• Proceedings of the Korea Society of Poultry Science Conference
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• 2005.11a
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• pp.44-52
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• 2005

The study, using sequence analysis and phylogenetic relationship of the fusion protein gene, divided the Korean epizootic isolates of Newcastle disease virus (NDV) into several lineages to determine the molecular epidemiology of the virus. A 695 base pair fragment was amplified by polymerase chain reaction between matrix protein gene and fusion protein gene of 30 Korean NDV isolates, which were isolated from field outbreaks of Newcastle disease between 1949 and 2002. All isolates showed the amino acid sequence 112 R-R-Q/R-K-R116 at the C-terminus of the F2 protein and phenylalanine (F) at the N-terminus of the F1 protein, residue 117. These amino acid sequences were identical to a known virulent motif. The region of the F gene between nucleotides 47 and 435 was compared by phylogenetic analysis. Based on nucleotide sequence, the Korean NDV isolates belonged to genotype III, V, VI and VII corresponding to isolates in 1949, 1982 to 1984, 1988 to 1997, and 1995 to 2002, respectively. These data showed that genotypes of five Korean Newcastle disease epizootics had replaced each other serially (III, V, VI and VII) in chronological order. Further, the five Korean Newcastle disease epizootics were closely related with the Necastle disease panzootics or Newcastle disease epizootics in other countries. Present study showed that the Korean genotype V isolated before 1984 was related with European Newcastle disease epizootics in the 1970s, whereas the Korean genotype VI and VII isolated after 1988 were more closely related with Far East Newcastle disease epizootics, especially Newcastle disease3 epizootics in Japan, Taiwan and China. Since 1988, the genotype VI and VII of Far East origin were dominant in South Korea. That might be due to the increased trade of agricultural products including poultry among Far East Asian countries.

• Journal of Veterinary Science
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• v.23 no.4
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• pp.25.1-25.14
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• 2022

Background: The commercially available Newcastle disease (ND) vaccines were developed based on Newcastle disease virus (NDV) isolates genetically divergent from field strains that can only prevent clinical disease, not shedding of virulent heterologous virus, highlighting the need to develop genotype-matched vaccines Objectives: This study examined the efficacy of the NDV genotype-matched vaccine, mIBS025 strain formulated in standard vaccine stabilizer, and in carboxymethyl sago starch-acid hydrogel (CMSS-AH) following vaccination via an eye drop (ED) and drinking water (DW). Methods: A challenge virus was prepared from a recent NDV isolated from ND vaccinated flock. Groups of specific-pathogen-free chickens were vaccinated with mIBS025 vaccine strain prepared in a standard vaccine stabilizer and CMSS-AH via ED and DW and then challenged with the UPM/NDV/IBS362/2016 strain. Results: Chickens vaccinated with CMSS-AH mIBS025 ED (group 2) developed the earliest and highest Hemagglutination Inhibition (HI) NDV antibody titer (8log₂) followed by standard mIBS025 ED (group 3) (7log₂) both conferred complete protection and drastically reduced virus shedding. By contrast, chickens vaccinated with standard mIBS025 DW (group 5) and CMSS-AH mIBS025 DW (group 4) developed low HI NDV antibody titers of 4log₂ and 3log₂, respectively, which correspondingly conferred only 50% and 60% protection and continuously shed the virulent virus via the oropharyngeal and cloacal routes until the end of the study at 14 dpc. Conclusions: The efficacy of mIBS025 vaccines prepared in a standard vaccine stabilizer or CMSS-AH was affected by the vaccination routes. The groups vaccinated via ED had better protective immunity than those vaccinated via DW.

• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.2060-2069
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• 2017

Newcastle disease is a serious infectious disease in the poultry industry. The commercial vaccines can only offer limited protection and some of them are expensive and need adjuvants. At present, DNA vaccines are widely used. However, the immune responses induced by DNA vaccines are too slow and low. Here, we constructed the transfer vectors with a different number of C3d as molecular adjuvants (n = 1, 2, 4, or 6), and the vectors were cloned into the optimal eukaryotic expression plasmid (pVAXI-optiF) that expressed the F gene of Newcastle disease virus (NDV), and named pVAXI-F(o)-C3d1, pVAXI -F(o)-C3d2, pVAXI-F(o)-C3d4, and pVAXI-F(o)-C3d6, respectively. Cell transfection test indicated that pVAXI-F(o)-C3d6 showed the highest expression. In vivo immunization showed that the chickens immunized with pVAXI-F(o)-C3d6 intramuscularly induced better immune responses than the chickens immunized with the other plasmids. The protective efficacy of pVAXI-F(o)-C3d6 was 80% after challenge with the highly virulent NDV strain F48E9. The results in this study showed that C3d6 could be used as a molecular adjuvant to quickly induce an effective immune response to control NDV.

• Korean Journal of Poultry Science
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• v.39 no.2
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• pp.113-120
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• 2012

Newcastle disease virus (NDV) Kr005/V strain was generated through 55 serial passages of NDV Kr005 strain in Vero cells. The Kr005/V virus yielded high infective titers of $10^{7.8}$ $TCID_{50}/mL$ in Vero cells and the infected cells showed cytopathic effects such as marked cell rounding, though less frequent syncytia. The Kr005/V virus was heat-stable and classified into the lentogenic type with a Mean Death Time (MDT) of 120h or greater while the Kr005 strain was heat-labile and velogenic (MDT of 49.6 h). Only the single amino acid substitution (T to S) was observed at position 433 of the HN protein of the Kr005/V strain, whereas no amino acid change was found in the F protein. The Kr005/V input virus correlated well (correlation coefficient $r^2$=0.97) with the Kr005 virus when ten field sera were tested by virus neutralization test. The biological properties and usefulness of Vero cell-adapted Kr005/V virus were discussed.

• Korean Journal of Veterinary Research
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• v.46 no.4
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• pp.371-379
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• 2006

Newcastle disease virus (NDV) is a single-stranded negative sense RNA virus, which has been classified as a member of the Avulavirus genus of the Paramyxoviridae family. It is also one of the most important pathogens in the poultry industry. The glycoproteins, fusion (F) and hemagglutinin-neuraminidase (HN), determine the virulence of NDV, and the relevant molecular structures have already been determined. NDV isolates differ in terms of virulence, and at least 2 of 9 genotypes (I-IX) have been shown to co-circulate. Therefore, it is clearly important to differentiate between vaccine strains and field isolates. In vivo pathogenicity tests have been the standard protocol for some time, but molecular methods appear preferable in terms of the rapidity of diagnosis, as well as animal welfare concerns. In this study, we have designed primer sets from HN gene for phylogenetic analysis and restriction enzyme analysis, and from F gene for pathotype-specific RT-PCR. Via the combination of 2 methods, 106 Korean NDV isolates obtained from 1980 to 2005 were differentiated into vaccine strains, and virulent genotypes VI and VII. The genotype VI viruses were only rarely isolated after 1999, and genotype VII, after it was initially isolated from poultry in 1995, recurred in 2000, and then became the main NDV constituting a threat to the Korean poultry industry.

• Korean Journal of Veterinary Research
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• v.42 no.3
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• pp.351-362
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• 2002

Newcastle disease (ND) is a highly contagious infection of poultry, Two pathology-based techniques, in situ RT-PCR and in situ hybridization (ISH) were applied to formalin-fixed, paraffin-embedded tissues from chickens naturally infected with velogenic ND virus (VNDV). Two pairs of primers and a probe for ISH and in situ RT-PCR, respectively, were selected from highly conserved region of matrix gene of NDV. The ISH experiment was carried out using MicroProbe$^{TM}$ capillary action system within 2 hours. In situ RT-PCR was performed using MicroProbe$^{TM}$ capillary action system and GeneAmp In Situ PCR system. With ISH and in situ RT-PCR, viral nucleic acid was detected in the central nervous system of chickens from infected with neurotropic velogenic Newcastle disease virus (NVNDV), whereas viral nucleic acid was detected in various organs or tissues of chickens from infected with viscerotropic velogenic Newcastle disease virus (VVNDV). In the NVND group, positive signals were characteristically defined in the cytoplasm of neuron, vascular endothelial cells, and perivascular mononuclear macrophages in the central nervous system. One of NVND group, chicken from one farm exhibited positive signals in the bronchial epithelium. The VVND group chickens showed positive reaction in the macrophages, vascular endothelium, and bronchiolar epithelium. Markedly, viral nucleic acid was detected in the macrophages of morphologically normal tissues which were peripheral or located in distant areas from lesions. The central nervous system of chickens infected with VVND virus had positive signals in the vascular endothelial cell, perivascular mononuclear macrophages and some neuron. The number and intensity of the positive cells by in situ RT-PCR were more and stronger, respectively, in comparison with those by ISH. Particularly, positive reaction was detected in macrophages infiltrating in cardiac muscle by in situ RT-PCR, but not obtained by ISH. Therefore, these results demonstrated that ISH is a rapid diagnostic method for detection of NDV and in situ RT-PCR can be used as an efficient method for detection of low viral load infection or subclinical viral infection of NDV.

• BMB Reports
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• v.40 no.5
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• pp.611-616
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• 2007

$E^{rns}$ is an envelope glycoprotein of classical swine fever virus (CSFV) and has an unusual feature of RNase activity. In the present study, we demonstrate that $E^{rns}$ counteracts Newcastle disease virus (NDV)-mediated induction of IFN-$\beta$. For this purpose, $E^{rns}$ fused to the enhanced green fluorescent protein (EGFP) was transiently expressed in porcine kidney 15 (PK15) cells. In luciferase activity assay, $E^{rns}$-EGFP was found to prevent IFN-$\beta$ promoter-driven luciferase expression and block the induction of IFN-$\beta$ promoter mediated by NDV in a dose-dependent manner. Through IFN-specific semi-quantitative RT-PCR detection, obvious decrease of IFN-$\beta$ mRNA in NDV-infected PK15 cells was observed in the presence of $E^{rns}$-EGFP. In contrast, EGFP alone showed none of this block capacity. In addition, $E^{rns}$-EGFP mutations with RNase inactivation were also found to block NDV-mediated induction of IFN-$\beta$. These evidences establish a novel function for CSFV $E^{rns}$ glycoprotein in counteraction of the IFN-$\beta$ induction pathway.

• Korean Journal of Veterinary Service
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• v.21 no.2
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• pp.133-139
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• 1998

Serum samples collected from 30 breeders and their progeny 30 chicks. The antibodies against infectious bronchitis(IB), infectious bursal disease (IBD) and Newcastle disease(ND) viruses were detected by ELISA using commercial ELISA kit. The breeders were vaccinated against IB, IBD and ND viruses according to general vaccination program. Geometric mean titers(GMT) of ELISA were monitored from 1-day old to 17-day old chicks and compared with breeder chickens. The GMT of ELISA to IB, IBD and ND were declined half level of the breeder antibody titer at 6-, 8- and 7-day old. And, the GMT of ELISA to IB, IBD and ND were declined than that of protective titer at 6-, 1-, and 4-day old. Thereafter, the GMT of ELISA was declined and disappeared according to ages of chicks. Taken together, this study led to conclusion that time-course of maternal antibody titers of chicks from vaccinated breeders, and this is very important data for vaccination to chicks.

• Journal of the korean veterinary medical association
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• v.9 no.3
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• pp.13-17
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• 1965

• Korean Journal of Veterinary Research
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• v.48 no.2
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• pp.153-159
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• 2008

Newcastle disease virus (NDV) is the causative agent of a highly contagious and devastating Newcastle disease of poultry. A NDV (isolate DK1/07) was isolated from apparently healthy wild spot-billed ducks (Anas poecilorhyncha) captured at upper branch of the SapGyo Creek in Chungbuk province, Korea during early 2007. The DK1/07 isolate of minimum chicken embryo lethal dose killed all SPF chicken embryos within 60 h. The cleavage site of the F protein possessed the amino acid sequence $^{112}R-R-Q-K-R-F^{117}$, which is a motif characteristic of virulent NDV strains. The F protein-based phylogenetic analysis revealed that the DK1/07 duck isolate was included in the cluster of genotype VIId and most closely related to recent NDV isolates obtained from chicken farms in Korea. Epidemiological importance of virulent NDV from wild duck is discussed.