Research (Published online: 25-05-2017)
13. The positive expression of genotype VII Newcastle disease virus
(Malaysian isolate) in
Japanese quails (Coturnix coturnix japonica)
Lizma Felisha Mazlan, Noor Farhana Bachek, Siti Nor Azizah Mahamud,
Lokman Hakim Idris, Tan Sheau Wei,
Abdul Rahman Omar and Mohd Hezmee Mohd Noor
Veterinary World, 10(5): 542-548
ABSTRACT
Aim: Genotype VII Newcastle disease virus (NDV) is the most predominant
NDV strains that circulating in Malaysia; thus, this study was aimed to
determine the susceptibility of Japanese quails toward genotype VII NDV.
Clinical signs, gross pathological lesions of organs, positive detection of
virus in organs and cloacal swabs, as well as the expression of the antibody
titer, were used as parameters to assess the susceptibility of Japanese quails
following infection of genotype VII NDV.
Materials and Methods: About 20 quails were divided
into three groups (n=8 for Groups A and B; n=4 for the control group). The
quails in the Groups A and B were infected via intraocular route with 0.03 ml
of 103.5 ELD50 and 107.0 ELD50 of NDV strain IBS 002, respectively, while the control
group received 1x phosphate-buffered saline. Cloacal swabs and necropsy were
taken on day 7 post-infection for all quails were subjected to one-step reverse
transcription real-time quantitative polymerase chain reaction (RT-qPCR) for
detection of virus and examination for gross pathological lesion, respectively.
Blood serums of infected quails were taken on day 10, 14, and 21 post-day
infections and were subjected for hemagglutination inhibition (HI) assay.
Results: Depression and ruffled feathers, trachea rales, leg paralysis, and
torticollis were shown in some of the quails in both infected groups. Based on
statistical analysis, there was no significant difference (p>0.05) in
clinical signs between the infected groups. The results for RT-qPCR were found
to be negative for all groups, and no gross pathological lesions of organs
observed for quails in both infected groups. Trachea, proventriculus, and cecal
tonsil were taken for the detection of NDV by RT-qPCR, and some of the organ
samples showed positive detection of virus in both infected groups. HI assay
showed an increase in mean titers of antibody across time and between infected
groups.
Conclusion: In summary, Japanese quails are susceptible to genotype VII NDV
based on parameters assessed.
Keywords: infections, intraocular, Japanese quails, Newcastle disease virus.