A review of virulent Newcastle disease viruses in the United States and the role of wild birds in viral persistence and spread

Breaking Barriers: Animal viruses as oncolytic and immunotherapeutic agents for human cancers

Oncolytic viruses, defined as viruses capable of lysing cancer cells, emerged as a groundbreaking class of therapeutic entities poised to revolutionize cancer treatment. Their mode of action encompasses both direct tumor cell lysis and the indirect enhancement of anti-tumor immune responses. Notably, four leading contenders in this domain, Rigvir® in Latvia, T-VEC in the United States, H101 in China and Teserpaturev (DELYTACT®) in Japan, have earned approval for treating metastatic melanoma (Rigvir and T-VEC), nasopharyngeal carcinoma and malignant glioma, respectively. Despite these notable advancements, the integration of oncolytic viruses into cancer therapy encounters several challenges. Foremost among these hurdles is the considerable variability observed in clinical responses to oncolytic virus interventions. Moreover, the adaptive immune system may inadvertently target the oncolytic viruses themselves, diverting immune resources away from tumor antigens and undermining therapeutic efficacy. Another significant limitation arises from the presence of preexisting immunity against oncolytic viruses in certain patient populations, hampering treatment outcomes. To circumvent this obstacle, researchers are investigating the utilization of animal viruses, for which humans lack preexisting immunity, as a compelling alternative to human-derived counterparts. In our comprehensive review, we delve into the intricate nuances of oncolytic virotherapy, elucidating the multifaceted mechanisms through which these viruses exert their anti-cancer effects. Furthermore, we provide a thorough examination of animal-derived oncolytic viruses, highlighting their respective strengths and limitations. Lastly, we explore the promising potential of leveraging animal viruses as potent oncolytic agents, offering new avenues for enhancing the efficacy and reach of human cancer therapeutics.

Clinicopathological and Molecular Investigation of Newcastle Disease Outbreaks in Vaccinated and Non-Vaccinated Broiler Chicken Flocks in Nepal

Newcastle disease (ND) is a highly contagious viral disease caused by the paramyxovirus, which is a single-stranded ribonucleic acid (RNA) virus. This study was conducted to investigate ND outbreaks in 10 vaccinated or non-vaccinated broiler farms, collectively housing 9840 birds of various ages in the Chitwan and Nawalpur districts of Nepal from July to December 2021. Clinically, the affected birds exhibited symptoms such as limb paralysis, greenish diarrhea (seven out of ten flocks), torticollis (two out of ten flocks), inappetence, and drowsiness (ten out of ten flocks). Birds that succumbed during the clinical course underwent a necropsy for gross pathology and samples were collected for the histopathology and molecular diagnosis. The gross and microscopic examination revealed hemorrhages in the proventriculus, erosions and ulcers in the small intestine, congestion, as well as sero-mucosal hemorrhages in the trachea of affected birds, which are typical of ND. Rapid test kits further confirmed the presence of the ND virus antigen while excluding the avian influenza virus. Furthermore, M gene-based real time polymerase chain reaction (RT-PCR) was performed in the pooled samples from the affected birds and the presence of a velogenic strain of the ND virus was identified. The phylogenetic analysis of the RT-PCR positive strain based on the partial F gene nucleotide sequence revealed these strains as genotype VII.2 (formerly VIIi). The findings highlight the occurrence of clinical ND outbreaks in farms despite adherence to recommended vaccination protocols in broiler flocks, underscoring the need for a regular comprehensive investigation involving in-depth examinations of available vaccines and genetic analyses.

Genetic Characterization, Pathogenicity, and Epidemiology Analysis of Three Sub-Genotype Pigeon Newcastle Disease Virus Strains in China

Pigeon Newcastle disease (ND) is a serious infectious illness caused by the pigeon Newcastle disease virus (NDV) or Paramyxovirus type 1 (PPMV-1). Genotype VI NDV is a primary factor in ND among Columbiformes (such as pigeons and doves). In a recent study, eight pigeon NDV strains were discovered in various provinces in China. These viruses exhibited mesogenic characteristics based on their MDT and ICPI values. The complete genome sequences of these eight strains showed a 90.40% to 99.19% identity match with reference strains of genotype VI, and a 77.86% to 80.45% identity match with the genotype II vaccine strain. Additionally, analysis of the F gene sequence revealed that these NDV strains were closely associated with sub-genotypes VI.2.2.2, VI.2.1.1.2.1, and VI.2.1.1.2.2. The amino acid sequence at the cleavage site of the F protein indicated virulent characteristics, with the sequences 112KRQKRF117 and 112RRQKRF117 observed. Pigeons infected with these sub-genotype strains had a low survival rate of only 20% to 30%, along with lesions in multiple tissues, highlighting the strong spread and high pathogenicity of these pigeon NDV strains. Molecular epidemiology data from the GenBank database revealed that sub-genotype VI.2.1.1.2.2 strains have been prevalent since 2011. In summary, the findings demonstrate that the prevalence of genotype VI NDV is due to strains from diverse sub-genotypes, with the sub-genotype VI.2.1.1.2.2 strain emerging as the current epidemic strain, highlighting the significance of monitoring pigeon NDV in China.

Detection of Avian Orthoavulavirus-1 genotypes VI.2.1 and VII.1.1 with neuro-viscerotropic tropism in some backyard pigeons (Columbidae) in Eastern Saudi Arabia

Introduction

Avian orthoavulavirus-1 (AOAV1) has a wide host range, including domestic and wild birds. The present study aimed to identify the currently circulating AOAV1 strains from some outbreaks in some backyard pigeons in the eastern region of Saudi Arabia (ERSA).

Methods

Tracheal/cloacal swabs and tissue specimens were collected from eight backyards in Al-Ahsa, ERSA, between January 2021 and March 2023. Samples were tested for the presence of AOAV1 using commercial real-time RT-PCR. Part of the fusion gene was also amplified by gel-based RT-PCR, and the obtained amplicons were sequenced.

Results and discussion

AOAV1 was detected in samples from the eight flocks. The retrieved sequences from samples of 6/8 pigeon backyards are reported. Phylogenetic analysis based on the obtained sequences from these backyard pigeons showed the segregation of the obtained sequences in AOAV1 genotypes VI.2.1 and VII.1.1. Clinically, nervous manifestations were dominant in pigeons infected with both genotypes. Respiratory manifestations and significantly higher overall mortality rate were induced by genotype VI.2.1. The deduced amino acid sequences of the fusion protein cleavage site (FPCS) showed that all the detected isolates belong to velogenic strains. Differences in clinical profiles induced by the natural infection of pigeons with AOAV1 genotypes VI.2.1 and VII.1.1 were reported. The present findings highlight the potential roles of some backyard pigeons in the long-distance spread and cross-species transmission of the reported AOAVI genotypes. Further research is required to perform biotyping and pathotyping of the reported strains.

Newcastle disease virus infection remodels plasma phospholipid metabolism in chickens

Newcastle disease is a global problem that causes huge economic losses and threatens the health and welfare of poultry. Despite the knowledge gained on the metabolic impact of NDV on cells, the extent to which infection modifies the plasma metabolic network in chickens remains unknown. Herein, we performed targeted metabolomic and lipidomic to create a plasma metabolic network map during NDV infection. Meanwhile, we used single-cell RNA sequencing to explore the heterogeneity of lung tissue cells in response to NDV infection in vivo. The results showed that NDV remodeled the plasma phospholipid metabolism network. NDV preferentially targets infected blood endothelial cells, antigen-presenting cells, fibroblasts, and neutrophils in lung tissue. Importantly, NDV may directly regulate ribosome protein transcription to facilitate efficient viral protein translation. In conclusion, NDV infection remodels the plasma phospholipid metabolism network in chickens. This work provides valuable insights to further understand the pathogenesis of NDV.

Study of Cellular and Humoral Immunity and Histopathology of Target Tissues Following Newcastle Clone12IR Vaccine Administration in SPF Chickens

Newcastle disease (ND) is a highly contagious viral infection affecting poultry production in many countries. Strict biosecurity and the administration of live attenuated vaccines against the ND virus (NDV) are the main implements of controlling programs. This study evaluated the efficacy and potency of the Razi Clone12IR Newcastle vaccine in specific pathogen-free (SPF) chickens. Chickens were vaccinated with either the Razi Clone12IR vaccine (group A1, n=20) or an imported Clone vaccine (B1, n=20) in the first week of life and boosted in the second week via eye drop, while negative control chickens received PBS (C1, n=20). Half of the birds in each group were challenged with the virulent NDV strain in the third post-vaccination week (A2, B2, and C2 groups). Specific antibody responses were determined in the collected sera by the hemagglutination inhibition (HI) assay for up to eight weeks. Cell-mediated immunity (CMI) was determined by the lymphocyte proliferation assay three and six weeks after the second vaccination. Sections of the tissues and organs, including the trachea, lungs, cecal tonsils, spleen, the bursa of Fabricius, liver, and small intestine, were subjected to histopathology. The immunized groups A1 and B1 showed significantly higher HI antibody titers before the challenge than the control group. In addition, lymphocyte proliferation responses significantly increased in the peripheral blood of the vaccinated groups. After the challenge, the A2 and B2 groups conferred good protection and drastically reduced virus shedding. No main lesions were noted in the tissues or organs of the vaccinated group in histopathology. In a few cases, mild microscopic lesions were observed, including the infiltration of inflammatory cells, which was related to the effect of the vaccine virus. These results indicate that the Razi Clone12IR vaccine is safe and can be an efficient tool for NDV infections by inducing protective humoral and CMI responses.

The Viral Knock: Ameliorating Cancer Treatment with Oncolytic Newcastle Disease Virus

The prospect of cancer treatment has drastically transformed over the last four decades. The side effects caused by the traditional methods of cancer treatment like surgery, chemotherapy, and radiotherapy through the years highlight the prospect for a novel, complementary, and alternative cancer therapy. Oncolytic virotherapy is an evolving treatment modality that utilizes oncolytic viruses (OVs) to selectively attack cancer cells by direct lysis and can also elicit a strong anti-cancer immune response. Newcastle disease virus (NDV) provides a very high safety profile compared to other oncolytic viruses. Extensive research worldwide concentrates on experimenting with and better understanding the underlying mechanisms by which oncolytic NDV can be effectively applied to intercept cancer. This review encapsulates the potential of NDV to be explored as an oncolytic agent and discusses current preclinical and clinical research scenarios involving various NDV strains.

Modification of surface glycan by expression of beta-1,4-N-acetyl-galactosaminyltransferase (B4GALNT2) confers resistance to multiple viruses infection in chicken fibroblast cell

Introduction

Infectious viruses in poultry, such as avian influenza virus (AIV) and Newcastle disease virus (NDV), are one of the most major threats to the poultry industry, resulting in enormous economic losses. AIVs and NDVs preferentially recognize α-2,3-linked sialic acid to bind to target cells. The human beta-1,4-N-acetyl-galactosaminyltransferase 2 (B4GALNT2) modifies α-2,3-linked sialic acid-containing glycan by transferring N-acetylgalactosamine to the sub-terminal galactose of the glycan, thus playing a pivotal role in preventing viruses from binding to cell surfaces. However, chickens lack a homolog of the B4GALNT2 gene.

Methods

Here, we precisely tagged the human B4GALNT2 gene downstream of the chicken GAPDH so that the engineered cells constitutively express the human B4GALNT2. We performed a lectin binding assay to analyze the modification of α-2,3-linked sialic acid-containing glycan by human B4GALNT2. Additionally, we infected the cells with AIV and NDV and compared cell survivability, viral gene transcription, and viral titer using the WST-1 assay, RT-qPCR and TCID50 assay, respectively.

Results

We validated human B4GALNT2 successfully modified α-2,3-linked sialic acid-containing glycan in chicken DF-1 cells. Following viral infection, we showed that human B4GALNT2 reduced infection of two AIV subtypes and NDV at 12-, 24-, and 36-hours post-infection. Moreover, cells expressing human B4GALNT2 showed significantly higher cell survivability compared to wild-type DF-1 cells, and viral gene expression was significantly reduced in the cells expressing human B4GALNT2.

Discussion

Collectively, these results suggest that artificially expressing human B4GALNT2 in chicken is a promising strategy to acquire broad resistance against infectious viruses with a preference for α-2,3-linked sialic acids such as AIV and NDV.

The use of RT-PCR in the diagnosis and differentiation of vaccine strains of chicken infectious bronchitis and Newcastle disease

Background

Infectious diseases of young and adult birds with respiratory syndrome are a significant deterrent to the development of industrial poultry farming due to decreased productivity and significant mortality. The only effective method of combating viral diseases is timely and targeted vaccination, which largely depends on laboratory diagnostic results.

Aim

This article aims to study the real-time reverse transcription polymerase chain reaction, (RT-PCR) which has the prospect of more effective diagnosis of vaccine strains of chicken infectious bronchitis and Newcastle disease.

Methods

The fastest and most accurate method for the differential diagnosis of pathogens in an associative viral infection is RT-PCR. The method proposed in the article for selecting primers for amplification made it possible to use this method for the simultaneous interspecies differential diagnosis of two or more viral agents, significantly accelerating their diagnosis.

Results

The correlation of the nucleotide sequence obtained from sequencing to a specific virus strain is complicated by the lack of a single nomenclature mechanism for separating genetic groups.

Conclusion

The results of this study will allow easy and fast typing of sequences into known and databased virus strains and avoid further confusion in the nomenclature of genetic groups in the future.

Phylogeny and Pathogenicity of Subtype XIIb NDVs from Francolins in Southwestern China and Effective Protection by an Inactivated Vaccine

Most genotype XII newcastle disease viruses (NDVs) were isolated from poultry, chickens, or geese, with the exception of one subtype, XIIa NDV, which was isolated from a peacock. Here, two subtype XIIb NDVs, francolin/China/GX01/2017 and francolin/China/GX02/2017 (GX01 and GX02 hereafter), were isolated from francolins, which are resident birds in southern China. GX01 and GX02 were characterized as velogenic NDVs. Based on the weaker pathogenicity of these viruses in chickens, the amino acid sequences of seven proteins from genotype XII NDVs were compared, which revealed 17, 40, 15, 7, 32, 25, and 31 variations in the NP, P, M, F, HN, L, and V proteins, respectively, some of which could be responsible for this decreased pathogenicity. Epidemiological and phylogenetic analyses suggest that subtype XIIb NDVs have multiple transmission chains, and that resident birds may be involved in this process as intermediate hosts in which viruses keep evolving. Because of the increased pathogenicity of subtype XIIb NDVs, the protective efficacy of GX01 as an inactivated vaccine was evaluated and compared with that of two commercial inactivated vaccines in chickens. The results showed that the subtype XIIb NDVs could be candidate genotype-matched vaccine strains against genotype XII NDVs.

Detection and assessment of risk factors associated with Newcastle disease virus infection in birds in backyard poultry in Laichau province of Vietnam

Newcastle disease (ND) is a highly pathogenic and contagious viral infectious disease of poultry that causes a very serious problem for poultry production and economic loss worldwide. ND has been an epizootic disease in Vietnam. Information about the risk factors that are associated with virus transmission in backyard chickens in Vietnam is limited. To provide more epidemiological information about ND in Vietnam, this study was performed to estimate NDV prevalence and identify the risk factors for ND virus (NDV) infection in birds at the backyard flock level. Choanal swabs were taken from 400 randomly selected birds from 100 apparently healthy flocks from May to July 2020. Based on RT-PCR analysis, 43 of 400 swab samples (10.75%; 95% CI 8-14.17) and 21 of 100 flocks (21%; 95% CI 14.17-29.98) were positive for the fusion (F) gene of NDV. The management practice risks were: backyard flocks contacting wild birds (OR = 3.89; P = 0.030), mixed flocks with different types and species of birds (OR = 5.46; P = 0.004), and infrequency of cleaning and disinfecting poultry houses (OR (odds ratio) = 4.43; P = 0.034). The second and third risks (above) showed a positive interaction on the risk of NDV infection in birds (OR = 39.38; P = 0.001), and the first risk showed a negative interaction. Further studies on NDV surveillance in domestic waterfowl, longitudinal studies, a well-optimized RT-qPCR assay, and genetic characterization are needed. The development of handbooks, flyers, or lessons for educating poultry keepers are also needed.RESEARCH HIGHLIGHT RT-PCR was used to detect the F gene of NDV in choanal swabs.Risk factors associated with NDV-positive samples were determined.The evidence for NDV circulation in backyard healthy birds was observed.Contact with wild birds, mixed flocks, and poor hygiene were major risk factors.

Susceptibility and Pathogenesis of Eurasian Tree Sparrows Experimentally Inoculated with Velogenic Newcastle Disease Virus

Wild-caught Eurasian tree sparrows (Passer montanus) were experimentally inoculated with genotype VII velogenic Newcastle disease virus (NDV) APMV1/chicken/Japan/Fukuoka-1/2004 to investigate the susceptibility and pathogenesis of infected sparrows. Intranasal inoculation of two groups with high or low doses of the virus resulted in the mortality of some birds in both groups on days 7-15 postinoculation. Neurologic signs, ruffled feathers, labored breathing, emaciation, diarrhea, depression, and ataxia were observed in a few birds that eventually succumbed to death. The inoculation of the higher viral load resulted in higher mortality and hemagglutination inhibition antibody detection rates. Tree sparrows that survived the 18-day observation period after inoculation exhibited no apparent clinical signs. Histologic lesions in dead birds were observed in the nasal mucosa, orbital ganglion, and central nervous system, accompanied by NDV antigens detected by immunohistochemistry. Viral inclusion bodies were rarely observed in the cytoplasm of neurons. NDV was isolated from the oral swab and brain of dead birds but not from other organs, including the lung, heart, muscle, colon, and liver. In another experimental group, tree sparrows were intranasally inoculated with the virus and then examined 1-3 days later to examine the early pathogenesis of the disease. Inoculated birds exhibited inflammation of the nasal mucosa with viral antigens, and virus was isolated from some oral swab samples on days 2 and 3 postinoculation. The results of the present study suggest that tree sparrows are susceptible to velogenic NDV, and the infection could be fatal, although some birds can exhibit asymptomatic or mild infection. The unique pathogenesis regarding the neurologic signs and viral neurotropism of velogenic NDV was characteristic in infected tree sparrows.

Design, Synthesis, and Antiviral Evaluation of Sialic Acid Derivatives as Inhibitors of Newcastle Disease Virus Hemagglutinin-Neuraminidase: A Translational Study on Human Parainfluenza Viruses

Global infections with viruses belonging to the Paramyxoviridae, such as Newcastle disease virus (NDV) or human parainfluenza viruses (hPIVs), pose a serious threat to animal and human health. NDV-HN and hPIVs-HN (HN hemagglutinin-neuraminidase) share a high degree of similarity in catalytic site structures; therefore, the development of an efficient experimental NDV host model (chicken) may be informative for evaluating the efficacy of hPIVs-HN inhibitors. As part of the broad research in pursuit of this goal and as an extension of our published work on antiviral drug development, we report here the biological results obtained with some newly synthesized C4- and C5-substituted 2,3-unsaturated sialic acid derivatives against NDV. All developed compounds showed high neuraminidase inhibitory activity (IC₅₀ 0.03-13 μM). Four molecules (9, 10, 23, 24) confirmed their high in vitro inhibitory activity, which caused a significant reduction of NDV infection in Vero cells, accompanied by very low toxicity.

Sero-prevalence of Newcastle disease and associated risk factors in chickens at backyard chicken production Kindo Koisha, Wolaita zone, Southern Ethiopia

Newcastle disease (ND) is a serious infectious disease of poultry caused by virulent strains of Avian Paramyxovirus-1 and has a substantial impact on villages where people's livelihood depends upon poultry farming in several developing countries including Ethiopia. In the district of the study area, no previous studies have been conducted. Thus, the aim of the present study was to estimate individual and household flock level seroprevalence and risk factors for ND in unvaccinated backyard chickens in Kindo Koisha district, Wolaita zone, Ethiopia. A cross-sectional study design was conducted. For the study, household flocks were sampled as a cluster, and backyard chickens within the cluster with an age of more than 3 months were sampled. A total of 598 blood samples were collected from 86 household flocks during the study period. Serum samples were tested for ND antibodies using an Indirect-Enzyme Linked Immuno Sorbent Assay. The overall seroprevalence of ND virus at individual and flock level was 17.06% (95% CI: 14.25-20.29%) and 73.26% (95% CI: 62.79-81.64%), respectively. The ND seropositivity and associated risk factors were assessed at the individual bird and flock level by using ordinary and mixed effect logistic regression, respectively. Ordinary logistic regression revealed that crossbreed chickens had significantly higher odds of ND seropositivity than local breeds, with an odds ratio of 2.15 (95% CI: 1.54-3.00; p < 0.001). The odds of ND seropositivity was significantly higher in backyard chickens which belongs flock size >9 in comparison to <9 with an odds ratio of 3.7 (95% CI: 1.12-12.30; p < 0.031). The potential flock level risk factors related to ND seropositivity in this study were flock size, chicken house cleaning frequency, water source for chickens, dead chicken disposal practice, and distance to the next neighbor household, mixing with wild birds and owning pets. In conclusion, the current study generates significant information on the seroprevalence and the potential risk factors associated with ND at individual and flock level in Kindo Koisha district, Wolaita zone. Consequently, ND vaccination campaigns should be launched, and effective extension programs should also be provided to raise awareness about the disease.

Characterization of Chicken-Derived Genotype VII Newcastle Disease Virus Isolates from Northwest China

Newcastle disease virus (NDV) threatens global poultry production, with genotype VII the most prevalent strain in China. However, little information is available regarding viral multiplication and pathogenicity based inoculation route. The objectives of this study were to sequence NDV VII isolates and to analyze their biological characteristics in detail. A total of 86 oral and cloacal swabs were collected from Shaanxi and Gansu provinces in northwest China. Identification of genotype VII NDV based on the M gene was performed by qPCR. Viral multiplication and pathogenicity were assessed as a function of route of infection. We observed increased morbidity and mortality using intravenous injection, whereas intranasal, intraocular, and cloacal infections resulted in slower progression and milder clinical disease, with viral proliferation obvious in different tissues. These results provide an important basis for the clinical control and prevention of NDV epidemics in poultry.

Seroprevalence and risk factors associated with Newcastle disease in backyard chickens in West Kordofan State, Sudan

Background and Aim

Newcastle disease (ND), a major constraint to poultry production worldwide, is a highly contagious disease of many species of domestic, exotic, and wild birds caused by ND virus (NDV). Epidemiological studies are lacking regarding ND in village chickens, including the traditional and intensive production systems used in Sudan. However, it is necessary to develop appropriate strategies to control the disease. Therefore, this study aimed to estimate the flock- and bird-level seroprevalence of NDV in backyard chickens in West Kordofan State, Sudan, and to identify the risk factors associated with ND in the study area.

Materials and Methods

The seroprevalence of the circulating NDV and bird-level risk factors associated with ND was determined in backyard chickens from March to October 2017, in six villages (Alnowara, Alleait, Geibaish, Baiad, Sougoh, and Alnuhoud) in the Geibaish and Elnuhoud localities of West Kordofan State.

Results

Using the hemagglutination-inhibition test, the bird- and flock-level seroprevalences of antibodies to NDV were estimated as 20.6% (78/378) and 45% (18/40), respectively. Bird-level NDV seropositivity in backyard chickens was significantly associated with the reason for raising chickens, type of housing, contact with neighboring poultry, contact with wild birds, and chicken mortality caused by infectious diseases (p ≤ 0.05).

Conclusion

This study indicated that NDV is circulating in backyard chickens and may act as a potential source of infection for other birds and thus persistence of ND among local traditionally managed chickens in the areas of West Kordofan State. Risk factors contributing to ND occurrence are important for designing appropriate prevention and control strategies.

SLC1A3 facilitates Newcastle disease virus replication by regulating glutamine catabolism

As obligate intracellular parasites, viruses rely completely on host metabolic machinery and hijack host nutrients for viral replication. Newcastle disease virus (NDV) causes acute, highly contagious avian disease and functions as an oncolytic agent. NDV efficiently replicates in both chicken and tumour cells. However, how NDV reprograms host cellular metabolism for its efficient replication is still ill-defined. We previously identified a significantly upregulated glutamate transporter gene, solute carrier family 1 member 3 (SLC1A3), during NDV infection via transcriptome analysis. To investigate the potential role of SLC1A3 during NDV infection, we first confirmed the marked upregulation of SLC1A3 in NDV-infected DF-1 or A549 cells through p53 and NF-κB pathways. Knockdown of SLC1A3 inhibited NDV infection. Western blot analysis further confirmed that glutamine, but not glutamate, asparagine, or aspartate, was required for NDV replication. Metabolic flux data showed that NDV promotes the decomposition of glutamine into the tricarboxylic acid cycle. Importantly, the level of glutamate and glutaminolysis were reduced by SLC1A3 knockdown, indicating that SLC1A3 propelled glutaminolysis for glutamate utilization and NDV replication in host cells. Taken together, our data identify that SLC1A3 serves as an important regulator for glutamine metabolism and is hijacked by NDV for its efficient replication during NDV infection. These results improve our understanding of the interaction between NDV and host cellular metabolism and lay the foundation for further investigation of efficient vaccines.

Study on Seroprevalence and Associated Risk Factors of Newcastle Disease in Smallholder Poultry Farms in Sodo Zuria District, Wolaita Zone, Southern Ethiopia

Newcastle disease (NCD) is a highly contagious viral disease of poultry and remains a constant threat in poultry farms that causes huge economic losses. The objective of this study was to estimate and assess the seroprevalence and associated risk factors of Newcastle disease in the Sodo Zuria district, southern Ethiopia. A cross-sectional survey followed by a simple random sampling technique was conducted from May to July 2021 on 384 apparently healthy nonvaccinated chickens on 30 smallholder poultry farms using commercial indirect ELISA kits and a questionnaire survey. The data were analyzed by using STATA for windows version 20 and a logistic regression reporting odds ratiowas applied to describe the seroprevalence of Newcastle disease with associated risk factors. The result of the study demonstrates that there was a high seroprevalence 48.7% (n= 187/384) of Newcastle disease in the study district. Information on associated risk factors were assessed using a semistructured questionnaire. The sex of the chicken showed a statistically significant difference (x² = 4.842; p = 0.028) with the seroprevalence of the disease. The difference in seroprevalence among intensive, semi-intensive, and extensive management system was statistically significant (x² = 3.84; p = 0.0001). There was also a statistical significant difference (x² = 2.3854; p = 0.496) in the absence and presence of safe disposal of a dead chicken with the occurence of Newcastle disease. However, no statistically significant difference was observed among age groups (x² = 4.335; p = 0.114), disinfection of poultry house (x² = 0.0; p = 0.998), presence and absence of footbath (x² = 2.969; p = 0.085), the breeds (x² = 4.490; p = 0.106), type of chicken (x² = 0.302; p = 0.583), and housing system (x² = 1.926; p = 0.588). A high seroprevalence without vaccination history showed that the virus was circulating within the poultry. Therefore, further molecular study has to be conducted to identify circulating strains and develop an evidence-based control program.

Dynamic paramyxovirus type 1 seroprevalence maps in broilers in the Valencian Community (eastern Spain) during a five-year period (2008-2012)

Newcastle disease is a devasting disease in poultry production worldwide, thus it is important to implement control measures to avoid entrance of the disease and its spread in the field. In this context, the aim of this study was to design and implement a seroprevalence map based on business intelligence for avian paramyxovirus type 1 (APMV-1) in broilers in the Valencia Community (eastern Spain). This tool consists in software mapping based on data collection, data analysis and data representation. In order to obtain the serological data, 12 495 sera from 131 broiler farms over 5 years were analysed (2008-2012). The data were represented on a map of the Valencian Community including geographical information of flock locations to facilitate disease monitoring. No clinical signs of APMV-1 were reported in the studied flocks. The data from this study showed no evidence contact with APMV-1 in broiler flocks and the novel software mapping tool as a valuable method for easily monitoring the serological response to avian paramyxovirus type 1 (APMV-1) including geographical information.

Measles and Nipah virus assembly: Specific lipid binding drives matrix polymerization

Measles virus, Nipah virus, and multiple other paramyxoviruses cause disease outbreaks in humans and animals worldwide. The paramyxovirus matrix (M) protein mediates virion assembly and budding from host cell membranes. M is thus a key target for antivirals, but few high-resolution structures of paramyxovirus M are available, and we lack the clear understanding of how viral M proteins interact with membrane lipids to mediate viral assembly and egress that is needed to guide antiviral design. Here, we reveal that M proteins associate with phosphatidylserine and phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] at the plasma membrane. Using x-ray crystallography, electron microscopy, and molecular dynamics, we demonstrate that PI(4,5)P2 binding induces conformational and electrostatic changes in the M protein surface that trigger membrane deformation, matrix layer polymerization, and virion assembly.

Risky business in Georgia's wild birds: contact rates between wild birds and backyard chickens is influenced by supplemental feed

Backyard chickens are increasingly popular, and their husbandry varies widely. How backyard chickens are housed may influence the accessibility of chicken feed and water to wild birds, and thus, the contact rates between both groups. Increased contacts have implications for pathogen transmission; for instance, Newcastle disease virus or avian influenza virus may be transmitted to and from backyard chickens from contaminated water or feed. Given this potentially increased pathogen risk to wild birds and backyard chickens, we examined which wild bird species are likely to encounter backyard chickens and their resources. We performed a supplemental feeding experiment followed by observations at three sites associated with backyard chickens in North Georgia, USA. At each site, we identified the species of wild birds that: (a) shared habitat with the chickens, (b) had a higher frequency of detection relative to other species and (c) encountered the coops. We identified 14 wild bird species that entered the coops to consume supplemental feed and were considered high-risk for pathogen transmission. Our results provide evidence that contact between wild birds and backyard chickens is frequent and more common than previously believed, which has crucial epidemiological implications for wildlife managers and backyard chicken owners.

Prevalence of Newcastle Disease Virus in Wild and Migratory Birds in Haryana, India

Newcastle disease virus (NDV) can infect approximately 250 avian species and causes highly contagious Newcastle disease (ND) in domestic poultry, leading to huge economic losses. There are three different pathotypes of NDV, i.e., lentogenic, mesogenic, and velogenic. Wild resident (wild) and migratory birds are natural reservoirs of NDV and are believed to play a key role in transmitting the virus to domestic poultry. The present study was conducted to determine the prevalence of NDV in wild and migratory birds in the state of Haryana, India, during two migratory seasons (2018-19 and 2019-20). In total 1379 samples (1368 choanal swabs and 11 tissue samples) were collected from live (n = 1368) or dead birds (n = 4) belonging to 53 different avian species. These samples belonged to apparently healthy (n = 1338), sick (n = 30), and dead (n = 4) birds. All samples were tested for NDV by real-time reverse transcription-PCR using M gene specific primers and probe. Of the 1379 samples, 23 samples from wild birds [Columba livia domestica (n = 12, 52.17%), Pavo cristatus (n = 9, 39.13%), and Psittaciformes (n = 2, 8.69%)] were found positive for NDV. Only one of the 23 samples (from P. cristatus) was positive for F gene, indicating it to be a mesogenic/velogenic strain. These results indicate that both lentogenic and velogenic strains of NDV are circulating in wild birds in Haryana and that further studies are needed to characterize NDV strains from wild/migratory birds and domestic poultry to determine the extent of virus transmission among these populations. This study considers the disease transmission risk from domestic pigeons and parrots to commercial poultry and vice versa, and the results emphasize the need for strict biosecurity strategies to protect commercial poultry in the region.

Detection of Velogenic Avian Paramyxoviruses in Rock Doves in New York City, New York

Avian paramyxovirus 1 (APMV-1), also known as Newcastle disease virus (NDV), causes severe and economically important disease in poultry around the globe. Although a limited amount of APMV-1 strains in urban areas have been characterized, the role of the urban wild bird population as an APMV-1 reservoir is unclear. Because urban birds may have an important role for long-term circulation of the virus, fecal and swab samples were collected by community scientists from wild birds in New York City (NYC), New York, United States. These samples were screened for APMV-1 and genotypically characterized by sequencing of the complete genome. A total of 885 samples were collected from NYC parks and from a local wildlife rehabilitation clinic from October 2020 through June 2021, and 255 samples obtained from 197 birds have been processed to date. Eight birds (4.1%) screened positive for the APMV-1 nucleoprotein gene by conventional reverse transcription PCR (RT-PCR), and two live viruses were isolated via egg culture. A multibasic F protein cleavage sequence, ¹¹²R R K K R F¹¹⁷, an indicator of highly pathogenic velogenic APMV-1 strains, was present in the two samples fully sequenced by next generation sequencing. Phylogenetic analysis of the F gene coding sequence classified both isolates into genotype VI, a diverse and predominant genotype responsible for APMV-1 outbreaks in pigeon and dove species worldwide.

IMPORTANCE Here we describe the first large-scale effort to screen for APMV-1 in New York City’s wild bird population as part of the New York City Virus Hunters program, a community science initiative. We characterized two isolates of APMV-1, with phylogenetic analyses suggesting diversity in established and circulating strains of pigeon paramyxoviruses. Our isolates are also domestic reference strains for future APMV-1 vaccine developments. Future surveillance in this region may contribute to our understanding of APMV-1’s evolution and genetic diversity, as well as inform poultry husbandry and vaccination practices in New York State.

Detection of Newcastle disease virus and assessment of associated relative risk in backyard and commercial poultry in Kerala, India

Background

Newcastle disease (ND) is an economically important viral disease affecting the poultry industry. In Kerala, a state in South India, incidences of ND in commercial and backyard poultry have been reported. But a systematic statewide study on the prevalence of the disease has not been carried out.

Objectives

A cross‐sectional survey was performed to detect the presence of Newcastle disease virus (NDV) in suspect cases and among apparently healthy commercial flocks and backyard poultry, in the state and to identify risk factors for NDV infection.

Methods

Real‐time reverse transcription‐PCR (RT‐PCR) was used to detect the M gene of NDV in choanal swabs and tissue samples collected from live and dead birds, respectively and the results were statistically analysed.

Results

The predominant clinical signs of the examined birds included mild respiratory signs, huddling together and greenish diarrhoea. Nervous signs in the form of torticollis were noticed in birds in some of the affected flocks. On necropsy, many birds had haemorrhages in the proventriculus and caecal tonsils which were suggestive of ND. Of the 2079 samples tested, 167 (8.0%) were positive for the NDV M‐gene by RT‐PCR. Among 893 samples collected from diseased flocks, 129 (14.5%), were positive for M gene with pairwise relative risk (RR) of 15.6 as compared to apparently healthy flocks where 6 out of 650 (0.9%) samples were positive. All positive samples were from poultry; none of the ducks, pigeons, turkey and wild birds were positive. Commercial broilers were at higher risk of infection than commercial layers (RR: 4.5) and backyard poultry (RR: 4.9). Similarly, birds reared under intensive housing conditions were at a higher risk of being infected as compared to those reared under semi‐intensive (RR: 6.7) or backyard housing (RR: 2.1). Multivariable analysis indicated that significantly higher risk of infection exists during migratory season and during ND outbreaks occurring nearby. Further, lower risk was observed with flock vaccination and backyard or semi‐intensive housing when compared to intensive housing. When the M gene positive samples were tested by RT‐PCR to determine whether the detected NDV were mesogenic/velogenic, 7 (4.2%) were positive.

Conclusions

In Kerala, NDV is endemic in poultry with birds reared commercially under intensive rearing systems being affected the most. The outcome of this study also provides a link between epidemiologic knowledge and the development of successful disease control measures. Statistical analysis suggests that wild bird migration season and presence of migratory birds influences the prevalence of the virus in the State. Further studies are needed to genotype and sub‐genotype the detected viruses and to generate baseline data on the prevalence of NDV strains, design better detection strategies, and determine patterns of NDV transmission across domestic poultry and wild bird populations in Kerala.

A study was carried out to detect Newcastle disease virus in commercial and backyard chicken in Kerala, India, by employing real time RT‐PCR. The overall percentage positivity obtained was 8%. Risk analysis revealed significantly higher risk for broiler birds and intensive type of housing. The risk was also higher for birds housed in facilities in areas with a history of occurrence of the disease, if migratory birds were present in the area, and during bird migration season. It was also observed that vaccination had a protective effect as indicated by lower relative risk values.

Plant-Derived Recombinant Vaccines against Zoonotic Viruses

Emerging and re-emerging zoonotic diseases cause serious illness with billions of cases, and millions of deaths. The most effective way to restrict the spread of zoonotic viruses among humans and animals and prevent disease is vaccination. Recombinant proteins produced in plants offer an alternative approach for the development of safe, effective, inexpensive candidate vaccines. Current strategies are focused on the production of highly immunogenic structural proteins, which mimic the organizations of the native virion but lack the viral genetic material. These include chimeric viral peptides, subunit virus proteins, and virus-like particles (VLPs). The latter, with their ability to self-assemble and thus resemble the form of virus particles, are gaining traction among plant-based candidate vaccines against many infectious diseases. In this review, we summarized the main zoonotic diseases and followed the progress in using plant expression systems for the production of recombinant proteins and VLPs used in the development of plant-based vaccines against zoonotic viruses.

Isolation of genotype VII avian orthoavulavirus serotype 1 from barn owl from Northeast India

Newcastle Disease Virus (NDV) affects both commercial poultry as well as other avian species in the wild and in captivity. Although the diversity of NDV in domestic chickens has been well understood, little light has been shed on NDV outbreaks in other avian species. We provide an annotated sequence of NDV/Owl/Guwahati/01/20, a virulent strain of NDV isolated from Barn Owls in captivity from Guwahati in Northeast India. The complete genome is 15192 bases long with a fusion protein (F) cleavage site ¹¹²KRQKR↓F¹¹⁷. The isolate showed 97.67% identity with its closest match, another highly virulent strain from Indonesia isolated from vaccinated commercial chickens; however, they differ in the F cleavage site. The NDV isolate from the owl shares 83.02% and 81.88% identity with the vaccine strains R2B and LaSota, respectively. Phylogenetic analysis with both F gene as well as whole-genome nucleotide sequence reveals that the NDV isolate from owl belongs to genotype VII, subgenotype VII.2 and differs significantly from any other isolate of NDV from India.

Serological Investigation of Newcastle Disease in Selected Districts of Buno Bedelle Zone, Ethiopia

Purpose

Newcastle disease causes considerable loss in the poultry industry worldwide and its outbreaks are regularly reported from all continents of the world, including Ethiopia. The investigation was conducted from October 2020 to June 2021 to determine the prevalence of Newcastle disease (ND) in districts selected from Buno Bedele zone, Western Oromia.

Methods

The study design used was a cross-sectional type. For this study, a total of 480 serum samples were collected as per sample collection guideline from randomly selected chickens that were apparently healthy and had no history of vaccination against Newcastle disease. Indirect ELISA was performed and all data were analyzed using SPSS statistical software.

Results

From serological investigation, overall seroprevalence of Newcastle disease was 30%. Seroprevalence of Newcastle disease was 34.94%, 22.22%, and 31.76% in Didessa, Chora, and Gachi districts, respectively. Among computed risk factors, breed showed statistically significant difference and the odds of infection were lower in adult than in young chickens. Similarly, the odds of infection with Newcastle disease virus were significantly higher in crossbred than in locally bred backyard chickens.

Conclusion

This study revealed Newcastle disease was prevalent in the study areas; therefore, regular investigation of Newcastle disease should be conducted along with detailed studies on molecular characterization of circulating field strains in the area.

Exposure assessment for avian influenza and Newcastle disease viruses from peridomestic wild birds in a conservation breeding site in the United Arab Emirates

Worldwide, wild birds are frequently suspected to be involved in the occurrence of outbreaks of different diseases in captive-bred birds although proofs are lacking and most of the dedicated studies are insufficiently conclusive to confirm or characterize the roles of wild birds in such outbreaks. The aim of this study was to assess and compare, for the most abundant peridomestic wild birds, the different exposure routes for avian influenza and Newcastle disease viruses in conservation breeding sites of Houbara bustards in the United Arab Emirates. To do so, we considered all of the potential pathways by which captive bustards could be exposed to avian influenza and Newcastle disease viruses by wild birds, and ran a comparative study of the likelihood of exposure via each of the pathways considered. We merged data from an ecological study dedicated to local wild bird communities with an analysis of the contacts between wild birds and captive bustards and with a prevalence survey of avian influenza and Newcastle disease viruses in wild bird populations. We also extracted data from an extensive review of the scientific literature and by the elicitation of expert opinion. Overall, this analysis highlighted those captive bustards had a high risk of being exposed to pathogens by wild birds. This risk was higher for Newcastle disease virus than avian influenza virus, and House sparrows represented the riskiest species for the transmission of both viruses through direct exposure from direct contact with an infectious bird that got inside the aviary and indirect exposure from consumption of water contaminated from the faeces of an infected bird that got inside the aviary for Newcastle disease virus and avian influenza virus, respectively. These results also reaffirm the need to implement biosecurity measures to limit contacts between wild and captive birds and highlight priority targets for a thoughtful and efficient sanitary management strategy.

Producing Vaccines against Enveloped Viruses in Plants: Making the Impossible, Difficult

The past 30 years have seen the growth of plant molecular farming as an approach to the production of recombinant proteins for pharmaceutical and biotechnological uses. Much of this effort has focused on producing vaccine candidates against viral diseases, including those caused by enveloped viruses. These represent a particular challenge given the difficulties associated with expressing and purifying membrane-bound proteins and achieving correct assembly. Despite this, there have been notable successes both from a biochemical and a clinical perspective, with a number of clinical trials showing great promise. This review will explore the history and current status of plant-produced vaccine candidates against enveloped viruses to date, with a particular focus on virus-like particles (VLPs), which mimic authentic virus structures but do not contain infectious genetic material.

Transboundary Animal Diseases, an Overview of 17 Diseases with Potential for Global Spread and Serious Consequences

Animals provide food and other critical resources to most of the global population. As such, diseases of animals can cause dire consequences, especially disease with high rates of morbidity or mortality. Transboundary animal diseases (TADs) are highly contagious or transmissible, epidemic diseases, with the potential to spread rapidly across the globe and the potential to cause substantial socioeconomic and public health consequences. Transboundary animal diseases can threaten the global food supply, reduce the availability of non-food animal products, or cause the loss of human productivity or life. Further, TADs result in socioeconomic consequences from costs of control or preventative measures, and from trade restrictions. A greater understanding of the transmission, spread, and pathogenesis of these diseases is required. Further work is also needed to improve the efficacy and cost of both diagnostics and vaccines. This review aims to give a broad overview of 17 TADs, providing researchers and veterinarians with a current, succinct resource of salient details regarding these significant diseases. For each disease, we provide a synopsis of the disease and its status, species and geographic areas affected, a summary of in vitro or in vivo research models, and when available, information regarding prevention or treatment.

Thymic transcriptome analysis after Newcastle disease virus inoculation in chickens and the influence of host small RNAs on NDV replication

Newcastle disease (ND), caused by virulent Newcastle disease virus (NDV), is a contagious viral disease affecting various birds and poultry worldwide. In this project, differentially expressed (DE) circRNAs, miRNAs and mRNAs were identified by high-throughput RNA sequencing (RNA-Seq) in chicken thymus at 24, 48, 72 or 96 h post LaSota NDV vaccine injection versus pre-inoculation group. The vital terms or pathways enriched by vaccine-influenced genes were tested through KEGG and GO analysis. DE genes implicated in innate immunity were preliminarily screened out through GO, InnateDB and Reactome Pathway databases. The interaction networks of DE innate immune genes were established by STRING website. Considering the high expression of gga-miR-6631-5p across all the four time points, DE circRNAs or mRNAs with the possibility to bind to gga-miR-6631-5p were screened out. Among DE genes that had the probability to interact with gga-miR-6631-5p, 7 genes were found to be related to innate immunity. Furthermore, gga-miR-6631-5p promoted LaSota NDV replication by targeting insulin induced gene 1 (INSIG1) in DF-1 chicken fibroblast cells. Taken together, our data provided the comprehensive information about molecular responses to NDV LaSota vaccine in Chinese Partridge Shank Chickens and elucidated the vital roles of gga-miR-6631-5p/INSIG1 axis in LaSota NDV replication.

Non-epidermidis coagulase-negative Staphylococcus isolated from farm animals can inhibit the hemagglutinating activity of Newcastle disease virus and bovine parainfluenza virus type 3

The Embp protein of Staphylococcus epidermidis inhibits the hemagglutination of the H1N1 influenza virus and protects birds from a viral respiratory infection. Several species of Coagulase-negative Staphylococcus (CoNS) are present in the respiratory cavity, particularly in nostrils. We hypothesize that non-epidermidis CoNS found in animals can have the same function as observed in S. epidermidis. Thirty Non-epidermidis CoNS isolates were obtained from poultry, sheep, goat, pig, and dairy cow nostrils. Haemagglutination inhibition (HI) activity was assayed in bacteria-free supernatants from non-epidermidis CoNS against Newcastle disease virus (NDV) and bovine parainfluenza virus type 3 (BPIV). In 13 of the 30 strains (43.3 %), bacteria-free supernatants showed HI activity for NDV and BPIV-3. Staphylococcus xylosus supernatants from poultry (one isolate), sheep (two isolates), goat (one isolate), and dairy cow (three isolates) had the highest frequency of HI activity on NDV and BPIV-3, followed by Staphylococcus sp. supernatants from goat (one isolate), dairy cow (two isolates), and finally Staphylococcus equorum, Staphylococcus chromogens and Staphylococcus gallinarum supernatants with single isolation from poultry, pig and poultry, respectively. Nine isolates had the homologous gene to the embp gene of S. epidermidis, and it was associated with HI activity in the studied viruses. By Pulsed-field gel electrophoresis, S. xylosus isolates showed to be different clones and related to the origin of isolation and HI activity. These results demonstrate that non-epidermidis CoNS supernatants from different animals and origins have the ability of HI on NDV and BPIV-3, indicating that not only S. epidermidis has the same function.

Emergence and molecular characterization of pigeon Paramyxovirus-1 in non-native Eurasian collared doves (Streptopelia decaocto) in California, USA

Eurasian collared doves (Streptopelia decaocto) were introduced into Florida in the 1980s and have since established populations throughout the continental United States. Pigeon paramyxovirus-1 (PPMV-1), a species-adapted genotype VI Avian orthoavulavirus 1, has caused periodic outbreaks among collared doves in the U.S. since 2001 with outbreaks occasionally involving native doves. In California, PPMV-1 mortality events were first documented in Riverside County in 2014 with subsequent outbreaks in 23 additional counties from southern to northern California between 2015 and 2019. Affected collared doves exhibited torticollis and partial paralysis. Pale kidneys were frequently visible on gross necropsy (65.4%; 51/78) while lymphoplasmacytic interstitial nephritis often with acute tubular necrosis (96.0%; 24/25) and pancreatic necrosis (80.0%; 20/25) were common findings on histopathology. In total, PPMV-1 was confirmed by rRT-PCR and sequence analysis from oropharyngeal and/or cloacal swabs in 93.0% (40/43) of the collared doves tested from 16 California counties. In 2017, Avian orthoavulavirus 1 was confirmed in a native mourning dove (Zenaida macroura) found dead during a PPMV-1 outbreak in collared doves by rRT-PCR from formalin-fixed paraffin-embedded (FFPE) tissues, after the initial rRT-PCR from swabs failed to detect the virus. Molecular sequencing of the fusion protein of isolates collected from collared doves during outbreaks in 2014, 2016, and 2017 identified two distinct subgenotypes, VIa and VIn. Subgenotype VIn has been primarily isolated from collared doves in the southern U.S., while VIa has been isolated from mixed avian species in the northeastern U.S., indicating two independent introductions into California. While populations of collared doves are not expected to be substantially impacted by this disease, PPMV-1 may pose a threat to already declining populations of native columbids. This threat could be assessed by monitoring native and non-native columbids for PPMV-1. Based on our study, swab samples may not be sufficient to detect infection in native columbids and may require the use of non-traditional diagnostic approaches, such as FFPE tissues, to ensure virus detection.

Comparison of flagellin and an oil-emulsion adjuvant in inactivated Newcastle disease vaccine in stimulation of immunogenic parameters

The present study was designed to investigate the potential application of native (N) and recombinant (truncated modified [tmFliC] and full-length [flFliC]) flagellin proteins along with inactivated Newcastle disease virus (NDV). Fifty six SPF chickens were immunized twice with PBS (control), inactivated NDV (Ag), inactivated NDV/flFliC (AgF), inactivated NDV/tmFliC (AgT), inactivated NDV/N (AgN), commercial vaccine containing Montanide (Vac) and Vac/N (VacN), with a two-week interval. Blood was collected weekly and spleens were harvested after chickens were sacrificed. Interleukin-6 (IL-6) and tumor necrotic factor-α (TNF-α) gene expression in peripheral blood mononuclear cells were analyzed by Real-Time PCR. Antibody response was assessed by haemagglutination inhibition (HI). Cellular activity was quantified by MTT assay. Results showed that the most IL-6 and TNF-α gene expression was observed in AgF group (P < 0.01). The lowest gene expression among vaccinated groups was observed in Ag group for IL-6 and Ag and Vac group for TNF-α. The highest HI titer was observed in Vac, VacN, AgF and AgT groups. The AgF group showed the highest cellular activity (P < 0.01). In conclusion, flagellin-adjuvanted groups showed a pro-inflammatory effect and acted similarly to or better than the Vac group. Hence, flagellin can be proposed as a potential adjuvant for ND vaccine.

Molecular Characterization of Velogenic Newcastle Disease Virus (Sub-Genotype VII.1.1) from Wild Birds, with Assessment of Its Pathogenicity in Susceptible Chickens

Simple Summary

Newcastle disease virus (NDV) is a highly contagious viral disease affecting a wide range of avian species. The disease can be particularly virulent in chickens, resulting in high mortality and morbidity. In this study, we characterized velogenic NDV sub-genotype VII.1.1 from wild birds and assessed its pathogenicity in susceptible chickens. One hundred wild birds from the vicinity of poultry farms with a history of NDV infection were examined clinically. Pooled samples from the spleen, lung, and brain were screened using real-time reverse transcriptase polymerase chain reaction (RRT-PCR) and reverse transcriptase polymerase chain reaction (RT-PCR) to detect the NDV F gene fragment, and phylogenetic analysis was carried out for identification of the genetic relatedness of the virus. Chickens were infected with the strains identified, and the major histopathological changes were assessed. Interestingly, NDV was detected in 44% of cattle egret samples and 26% of house sparrow samples by RRT-PCR, while RT-PCR detected NDV in 36% of cattle egrets examined and 20% of house sparrow samples. Phylogenetic analysis revealed close identity, of 99.7–98.5% (0.3–1.5% pairwise distance), between the isolates used in our study and other Egyptian class II, sub-genotype VII.1.1 NDV strains. Histopathological examination identified marked histopathological changes that are consistent with NDV. These findings provide interesting data in relation to the detection of NDV sub-genotype VII.1.1 in wild birds and reveal the major advantages of the combined use of molecular and histopathological methods in the detection and characterization of the virus. More research is needed to determine the characteristics of this contagious disease in the Egyptian environment.

Abstract

Newcastle disease (ND) is considered to be one of the most economically significant avian viral diseases. It has a worldwide distribution and a continuous diversity of genotypes. Despite its limited zoonotic potential, Newcastle disease virus (NDV) outbreaks in Egypt occur frequently and result in serious economic losses in the poultry industry. In this study, we investigated and characterized NDV in wild cattle egrets and house sparrows. Fifty cattle egrets and fifty house sparrows were collected from the vicinity of chicken farms in Kafrelsheikh Governorate, Egypt, which has a history of NDV infection. Lung, spleen, and brain tissue samples were pooled from each bird and screened for NDV by real-time reverse transcriptase polymerase chain reaction (RRT-PCR) and reverse transcriptase polymerase chain reaction (RT-PCR) to amplify the 370 bp NDV F gene fragment. NDV was detected by RRT-PCR in 22 of 50 (44%) cattle egrets and 13 of 50 (26%) house sparrows, while the conventional RT-PCR detected NDV in 18 of 50 (36%) cattle egrets and 10 of 50 (20%) of house sparrows. Phylogenic analysis revealed that the NDV strains identified in the present study are closely related to other Egyptian class II, sub-genotype VII.1.1 NDV strains from GenBank, having 99.7–98.5% identity. The pathogenicity of the wild-bird-origin NDV sub-genotype VII.1.1 NDV strains were assessed by experimental inoculation of identified strains (KFS-Motobas-2, KFS-Elhamoul-1, and KFS-Elhamoul-3) in 28-day-old specific-pathogen-free (SPF) Cobb chickens. The clinical signs and post-mortem changes of velogenic NDV genotype VII (GVII) were observed in inoculated chickens 3 to 7 days post-inoculation, with 67.5–70% mortality rates. NDV was detected in all NDV-inoculated chickens by RRT-PCR and RT-PCR at 3, 7, and 10 days post-inoculation. The histopathological findings of the experimentally infected chickens showed marked pulmonary congestion and pneumonia associated with complete bronchial stenosis. The spleen showed histocytic cell proliferation with marked lymphoid depletion, while the brain had malacia and diffuse gliosis. These findings provide interesting data about the characterization of NDV in wild birds from Egypt and add to our understanding of their possible role in the transmission dynamics of the disease in Egypt. Further research is needed to explore the role of other species of wild birds in the epidemiology of this disease and to compare the strains circulating in wild birds with those found in poultry.

The oncolytic Newcastle disease virus as an effective immunotherapeutic strategy against glioblastoma

Glioblastoma is the most frequent primary brain tumor in adults, with a dismal prognosis despite aggressive resection, chemotherapeutics, and radiotherapy. Although understanding of the molecular pathogenesis of glioblastoma has progressed in recent years, therapeutic options have failed to significantly change overall survival or progression-free survival. Thus, researchers have begun to explore immunomodulation as a potential strategy to improve clinical outcomes. The application of oncolytic virotherapy as a novel biological to target pathogenic signaling in glioblastoma has brought new hope to the field of neuro-oncology. This class of immunotherapeutics combines selective cancer cell lysis prompted by virus induction while promoting a strong inflammatory antitumor response, thereby acting as an effective in situ tumor vaccine. Several investigators have reported the efficacy of experimental oncolytic viruses as demonstrated by improved long-term survival in cancer patients with advanced disease. Newcastle disease virus (NDV) is one of the most well-researched oncolytic viruses known to affect a multitude of human cancers, including glioblastoma. Preclinical in vitro and in vivo studies as well as human clinical trials have demonstrated that NDV exhibits oncolytic activity against glioblastoma, providing a promising avenue of potential treatment. Herein, the authors provide a detailed discussion on NDV as a mode of therapy for glioblastoma. They discuss the potential therapeutic pathways associated with NDV as demonstrated by in vitro and in vivo experiments as well as results from human trials. Moreover, they discuss current challenges, potential solutions, and future perspectives in utilizing NDV in the treatment of glioblastoma.

Virulence during Newcastle Disease Viruses Cross Species Adaptation

The hypothesis that host adaptation in virulent Newcastle disease viruses (NDV) has been accompanied by virulence modulation is reviewed here. Historical records, experimental data, and phylogenetic analyses from available GenBank sequences suggest that currently circulating NDVs emerged in the 1920-1940's from low virulence viruses by mutation at the fusion protein cleavage site. These viruses later gave rise to multiple virulent genotypes by modulating virulence in opposite directions. Phylogenetic and pathotyping studies demonstrate that older virulent NDVs further evolved into chicken-adapted genotypes by increasing virulence (velogenic-viscerotropic pathotypes with intracerebral pathogenicity indexes [ICPIs] of 1.6 to 2), or into cormorant-adapted NDVs by moderating virulence (velogenic-neurotropic pathotypes with ICPIs of 1.4 to 1.6), or into pigeon-adapted viruses by further attenuating virulence (mesogenic pathotypes with ICPIs of 0.9 to 1.4). Pathogenesis and transmission experiments on adult chickens demonstrate that chicken-adapted velogenic-viscerotropic viruses are more capable of causing disease than older velogenic-neurotropic viruses. Currently circulating velogenic-viscerotropic viruses are also more capable of replicating and of being transmitted in naïve chickens than viruses from cormorants and pigeons. These evolutionary virulence changes are consistent with theories that predict that virulence may evolve in many directions in order to achieve maximum fitness, as determined by genetic and ecologic constraints.

Surveillance and Genetic Characterization of Virulent Newcastle Disease Virus Subgenotype V.3 in Indigenous Chickens from Backyard Poultry Farms and Live Bird Markets in Kenya

Kenyan poultry consists of ~80% free-range indigenous chickens kept in small flocks (~30 birds) on backyard poultry farms (BPFs) and they are traded via live bird markets (LBMs). Newcastle disease virus (NDV) was detected in samples collected from chickens, wild farm birds, and other domestic poultry species during a 2017–2018 survey conducted at 66 BPFs and 21 LBMs in nine Kenyan counties. NDV nucleic acids were detected by rRT-PCR L-test in 39.5% (641/1621) of 1621 analyzed samples, of which 9.67% (62/641) were NDV-positive by both the L-test and a fusion-test designed to identify the virulent virus, with a majority being at LBMs (64.5%; 40/62) compared to BPFs (25.5%; 22/62). Virus isolation and next-generation sequencing (NGS) on a subset of samples resulted in 32 complete NDV genome sequences with 95.8–100% nucleotide identities amongst themselves and 95.7-98.2% identity with other east African isolates from 2010-2016. These isolates were classified as a new sub-genotype, V.3, and shared 86.5–88.9% and 88.5–91.8% nucleotide identities with subgenotypes V.1 and V.2 viruses, respectively. The putative fusion protein cleavage site (¹¹³R-Q-K-R↓F ¹¹⁷) in all 32 isolates, and a 1.86 ICPI score of an isolate from a BPF chicken that had clinical signs consistent with Newcastle disease, confirmed the high virulence of the NDVs. Compared to genotypes V and VI viruses, the attachment (HN) protein of 18 of the 32 vNDVs had amino acid substitutions in the antigenic sites. A time-scaled phylogeographic analysis suggests a west-to-east dispersal of the NDVs via the live chicken trade, but the virus origins remain unconfirmed due to scarcity of continuous and systematic surveillance data. This study reveals the widespread prevalence of vNDVs in Kenyan backyard poultry, the central role of LBMs in the dispersal and possibly generation of new virus variants, and the need for robust molecular epidemiological surveillance in poultry and non-poultry avian species.

Host Cell Restriction Factors of Paramyxoviruses and Pneumoviruses

The paramyxo- and pneumovirus family includes a wide range of viruses that can cause respiratory and/or systemic infections in humans and animals. The significant disease burden of these viruses is further exacerbated by the limited therapeutics that are currently available. Host cellular proteins that can antagonize or limit virus replication are therefore a promising area of research to identify candidate molecules with the potential for host-targeted therapies. Host proteins known as host cell restriction factors are constitutively expressed and/or induced in response to virus infection and include proteins from interferon-stimulated genes (ISGs). Many ISG proteins have been identified but relatively few have been characterized in detail and most studies have focused on studying their antiviral activities against particular viruses, such as influenza A viruses and human immunodeficiency virus (HIV)-1. This review summarizes current literature regarding host cell restriction factors against paramyxo- and pneumoviruses, on which there is more limited data. Alongside discussion of known restriction factors, this review also considers viral countermeasures in overcoming host restriction, the strengths and limitations in different experimental approaches in studies reported to date, and the challenges in reconciling differences between in vitro and in vivo data. Furthermore, this review provides an outlook regarding the landscape of emerging technologies and tools available to study host cell restriction factors, as well as the suitability of these proteins as targets for broad-spectrum antiviral therapeutics.

Mulberry leaf polysaccharide supplementation contributes to enhancing the respiratory mucosal barrier immune response in Newcastle disease virus-vaccinated chicks

Despite high global vaccination coverage, Newcastle disease (ND) remains a constant threat to poultry producers owing to low antibody levels. Given the respiratory mucosa is the important site for Newcastle disease virus (NDV) vaccination, enhancing respiratory mucosal immunity may help control ND. Our previous study showed that mulberry leaf polysaccharide (MLP) is very promising in delivering a robust balanced immune response, but the effects of it on respiratory immunity in chicks are unknown. In this study, we evaluated the potential of MLP to activate respiratory mucosal immunity and revealed the possible mechanism of MLP as an immunopotentiator for ND vaccines. Chicks were randomly divided into 5 groups: blank control, vaccination control (VC), and low-, middle-, and high-dose MLP (MLP-L, MLP-M, and MLP-H) (n = 30). The serum results of humoral and cell-mediated immune responses showed significant increases in NDV hemagglutination inhibition antibody titer, IgG and IgA antibody levels, and the T-lymphocyte population in the MLP-M group compared with the VC group. Validation of results also indicated remarkable increases in tracheal antibody-mediated immunity and a mucosal immune response in the MLP-M group. Furthermore, the upregulation of TLR7 revealed a possible mechanism. Our findings provided evidence to consider MLP as a potential mucosal vaccine adjuvant candidate against ND in chickens.

Comparative Metagenomics of Palearctic and Neotropical Avian Cloacal Viromes Reveal Geographic Bias in Virus Discovery

Our understanding about viruses carried by wild animals is still scarce. The viral diversity of wildlife may be best described with discovery-driven approaches to the study of viral diversity that broaden research efforts towards non-canonical hosts and remote geographic regions. Birds have been key organisms in the transmission of viruses causing important diseases, and wild birds are threatened by viral spillovers associated with human activities. However, our knowledge of the avian virome may be biased towards poultry and highly pathogenic diseases. We describe and compare the fecal virome of two passerine-dominated bird assemblages sampled in a remote Neotropical rainforest in French Guiana (Nouragues Natural Reserve) and a Mediterranean forest in central Spain (La Herrería). We used metagenomic data to quantify the degree of functional and genetic novelty of viruses recovered by examining if the similarity of the contigs we obtained to reference sequences differed between both locations. In general, contigs from Nouragues were significantly less similar to viruses in databases than contigs from La Herrería using Blastn but not for Blastx, suggesting that pristine regions harbor a yet unknown viral diversity with genetically more singular viruses than more studied areas. Additionally, we describe putative novel viruses of the families Picornaviridae, Reoviridae and Hepeviridae. These results highlight the importance of wild animals and remote regions as sources of novel viruses that substantially broaden the current knowledge of the global diversity of viruses.

Genomic Diversity and Evolution of Quasispecies in Newcastle Disease Virus Infections

Newcastle disease virus (NDV) infections are well known to harbour quasispecies, due to the error-prone nature of the RNA polymerase. Quasispecies variants in the fusion cleavage site of the virus are known to significantly change its virulence. However, little is known about the genomic patterns of diversity and selection in NDV viral swarms. We analyse deep sequencing data from in vitro and in vivo NDV infections to uncover the genomic patterns of diversity and the signatures of selection within NDV swarms. Variants in viruses from in vitro samples are mostly localised in non-coding regions and 3′ and 5′ untranslated regions (3′UTRs or 5′UTRs), while in vivo samples contain an order of magnitude more variants. We find different patterns of genomic divergence and diversity among NDV genotypes, as well as differences in the genomic distribution of intra-host variants among in vitro and in vivo infections of the same strain. The frequency spectrum shows clear signatures of intra-host purifying selection in vivo on the matrix protein (M) coding gene and positive or diversifying selection on nucleocapsid (NP) and haemagglutinin-neuraminidase (HN). The comparison between within-host polymorphisms and phylogenetic divergence reveals complex patterns of selective pressure on the NDV genome at between- and within-host level. The M sequence is strongly constrained both between and within hosts, fusion protein (F) coding gene is under intra-host positive selection, and NP and HN show contrasting patterns: HN RNA sequence is positively selected between hosts while its protein sequence is positively selected within hosts, and NP is under intra-host positive selection at the RNA level and negative selection at the protein level.

Chitosan Nanoparticle Based Mucosal Vaccines Delivered Against Infectious Diseases of Poultry and Pigs

Infectious disease of poultry and pig are major threat to health and cause severe economic loss to the food industry and a global food safety issue. Poultry and pig act as a mixing vessel of zoonotic transmission of disease to humans. Effective mucosal vaccines used in animals could reduce the impact of diseases in food animals. Chitosan is a biocompatible polymer, and its positive charge makes it a natural mucoadhesive agent. Therefore, since last one-decade chitosan derived nanoparticles (CS NPs) have been in use widely to deliver vaccine antigens in animals through mucosal route. Primary route of entry of most infectious disease pathogen is through oral and nasal routes, and the CS NPs based vaccines delivered through that routes enhance the immunogenicity of encapsulated vaccine antigens by targeting the cargo to mucosal microfold cells, dendritic cells and macrophages. Resulting in induction of robust secretory and systemic antibodies and/or cell mediated immune response which provides protection against infections. To date, CS NPs is being widely used for mucosal vaccine delivery in poultry and pigs to control bacterial and viral infections, and tested in several preclinical trials for vaccine delivery in humans. In this review, we highlighted the progress so far made in using CS NPs as a vehicle for mucosal vaccine delivery against infectious and zoonotic diseases of poultry and pigs. Discussed about the need of CS NPs modifications, CS NPs based vaccines induced immune responses and its role in protection, and challenges in vaccination and future directions.

Molecular and virological characterization of the first poultry outbreaks of Genotype VII.2 velogenic avian orthoavulavirus type 1 (NDV) in North-West Europe, BeNeLux, 2018

After two decades free of Newcastle disease, Belgium encountered a velogenic avian orthoavulavirus type 1 epizootic in 2018. In Belgium, 20 cases were diagnosed, of which 15 occurred in hobby flocks, 2 in professional poultry flocks and 3 in poultry retailers. The disease also disseminated from Belgium towards the Grand Duchy of Luxembourg by trade. Independently, the virus was detected once in the Netherlands, almost simultaneously to the first Belgian detection. As such Newcastle disease emerged in the entire BeNeLux region. Both the polybasic sequence of the fusion gene cleavage site and the intracerebral pathotyping assay demonstrated the high pathogenicity of the strain. This paper represents the first notification of this specific VII.2 subgenotype in the North-West of Europe. Time-calibrated full genome phylogenetic analysis indicated the silent or unreported circulation of the virus prior to the emergence of three genetic clusters in the BeNeLux region without clear geographical or other epidemiological correlation. The Dutch strain appeared as an outgroup to the Belgian and Luxembourgian strains in the time-correlated genetic analysis and no epidemiological link could be identified between the Belgian and Dutch outbreaks. In contrast, both genetic and epidemiological outbreak investigation data linked the G.D. Luxembourg case to the Belgian outbreak. The genetic links between Belgian viruses from retailers and hobby flocks only partially correlated with epidemiological data. Two independent introductions into the professional poultry sector were identified, although their origin could not be determined. Animal experiments using 6-week- old specific pathogen-free chickens indicated a systemic infection and efficient transmission of the virus. The implementation of re-vaccination in the professional sector, affected hobby and retailers, as well as the restriction on assembly and increased biosecurity measures, possibly limited the epizootic and resulted in the disappearance of the virus. These findings emphasize the constant need for awareness and monitoring of notifiable viruses in the field.

The role of live chicken markets as a source of replication and dissemination of Newcastle disease virus in chickens, northwest Ethiopia

Newcastle disease (ND) is perceived to be the major constraint in village chickens of Ethiopia causing huge economic loss. Village chickens are mobile and pass through markets, and live chicken markets are a highly productive source of ND virus replication, maintenance, and spread. However, in northwest of Ethiopia, there is a dearth of information on the role of live chicken markets in the maintenance and spread of ND in the village chickens. Therefore, a total of 480 apparently healthy chickens in the 4 live chicken markets were sampled with the aim to detect and estimate ND virus infection. Tracheal and cloacal swabs were collected from each bird and processed for virus isolation in 9- to 11-day-old embryonated chicken eggs, and hemagglutination inhibition (HI) assay was performed on all sera samples. The overall infection rate of ND virus was reported to be 39.2% (95% CI: 34.8–43.5). Of all chickens, 34.6% (95% CI: 30.3–38.9) had mean HI titer ≥4 log₂, which was considered as protective. The mean hemagglutination titer for the ND virus was reported to be 6.0 log₂, and mean antibody titer was reported to be 6.2 log₂, with no statistically significant variation among the markets (P > 0.05). Newcastle disease occurrence was detected in all seasons of the year in the live bird markets, with the highest prevalence (55.8%) during the prerainy dry season (April and May), showing evidence for climatic and socioeconomic aspects as a risk factor in the occurrence of ND in indigenous chicken. In vivo virulence tests, mean death time of the embryo, and the intracerebral pathogenicity index revealed the presence of all pathotypes of ND virus strains: velogenic, mesogenic, and lentogenic. Apparently, healthy appearing birds were reported to be reservoirs of velogenic ND virus strains that could initiate endemicity of ND cycles in the village setting. Hence, it is strongly recommended to implement appropriate prevention and control measures to mitigate the economic loss caused by the disease.

Development of a coagglutination kit as a rapid test for diagnosing Newcastle disease in poultry

Background and Aim:

Newcastle disease (ND) is a viral infection that causes high mortality and economic loss in the poultry industry. The Office International des Epizooties (OIE) recommends several diagnostic methods for the detection of ND, including isolation and molecular tests. However, these detection methods are time-consuming and highly expensive. Therefore, this study was conducted to develop a coagglutination kit as a novel diagnostic tool for ND in the poultry industry.

Materials and Methods:

Two adult male New Zealand White rabbits weighing 2.5 kg were vaccinated using ND life vaccine intraperitoneally. The vaccination was conducted once a week for 4 weeks with multilevel doses. Rabbits’ serum was collected at week 6 and inactivated at 56°C for 30 min. The serum was precipitated using ammonium sulfate and reacted with protein A of Staphylococcus aureus to produce the agglutination kit for detecting ND virus. A total of 25 chickens suspected with ND infection from a local poultry farm in Yogyakarta were used as the test samples. The chickens were necropsied, and the brain, spleen, lung, intestine, and feces were collected. Half of these organs were subjected to tests using the coagglutination kit and reverse transcription-polymerase chain reaction (RT-PCR). The other half was processed for histopathology. Data were analyzed qualitatively.

Results:

Of the 25 samples, 13 (52%) were positive for ND infection when tested using both the ND coagglutination kit and RT-PCR. The positive samples also exhibited several histopathological changes, including perivascular cuffing surrounding the cerebral blood–brain barrier, hemorrhagic pneumonia, splenitis, and necrotic hemorrhage enteritis.

Conclusion:

This study confirmed that the ND coagglutination kit could be used as a novel diagnostic tool for the detection of ND virus infection in the poultry industry.

Early Stage Development of a Newcastle Disease Vaccine Candidate in Corn

Newcastle disease (ND) is a viral disease that causes labored breathing, periorbital oedema, and ataxia in the majority of avian species. The available vaccines against Newcastle disease virus (NDV) are limited, owing to their low reactivity and multiple dosage requirements. Plant-based machinery provides an attractive and safe system for vaccine production. In the current study, we attempted to express fusion (F) and hemagglutinin-neuraminidase (HN) proteins (the protective antigens against NDV) under constitutive 35S and seed-specific Zein promoters, respectively. Almost 2-7.1-fold higher expression of F gene mRNA in transgenic corn leaves and 8-28-fold higher expression of HN gene mRNA in transgenic corn seeds were observed, when the expression was analyzed by real-time PCR on a relative basis as compared to non-transgenic control plant material (Leaves and seeds). Similarly, 1.66 μg/ml of F protein in corn leaves, i.e., 0.5% of total soluble protein, and 2.4 μg/ml of HN protein in corn seed, i.e., 0.8% of total seed protein, were found when calculated through ELISA. Similar levels of immunological response were generated in chicks immunized through injection of E. coli-produced pET F and pET HN protein as in chickens orally fed leaves and seeds of maize with expressed immunogenic protein. Moreover, the detection of anti-NDV antibodies in the sera of chickens that were fed maize with immunogenic protein, and the absence of these antibodies in chickens fed a normal diet, confirmed the specificity of the antibodies generated through feeding, and demonstrated the potential of utilizing plants for producing more vaccine doses, vaccine generation at higher levels and against other infectious diseases.