Genetic Evolutionary Analysis of Lumpy Skin Disease Virus Strain Under Immune Pressure Exerted by Heterologous Goat...

Lumpy skin disease (LSD) is an important infectious disease that threatens the global cattle industry. Recently, LSD has occurred frequently in Asia. The attenuated goat poxvirus (GTPV) vaccine is widely used to prevent LSD in cattle in China; however, sporadic cases of LSD still occur in immunized cattle. This study aimed to investigate the genetic evolution of isolated LSD virus (LSDV) strain under GTPV heterologous vaccine immune pressure. We isolated a new strain of LSDV, named LSDV/China/SX/2023, from a cattle herd immunized with a GTPV-attenuated vaccine in Shaanxi Province, Northwest China, and conducted whole-genome sequencing and genetic evolution studies. There are several open reading frames (ORFs) differences between the isolated strain and the Chinese reference strains, among which truncated expression of the Kelch-like protein encoded by ORF 19 may affect its growth characteristics. Phylogenetic analysis revealed that the isolated strain is in the same evolutionary clade as previous isolates from China and Southeast Asia. RDP4 and Simplot simultaneously showed that all strains in this branch had the same 15 recombination events, and there was one recombination event associated with the GTPV. This study presents the recent genetic evolution of LSDV under GTPV vaccine immune pressure and discusses the viral recombination events that are thought to influence transmission which are critical for the control and purification of LSD.