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

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.

Molecular evaluation and genetic characterisation of Newcastle disease virus's haemagglutinin-neuraminidase protein isolated from broiler chickens in Iran

Background

Newcastle disease (ND) virus (NDV) is one of the major pathogens in poultry farms that causes severe economic damages to the poultry industry, especially broiler chicken and turkey farms. Despite the endemicity of ND and its many epidemics in the country, the nature of the Iranian strain of the Newcastle virus is still largely unknown. This study aimed to characterise and evaluate NDV isolates obtained from commercial poultry farms in Iran in 2019 through haemagglutinin‐neuraminidase (HN) gene sequencing.

Method

HN gene of each NDV isolate was amplified and sequenced using specific primers followed by phylogenetic analysis of full length of HN gene open reading frame and amino acid (aa) sequence of HN.

Results

Phylogenetic analysis of the HN gene showed that the virus is very closely related to genotypes VII and III. Analysis of HN gene nucleotide sequences showed that all isolates encode proteins with a length of 571 aa.

Conclusion

Results of the present study are useful for a better understanding of molecular epidemiology of indigenous NDV strains and determining important molecular differences between fields and commonly used vaccine strains related to main immunogenic proteins.

Newcastle disease virus suppress glycolysis pathway and induce breast cancer cells death

Newcastle disease virus (NDV) can modulate cancer cell signaling pathway and induce apoptosis in cancer cells. Cancer cells increase their glycolysis rates to meet the energy demands for their survival and generate ATP as the primary energy source for cell growth and proliferation. Interfering the glycolysis pathway may be a valuable antitumor strategy. This study aimed to assess the effect of NDV on the glycolysis pathway in infected breast cancer cells. Oncolytic NDV attenuated AMHA1 strain was used in this study. AMJ13 and MCF7 breast cancer cell lines and a normal embryonic REF cell line were infected with NDV with different multiplicity of infections (moi) to determine the IC50 of NDV through MTT assay. Crystal violet staining was done to study the morphological changes. NDV apoptosis induction was assessed using AO/PI assay. NDV interference with the glycolysis pathway was examined through measuring hexokinase (HK) activity, pyruvate, and ATP concentrations, and pH levels in NDV infected and non-infected breast cancer cells and in normal embryonic cells. The results showed that NDV replicates efficiently in cancer cells and spare normal cells and induce morphological changes and apoptosis in breast cancer cells but not in normal cells. NDV infected cancer cells showed decreased in the HK activity, pyruvate and ATP concentrations, and acidity, which reflect a significant decrease in the glycolysis activity of the NDV infected tumor cells. No effects on the normal cells were observed. In conclusion, oncolytic NDV ability to reduce glycolysis pathway activity in cancer cells can be an exciting module to improve antitumor therapeutics.

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

BACKGROUND

The frequent outbreaks of Newcastle disease virus (NDV) in Iraq pose a constant threat to commercial poultry, despite the introduction of routine vaccination programmes. Several factors, particularly stress factors and coinfections, might play a role in increasing NDV outbreaks in poultry species.

OBJECTIVES

The current study was aimed to characterize an NDV isolate from an outbreak in North Baghdad, Iraq.

METHODS

Clinical pathogenicity of the isolate was determined experimentally in chickens. In vitro studies included cytopathological examination, as well as molecular and phylogenetic analyses.

RESULTS

Based on the clinical studies and pathogenicity indices (mean death time and intracerebral and intravenous pathogenicity indices), the isolate was characterized as velogenic (highly virulent). Reverse transcriptase polymerase chain reaction targeting the partial fusion protein gene of the NDV genome confirmed the detection. Partial sequencing of the hypervariable region of the fusion gene identified the presence of an avirulent (lentogenic) fusion protein motif (GRQGRL). Phylogenetic analysis of the new isolate along with previously known regional isolates revealed that the new isolate was related to genotype II strains. Additionally, sequence analysis indicated a distinct genetic lineage of the new isolate, which was related to some of the lineages identified in previous outbreaks in the Middle East.

CONCLUSION

The current study offers essential information on the epidemiology, characteristics and diagnosis of NDV for disease control in Iraq. The isolate was found to belong to genotype II and possess an avirulent fusion protein motif.