Determination of Genetic Variability in Avian Infectious Bronchitis Virus (AIBV) Isolated from Pakistan
Determination of Genetic Variability in Avian Infectious Bronchitis Virus (AIBV) Isolated from Pakistan
Saba Rafique1,2,*, Khalid Naeem1, Naila Siddique1, Muhammad Athar Abbas1, Aamer Ali Shah2, Akbar Ali1, Abdul Rahim1 and Farooq Rashid1
ABSTRACT
This study was designed to undertake molecular characterization of an Infectious bronchitis virus (IBV) recovered from a suspected case of avian infectious bronchitis from commercial poultry. Initially the isolated IB-virus was characterized by RFLP using enzymes Alu I, Hae III, BstYI and XcmI. On the basis of its distinct RFLP pattern from other known IBV vaccine strains, the isolate was named as KU145467_NARC/786_Pakistan_2013 (also named as Pak-786) was subjected to Spike gene sequencing covering the amino-terminus region of 01 to 974 base pairs. The S protein sequence was submitted to the GenBank with accession number KU145467. Phylogenetic grouping and maximum nucleotide sequence identity values were used to identify the isolate that looked to be derived from recombination. It showed maximum nucleotide homology 99.5% with ck/CH/LHB/121010 (KP036503), India/IBV572 (KF809797) and Japan/JP/Wakayama-2/2004 (AB363951.2) and 99.3% with 4/91 vaccine (KF377577), Iran/491/08 (HQ842715) and 99.1% with India/NMK/72/VRI/10 (HM748585) and was least related to rest of IBV lineages compared in this study. It is concluded that Pak-786 isolate belongs to GI-13 lineage that include both the vaccine and virulent field strains, previously assigned to the 793B like. The study supports the concept that due to mass usage of live IBV vaccinal strains of diverse origin, variety of variants originate through random spontaneous mutation and genetic recombination which could lead to genetic drift. The emergent strain of IBV in this study points out the need to include such variants in killed-vaccine form in the vaccination program of the affected region.
To share on other social networks, click on any share button. What are these?
April 2018
Vol. 50, Iss. 2, Pages 401-797
