Molecular screening and isolation of Newcastle disease virus from live poultry markets and chickens from commercial poultry farms in Zaria, Kaduna state, Nigeria

Abstract

Newcastle disease is one of the major economic threats to poultry population  because of its high morbidity and mortality varying from 90-100%. It is caused by Avian Paramyxovirus-1 (APMV-1). This research work was carried out to identify Newcastle disease virus (NDV) by using reverse transcription-polymerase chain reaction (RT-PCR) assay and further isolate the virus in embryonated chicken eggs. A total of 127 cloacal 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 Reverse  Transcriptase-Polymerase Chain Reaction (RT-PCR). Newcastle disease positive samples were further inoculated into embryonated chicken eggs for isolation of Newcastle disease virus. Isolates were confirmed as Newcastle disease virus by haemaggulitination inhibition (HI) test. Newcastle disease virus Matrix-gene was detected in 16 (12.5%) out of 127 cloacal swabs; 13 (10.2%) from live bird markets and 3 (2.3%) from commercial poultry farms. However, only 10 Newcastle disease viruses were isolated in embryonated chicken eggs as confirmed by Haemagglutination inhibition (HI) test. Due to the higher detection rate recorded by reverse transcriptase-polymerase chain reaction (RT-PCR), it is therefore important that molecular technique be made easily accessible so that samples from each suspected outbreaks of NDV be screened so that rapid and confirmatory diagnosis can be achieved.

Keywords: Embryonated chicken eggs, Haemagglutination inhibition test, Newcastle disease virus, RT-PCR