title: Characterization of Newcastle disease virus isolates obtained from outbreak cases in commercial chickens and wild pigeons in 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.
authors.affiliation: National Animal Health Diagnostic and Investigation Center, P.O. Box 04, Sebeta, Ethiopia.
authors.forename: Delesa
authors.initials: D
authors.lastname: Damena
authors.affiliation: Research and Innovation Department, Istituto Zooprofilattico Sperimentale delle Venezie, OIE/FAO and National Reference Laboratory for Newcastle Disease and Avian Influenza, OIE Collaborating Center for Diseases at the Human-Animal Interface, Legnaro, Padova Italy.
authors.forename: Alice
authors.initials: A
authors.lastname: Fusaro
authors.affiliation: National Animal Health Diagnostic and Investigation Center, P.O. Box 04, Sebeta, Ethiopia.
authors.forename: Melaku
authors.initials: M
authors.lastname: Sombo
authors.affiliation: National Animal Health Diagnostic and Investigation Center, P.O. Box 04, Sebeta, Ethiopia.
authors.forename: Redeat
authors.initials: R
authors.lastname: Belaineh
authors.affiliation: Research and Innovation Department, Istituto Zooprofilattico Sperimentale delle Venezie, OIE/FAO and National Reference Laboratory for Newcastle Disease and Avian Influenza, OIE Collaborating Center for Diseases at the Human-Animal Interface, Legnaro, Padova Italy.
authors.forename: Alireza
authors.initials: A
authors.lastname: Heidari
authors.affiliation: National Animal Health Diagnostic and Investigation Center, P.O. Box 04, Sebeta, Ethiopia.
authors.forename: Abera
authors.initials: A
authors.lastname: Kebede
authors.affiliation: National Animal Health Diagnostic and Investigation Center, P.O. Box 04, Sebeta, Ethiopia.
authors.forename: Menbere
authors.initials: M
authors.lastname: Kidane
authors.affiliation: National Animal Health Diagnostic and Investigation Center, P.O. Box 04, Sebeta, Ethiopia.
authors.forename: Hassen
authors.initials: H
authors.lastname: Chaka
keywords: Chickens; Molecular characterization; Newcastle disease virus; Pigeons, Ethiopia