Typing of bluetongue virus serotype 1 and 23 by RT-PCR

Abstract

Two primer pairs were evaluated for amplification of unique regions on the serotype-specific segment 2 (VP2 gene) of bluetongue virus (BTV) by reverse transcription-polymerase chain reaction (RT-PCR). A new set of primer pair [forward primer (FP): 1240-1271 bp and reverse primer (RP): 1844-1813 bp] specific to VP2 gene of BTV serotype 1 (BTV-1) was designed. This primer pair successfully amplified the cell-culture-grown six BTV-1 Indian isolates from different geographical regions, yielding an expected PCR product of 604 bp. However, the primer pair failed to amplify Indian isolates of BTV-18 and BTV-23. Similarly, the primer pair for BTV-23 serotype (FP: 604-623 bp; RP: 1262-1243 bp) amplified 658 bp amplicon with Indian isolates of only BTV-23 and not with the isolates of BTV-1<i style=""> </i>and BTV-18 serotypes. These VP2 gene based serotype specific primers when aligned with other BTV serotype sequences available in the GenBank revealed no significant sequence identity except with the serotypes for which they were designed. This strongly suggests that the serotype specific primers have potential application for detection of BTV-1 and BTV-23 by using rapid, reliable and specific RT-PCR assay.