A novel HRM-based gap-qRT-PCR for identification and quantitation of the vaccine and field strain(s) of lumpy skin disease virus.

Abstract

Lumpy skin disease (LSD) has become the most important animal health problem in India due to high morbidity, mortality and production losses caused by it. A homologous live-attenuated LSD vaccine (Lumpi-ProVac) was recently developed by using a local LSD virus (LSDV) strain (LSDV/2019/India/Ranchi) in India which is likely to replace the existing practice of vaccinating cattle with goatpox vaccine. It is essential to differentiate the vaccine and field strains, if a live-attenuated vaccine has been used for control and eradication of the disease. As compared to the prevailing vaccine and field/virulent strains, the Indian vaccine strain (Lumpi-ProVac) has a unique deletion of 801 nucleotides in its inverted terminal repeat (ITR) region. We exploited this unique feature and developed a novel high resolution melting-based gap quantitative real-time PCR (HRM-gap-qRT-PCR) for rapid identification and quantitation of the vaccine and field strain(s) of LSDV.