Insights into the chicken bursa of fabricius response to Newcastle disease virus at 48 and 72 hours post-infection through RNA-seq

Abstract Newcastle disease virus (NDV) has caused significant outbreaks in South-East Asia, particularly in Indonesia in recent years. Recently emerged genotype VII NDVs (NDV-GVII) have shifted their tropism from gastrointestinal/respiratory tropism to a lymphotropic virus, invading lymphoid organs including spleen and bursa of Fabricius to cause profound lymphoid depletion. In this study, we aimed to identify candidate genes and biological pathways that contribute to the disease caused by this neurotropic velogenic NDV-GVII. A transcriptomic analysis based on RNA-Seq of spleen was performed in chickens challenged with NDV-GVII and a control group. In total, 6361 genes were differentially expressed that included 3506 up-regulated genes and 2855 down-regulated genes. Real-Time PCR of ten selected genes validated the RNA-Seq results as the correlation between them is 0.98. Functional and network analysis of DEGs showed altered regulation of ElF2 signalling, mTOR signalling, proliferation of lymphatic system cells, signalling by Rho family GTPases and synaptogenesis signalling in spleen. We have also identified modified expression of IFIT5, PI3K, AGT and PLP1 genes in NDV-GVII infected chickens. Our findings in activation of autophagy-mediated cell death, lymphotropic and synaptogenesis signalling pathways provide new insights into the molecular pathogenesis of this newly emerged NDV-GVII.

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Indicators of the molecular pathogenesis of virulent Newcastle disease virus in chickens revealed by transcriptomic profiling of spleen

Scientific Reports ◽

10.1038/s41598-021-96929-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Mohammad Rabiei ◽

Wai Yee Low ◽

Yan Ren ◽

Mohamad Indro Cahyono ◽

Phuong Thi Kim Doan ◽

...

Keyword(s):

Newcastle Disease Virus ◽

Disease Virus ◽

Newcastle Disease ◽

Molecular Pathogenesis ◽

Differentially Expressed ◽

Bursa Of Fabricius ◽

Control Group ◽

Rna Seq ◽

Virulent Newcastle Disease Virus ◽

Lymphoid Depletion

AbstractNewcastle disease virus (NDV) has caused significant outbreaks in South-East Asia, particularly in Indonesia in recent years. Recently emerged genotype VII NDVs (NDV-GVII) have shifted their tropism from gastrointestinal/respiratory tropism to a lymphotropic virus, invading lymphoid organs including spleen and bursa of Fabricius to cause profound lymphoid depletion. In this study, we aimed to identify candidate genes and biological pathways that contribute to the disease caused by this velogenic NDV-GVII. A transcriptomic analysis based on RNA-Seq of spleen was performed in chickens challenged with NDV-GVII and a control group. In total, 6361 genes were differentially expressed that included 3506 up-regulated genes and 2855 down-regulated genes. Real-Time PCR of ten selected genes validated the RNA-Seq results as the correlation between them is 0.98. Functional and network analysis of Differentially Expressed Genes (DEGs) showed altered regulation of ElF2 signalling, mTOR signalling, proliferation of cells of the lymphoid system, signalling by Rho family GTPases and synaptogenesis signalling in spleen. We have also identified modified expression of IFIT5, PI3K, AGT and PLP1 genes in NDV-GVII infected chickens. Our findings in activation of autophagy-mediated cell death, lymphotropic and synaptogenesis signalling pathways provide new insights into the molecular pathogenesis of this newly emerged NDV-GVII.

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Pathogenesis of Newcastle Disease Virus Genotype VII in Chickens Vaccinated with LaSota and Inactivated Newcastle Disease Vaccines

International Journal of Veterinary Science ◽

10.37422/ijvs/20.011 ◽

2020 ◽

Keyword(s):

Newcastle Disease Virus ◽

Disease Virus ◽

Newcastle Disease ◽

Clinical Signs ◽

Bursa Of Fabricius ◽

Virus Genotype ◽

Challenge Virus ◽

Significant Difference ◽

Group D ◽

Genotype Vii

Newcastle disease (ND) is one of the most serious viral diseases affecting poultry farms in different countries. Many outbreaks -even in vaccinated poultry flocks- were recorded in the last few years caused by Newcastle disease virus (NDV) genotype VII. This study was conducted to compare the pathogenesis of NDV genotype VII in non-vaccinated chickens and chickens vaccinated with NDV genotype II live (LaSota) and inactivated vaccines. One hundred 1-day-old chicks were divided into four equal groups; 25 for each. Groups A and B were kept unvaccinated. Group C was vaccinated with LaSota, and group D was vaccinated with both LaSota and inactivated NDV vaccine. Group A was kept as nonchallenged control blank group, while groups B, C and D were challenged intranasally by 0.1 ml 106 EID50 NDV genotype VII at 25-day of age. Three chickens were sacrificed from each group at 2, 5- and 10-days post challenge (dpc). Tissue specimens from trachea, lungs, bursa of fabricius, spleen and thymus were collected for histopathology and immunohistochemistry. NDV genotype VII challenge virus did not induce mortality in both vaccinated groups. Both vaccination programs resulted also in less severe clinical signs and histopathological lesions comparing to non-vaccinated challenged birds. Tracheal lesion score was significantly low in group D at 10 dpc while no significant difference was recorded between groups C and D in lungs. All lymphoid organs showed significantly less severe pathological alterations and depletion in groups C and D comparing to group B. Our results indicated that mis-matched genotype NDV vaccines could alleviate the pathological effect of the NDV challenge virus but do not provide complete protection of the infected host organs.

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DETERMINATION OF IN-VIVO GROWTH KINETICS OF VIRULENT NEWCASTLE DISEASE VIRUS IN BROILER CHICKENS

Bangladesh Journal of Veterinary Medicine ◽

10.3329/bjvm.v7i2.5996 ◽

1970 ◽

Vol 7 (2) ◽

pp. 304-312

Author(s):

MJ Ara ◽

MT Islam ◽

MT Hossain ◽

MA Haque ◽

R Ahmed ◽

...

Keyword(s):

Cell Culture ◽

Body Temperature ◽

Newcastle Disease Virus ◽

Disease Virus ◽

Newcastle Disease ◽

Research Work ◽

Clinical Signs ◽

Bursa Of Fabricius ◽

Avian Embryo ◽

Virulent Newcastle Disease Virus

The research work was conducted on 105 broiler chicks (Cobb-500) with a view to determine the rate of distribution of Newcastle disease virus (NDV) in various organs following infection through natural (intranasal, intraocular and oral) and parenteral (intravenous, intramuscular and subcutaneous) routes of inoculation at different ages (7, 15 and 28 days of old). Each bird received a dose of 0.2 ml of NVNDV (300 ELD50). Body temperature, onset of clinical signs and mortality of birds (if any) were recorded daily. Blood samples were collected from the birds to determine the serum HI titre before and after infection. Faeces and various tissue samples (brain, lungs, kidney, colon, bursa of Fabricius, spleen and thymus) were collected daily following post-mortem examination of one bird from each sub-group to determine the presence of NDV along with their HA titre through inoculation into embryonated hen eggs. Some representative samples were also inoculated into chicken embryo fibroblast (CEF) cell culture for isolation of NDV. The highest body temperature (³1080F) was recorded in the birds of almost all the experimental groups between 48 and 72 hours of PI. Appearance of clinical sings was observed earlier (between 48 to 72 hours of PI) in parenterally infected birds than those of inoculated through natural routes. The shortest duration (>26-54 hours of PI) and longest duration (67-132 hours of PI) of death time recorded in birds those were inoculated through IV and oral routes of infection respectively. Isolation of NDV was positive from day 2 of PI and onward in all the groups with some minor variations in some cases. The CEF cell culture system was found more sensitive compared to avian embryo. Irrespective of routes of inoculation and age of birds, there was significant (p<0.01) increase in the mean HA titre of NDV with the progression of time. The highest HA titre of NDV was found in the brain tissue followed by lungs and kidney. Significantly (p<0.01) higher HA titre of NDV isolate was recorded in the birds of all the experimental groups inoculated through IV route. Following infection, the MDA titres decreased day by day in the birds with the increase of HA titres of NDV.

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A Pigeon-Derived Sub-Genotype XXI.1.2 Newcastle Disease Virus from Bangladesh Induces High Mortality in Chickens

Viruses ◽

10.3390/v13081520 ◽

2021 ◽

Vol 13 (8) ◽

pp. 1520

Author(s):

Mohammed Nooruzzaman ◽

Lalita Rani Barman ◽

Tanjin Tamanna Mumu ◽

Emdadul Haque Chowdhury ◽

Kiril M. Dimitrov ◽

...

Keyword(s):

Newcastle Disease Virus ◽

Disease Virus ◽

High Mortality ◽

Newcastle Disease ◽

Fusion Gene ◽

Biological Properties ◽

Bursa Of Fabricius ◽

Complete Fusion ◽

Protein Cleavage

Newcastle disease virus (NDV) is a significant pathogen of poultry; however, variants also affect other species, including pigeons. While NDV is endemic in Bangladesh, and poultry isolates have been recently characterized, information about viruses infecting pigeons is limited. Worldwide, pigeon-derived isolates are commonly of low to moderate virulence for chickens. Here, we studied a pigeon-derived NDV isolated in Bangladesh in 2010. To molecularly characterize the isolate, we sequenced its complete fusion gene and performed a comprehensive phylogenetic analysis. We further studied the biological properties of the virus by estimating mean death time (MDT) and by experimentally infecting 5-week-old naïve Sonali chickens. The studied virus clustered in sub-genotype XXI.1.2 with NDV from pigeons from Pakistan isolated during 2014–2018. Deduced amino acid sequence analysis showed a polybasic fusion protein cleavage site motif, typical for virulent NDV. The performed in vivo pathogenicity testing showed a MDT of 40.8 h, and along with previously established intracerebral pathogenicity index of 1.51, these indicated a velogenic pathotype for chickens, which is not typical for pigeon-derived viruses. The experimental infection of chickens resulted in marked neurological signs and high mortality starting at 7 days post infection (dpi). Mild congestion in the thymus and necrosis in the spleen were observed at an advanced stage of infection. Microscopically, lymphoid depletion in the thymus, spleen, and bursa of Fabricius were found at 5 dpi, which progressed to severe in the following days. Mild to moderate proliferation of glial cells was noticed in the brain starting at 2 dpi, which gradually progressed with time, leading to focal nodular aggregation. This study reports the velogenic nature for domestic chickens of a pigeon-derived NDV isolate of sub-genotype XXI.1.2. Our findings show that not all pigeon-derived viruses are of low virulence for chickens and highlight the importance of biologically evaluating the pathogenicity of NDV isolated from pigeons.

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Sequential Pathology of a Genotype XIII Newcastle Disease Virus from Bangladesh in Chickens on Experimental Infection

Pathogens ◽

10.3390/pathogens9070539 ◽

2020 ◽

Vol 9 (7) ◽

pp. 539

Author(s):

Congriev Kumar Kabiraj ◽

Tanjin Tamanna Mumu ◽

Emdadul Haque Chowdhury ◽

Mohammad Rafiqul Islam ◽

Mohammed Nooruzzaman

Keyword(s):

Newcastle Disease Virus ◽

Disease Virus ◽

Newcastle Disease ◽

Bursa Of Fabricius ◽

Lymphoid Tissues ◽

Hemorrhagic Pneumonia ◽

Advanced Stages ◽

Lymphoid Depletion ◽

The Brain ◽

Bangladeshi Strain

The sequential pathology of a genotype XIII Bangladeshi strain of Newcastle disease virus (NDV) was studied in 5-weeks old chickens. Layer chickens of ISA Brown breed were inoculated through the intranasal and intraocular routes with the BD-C161/2010 strain of NDV and examined at different times post-infection (pi). NDV-infected chickens showed depression at 3 days pi (dpi) followed by dropped wings, paralysis and death starting at 4 dpi. Lungs of infected chickens showed hemorrhagic lesions starting at 24 hours pi (hpi) that was followed by pallor and slight contraction by 2 to 3 dpi and subsequently developed into severe hemorrhagic pneumonia with mononuclear cell infiltration. Hemorrhagic and necrotizing lesions were found in different visceral organs including proventriculus, intestine, gut-associated lymphoid tissues, liver and kidneys starting at 3 dpi that progressed rapidly. Severe lymphoid depletion was observed in the thymus, spleen and bursa of Fabricius starting at 1–3 dpi followed by hemorrhages, necrosis, inflammation and atrophy at 4–5 dpi. In the brain, mild neuronal lesions such as focal to diffuse encephalitis with encephalomalacia was observed at 2–3 dpi and moderate and diffuse meningoencephalitis with encephalomalacia at advanced stages. In conclusion, the BD-C161/2010 strain of NDV produced lesions typical of velogenic viscerotropic pathotype of NDV.

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