Detection and molecular identification of infectious bronchitis virus isolated in Malaysia

Infectious bronchitis is a disease of economic importance in the poultry industry in Malaysia. Currently, natural outbreaks of IB are controlled through the use of vaccine. However, outbreaks still occur in vaccinated flocks. One of the major factors speculated for these outbreaks is the heterolo...

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Main Author:	Mohamed, Maizan
Format:	Thesis
Language:	English English
Published:	2000
Subjects:	Infectious bronchitis in poultry - Malaysia
Online Access:	http://psasir.upm.edu.my/id/eprint/9189/1/FSAS_2000_44_IR.pdf
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spelling	my-upm-ir.91892024-02-02T03:39:48Z Detection and molecular identification of infectious bronchitis virus isolated in Malaysia 2000-08 Mohamed, Maizan Infectious bronchitis is a disease of economic importance in the poultry industry in Malaysia. Currently, natural outbreaks of IB are controlled through the use of vaccine. However, outbreaks still occur in vaccinated flocks. One of the major factors speculated for these outbreaks is the heterologous protection afforded by the current standard IB vaccines against different IB virus (IBV) serotypes and variants present in the country. Rapid and sensitive methods for the detection and identification of serotypes causing these outbreaks would therefore be valuable to the understanding and control of IB. In this study, reverse-transcription polymerase chain reaction (RT-PCR) using the published primers (C2U/C3L, S1oligo3'/S1oligo5', S1oligo3'/S1Newoligo5', IBP1+IIBRP2-, IBVN2+IIBVN1- and UTR2+/UTR1-) were used to detect 14 Malaysian IBV isolates. Only primers UTR2+/uTR1- and IBP l +IIBRP2- were found to be able to detect all of the 14 Malaysian isolates. These primers could therefore be used as universal primers for the detection of Malaysian IBV isolates. The Sl gene of a Malaysian nephropathogenic IBV (MH5365/95) and the variable region in the S l gene of the remaining 13 IBV isolates were RT-PCR using primers Slolig05-1/Sl olig03' and TM897FffM1328R respectively. The PCR products were cloned, sequenced and compared the sequences with published sequences of the S1 gene of other IBV strains. Based on this sequence comparison, MH5365/95 was found to be different from the other IBV strains. The remaining 13 isolates were classified into 2 general groups. The first group, that was designated as Group A, consists of three isolates and was closely related (more than 95% homology) to Massachusetts type (M41), the most commonly used vaccine strain in this country. The second group which consists of 10 isolates was genetically different from the published IBVs showing not more than 82% homology with the published sequence. These 10 isolates were further subdivided into Groups B and C, comprising 7 and 3 isolates respectively. The 3 isolates of Group C belong to the same group as MH5365/95. The Group B isolates, however, were more closely related to the M41 serotype (about 82% in homology) compared with that of Group C isolates (less than 80%). There was about 78% nucleic acid homology when Groups B and C were compared. It could therefore be concluded that the outbreaks in this country were caused by the new strains of IBV, which were different from the vaccine strains, thereby resulting in the vaccines becoming less efficacious to protect the chickens against the local IBVs. Infectious bronchitis in poultry - Malaysia 2000-08 Thesis http://psasir.upm.edu.my/id/eprint/9189/ http://psasir.upm.edu.my/id/eprint/9189/1/FSAS_2000_44_IR.pdf text en public masters Universiti Putra Malaysia Infectious bronchitis in poultry - Malaysia Faculty of Science and Environmental Studies Mohd. Yusoff, Khatijah English
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English English
advisor	Mohd. Yusoff, Khatijah
topic	Infectious bronchitis in poultry - Malaysia
spellingShingle	Infectious bronchitis in poultry - Malaysia Mohamed, Maizan Detection and molecular identification of infectious bronchitis virus isolated in Malaysia
description	Infectious bronchitis is a disease of economic importance in the poultry industry in Malaysia. Currently, natural outbreaks of IB are controlled through the use of vaccine. However, outbreaks still occur in vaccinated flocks. One of the major factors speculated for these outbreaks is the heterologous protection afforded by the current standard IB vaccines against different IB virus (IBV) serotypes and variants present in the country. Rapid and sensitive methods for the detection and identification of serotypes causing these outbreaks would therefore be valuable to the understanding and control of IB. In this study, reverse-transcription polymerase chain reaction (RT-PCR) using the published primers (C2U/C3L, S1oligo3'/S1oligo5', S1oligo3'/S1Newoligo5', IBP1+IIBRP2-, IBVN2+IIBVN1- and UTR2+/UTR1-) were used to detect 14 Malaysian IBV isolates. Only primers UTR2+/uTR1- and IBP l +IIBRP2- were found to be able to detect all of the 14 Malaysian isolates. These primers could therefore be used as universal primers for the detection of Malaysian IBV isolates. The Sl gene of a Malaysian nephropathogenic IBV (MH5365/95) and the variable region in the S l gene of the remaining 13 IBV isolates were RT-PCR using primers Slolig05-1/Sl olig03' and TM897FffM1328R respectively. The PCR products were cloned, sequenced and compared the sequences with published sequences of the S1 gene of other IBV strains. Based on this sequence comparison, MH5365/95 was found to be different from the other IBV strains. The remaining 13 isolates were classified into 2 general groups. The first group, that was designated as Group A, consists of three isolates and was closely related (more than 95% homology) to Massachusetts type (M41), the most commonly used vaccine strain in this country. The second group which consists of 10 isolates was genetically different from the published IBVs showing not more than 82% homology with the published sequence. These 10 isolates were further subdivided into Groups B and C, comprising 7 and 3 isolates respectively. The 3 isolates of Group C belong to the same group as MH5365/95. The Group B isolates, however, were more closely related to the M41 serotype (about 82% in homology) compared with that of Group C isolates (less than 80%). There was about 78% nucleic acid homology when Groups B and C were compared. It could therefore be concluded that the outbreaks in this country were caused by the new strains of IBV, which were different from the vaccine strains, thereby resulting in the vaccines becoming less efficacious to protect the chickens against the local IBVs.
format	Thesis
qualification_level	Master's degree
author	Mohamed, Maizan
author_facet	Mohamed, Maizan
author_sort	Mohamed, Maizan
title	Detection and molecular identification of infectious bronchitis virus isolated in Malaysia
title_short	Detection and molecular identification of infectious bronchitis virus isolated in Malaysia
title_full	Detection and molecular identification of infectious bronchitis virus isolated in Malaysia
title_fullStr	Detection and molecular identification of infectious bronchitis virus isolated in Malaysia
title_full_unstemmed	Detection and molecular identification of infectious bronchitis virus isolated in Malaysia
title_sort	detection and molecular identification of infectious bronchitis virus isolated in malaysia
granting_institution	Universiti Putra Malaysia
granting_department	Faculty of Science and Environmental Studies
publishDate	2000
url	http://psasir.upm.edu.my/id/eprint/9189/1/FSAS_2000_44_IR.pdf
_version_	1794018797982580736

Detection and molecular identification of infectious bronchitis virus isolated in Malaysia

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