Newcastle disease (ND) is regarded as a highly contagious and economically important disease in poultry and has a worldwide distribution. Viral determinants for Newcastle disease virus (NDV) virulence are not completely understood and viruses of different pathotypes can be found at live-bird markets in different geographical areas. The prevalence of Newcastle disease in village poultry in Mozambique is not well documented and strains of NDV involved in yearly outbreaks are unknown. The fusion (F) protein is an important determinant of pathogenicity of the virus and is used commonly for phylogenetic analysis. Newcastle disease viruses from various geographical regions of Mozambique were sequenced and compared genetically to published sequences obtained from GenBank. Samples were collected in three different areas of Mozambique and NDV was isolated by infection of embryonated chicken eggs. Sequence analysis of the F-protein encoding gene was used to classify 28 isolates from Mozambique into genotypes and compare these genotypes phylogenetically with existing genotypes found in GenBank. The isolates obtained from Mozambique grouped mainly into two clades. In the first clade, 12 isolates grouped together with sequences of isolates representing genotypes from Mozambique that were previously described. In the second clade, 16 isolates group together with sequences obtained from GenBank originating from Australia, China, South Africa and the USA. Eleven of these isolates showed a high similarity with sequences from South Africa. The number of samples sequenced (<em>n</em> = 28), as well as the relatively small geographical collection area used in this study, are too small to be a representation of the circulating viruses in Mozambique in 2005. Viruses characterised in this study belonged to lineage 5b, a similar finding of a previous study 10 years ago. From this data, it merely can be concluded that no new introduction of the virus occurred from 1995 to 2005 in Mozambique.

Free-range rural chickens (FRCs) dominate the poultry industry in developing countries and chickens are exposed to multi-host infections, including Newcastle disease virus (NDV). The knowledge about the characteristics of NDV from FRCs is limited. This study investigated the persistence, spread and risks of NDV from FRCs. NDV isolates (n = 21) from unvaccinated FRCs in Tanzania were characterised by conventional intracerebral pathogenicity index (ICPI) and sequence analysis of a partial region of the deduced fusion protein encompassing the cleavage site. Results showed that five isolates were screened as lentogenic, nine as mesogenic and six as velogenic. Phylogenetic analysis of the 21 isolates compared to reference sequences revealed three, four, nine and five isolates in genotypes 1, 2, 3c and 4a, respectively. Genotype 3c also included published sequences of Tanzanian isolates obtained from exotic birds and chicken isolates from Uganda. The analysis showed that NDV were persistently present among chicken populations and possibly spread through live chicken markets or migration of wild birds. Differences in amino acid sequences detected around the cleavage site separated the isolates in six types. However, cleavage site pattern could not fully differentiate mesogenic isolates from velogenic isolates.

Objective: Indonesia is one of the Newcastle disease (ND) endemic countries in the world. An outbreak of the ND virus(NDV) was first reported in Indonesia in 1926. This study aimed to detect, isolate, and classify the NDV by molecular approaches from poultry farms in South Sulawesi Province of Indonesia in 2019. Materials and Methods: As many as 36 pooling samples from the cloacal swab, trachea swab, proventriculus, and spleen tissues obtained from ND-suspected chickens were isolated in 11-day old embryonated chicken eggs type-specific antibody-negative. The viruses were confirmed by reverse transcription-polymerase chain reaction (RT-PCR), followed by sequencing. Results: The results showed that 18 out of 36 pooling samples were NDV-positive based on the isolation result and RT-PCR test. The sequencing results showed that 10 NDV isolates had a motif 112R-R-Q-K-R-F117 in the fusion protein cleavage site region, which suggested that the NDV isolates were of virulent pathotype. The phylogenetic studies based on the F genes partial nucleotide sequence classified the study isolates into NDV virus genotype/subgenotype VII.2. Conclusion: These findings are expected to help provide the latest characteristic information of NDV in South Sulawesi Province to determine the seed vaccine for control strategies of ND. [J Adv Vet Anim Res 2021; 8(1.000): 129-137]

Recurrent infection with Newcastle disease virus in flocks that have received vaccinations and high economic losses in Egypt in the last few years urged us to study the diversity and genetic changes in isolated NDV from chickens and its pathogenesis in other species such as turkey poults. Fifteen positive NDVs were isolated from chicken flocks suffering from a respiratory infection. Sequencing of three isolates out from the 15 NDV positive isolates (20%) revealed that NDV was genotype VII.1.1. When compared to other previously isolated worldwide and Egyptian strains, the three isolates’ amino acid sequences show (99.1-99.8 %) identity with genotype VII.1.1.Thirty four weeks old Black Burzi turkey poults, separated into two groups: control (n=15) and infected (n=15), were used to study the pathogenesis of the isolated NDV genotype VII.1.1. Each afflicted bird was given an inoculation with 0.1 mL of 106EID50 of NDV genotype VII.1.1( ND /chicken /Egypt /Dakahlia /31 /2020) at 4 weeks of age via an ocular route. Proventriculus, conjunctiva, lung, spleen, trachea, and caecal tonsil samples were collected from both groups at (6, 12, 24, 48 hours, and 5 days after infection) and tested for the presence of NDV using Quantitative Reverse transcription-polymerase Chain Reaction (QRT-PCR). The virus was found in the challenged birds’ spleen as soon as 12 hours after infection, followed by the lungs and trachea. After 2 and 5 days after NDV infection, histologically significant lesions were found, particularly in lymphoid organs. It is concluded that the presence of NDV in Egyptian flocks of chickens could induce major disease in commercial turkeys, necessitating the development of novel vaccinations based on the circulating NDV genotype VII.1.1 in Egypt to protect domestic poultry from recurrent infection.

Transmission of avian viruses both bird-to-bird and from birds to non-avian species is a major health concern. Newcastle disease virus (NDV) is an economically important avian virus that poses substantial risks to the poultry industry. Rapid and sensitive diagnostic methods, such as the enzyme-linked immunosorbent assay (ELISA), are required to track such infections. To develop an ELISA for detecting anti-NDV antibody in avian sera, the nucleocapsid protein (NCP) gene of the NDV La Sota strain was cloned and expressed in Escherichia coli and the 513-amino acid recombinant NCP was purified by Ni-NTA affinity chromatography. To evaluate its ability to replace NDV whole virus antigen as a coating antigen, NCP-coated and whole NDV-coated ELISAs were tested and compared using a panel of NDV positive antisera from chickens. Results using purified NCP were highly correlated with those obtained using whole NDV (r=0.927), demonstrating that recombinant NCP expressed in Escherichia coli is a suitable substitute antigen for whole NDV in a diagnostic ELISA.

The B1 strain of Newcastle disease virus (NDV-B1), which is nonpathogenic for newly hatched chickens, killed embryos when it was used to inoculate chicken eggs at embryonation day 18. Treatment of NDV-B1 with an alkylating agent, ethylmethane sulfonate (EMS) markedly reduced the pathogenicity of the virus for 18-day-old chicken embryos. Eggs inoculated with the modified virus (NDV-B1-EMS) hatched, and the virus was isolated from lungs and spleen of 1-day-old chickens. The hatched chickens developed antibody to NDV and were protected against challenge exposure (at 4 weeks of age) with a highly virulent GB-Texas strain of NDV. Presence of maternal antibody to NDV in embryonating eggs did not influence the protective ability of NDV-B1-EMS, which also induced protective immunity when administered to 4-week-old chickens. The 50% protective dose of NDV-B1-EMS in maternal antibody-negative and -positive embryos was calculated to be 10.77 and 17.70 embryo 50% lethal doses, respectively. Results of the study indicated that NDV-B1-EMS may be used as an embryo vaccine to protect chickens against Newcastle disease.

T-cell-mediated and humoral immune responses were measured in chickens infected with standard and variant strains of infectious bursal disease virus. One-day-old and 3-week-old chickens were infected with these viruses and then given sheep RBC, killed Brucella abortus strain 19, and Newcastle disease virus. Appropriate serologic tests were used to monitor the primary and secondary responses to the antigens. Lymphoblast transformation assays were performed weekly. The response to the infectious bursal disease virus was determined by virus neutralization tests, microscopic examination of bursas, and bursal to body weight ratios. One-day-old chickens had T-cell-mediated and humoral immune suppression with both strains of virus, compared with controls. The lymphoblast transformation responses indicated that the variant strain was significantly (P < 0.05) more suppressive than the standard strain. Three-week-old chickens had humoral immune suppression with the standard strain, but not with the variant strain. The lymphoblast transformation response was transiently suppressed at this age by the variant strain only. During the first week of infection, 1-day-old and 3-week-old chickens had lower neutralizing antibody titers to the variant strain than to the standard strain.

Kinetics of large-scale production of naturally derived bovine leukocyte interferon (IFN) was investigated using Sendai virus, Newcastle disease virus, and infectious bovine rhinotracheitis virus inducers. Cultures were tested for IFN production every 6 hours for 66 hours. The effect of varying the priming dose of Sendai virus from 0 to 50% of total virus dose and the effect of varying the priming time from 0 to 4 hours before induction also were investigated. Other factors explored were effects of varying the fetal bovine serum concentration (from 0 to 8%) and individual cow donors on bovine IFN titers. Highest bovine leukocyte IFN titers (15,314 U/ml) were obtained using Sendai virus (priming dose, 60 hemagglutinating units/ml;inducing dose, 240 hemagglutinating units/ml) and incubating for 12 hours. Up to 24 L (over 360 million U) of naturally derived leukocyte IFN were produced at one time.

The lack of effective therapeutic modalities for mammary cancer is attributed to side effects and therapy resistance, necessitating the exploration of alternative treatment options. Newcastle Disease Virus (NDV) exhibits oncolytic activity, making it a promising candidate for cancer therapy. This study aims to assess the effectiveness of the virulent NDV Tabanan-1/ARP/2017 on the growth of mammary carcinoma. The study involved 15 white female Sprague-Dawley rats induced with mammary carcinoma. After the tumors had developed, the rats were divided into two treatment groups, i.e., treatment 0 (P0) and treatment 1 (P1), which received 500 μL of phosphate-buffered saline and 128 HAU/500 μL of NDV Tabanan-1/ARP/2017, respectively. The rats were euthanized on day 15 post-virotherapy. Rats were necropsied, the tumor was excised to measure its weight, percentage of tumor inhibition, and subsequently routinely processed for histopathological preparations. The tumor weights in each treatment group were 3.70±0.72 and 2.34±0.64 grams, respectively, with a tumor inhibition percentage of 36.62%. The angiogenesis, hemorrhage, and mitotic activity of P1 were lower than those of P0, while inflammatory cell infiltration and areas of necrosis appeared more prominent in the group treated with the NDV. In conclusion, the NDV Tabanan-1/ARP/2017 shows potential as a virotherapy agent for rat mammary carcinoma models.