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Characterization of Newcastle disease virus isolates obtained from outbreak cases in commercial chickens and wild pigeons in Ethiopia.

Damena D, Fusaro A, Sombo M, Belaineh R, Heidari A, Kebede A, Kidane M, Chaka H - Springerplus (2016)

Bottom Line: The similarity between the viruses obtained from chickens and those obtained from pigeons ranged from 82.5 to 85.6 %.This suggests that different sub genotypes of genotype VI are circulating in chicken and wild pigeon population in Ethiopia.This warrants further study to understand the role of wild birds in the epidemiology of NDV in Ethiopia and as well highlights the importance of continuous surveillances both in wild birds and domestic poultry.

View Article: PubMed Central - PubMed

Affiliation: National Animal Health Diagnostic and Investigation Center, P.O. Box 04, Sebeta, Ethiopia.

ABSTRACT
Newcastle disease (ND), caused by virulent avian paramyxovirus type 1, is one of the most important diseases responsible for devastating outbreaks in poultry flocks in Ethiopia. However, the information about genetic characteristics of the Newcastle disease viruses (NDVs) circulating in commercial chickens and wild birds is scarce. In this study, we characterized isolates obtained from ND suspected outbreaks during 2012-2014 from poultry farms (n = 8) and wild pigeons (n = 4). The NDVs isolated from pathological specimens, through inoculation in embryonated chicken eggs, were characterized biologically by conventional intracerebral pathogenicity indices (ICPI), and genetically on the basis of Phylogenic analysis of partial F-gene sequences (260 bp) encompassing the cleavage site. The ICPI values of isolates from chickens ranged from 0.9 to 1.8; whereas, the ICPI of pigeon isolates was 1.4. All isolates contained multiple basic amino acids at the deduced cleavage site of fusion protein, which is a typical feature of virulent viruses. Phylogenic analysis of the partial cleavage site of F-gene (260 bp) indicated that all the sequences of viruses obtained from pigeons were identical and clustered within the genotype VIh while the sequences of viruses obtained from chickens were clustered together within the genotype VIf. The similarity between the viruses obtained from chickens and those obtained from pigeons ranged from 82.5 to 85.6 %. This suggests that different sub genotypes of genotype VI are circulating in chicken and wild pigeon population in Ethiopia. This warrants further study to understand the role of wild birds in the epidemiology of NDV in Ethiopia and as well highlights the importance of continuous surveillances both in wild birds and domestic poultry.

No MeSH data available.


Related in: MedlinePlus

ML phylogenic analysis of partial F-gene sequences (260 bp) encompassing the cleavage site of APMV-1 viruses. Sequences under study are marked in red. Numbers at the nodes represent bootstrap values (>70)
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Fig2: ML phylogenic analysis of partial F-gene sequences (260 bp) encompassing the cleavage site of APMV-1 viruses. Sequences under study are marked in red. Numbers at the nodes represent bootstrap values (>70)

Mentions: All eight haemagglutinating isolates obtained from poultry farm outbreaks were identified as Newcastle disease virus that reacted with monospesific antiserum specific for avian paramyxovirus 1. All four isolates obtained from pigeon outbreak were identified as Pigeon paramyxovirus 1 that reacted with monoclonal antibody specific for Pigeon paramyxovirus 1. Besides, all the isolates were confirmed positive for virulent NDVs by reverse transcriptase real time PCR. The ICPI values of isolates from chickens ranged from 0.9 to 1.8; whereas, the ICPI of both pigeon isolates was 1.4 (Table 1). In addition, the pathotype prediction according to the deduced amino acid sequence of the cleavage site of the fusion protein showed that, the pigeon isolates have sequence motifs SVGRRRKR*F and chicken isolates have sequence motifs SGGRRQKR*F and SGGRRRKR*F suggestive of virulent strains (Table 1). Phylogenic analysis of partial F-gene sequences (260 bp) encompassing the cleavage site revealed that, all the sequences from pigeons (Fig. 2) were identical and clustered within the genotype VIh with viruses collected from pigeons in Nigeria between 2007 and 2013. The chicken viruses were clustered together with other Ethiopian isolates within the genotype VIf. However, isolates from the same farm do not always seem to end up in the same branch (Fig. 2). Specifically, one of the isolates from Kombolcha with sample Id 15925 is slightly different from the other isolate collected from the same place and was completely identical to the isolates from Sodo farm. It ended up on the same branch of the phylogenetic tree and contained the same cleavage site motifs (Table 1). The similarity between the viruses from chickens and those from pigeons ranged from 82.5 to 85.6 %.Table 1


Characterization of Newcastle disease virus isolates obtained from outbreak cases in commercial chickens and wild pigeons in Ethiopia.

Damena D, Fusaro A, Sombo M, Belaineh R, Heidari A, Kebede A, Kidane M, Chaka H - Springerplus (2016)

ML phylogenic analysis of partial F-gene sequences (260 bp) encompassing the cleavage site of APMV-1 viruses. Sequences under study are marked in red. Numbers at the nodes represent bootstrap values (>70)
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835400&req=5

Fig2: ML phylogenic analysis of partial F-gene sequences (260 bp) encompassing the cleavage site of APMV-1 viruses. Sequences under study are marked in red. Numbers at the nodes represent bootstrap values (>70)
Mentions: All eight haemagglutinating isolates obtained from poultry farm outbreaks were identified as Newcastle disease virus that reacted with monospesific antiserum specific for avian paramyxovirus 1. All four isolates obtained from pigeon outbreak were identified as Pigeon paramyxovirus 1 that reacted with monoclonal antibody specific for Pigeon paramyxovirus 1. Besides, all the isolates were confirmed positive for virulent NDVs by reverse transcriptase real time PCR. The ICPI values of isolates from chickens ranged from 0.9 to 1.8; whereas, the ICPI of both pigeon isolates was 1.4 (Table 1). In addition, the pathotype prediction according to the deduced amino acid sequence of the cleavage site of the fusion protein showed that, the pigeon isolates have sequence motifs SVGRRRKR*F and chicken isolates have sequence motifs SGGRRQKR*F and SGGRRRKR*F suggestive of virulent strains (Table 1). Phylogenic analysis of partial F-gene sequences (260 bp) encompassing the cleavage site revealed that, all the sequences from pigeons (Fig. 2) were identical and clustered within the genotype VIh with viruses collected from pigeons in Nigeria between 2007 and 2013. The chicken viruses were clustered together with other Ethiopian isolates within the genotype VIf. However, isolates from the same farm do not always seem to end up in the same branch (Fig. 2). Specifically, one of the isolates from Kombolcha with sample Id 15925 is slightly different from the other isolate collected from the same place and was completely identical to the isolates from Sodo farm. It ended up on the same branch of the phylogenetic tree and contained the same cleavage site motifs (Table 1). The similarity between the viruses from chickens and those from pigeons ranged from 82.5 to 85.6 %.Table 1

Bottom Line: The similarity between the viruses obtained from chickens and those obtained from pigeons ranged from 82.5 to 85.6 %.This suggests that different sub genotypes of genotype VI are circulating in chicken and wild pigeon population in Ethiopia.This warrants further study to understand the role of wild birds in the epidemiology of NDV in Ethiopia and as well highlights the importance of continuous surveillances both in wild birds and domestic poultry.

View Article: PubMed Central - PubMed

Affiliation: National Animal Health Diagnostic and Investigation Center, P.O. Box 04, Sebeta, Ethiopia.

ABSTRACT
Newcastle disease (ND), caused by virulent avian paramyxovirus type 1, is one of the most important diseases responsible for devastating outbreaks in poultry flocks in Ethiopia. However, the information about genetic characteristics of the Newcastle disease viruses (NDVs) circulating in commercial chickens and wild birds is scarce. In this study, we characterized isolates obtained from ND suspected outbreaks during 2012-2014 from poultry farms (n = 8) and wild pigeons (n = 4). The NDVs isolated from pathological specimens, through inoculation in embryonated chicken eggs, were characterized biologically by conventional intracerebral pathogenicity indices (ICPI), and genetically on the basis of Phylogenic analysis of partial F-gene sequences (260 bp) encompassing the cleavage site. The ICPI values of isolates from chickens ranged from 0.9 to 1.8; whereas, the ICPI of pigeon isolates was 1.4. All isolates contained multiple basic amino acids at the deduced cleavage site of fusion protein, which is a typical feature of virulent viruses. Phylogenic analysis of the partial cleavage site of F-gene (260 bp) indicated that all the sequences of viruses obtained from pigeons were identical and clustered within the genotype VIh while the sequences of viruses obtained from chickens were clustered together within the genotype VIf. The similarity between the viruses obtained from chickens and those obtained from pigeons ranged from 82.5 to 85.6 %. This suggests that different sub genotypes of genotype VI are circulating in chicken and wild pigeon population in Ethiopia. This warrants further study to understand the role of wild birds in the epidemiology of NDV in Ethiopia and as well highlights the importance of continuous surveillances both in wild birds and domestic poultry.

No MeSH data available.


Related in: MedlinePlus