scholarly journals Pathotyping of recent Indian field isolates of Marek's disease virus serotype 1

2015 ◽  
Vol 59 (02) ◽  
pp. 156-165 ◽  
Author(s):  
P. SURESH ◽  
J. JOHNSON RAJESWAR ◽  
K. SUKUMAR ◽  
T. J. HARIKRISHNAN ◽  
P. SRINIVASAN
2007 ◽  
Vol 88 (8) ◽  
pp. 2121-2128 ◽  
Author(s):  
Aminul Islam ◽  
Stephen W. Walkden-Brown

The shedding profile of Marek's disease virus serotype 1 (MDV1, virulent), serotype 2 (MDV2, vaccinal) and herpesvirus of turkeys (HVT, vaccinal) in commercial broiler chickens was determined by measuring the daily rate of production of feather dander from chickens housed in isolators and by quantifying the viral load of each of these serotypes in the dander using quantitative real-time PCR (qPCR). MDV1 and HVT viruses were detectable in dander filtered from isolator exhaust air from day 7 and MDV2 from day 12 after infection and thereafter until the end of the experiment at 61 days of age of the chickens. There was no difference in shedding rate among the three MDV1 isolates. Daily shedding of MDV1 increased sharply between days 7 and 28 and stabilized thereafter at about 109 virus copies per chicken per day, irrespective of vaccination status. Challenge with the three different MDV1 isolates markedly increased shedding of the vaccinal viruses HVT and MDV2 in dander by 38- and 75-fold, respectively. These results demonstrate the utility of qPCR for the differentiation and quantification of different MDV serotypes in feather dander and have significant implications for the routine monitoring of Marek's disease using qPCR assays of dust, for epidemiological modelling of the behaviour and spread of MDVs in chicken populations and for studies into the evolution of virulence in MDV1 in the face of blanket vaccination with imperfect vaccines that ameliorate disease but do not prevent infection and replication of virulent virus.


Author(s):  
P Suresh ◽  
J Johnson Rajeswar ◽  
K Sukumar. ◽  
T J Harikrishnan ◽  
P Srinivasan

This study was undertaken to characterize the oncogenicity associated vIL8 (viral interleukin-8) gene at molecular level for three serotype 1 Marek’s Disease Virus (MDV) field isolates recovered from vaccinated poultry flocks. The prime aim was to generate nucleotide sequence data for important oncogenicity associated vIL8 gene of MDV1 which is very much lacking in India. Eighty six blood samples were collected from 15 commercial layer and broiler breeder farms. Isolation was done in duck embryo fibroblasts (DEF) and vIL8 gene was amplified by Polymerization Chain Reaction (PCR) and sequenced. The isolates were shown to have a homology of 99.8-100 per cent within themselves and 94.6-95.1 per cent with various isolates of China and 96.6 – 99.5 per cent with other isolates of USA for vIL8 gene. Alignment analysis of the nucleotide sequences had shown nucleotide mutations at three different positions and displayed perfect regularity. Phylogenetic analysis of vIL8 sequence of three isolates and other six reference strains showed that the analyzed nine MDVs could be distinctly separated into two clusters. The study revealed that the field isolates of serotype 1 MDVs circulating in vaccinated flocks had been shown to have consistent mutations in different positions in vIL8 gene.


2000 ◽  
Vol 62 (3) ◽  
pp. 287-292 ◽  
Author(s):  
Sung-Il LEE ◽  
Michihiro TAKAGI ◽  
Kazuhiko OHASHI ◽  
Chihiro SUGIMOTO ◽  
Misao ONUMA

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