Genotypic characterization of Indian isolates of infectious bursal disease virus strains by reverse transcription-polymerase chain reaction combined with restriction fragment length polymorphism analysis

Abstract

Summary. -Th e reverse transcription PCR (RT-PCR) combined with restriction fragment length polymorphism (RFLP) is used for the diff erentiation of classical virulent (cv), virulent (v) and very virulent (vv) strains of infectious bursal disease virus (IBDV) isolates from chicken bursal tissues in southern states of India. In the present study, six diff erent isolates (MB11, HY12, PY12, BGE14, VCN14 and NKL14) of IBDV strains were subjected for genotyping along with vaccine virus (Georgia, intermediate strain) using RT-PCR for amplifi cation of a 743 bp sequence in the hypervariable region of VP2 gene followed by restriction enzyme digestion with 5 diff erent restriction enzymes (BspMI, SacI, HhaI, StuI and SspI). Th e RT-PCR products obtained from vvIBDV strains were digested by SspI enzyme except PY12, BGE14 and MB11 isolates. Th e SacI digested the isolate MB11, PY12 and the vaccine strain, but it did not cleave the very virulent isolates of IBDV. HhaI cleaved all the isolates with diff erent restriction profi le patterns. StuI digested all the vvIBDV isolates and BspMI was not able to diff erentiate fi eld isolates from vaccine strain. Th ough RT-PCR combined with RFLP is a genotypic method, further confi rmation of serotypes to distinguish the vvIBDV from cvIBDV has to be carried out using pathogenicity studies.Keywords: infectious bursal disease virus; reverse transcription polymerase chain reaction; restriction fragment length polymorphism; VP2 gene; genotyping * Corresponding author. E-mail: tmaskumar@yahoo.com, tmaskumar@tanuvas.org.in; phone: +91-44-25369301. Abbreviations: RT-PCR = reverse transcription PCR; RFLP = restriction fragment length polymorphism; cvIBDV = classical virulent infectious bursal disease virus; vvIBDV = very virulent infectious bursal disease virus

Molecular Characterization of Infectious Bursal Disease Virus From Commercial Poultry in Pakistan

“…Remaining amino acid alterations were mostly conservative in nature [54][55][56][57]. The changes in the hydrophilic regions of the VP2 protein were important as they are indicative of continuous changes going on in viral genome [58][59][60][61][62].…”