MOLECULARCHARACTERIZATION OF NEWCASTLE DISEASE VIRUS ISOLATES FROM CHICKENSIN ZARIA AND ITS ENVIRONS, KADUNA STATE, NIGERIA
MOLECULARCHARACTERIZATION OF NEWCASTLE DISEASE VIRUS ISOLATES FROM CHICKENSIN ZARIA AND ITS ENVIRONS, KADUNA STATE, NIGERIA
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Date
2016-05
Authors
HAMISU, Tasiu Mallam
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Abstract
Newcastle disease virus (NDV) has a negative-sense,single-strand RNA genome.Although all NDVs are members of Avian Paramyxovirus-1 (APMV-1), antigenic and genetic diversity is recognized. Consequently, different genotypes of APMV-1 circulate in different parts of the world. Therefore, this study aimed to characterize circulating field NDV strains in Zaria and identify their genotype/sub-genotype. A total of 127cloacal swabs were collected from local chickens in live bird market and exotic chickens in commercial poultry farms in Zaria and environs, Nigeria between November, 2014 and January, 2015. Five commercial poultry farms and four live bird markets were purposively sampled.Molecular screening of NDV Matrix-gene (M-gene) was performed on all the samples using ReverseTranscriptase-Polymerase Chain Reaction (RT-PCR). Newcastle disease positive samples were further inoculated in to embryonated chicken eggs for isolation of NDV. Isolates were confirmed as NDV by haemaggulitination (HA) test and detection of the Fusion-gene using RT-PCR. The partial F-gene amplicons (containing nucleotide position 610 of NDV M-gene to position 581 of NDV F-gene) were sequenced in Inqaba Biotechnology, South Africa and the results were analyzed using BioEdit sequence analysis program and MEGA 6.6 software. Newcastle disease virus M-gene were detected in 16 out of 127 cloacal swabs; 13 from live bird markets and 3 from commercial poultry farms. However, only 10 NDVs were isolated in embryonated chicken eggs as confirmed by HA and RT-PCR. Eight of the 10 amplicons of the partial F-gene were successfully sequenced. Analysis of the 47-419 nucleotide region of the partial F-gene of these sequences revealed that all the NDVs isolated in this study were virulent and based on the bootstrap value of>60% and the tree topology, all the strains belonged to sub-genotype XIVb. Three strains from this study shared common amino acid mutations P→L10 and A→V11 as the representatives of sub-genotype XIVb. In addition, one strain from this study sharedL→P36 common amino acid mutation with two representative strains of sub-genotype XIVb from Nigeria and Benin Republic. However, when compared with two representatives of sub-genotype XIVb, all strains from this study had R→Q114 mutations. This study therefore, highlights the importance of continuous surveillance, characterisation and phylogenetic study of NDV in Nigeria so that effective control andpreventive measures against the disease can be implemented
Description
A DISSERTATION SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES, AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE AWARD OF THE DEGREE OF MASTER OF SCIENCE IN VETERINARY MICROBIOLOGY DEPARTMENT OF VETERINARY MICROBIOLOGY, AHMADU BELLO UNIVERSITY, ZARIA NIGERIA
Keywords
MOLECULARCHARACTERIZATION,, NEWCASTLE DISEASE VIRUS ISOLATES,, CHICKENSIN ZARIA,, ENVIRONS,, KADUNA STATE,, NIGERIA