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Showing papers on "Newcastle disease published in 2010"


Journal ArticleDOI
TL;DR: The results demonstrate that the H5N1 AIVs circulating in nature have complex biological characteristics and pose a continued challenge for disease control and pandemic preparedness.
Abstract: Despite substantial efforts to control H5N1 avian influenza viruses (AIVs), the viruses have continued to evolve and cause disease outbreaks in poultry and infections in humans. In this report, we analyzed 51 representative H5N1 AIVs isolated from domestic poultry, wild birds, and humans in China during 2004 to 2009, and 21 genotypes were detected based on whole-genome sequences. Twelve genotypes of AIVs in southern China bear similar H5 hemagglutinin (HA) genes (clade 2.3). These AIVs did not display antigenic drift and could be completely protected against by the A/goose/Guangdong/1/96 (GS/GD/1/96)-based oil-adjuvanted killed vaccine and recombinant Newcastle disease virus vaccine, which have been used in China. In addition, antigenically drifted H5N1 viruses, represented by A/chicken/Shanxi/2/06 (CK/SX/2/06), were detected in chickens from several provinces in northern China. The CK/SX/2/06-like viruses are reassortants with newly emerged HA, NA, and PB1 genes that could not be protected against by the GS/GD/1/96-based vaccines. These viruses also reacted poorly with antisera generated from clade 2.2 and 2.3 viruses. The majority of the viruses isolated from southern China were lethal in mice and ducks, while the CK/SX/2/06-like viruses caused mild disease in mice and could not replicate in ducks. Our results demonstrate that the H5N1 AIVs circulating in nature have complex biological characteristics and pose a continued challenge for disease control and pandemic preparedness.

178 citations


Journal ArticleDOI
TL;DR: In this article, sequence analysis, pathotyping and detailed genetic characterization of virulent Newcastle disease (ND) strains detected in rural poultry in West and Central Africa revealed the circulation of a new genetic lineage, distinguishable from the lineages described in the Eastern and Southern parts of the continent.

104 citations


Journal ArticleDOI
08 Jan 2010-Vaccine
TL;DR: The innovative rHVT-ND/live ND-chitosan vaccination regimen provided the best protection against mortality and morbidity as well as the strongest reduction of virus shedding that could be related to the higher measured cellular immune response and digestive antibody-mediated immunity.

95 citations


Journal ArticleDOI
TL;DR: Three needle-free, highly attenuated NDV-vectored vaccines expressing either HPAIV HA, HA(RV), or NA have been developed and demonstrated to be individually immunogenic and protective in a primate model of H PAIV infection.
Abstract: H5N1 highly pathogenic avian influenza virus (HPAIV) causes periodic outbreaks in humans, resulting in severe infections with a high (60%) incidence of mortality. The circulating strains have low human-to-human transmissibility; however, widespread concerns exist that enhanced transmission due to mutations could lead to a global pandemic. We previously engineered Newcastle disease virus (NDV), an avian paramyxovirus, as a vector to express the HPAIV hemagglutinin (HA) protein, and we showed that this vaccine (NDV/HA) induced a high level of HPAIV-specific mucosal and serum antibodies in primates when administered through the respiratory tract. Here we developed additional NDV-vectored vaccines expressing either HPAIV HA in which the polybasic cleavage site was replaced with that from a low-pathogenicity strain of influenza virus [HA(RV)], in order to address concerns of enhanced vector replication or genetic exchange, or HPAIV neuraminidase (NA). The three vaccine viruses [NDV/HA, NDV/HA(RV), and NDV/NA] were administered separately to groups of African green monkeys by the intranasal/intratracheal route. An additional group of animals received NDV/HA by aerosol administration. Each of the vaccine constructs was highly restricted for replication, with only low levels of virus shedding detected in respiratory secretions. All groups developed high levels of neutralizing antibodies against homologous and heterologous strains of HPAIV and were protected against challenge with 2 x 10(7) PFU of homologous HPAIV. Thus, needle-free, highly attenuated NDV-vectored vaccines expressing either HPAIV HA, HA(RV), or NA have been developed and demonstrated to be individually immunogenic and protective in a primate model of HPAIV infection. The finding that HA(RV) was protective indicates that it would be preferred for inclusion in a vaccine. The study also identified NA as an independent protective HPAIV antigen in primates. Furthermore, we demonstrated the feasibility of aerosol delivery of NDV-vectored vaccines.

94 citations


Journal ArticleDOI
TL;DR: The Newcastle disease virus was detected in the dissected gastrointestinal tract of laboratory‐exposed flies for up to 72 h post‐exposure, whereas the untreated control flies were negative.
Abstract: Newcastle disease (Paramyxoviridae) is a highly infectious virus shed in the faeces of infected birds. Non-biting Muscid flies characteristically visit manure and decaying organic material to feed and oviposit, and may contribute to disease transmission. The housefly, Musca domestica (Linnaeus, 1758) (Diptera: Muscidae), has been implicated as a mechanical vector of numerous pathogens. In this study 2000 aerial net-captured houseflies were examined for their ability to harbour Newcastle disease virus (NDV). In an adjacent study, laboratory-reared flies were experimentally exposed to NDV La Sota strain. The virus was detected in the dissected gastrointestinal tract of laboratory-exposed flies for up to 72 h post-exposure, whereas the untreated control flies were negative.

87 citations


Journal ArticleDOI
TL;DR: There was no indication that M2 is immunogenic or protective, and inclusion of NA in addition to HA in a vaccine preparation for chickens may not enhance the high level of protection provided by HA.
Abstract: Highly pathogenic avian influenza virus (HPAIV) subtype H5N1 causes severe disease and mortality in poultry. Increased transmission of H5N1 HPAIV from birds to humans is a serious threat to public health. We evaluated the individual contributions of each of the three HPAIV surface proteins, namely, the hemagglutinin (HA), the neuraminidase (NA), and the M2 proteins, to the induction of HPAIV-neutralizing serum antibodies and protective immunity in chickens. Using reverse genetics, three recombinant Newcastle disease viruses (rNDVs) were engineered, each expressing the HA, NA, or M2 protein of H5N1 HPAIV. Chickens were immunized with NDVs expressing a single antigen (HA, NA, and M2), two antigens (HA+NA, HA+M2, and NA+M2), or three antigens (HA+NA+M2). Immunization with HA or NA induced high titers of HPAIV-neutralizing serum antibodies, with the response to HA being greater, thus identifying HA and NA as independent neutralization antigens. M2 did not induce a detectable neutralizing serum antibody response, and inclusion of M2 with HA or NA reduced the magnitude of the response. Immunization with HA alone or in combination with NA induced complete protection against HPAIV challenge. Immunization with NA alone or in combination with M2 did not prevent death following challenge, but extended the time period before death. Immunization with M2 alone had no effect on morbidity or mortality. Thus, there was no indication that M2 is immunogenic or protective. Furthermore, inclusion of NA in addition to HA in a vaccine preparation for chickens may not enhance the high level of protection provided by HA.

80 citations


Journal ArticleDOI
TL;DR: Data show that vaccination with live attenuated viruses has changed the evolution of aPMV-1 by maintaining a large effective population size of a vaccine-related genotype, allowing for coinfection and recombination of vaccine and wild type strains, and by applying unique selective pressures on viral glycoproteins.
Abstract: Newcastle Disease Virus (NDV) is a pathogenic strain of avian paramyxovirus (aPMV-1) that is among the most serious of disease threats to the poultry industry worldwide. Viral diversity is high in aPMV-1; eight genotypes are recognized based on phylogenetic reconstruction of gene sequences. Modified live vaccines have been developed to decrease the economic losses caused by this virus. Vaccines derived from avirulent genotype II strains were developed in the 1950s and are in use globally, whereas Australian strains belonging to genotype I were developed as vaccines in the 1970s and are used mainly in Asia. In this study, we evaluated the consequences of attenuated live virus vaccination on the evolution of aPMV-1 genotypes. There was phylogenetic incongruence among trees based on individual genes and complete coding region of 54 full length aPMV-1 genomes, suggesting that recombinant sequences were present in the data set. Subsequently, five recombinant genomes were identified, four of which contained sequences from either genotype I or II. The population history of vaccine-related genotype II strains was distinct from other aPMV-1 genotypes; genotype II emerged in the late 19th century and is evolving more slowly than other genotypes, which emerged in the 1960s. Despite vaccination efforts, genotype II viruses have experienced constant population growth to the present. In contrast, other contemporary genotypes showed population declines in the late 1990s. Additionally, genotype I and II viruses, which are circulating in the presence of homotypic vaccine pressure, have unique selection profiles compared to nonvaccine-related strains. Collectively, these data show that vaccination with live attenuated viruses has changed the evolution of aPMV-1 by maintaining a large effective population size of a vaccine-related genotype, allowing for coinfection and recombination of vaccine and wild type strains, and by applying unique selective pressures on viral glycoproteins.

77 citations


Journal ArticleDOI
TL;DR: Phylogenetic analysis and pathotyping confirmed that virulent viruses of different genotypes are circulating in Pakistan.
Abstract: Eight Newcastle disease virus isolates from Pakistan were sequenced and characterized. A PCR matrix gene assay, designed to detect all avian paramyxovirus 1, did not detect four of the isolates. A new matrix gene test that detected all isolates was developed. Phylogenetic analysis and pathotyping confirmed that virulent viruses of different genotypes are circulating in Pakistan.

77 citations


Journal ArticleDOI
TL;DR: The chitosan is a cell-promising adjuvant for the mucosal delivery of live vaccine in poultry, by enhancing the Th1 pathway of immunity, however, further investigations are required to explore its mechanism of action and to evaluate the inferred protection.

65 citations


Journal ArticleDOI
19 Apr 2010-Vaccine
TL;DR: It is suggested that NDV can be used as a vaccine vector in bovines and that BHV-1 gD may be useful in mucosal vaccine against BHv-1 infection, but might require augmentation by a second dose or the inclusion of additional BH V-1 antigens.

59 citations


Journal ArticleDOI
TL;DR: For both HPAI virus infections of ducks, the ID50 was lower than the LD50, indicating that infected birds were able to survive and thus excrete virus over a longer period than chickens and turkeys.
Abstract: A range of virus doses were used to infect 3-week-old chickens, turkeys and ducks intranasally/intraocularly, and infection was confirmed by the detection of virus shedding from the buccal or cloacal route by analysis of swabs collected using real-time reverse transcriptase-polymerase chain reaction assays. The median infectious dose (ID(50)) and the median lethal dose (LD(50)) values for two highly pathogenic avian influenza (HPAI) viruses of H5N1 and H7N1 subtypes and one virulent Newcastle disease virus (NDV) were determined for each virus and host combination. For both HPAI viruses, turkeys were >100-fold more susceptible to infection than chickens, while both these hosts were >10-fold more susceptible to H5N1 virus than the H7N1 virus. All infected chickens and turkeys died. Ducks were also much more readily infected with the H5N1 virus (ID(50)< or =10(1) median embryo infective dose [EID(50)]) than the H7N1 virus (ID(50)=10(4.2) EID(50)). However, the most notable difference between the two viruses was their virulence for ducks, with a LD(50) of 10(3) EID(50) for the H5N1 virus, but no deaths in ducks being attributed to infection with H7N1 virus even at the highest dose (10(6) EID(50)). For both HPAI virus infections of ducks, the ID(50) was lower than the LD(50), indicating that infected birds were able to survive and thus excrete virus over a longer period than chickens and turkeys. The NDV strain used did not appear to establish infection in ducks even at the highest dose used (10(6) EID(50)). Some turkeys challenged with 10(6) EID(50), but not other doses, of NDV excreted virus for a number of days (ID(50)=10(4.6) EID(50)), but none died. In marked contrast, chickens were shown to be extremely susceptible to infection and all infected chickens died (ID(50)/LD(50)=10(1.9) EID(50)).

Journal ArticleDOI
08 Mar 2010-Vaccine
TL;DR: The RVFV-neutralizing activity of the antisera from intramuscularly vaccinated calves was demonstrated, suggesting that NDV is a promising vaccine vector for the prevention of RVF in calves.

Journal ArticleDOI
TL;DR: Paramyxoviruses, measles virus (MV), mumps virus (MuV) and Newcastle disease virus (NDV) are well known for causing measles and mumps in humans and Newcastle disease in birds.
Abstract: Paramyxoviruses, measles virus (MV), mumps virus (MuV) and Newcastle disease virus (NDV), are well known for causing measles and mumps in humans and Newcastle disease in birds. These viruses have been tamed (attenuated) and successfully used as vaccines to immunize their hosts. Remarkably, pathogenic MuV and vaccine strains of MuV, MV and NDV efficiently infect and kill cancer cells and are consequently being investigated as novel cancer therapies (oncolytic virotherapy). Phase I/II clinical trials have shown promise but treatment efficacy needs to be enhanced. Technologies being developed to increase treatment efficacy include: virotherapy in combination with immunosuppressive drugs (cyclophosphamide); retargeting of viruses to specific tumor types or tumor vasculature; using infected cell carriers to protect and deliver the virus to tumors; and genetic manipulation of the virus to increase viral spread and/or express transgenes during viral replication. Transgenes have enabled noninvasive imaging or tracking of viral gene expression and enhancement of tumor destruction.

Journal ArticleDOI
TL;DR: AP-OM could significantly improve the immune efficacy of Newcastle disease vaccine, astragalus polysaccharide and oxymatrine possessed synergistical immunoenhancement.

Journal ArticleDOI
TL;DR: A protective dose of a live recombinant LaSota Newcastle disease virus (NDV)–avian influenza H5 vaccine was determined in broiler chickens with high levels of maternal antibodies against NDV and avian influenza virus (AIV) and one hundred percent of the chickens vaccinated were protected against HPAIV and VVNDV.
Abstract: The protective dose of a live recombinant LaSota Newcastle disease virus (NDV)-avian influenza H5 vaccine (rNDV-LS/AI-H5) was determined in broiler chickens with high levels of maternal antibodies against NDV and avian influenza virus (AIV). At hatch the geometric mean titers (GMT) of the chickens' maternal antibodies were 2(5.1) and 2(10.3) for NDV and AIV, respectively. At the time of vaccination the GMT was 2(3.1) for NDV and 2(7.9) for AIV. The chickens were vaccinated with one drop (0.03 ml) in the eye at 10 days of age as is typical under field conditions. The test chickens received 10(4.8), 10(5.8), 10(6.8), or 10(7.8) mean chicken embryo infective doses (CEID50) of the rNDV-LS/AI-H5 vaccine. Control chickens were either nonvaccinated, or vaccinated with 10(5.8) or 10(6.8) CEID50 of a commercial live LaSota NDV vaccine. Birds were challenged with either the Mexican highly pathogenic avian influenza virus (HPAIV) strain A/Chicken/Queretaro/14588-19/95 (H5N2) or a Mexican velogenic viscerotropic (VV) NDV strain. One hundred percent of the chickens vaccinated with the rNDV-LS/AI-H5 vaccine were protected against HPAIV and VVNDV when a challenge dose of 10(6.8) EID50 or higher was administered by eye drop. Birds vaccinated with the LaSota NDV vaccine were protected against VVNDV, but not against HPAIV.

Journal ArticleDOI
TL;DR: The results indicate that feral rock pigeons were exposed to NDV and T. gondii, although the exposure was low, and these birds had Salmonella spp.
Abstract: The rock pigeon (Columba livia) may serve as a reservoir for several pathogenic agents that can be transmitted to poultry, wildlife, domesticated pets, and/or humans via excreta, secretions, or dust from feathers. In addition, ingestion of infected pigeons by wild and domestic animals can also transmit these pathogenic agents. The health status of 126 free-living pigeons in an urban area was evaluated by microbiologic culture for Salmonella and serologic testing for the presence of antibodies for Toxoplasma gondii and for Newcastle disease virus (NDV) from 120 and 109 pigeons, respectively. After drawing blood, the birds were euthanized, and fragments of the liver, spleen, lungs, and gonads, and feces were cultured for Salmonella spp. Salmonella spp. was isolated from 10 birds (7.94%), of which 8 were Salmonella typhimurium, one was Salmonella enterica subsp. enterica serotype 4,12 and one was Salmonella enterica subsp. enterica serotype 4,12,i. Six of 109 pigeons (5.50%) were positive for NDV antibodies when using the hemagglutination inhibition test. Toxoplasma gondii antibodies were detected by immunofluorescence in one of 120 sera tested (0.83%). The results indicate that feral rock pigeons were exposed to NDV and T. gondii, although the exposure was low. In addition, these birds had Salmonella spp. and could disseminate this pathogen in the environment.

Journal ArticleDOI
TL;DR: The BC V protein exhibits a 4-fold greater ability to rescue replication of NDV-GFP than the La Sota V protein, indicating four amino acid differences contribute to the difference in IFN-antagonistic activity between the two V proteins.

Journal ArticleDOI
TL;DR: Direct isolation of a velogenic Newcastle disease virus (NDV) strain currently found in Indonesia for establishing a domestic reference virus for future pathological and molecular epidemiological studies revealed the NDV isolate to be a novel Indonesian velogenic NDV strain belonging to group VII.
Abstract: This study was performed to isolate a velogenic Newcastle disease virus (NDV) strain currently found in Indonesia for establishing a domestic reference virus for future pathological and molecular epidemiological studies. A chicken suspected to have contracted Newcastle disease (ND) in a local outbreak in Bali was selected for NDV isolation. Atrophy of lymphoid tissues such as the bursa of Fabricius, thymus, and spleen; intestinal haemorrhage; and oedema of the brain were observed in the chicken. Histopathological examination revealed severe non-suppurative meningoencephalomyelitis characterised by neuronal necrosis, multifocal to diffuse gliosis, and perivascular cuffing of mononuclear cells, hemorrhagic necrosis of the trachea, intestines and bursa of Fabricius, and various degree of lymphoid depletion and necrosis of the lymphoid tissues. After ND was confirmed immunohistochemically, the NDV was propagated by inoculating tissue homogenate of the diseased chicken in embryonated eggs. Phylogenetic analysis based on the F gene nucleotide sequence revealed that this isolate belonged to genotype VII. The deduced amino acid sequence of the isolated NDV F protein at the cleavage site was (112)RRQKRF(117), which is typically found in virulent NDV isolates. Pathogenicity indexes such as the mean death time (MDT) and intracerebral pathogenicity index (ICPI) were 54 hr and 1.77, respectively. Pathological findings, phylogenetic analysis, amino acid sequence of the F protein cleavage site, and pathogenicity index test results revealed the NDV isolate, designated as NDV/Bali-1/07, to be a novel Indonesian velogenic NDV strain belonging to group VII.

Journal ArticleDOI
TL;DR: It is shown that Bax conformational change and subcellular distribution is involved in the intrinsic pathway of apoptosis induced by NDV.
Abstract: Background/Aims: Newcastle disease virus (NDV) is an avian paramyxovirus that has gained a lot of interest in cancer viro-therapeutic applications because of its ability to selectiv


Journal ArticleDOI
TL;DR: The study concluded that the occurrence of three types of NDV genotypes and presence of varied carboxyl terminus extension lengths among Malaysian isolates incriminated for sporadic cases are concluded.
Abstract: Newcastle disease (ND), caused by Newcastle disease virus (NDV), is a highly contagious disease of birds and has been one of the major causes of economic losses in the poultry industry. Despite routine vaccination programs, sporadic cases have occasionally occurred in the country and remain a constant threat to commercial poultry. Hence, the present study was aimed to characterize NDV isolates obtained from clinical cases in various locations of Malaysia between 2004 and 2007 based on sequence and phylogenetic analysis of partial F gene and C-terminus extension length of HN gene. The coding region of eleven NDV isolates fusion (F) gene and carboxyl terminal region of haemagglutinin-neuraminidase (HN) gene including extensions were amplified by reverse transcriptase PCR and directly sequenced. All the isolates have shown to have non-synonymous to synonymous base substitution rate ranging between 0.081 - 0.264 demonstrating presence of negative selection. Analysis based on F gene showed the characterized isolates possess three different types of protease cleavage site motifs; namely 112RRQKRF117, 112RRRKRF117 and 112GRQGRL117 and appear to show maximum identities with isolates in the region such as cockatoo/14698/90 (Indonesia), Ch/2000 (China), local isolate AF2240 indicating the high similarity of isolates circulating in the South East Asian countries. Meanwhile, one of the isolates resembles commonly used lentogenic vaccine strains. On further characterization of the HN gene, Malaysian isolates had C-terminus extensions of 0, 6 and 11 amino acids. Analysis of the phylogenetic tree revealed that the existence of three genetic groups; namely, genotype II, VII and VIII. The study concluded that the occurrence of three types of NDV genotypes and presence of varied carboxyl terminus extension lengths among Malaysian isolates incriminated for sporadic cases.

Journal ArticleDOI
TL;DR: It is proved that house sparrow can carry the virulent NDV strains and the same genotype of viruses that are circulating in poultry are existing in house sp Sparrows living around poultry farm in southern China.
Abstract: House sparrow (Passer domesticus) is one of the most widely distributed wild birds in China. Five Newcastle disease virus (NDV) strains were isolated from house sparrows living around the poultry farms in southern China. These isolates were characterized by pathogenic assays and phylogenetic analysis. The results showed that all NDV isolates except one were velogenic and virulent for chickens. These four virulent strains for chickens possess the amino acid sequence 112R/K-R-Q-K/R-R-F117 in the F0 cleavage site which is typical of velogenic NDV. Phylogenetic analysis indicated that these isolates belong to genotype VII and were closely related to the strains which were isolated from NDV outbreaks in chickens since 2000. One isolate of NDV from house sparrow belong to genotype II and was proved to be vaccine strain (Chicken/U.S./LaSota/46). The result of this study proved that house sparrow can carry the virulent NDV strains and the same genotype of viruses that are circulating in poultry are existing in house sparrows living around poultry farm in southern China.

Patent
05 Feb 2010
TL;DR: In this article, the chimeric Newcastle disease viruses are engineered to express a heterologous interferon antagonist and compositions comprising such viruses are used in the treatment of cancer, which is useful in the diagnosis of cancer.
Abstract: Described herein are chimeric Newcastle disease viruses engineered to express a heterologous interferon antagonist and compositions comprising such viruses. The chimeric Newcastle disease viruses and compositions are useful in the treatment of cancer.

Journal ArticleDOI
03 Feb 2010-Vaccine
TL;DR: Full length and mature chicken IL-18 expressed using a prokaryotic system and using a eukaryoticSystem showed equivalent in vitro and in vivo biological activities, and all forms effectively enhanced cell-mediated and humoral immunity, suggesting possible future use as a potential adjuvant in chicken NDTC vaccine production.

Journal ArticleDOI
TL;DR: It was shown that the RT-LAMP assay has potential usefulness for rapid and sensitive diagnosis in outbreak of IBV and was compared to conventional RT-PCR.

Journal ArticleDOI
TL;DR: The complete genome sequence of a Newcastle disease virus isolated from a chicken in Sweden was determined and compared with other NDV sequences and was shown to belong to genotype VIIb, which arose in the Far East and spread around the world during the 1990s.
Abstract: The complete genome sequence of a Newcastle disease virus (NDV) isolated from a chicken in Sweden was determined and compared with other NDV sequences. The isolate was shown to belong to genotype VIIb, which arose in the Far East and spread around the world during the 1990s. It had a length of 15,192 bases and consisted of six genes in the order 3′-NP-P-M-F-HN-L-5′. The F protein cleavage site was 112-RRQRRF-117, corresponding to that of a virulent pathotype.

Journal ArticleDOI
TL;DR: It is suggested that recombinant NDV is suitable as a potential bivalent live attenuated vaccine against both NDV and H9 AIV infection in poultry.
Abstract: Infection with H9 avian influenza virus (AIV) and Newcastle disease virus (NDV) are two important causes of egg drop in layer and breeder poultry, leading to severe economic loss in the industry. Currently in China, inactivated H9 AIV vaccine and live attenuated NDV vaccine have to be repeatedly administered to prevent egg drop in layer animals. Using reverse genetics, we constructed a recombinant NDV expressing an H9 AIV hemagglutinin (HA) from an H9N2 field isolate, A/Chicken/Shandong/2/2007. The HA gene was inserted into the intergenic region between the phosphoprotein (P) and matrix (M) genes of the LaSota NDV vaccine strain. The recombinant virus stably expressing the HA gene, rL-H9, was found to be innocuous after intracerebral inoculation of 1-day-old chickens. A single dose of 106 50% egg infectious dose of the recombinant virus intranasally inoculated into chickens induced high levels of NDV- and AIV H9-specific hemagglutination-inhibition antibody. Complete protection from clinical dise...

Journal ArticleDOI
TL;DR: The synthetic bearing RRQKRF motif reacted with 60% to 91% of sera taken from surviving chickens on ND outbreak farms but not with sera from vaccinated birds, even though most of the sera had antibody to NDV due to vaccination.
Abstract: Newcastle disease (ND) caused by virulent Newcastle disease virus (NDV) is a highly contagious viral disease of poultry. Virulent NDVs characteristically have a multibasic amino acid sequence (virulence motif) such as (112)RRQKRF(117) at the cleavage site of the precusor fusion (F0) protein. The antigenic and immunogenic characteristics of the virulence motif (112)RRQKRF(117) in the F0 protein of virulent NDVs were investigated. Epitope mapping analysis revealed that a RRQKRF-specific monoclonal antibody 4G2 recognized the KRF section of the motif. A synthetic peptide bearing the RRQKRF motif reacted strongly with sera from virulent NDV (with RRQKRF motif)-infected chickens. These sera also showed reactivity to peptides bearing other virulence motifs ((112)KRQKRF(117), (112)RRQRRF(117) and (112)RRRKRF(117)) but not an avirulence motif ((112)GRQGRL(117)) by ELISA. The synthetic bearing RRQKRF motif reacted with 60% to 91% of sera taken from surviving chickens on ND outbreak farms but not with sera from vaccinated birds, even though most of the sera had antibody to NDV due to vaccination. This indicates that the virulence motif has the potential to differentiate virulent NDV infected birds from vaccinated birds.

Journal ArticleDOI
TL;DR: The results of this study indicate that the NDV (B1) and IBV (ARK) vaccines and a multivalent vaccine constituted by NDV and/or the IBv (ARK and MASS) did not interfere with the protection induced by the CEO ILTV vaccine.
Abstract: Two types of live attenuated vaccines have been used worldwide for the control of infectious laryngotracheitis virus (ILTV): 1) chicken embryo origin (CEO) vaccines; and 2) tissue culture origin vaccines (TCO). However, the disease persists in spite of extensive use of vaccination, particularly in areas of intense broiler production. Among the factors that may influence the efficiency of ILTV live attenuated vaccines is a possible interference of Newcastle Disease virus (NDV) and infectious bronchitis virus (IBV) vaccines with the protection induced by ILTV vaccines. The protection induced by CEO and TCO vaccines was evaluated when administered at 14 days of age alone or in combination with the B1 type strain of NDV (B1) and/or the Arkansas (ARK) and Massachusetts (MASS) serotypes of IBV vaccines. Two weeks after vaccination (28 days of age), the chickens were challenged with a virulent ILTV field strain (63140 isolate, group V genotype). Protection was evaluated at 5 and 7 days postchallenge by ...

Journal ArticleDOI
TL;DR: A phylogenetic analysis of the fusion protein gene of isolates obtained from outbreaks of ND in Sudan found that all contemporary strains isolated between 2003 and 2006 were of genotype 5d, containing the virulent fusion protein cleavage site (F0) motif 112RRQKRF117.
Abstract: Newcastle disease (ND) is a serious neurological and respiratory disease of poultry that affects all types of birds but has traditionally not caused symptoms in wild aquatic birds, the natural hosts. In the late 1990s, a new genotype, viz. 5d that is pathogenic to all types of birds, including waterfowl, arose in China and has since spread from East Asia into parts of Europe, the Middle East and Africa. We performed a phylogenetic analysis of the fusion protein gene of isolates obtained from outbreaks of ND in Sudan and found that all contemporary strains isolated between 2003 and 2006 were of genotype 5d, containing the virulent fusion protein cleavage site (F0) motif 112RRQKRF117. Introduction via a Middle Eastern trade partner is likely to be the source of infection since phylogenetic analysis excluded the possibility of introduction from western and southern Africa.