for most Newcastle disease outbreaks in China. The proportion of isolates of genotype VIId NDV shows an increasing trend, according to studies on the molecular epidemiology of NDV in China from 2002 to 2006. 相似文献
17.
Molecular characterization and phylogenetic analysis of new Newcastle disease virus isolates from the mainland of China 总被引：2，自引：0，他引：2
Seventy-nine velogenic Newcastle disease virus (NDV) isolates were obtained from infected chicken flocks during the outbreaks of Newcastle disease (ND) in various regions of the mainland of China in 2006. The F gene fragment (535 bp, from nt 47 to 581 of the F gene) which codes the main functional region of the F protein was obtained by RT-PCR and sequenced. All sequences obtained in this study have been submitted to GenBank. All the isolates have the motif 112R-R-Q/R-K/R-R-F117 at the cleavage site of the fusion protein, which is typical of velogenic NDV isolates. For genotyping, a phylogenetic tree based on nucleotides 47–435 of the F gene was constructed, and the 79 isolates could be divided into two genotypes, namely VIId and III. Most of the isolates proved to be of genotype VIId; only two isolates were of genotype III. Genotype VIId NDV has been the predominant pathogen responsible for most Newcastle disease outbreaks in China. The proportion of isolates of genotype VIId NDV shows an increasing trend, according to studies on the molecular epidemiology of NDV in China from 2002 to 2006. 相似文献
18.
Raghavan V.S. Kumanan K. Thirumurugan G. Nachimuthu K. 《Tropical animal health and production》1998,30(5):287-293
Eleven Newcastle disease viruses (NDV), isolated from apparently healthy and ailing Desi chickens were subjected to both conventional and modern characterization techniques. The virulence and strain differentiating experiments placed 10 isolates in the velogenic group and one in the mesogenic group. In MDBK cells, 9 isolates produced characteristic cytopathogenic effects up to 5 and 2 up to 3 passages. Molecular characterization with a 21-mer oligonucleotide probe placed all the isolates in the velogenic/mesogenic group. The results of this study clearly indicated that the isolates obtained are either velogenic or mesogenic but not lentogenic. 相似文献
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Immune response to oil-emulsion vaccines with single or mixed antigens of Newcastle disease, avian influenza, and infectious bronchitis 总被引：1，自引：0，他引：1
Inactivated Newcastle disease virus (NDV), avian influenza virus (AIV), and infectious bronchitis virus (IBV) antigens were evaluated for immunological efficacy in monovalent and polyvalent vaccines. Vaccinated broilers were bled for hemagglutination-inhibition (HI) tests at 1- or 2-week intervals. Half of the chickens were challenged with the Largo isolate of velogenic viscerotropic (VV) NDV at 8 weeks post-vaccination, and the remainder were challenged with the Massachusetts 41 strain IBV at 9 weeks post-vaccination. Newcastle disease HI titers were reduced significantly (P less than 0.05) from those of monovalent control vaccine groups when IBV antigen was emulsified in mixtures with low (1-3x) concentrated NDV or NDV and AIV antigens. Avian influenza HI titers were significantly (P less than 0.05) lower than those of the control monovalent groups when highly concentrated NDV was part of the polyvalent vaccine. Infectious bronchitis HI titers were higher than those of control monovalent groups in 13 of 15 vaccine groups when IBV antigen was in polyvalent formulations. VV NDV challenge killed all non-NDV vaccinates and induced increased HI titers in NDV vaccinates but no morbidity or mortality. Sixty of 80 IBV vaccinates experienced a fourfold or greater HI titer increase following challenge. All non-IBV vaccinates seroconverted at 1 week post-challenge. 相似文献