Newcastle Disease Virus Isolates Research Articles

Isolation of Newcastle Disease Virus from Wild Migratory Birds in Egypt

Isolation of Newcastle Disease Virus from Wild Migratory Birds in Egypt

Efficacy of an inactivated Vaccine prepared from a new isolate of Newcastle Disease Virus

The incidence of Newcastle Disease virus (NDV) outbreaks in Egypt is still frequent even massive vaccination programs that due to viral mutation and appearing new isolates that need new vaccination program. Inactivated Newcastle Disease virus (NDV) vaccine was prepared using a new local isolate (NDV/Ch/Giza2014), from Giza governorate, Egypt, inactivated with binary ethylenimine (BEI) and emulsified with Montanide ISA70VG as an oil adjuvant. The prepared vaccine was evaluated in comparison with an inactivated imported vaccine. Chick groups vaccinated with either prepared or imported vaccines showed high serum antibody titers from the third week post vaccination until reached the maximum titer at the 9th week post vaccination using Haemagglutination Inhibition (HI) test. The prepared and imported vaccines gave 95-100% of protection against the local and the classical strain in chicks, during challenge period, there no clinical signs or lesions on examination. Our Conclusion that the locally prepared inactivated NDV vaccine can protect chicken against either homologous or heterologous challenging viruses.

Molecular Characterization of Newcastle Disease Viruses Isolated from Chickens in Tanzania and Ghana.

Newcastle disease (ND) is one of the most challenging infectious diseases affecting poultry production in Africa, causing major economic losses. To date, Newcastle disease virus isolates from several African countries have been grouped into class II NDV genotypes I, IV, V, VI, VII, XI, XIII, XIV, XVII, XVIII and XXI. Although ND is endemic in many African countries, information on circulating genotypes is still scarce. In Tanzania, outbreaks with genotypes V and XIII have been reported. In West and Central Africa, genotypes XIV, XVII, and XVIII are the most predominant. To investigate other genotypes circulating in Tanzania and Ghana, we performed molecular genotyping on isolates from Tanzania and Ghana using the MinION, a third-generation portable sequencing device from Oxford Nanopore Technologies. Using the MinION, we successfully sequenced the NDV F gene hypervariable region of 24 isolates from Tanzania and four samples from Ghana. In Tanzania, genotypes V, VII and XIII were detected. All isolates from Ghana belonged to genotype XVIII. The data obtained in this study reflect the genetic diversity of NDV in Africa and highlight the importance of surveillance for monitoring the distribution of NDV genotypes and viral evolution.

Sequence analysis and pathogenicity of Avian Orthoavulavirus 1 strains isolated from poultry flocks during 2015\u20132019

BackgroundNewcastle disease (ND) causes severe economic losses in poultry industry worldwide. Egyptian poultry industry suffered from severe economic losses since the isolation of Velogenic Newcastle disease virus (vNDV) genotype VIId in 2011 and up till now despite the use of different vaccination programs. So, this study aimed to isolate and characterize the vNDV from a total of 120 poultry flocks from ten provinces in the Egyptian Delta region with a history of respiratory manifestation, high mortalities or a decrease in egg production between 2015 and 2019. Seventy-three samples’ allantoic fluid (73/120, 60.8%) were positive for hemagglutination with chicken RBCs. These samples were submitted to molecular examination using qRT-PCR specific primers for AOAV-1, highly pathogenic avian influenza (HPAI-H5), low pathogenic avian influenza (LPAI-H9) and infectious bronchitis virus (IBV).ResultsFifty samples (50/120: 41.6%) were confirmed positive for AOAV-1, based on genetic analysis of matrix and fusion protein. The co-infection rate of other respiratory viral diseases examined was 1.6, 14.1, and 4.1%, for HPAI-H5, LPAI-H9, and IBV, respectively. Biologically, the intracerebral pathogenicity index of ten selected AOAV-1 isolates ranged from 1.70 to 1.98, which indicated the velogenic nature of these isolates. All the sixteen sequenced isolates were AOAV-1 genotype VII.1.1. The full F gene sequence of six examined AOAV-1 VII.1.1 isolates contained the seven neutralizing epitopes, and the glycosylation motif of six-potential sites for N linked glycosylation at residues 85, 191, 366, 447, 471, and 541.ConclusionIt could be concluded that the high prevalence of AOAV-1 genotype VII.1.1 in the Egyptian chicken flocks despite the intensive vaccination with live and killed ND vaccines, as all the 16 isolates tested were belonged to this genotype. Homologous vaccination is badly needed to control and reduce the spread of AOAV-1 genotype VII.1.1infection in Egyptian poultry flocks.

Comparative pathogenicity of two closely related Newcastle disease virus isolates from chicken and pigeon respectively

Newcastle disease (ND), caused by virulent Newcastle disease virus (NDV), is a highly contagious disease that has led to tremendous economic losses worldwide. Pigeon paramyxovirus type 1 (PPMV-1) is an antigenic and host variant of NDV. However, limited in-depth studies are available concerning side-by-side comparison of pathogenicity of PPMV-1 and its phylogenetically close NDV both in chickens and pigeons. To this end, two phylogenetically closely related NDV isolates, Kuwait 256 and JS/07/04/Pi from chicken and pigeon respectively were pathotypically and genotypically characterized in this study. The results indicated that Kuwait 256 was a velogenic strain, while JS/07/04/Pi was a mesogenic strain based on the mean death time of chick embryos (MDT) and intracerebral pathogenicity index in 1-day-old chicks (ICPI). Pathogenicity tests showed that Kuwait 256 caused severe clinical signs and 100 % mortality, while JS/07/04/Pi caused no apparent disease in chickens. Interestingly, both Kuwait 256 and JS/07/04/Pi caused morbidity and mortality in pigeons. Notably, pigeons infected with JS/07/04/Pi exhibited viral shedding for longer time compared to Kuwait 256-infected pigeons. Collectively, the findings of this study suggested that PPMV-1 decreased the pathogenicity in chickens but gained a survival advantage over NDV of chicken origin after its adaptive variation in pigeons based on the previous evidence that PPMV-1 originated from chicken-origin viruses. This study laid the foundation for the elucidation of the molecularmechanism underlying difference in pathogenicity of PPMV-1 and chicken-origin NDV in chickens.

Expression of Recombinant Fusion Protein from Local Isolate of Newcastle Disease Virus and Antibody Response to Recombinant Fusion Protein in Broiler Chickens Post-Vaccination

This research aimed to express and purify the recombinant Fusion (F) protein of Newcastle Disease Virus (NDV) from a local isolate in Galur, Kulon Progo, Indonesia (0663/04/2013) from recombinant vector plasmid pBT7-N-His F, and to study the antibody response in the broiler sera which were injected with pure recombinant F protein compared with treated broilers that were vaccinated with commercial inactive NDV vaccines and control broilers without vaccination. The results showed that the recombinant F protein of NDV was successfully expressed, purified and visualized by SDS-PAGE with Coomassie Brilliant Blue staining and Westernblotting methods as a specific recombinant F protein with a molecular weight of 28 kDa. The pure recombinant F protein then was injected into broilers to determine the antibody response in broiler serum. Indirect ELISA showed that the production of antibodies was high in F protein vaccinated groups in comparison with other treated and control groups. The recombinant F protein has potential to be developed as a recombinant vaccine candidate after truncating the 6x His-tag part to obtain higher antibody respond if compared with antibody production in broiler serum post vaccinated with some commercially available broiler vaccines.

A HIGHLY SENSITIVE REAL-TIME REVERSE TRANSCRIPTION POLYMERASE CHAIN REACTION FOR DETECTING NUCLEOCAPSID PROTEIN GENE OF BOTH CLASSES I AND II OF NEWCASTLE DISEASE VIRUS

Newcastle disease virus (NDV) is a worldwide viral agent that infects over 200 species of birds and is responsible for outbreaks of ND. Although a series of real-time reverse transcription polymerase chain reaction (rRT-PCR) assays have been developed for detecting different genes of NDV, diagnostic sensitivity and efficiency still can be improved. This study describes a nucleocapsid protein gene rRT-PCR screening assay based on TaqMan technology for the detection of divergent NDV strains. All 23 representative NDV strains of classes I and II in the tested panel were detected using the NP-gene rRT-PCR assay, whereas eight class I and two class II NDV isolates cannot be detected by the USDA-validated matrix-gene assay. The detection limit of the NP-gene assay was approximately 10[Formula: see text] EID[Formula: see text]/mL. The new assay also demonstrated a high degree of specificity with no false-positive results of 35 non-NDV viruses. A total of 146 clinical specimens were also tested and the NP-gene assay gave high relative sensitivity (100%) and specificity (96.61%) when compared with virus isolation. This NP-gene rRT-PCR assay offers a sensitive, specific and rapid assay for detecting both class I and II NDV and can be used alongside with the existing diagnostic assays for this notifiable disease agent.

In Ovo evaluation of antiviral effects of aqueous garlic (Allium sativum) extract against a velogenic strain of Newcastle disease virus

Introduction: The antiviral property of aqueous garlic extract against a virulent velogenic field isolate of Newcastle disease virus (NDV) was investigated in a time of addition assay in embryonated chicken eggs (ECEs). Methods: The ECEs were inoculated with the lowest concentration of the virus with HA (haemagglutination) positive activity. After determination of extract toxicity in ECEs, administration of different concentrations of the extract (0.5, 1, 2, 4 mg/mL) or ribavirin (comparative control) was performed 8 hours before (pretreatment), simultaneously (cotreatment) or 8 hours after (post treatment) virus injection. Allantoic fluids were harvested for infectivity determination, transmission electron microscopy (TEM) and viral load (HA titer) assay. In vitro HA blocking activity test was also performed. Results: Allicin content of the extract was 16.6% by HPLC method. The best viability results were related to the extract in pretreatment and ribavirin in co-treatment trials (p<0.05 as compared to infected ECEs with no treatment). Pre and co-treatment assays showed better results on HA titer of garlic treated groups. In infectivity assay, the 50% embryo lethal dose (ELD50) values of NDV were roughly 500 and 50 folds of ELD50 of the untreated virus in pre and co-treatment, respectively. No change was observed in viral shapes in TEM analysis nor HA blocking activity in vitro. Conclusion: Aqueous extract of garlic shows antiviral effects against a velogenic strain of NDV in ovo accompanied by a reduction in virus infectivity and titer. These effects are most pronounced in pretreatment trial.

English

Newcastle disease (ND) is a highly contagious viral disease constituting a continuous threat to the poultry industry worldwide. This study evaluated the genetic characteristics of Newcastle disease viruses (NDVs) obtained from backyard commercial poultry farms and live bird markets during active and passive surveillance in different regions of Plateau and Nasarawa States of Nigeria between 2009 and 2017. The partial fusion (F) gene coding sequence and cleavage site of five NDV isolates was determined. This was aligned and compared with sequences of representative NDV from the GenBank. Deduced amino acid sequence of the protein revealed that four isolates had virulent motifs (112RRQKRF117) while one had an avirulent motif (112GRQGRL117). One virulent strain was recovered from an apparently healthy duck. Phylogenetic analysis based on comparison with different classes of NDVs revealed that two isolates clustered with genotype XIVb NDVs, another two isolates clustered with genotype XVIIa while one isolate clustered with genotype II. The phylogenetic analysis revealed that the velogenic isolates clustered with published class II genotype XIVb and XVIIa closely related to isolates from Benin and Niger republic. This highlights the need for ND control programmes to place more stringent measures on cross-border trade of live bird and poultry products to prevent the introduction of new strains of NDV that would be more difficult to control. Key words: Chickens, duck, live bird market, Newcastle disease virus, genotypes, Nigeria. &nbsp

Clinical, molecular and cytopathological characterization of a Newcastle disease virus from an outbreak in Baghdad, Iraq

BackgroundThe frequent outbreaks of Newcastle disease virus (NDV) in Iraq pose a constant threat to commercial poultry, despite the introduction of routine vaccination programmes. Several factors, particularly stress factors and coinfections, might play a role in increasing NDV outbreaks in poultry species.ObjectivesThe current study was aimed to characterize an NDV isolate from an outbreak in North Baghdad, Iraq.MethodsClinical pathogenicity of the isolate was determined experimentally in chickens. In vitro studies included cytopathological examination, as well as molecular and phylogenetic analyses.ResultsBased on the clinical studies and pathogenicity indices (mean death time and intracerebral and intravenous pathogenicity indices), the isolate was characterized as velogenic (highly virulent). Reverse transcriptase polymerase chain reaction targeting the partial fusion protein gene of the NDV genome confirmed the detection. Partial sequencing of the hypervariable region of the fusion gene identified the presence of an avirulent (lentogenic) fusion protein motif (GRQGRL). Phylogenetic analysis of the new isolate along with previously known regional isolates revealed that the new isolate was related to genotype II strains. Additionally, sequence analysis indicated a distinct genetic lineage of the new isolate, which was related to some of the lineages identified in previous outbreaks in the Middle East.ConclusionThe current study offers essential information on the epidemiology, characteristics and diagnosis of NDV for disease control in Iraq. The isolate was found to belong to genotype II and possess an avirulent fusion protein motif.

Characterization and genetic analysis of recent and emergent virulent newcastle disease viruses in Egypt.

Extensive vaccination against Newcastle disease virus (NDV) induced more selective immune pressure from hosts that enhanced the evolutionary process of NDV. Herein, we characterized 13 recently isolated NDV isolates from vaccinated chicken flocks during 2014-2017. Sequence analysis of F gene showed the presence of 112 RRQKRF117 velogenic cleavage motif in 11 isolates, whereas the other two isolates (Ck/ME3/Eg/16 and Ck/ME5/Eg/16) showed the monobasic motif 112 GGRQGRL117 . Interestingly, isolate Ck/ME5/Eg/16 showed 100% and 99.82% nucleotide identity with the LaSota F gene hypervariable region and full-length gene, respectively. On the other hand, isolate Ck/ME3/Eg/16 revealed natural recombination with strains NDV/Ck/Egypt/3/2006 and NDV/Teal/VRLCU/Egypt/2015 that indicates re-emergence of that old strain. Interestingly, all 13 isolates showed high intracerebral pathogenicity (ICPI) and mean death time (MDT) despite the presence of lentogenic motif in both Ck/ME5/Eg/16 and Ck/ME3/Eg/16 isolates. Comparative analysis of F antigenic epitopes in our isolates with other published sequences from Egypt revealed high sequence conservation; recent isolates had one fixed amino acid substitution (K78R) and a novel V168I substitution, whereas a D170N substitution was detected in older strains (NDV-EG-35-2014 and NDV-KFR-B7-2012). Taken together, our results support the first isolation of virulent NDV isolates with a lentogenic motif; isolate Ck/ME5/Eg/16 might be generated in nature from LaSota live vaccine, whereas isolate Ck/ME3/Eg/16 is emergent from NDV/Ck/Egypt/3/2006. We conclude that the current diagnostic evaluation of the virulence of NDV isolates by characteristic amino acid residues at the F protein cleavage site is insufficient. There is a need to link virologic and epidemiologic data together, and routine and emergency LaSota vaccination protocols should be carefully and optimally applied, with regards to the timing and presence of co-infecting agents in the field.

Molecular characterization of full genome sequences of Newcastle disease viruses circulating among vaccinated chickens in Egypt during 2011-2013.

Although intensive vaccination programs have been implemented, Newcastle disease (ND) outbreaks, accompanied by severe economic losses, are still reported in Egypt. The genetic characterization of ND virus (NDV) strains isolated from ND-vaccinated chicken flocks provides essential information for improving ND control strategies. Therefore, here, 38 NDV strains were isolated and identified from outbreaks among vaccinated flocks of broiler chickens located in the provinces of Qena, Luxor, and Aswan of Upper Egypt during 2011–2013. The investigated broiler chicken flocks (aged 28 to 40 days) had high mortality rates of up to 80%. All NDV isolates were genetically analyzed using next-generation DNA sequencing. From these isolates, 10 representative NDV strains were selected for further genetic analyses. Phylogenetic analysis of full-length coding genes revealed that the Egyptian NDV isolates belonged to a single sub-genotype, VII.1.1. These isolates were phylogenetically distant from the vaccine strains, including La Sota or Clone 30 (genotype II), which have been commonly used to vaccinate chicken flocks. Amino acid substitution K78R was observed in the neutralizing epitopes of the F proteins; whereas several mutations were found in the neutralizing epitopes of the hemagglutinin-neuraminidase proteins, notably, E347K. Overall, our results suggested that the occurrence of neutralizing epitope variants may be one of potential reasons for ND outbreaks. Further studies are needed to determine the protective effect of current vaccines against circulating virulent NDV strains.

Isolation and molecular identification of wild Newcastle disease virus isolated from broiler farms of Diyala Province, Iraq

Background and Aim:Newcastle disease virus (NDV) remains a major viral disease of poultry. The morbidity and mortality rates of chickens vaccinated with NDV in broiler farms in Diyala Province were 100% and 80%, respectively, rates due to suspected infection with the highly virulent NDV. The present study aimed to isolate and identify the NDV virus and evaluate its pathogenicity in infected broiler chickens at poultry farms.Materials and Methods:Broiler chickens at two commercial poultry farms were suspected of being infected with virulent NDV due to high mortality rates. Virus isolated from samples of intestinal tissues, lungs, trachea, spleen, kidneys, and air sacs was adapted in the allantoic cavity of embryonated specific-pathogen-free (SPF) chicken eggs. The NDV pathotype was determined based on the mean death time (MDT) in eggs as well as the intracerebral pathogenicity index (ICPI) and intravenous pathogenicity index pathogenicity indexes of the isolated samples. Broilers were experimentally infected by inoculation with fluids collected from the allantoic cavities of 60 broilers aged 35 days. Serological and molecular tests were followed by enzyme-linked immunosorbent assay to determine levels of anti-NDV immunoglobulin G, and isolates were identified using a hyperimmune (HI) test and real-time polymerase chain reaction (RT-PCR).Results:Suspected and isolated NDV field samples propagated in the allantoic cavity of 10-day-old fertile SPF chickens were NDV positive in the rapid hemagglutination test within a few seconds. Pathogenicity indices and MDT showed that the isolated NDV was viscerotropic and velogenic. The virus was identified as NDV by the HI test using specific anti-LaSota HI serum and RT-PCR with specific primers and probes. Propagation of the virus in the allantoic cavity of embryonated hen eggs produced a viral titer of 109.5 EID50/0.1 mL.Conclusion:The virus isolated from broiler chicken farms in Diyala Province, Iraq, was viscerotropic and velogenic according to the pathogenicity indices and RT-PCR. The isolated NDV caused 100% morbidity and 90% mortality in NDV-vaccinated and experimentally infected broiler chickens.

Expression of Recombinant Fusion Protein of Newcastle Disease Virus from Escherichia coli Plasmid Clone C-2a by In-vitro Cell-free Protein Expression System

Newcastle Disease Virus (NDV) is an infectious disease that infect many kinds of wild and domesticated birds. Infection of NDV become a massive problem for poultry industry around the world especially in Indonesia. Vaccination is an effort to prevent the infection of NDV in poultry. NDV vaccine that used in Indonesia is a conventional life vaccine from LaSota and B1 strains. These type of vaccine is 21%-23% genetically distinct with the virus that spread in the environment. The antibody protection provided by the vaccine is not effective. Therefore, vaccination with new local NDV strain is needed to prevent the NDV infection in Indonesia. The previously study research reported that the local isolate of NDV from Kulon Progo, Indonesia has been isolated. Fusion (F) protein encoding gene that has been inserted into pBT7-N-His expression p lasmid which isolated from clone C-2a of E. coli, then it was expressed by the Cell-free protein expression system. The aim of this study was to confirm whether clone C-2a of E.coli carrying a recombinant plasmid pBT7-N-His-Fusion NDV and to express a recombinant F protein of NDV in-vitro from expression plasmid by cell-free protein expression system. This work started by detection of recombinant plasmid pBT7-N-His-Fusion NDV by DNA plasmid extraction followed by agarose gel electrophoresis. The recombinant F protein was in-vitro expressed by cell-free protein expression kit. The expressed F protein of NDV then was visualized by SDS-PAGE and Westernblott to analyse the expression of NDV recombinant F protein. It confirmed that clone C-2a of E. coli contained plasmid pBT7-N-His (4.001 bp) inserted by recombinant F protein of NDV gene (642 bp). The visualisation of expressed recombinant F protein by SDS-PAGE and Westernblott showed the NDV recombinant F protein was a specific protein fragment with molecular weight of 25,6 kDa..

Characterization of Newcastle disease virus obtained from toco toucan.

Given that the current Newcastle disease virus (NDV) infection in wild birds poses the threat to poultry, surveillance of Newcastle disease in captive wild birds was carried out in Jilin, China in 2018. Here, an NDV strain obtained from toco toucan was firstly characterized. The results showed that the F gene of the NDV isolate Toucan/China/3/2018 is classified as genotype II in class II. Sequence analysis of the F0 cleavage site was 113RQGR/L117, which supports the result of the intracerebral pathogenicity index assay indicating classification of the isolate as low-pathogenicity. Experimental infection demonstrated that Toucan/China/3/2018 can effectively replicate and transmit among chickens. To our knowledge, this is the first report on genetically and pathogenically characterizing NDV strain isolated from toucan, which enriches the epidemiological information of NDV in wild birds.

Pathological Lesions in Chicken Embryo Caused by Newly Virulent Isolate of Newcastle Disease Virus (LESI PATOLOGIS PADA EMBRIO AYAM YANG DISEBABKAN ISOLAT VIRUS PENYAKIT TETELO TERBARU YANG VIRULEN)

Newcastle disease is a pathogenic viral disease in poultry which is infectious and can cause massive economic losses. The disease is still endemic in Indonesia. To understand the pathogenesis and the distribution pattern of the virus in the tissues, pathological observation was evaluated using newly virulent isolate Newcastle disease virus (NDV) that was inoculated in embryonated chicken eggs. As many as seven embryonic chicken eggs aged 11 days and specific antibody negative against Newcastle disease, divided into two categories: inoculated with phosphate buffer saline and inoculated with isolates. Then the allantois fluid was tested using hemagglutination assay and hemagglutination inhibition tests to prove the infection serologically. The hearts, lungs, livers and small intestines of the inoculated products were collected and followed with the process of histopathological preparation using Hematoxylin and Eosin (HE) stain. The pathological analysis showed that all organs had necrosis, hemorrhages, inflammation, and congestion. Congestion and hemorrhages in the hearts only occurred at 60% of the samples. However, necrosis, hemorrhages, and inflammation that were observed in liver occurred at 60%, 40% and 60% of the samples, respectively. Furthermore, the hearts were edema, thinner in the heart muscle fibers; while in the lungs, proliferation of pneumocyte type II was founded. Our finding provided valuable insight into the pathology of a virulent isolate of NDV which is dominated by blood circulation disorders with necrosis and inflammation in the chicken’s embryos and have important implication for the future studies.

Coding-complete genome sequencing suggests that Newcastle disease virus challenge strain Herts\u201933 (IVMP) may represent a distinct genotype

We determined the genomic sequence of a Newcastle disease virus (NDV) line obtained directly from the first NDV isolate, named Herts’33. This strain shared ≤ 90% nucleotide sequence identity with the NDV sequences available in the GenBank database, and formed a distinct branch in a phylogenetic tree. This branch may be considered to represent a separate NDV genotype. Our study indicates that investigation of the genomic sequences of old NDV strains that originated from the early outbreaks of Newcastle disease may alter the phylogenetic grouping of the NDV strains and provide data on the evolution of viral genomes over time.

Molecular Characterization of the Newcastle Disease Virus detected in some provinces of The West Delta in Egypt

ABSTRACTIn the last couples of years, Egyptian poultry farms have faced many outbreak mortalities. Newcastle disease virus (NDV) was suggested as one leading cause of these mortalities. In the current study, we characterized the NDV from outbreaks affecting poultry farms in Egypt between 2012 and 2014. Different organ tissues were collected from twenty different chicken farms showing clinical signs of NDV infection in El-Behira and Kafr-Elshiekh provinces. Inoculation of the processed samples in 10-day-old embryonated chicken specific-pathogen-free eggs indicated presence of haemagglutinating agent in 12 samples. These haemagglutinating agents were confirmed as NDV by real-time reverse transcription polymerase chain reaction (rRT-PCR). In the employed rRT-PCR assay, two sets of primers and probes were used. A first primer- probe set was designed to detect sequences from a conserved region of the Matrix gene that recognizes a diverse set of virus isolates. A second primer-probe set was targeted to comprise the cleavage site of the F gene and to detect potentially virulent NDV isolates. The rRT-PCR results revealed that seven detected ND viruses were of velogenic type, whereas the other five detected ND viruses were of lentogenic nature. Sequencing of two suspected ND velogenic viruses was carried out. The phylogenetic analysis based on the partial sequence of F protein gene showed that the detected viruses were closely related to viruses from genotype VII subgroup D. Furthermore, the nucleotide and amino acid analysis approved the previous finding. Overall, the study confirmed circulating of NDV genotype VII among Egyptian poultry farms.

Isolation, identification and molecular characterization of Newcastle disease virus using SDS-PAGE

Field isolates of Newcastle disease virus (NDV) were subjected to polypeptide analysis using SDS-PAGE. On electrophoresis the NDV proteins were settled into several peptide components related to structural elements of the virus. The field isolates of NDV were recovered from different outbreaks in commercial chicken flocks. The virus grew well into 9th day old embryonated chicken eggs. The presence of virus in harvested allantoic fluids was assessed by Haemagglutination Test (HA). The HA titer of virus ranged from 1:512 to 1:1024. All the field isolates were purified by chloroform extraction method. Same quantities of samples were loaded on 12.5% discontinuous SDS-PAGE system. There were 6 to 13 polypeptides recorded with a molecular weight ranged from 12 KDa to 160 KDa. The results of SDS-PAGE denoted that the indigenous isolates of NDV are almost identical and comparable with vaccines. SDS-PAGE, using 12.5 percent gel is a simple, economical, and easy way for the characterization of NDV and other viruses. Furthermore, the potency of the vaccines can easily be checked through this technique and comparison can be made between field and vaccine ND viruses. It is recommended that more work should be done at the molecular level of local isolates of NDV to confirm the molecular nature of these isolates.

First Isolation and Rapid Identification of Newcastle Disease Virus from Aborted Fetus of Dromedary Camel Using Next-Generation Sequencing

Newcastle disease virus (NDV) causes morbidities and mortalities in wild and domestic birds globally. For humans, exposure to infected birds can cause conjunctivitis and influenza-like symptoms. NDV infections in mammals are rarely reported. In this study, using next-generation sequencing, an NDV was identified and isolated from Vero cells inoculated with the nasal swab of an aborted dromedary fetus in Dubai, during the time when an NDV outbreak occurred in a pigeon farm located in close proximity to the dairy camel farm where the mother of the aborted dromedary fetus resided, and there were a lot of pigeons in the camel farm. Genome analysis revealed that the structurally and functionally important features of other NDVs were also present in this dromedary NDV genome. Phylogenetic analysis based on the nucleotide sequences of fusion protein (F), hemagglutinin-neuraminidase protein (HN) and complete polyprotein showed that the virus belonged to sub-genotype VIg of class II NDV and is most closely related to pigeon NDVs in Egypt in the same year. The present study is the first that demonstrated isolation of NDV in dromedaries. Further study is warranted to investigate the relationship between NDV infection and abortion.