Rapid Spread and Genetic Characterisation of a Recently Emerged Recombinant Lumpy Skin Disease Virus in Thailand

Abstract

The emergence of the lumpy skin disease virus (LSDV) was first detected in north-eastern Thailand in March 2021. Since then, the abrupt increase of LSD cases was observed throughout the country as outbreaks have spread rapidly to 64 out of a total of 77 provinces within four months. Blood, milk, and nodular skin samples collected from affected animals have been diagnosed by real-time PCR targeting the p32 gene. LSDV was isolated by primary lamb testis (PLT) cells, followed by Madin-Darby bovine kidney (MDBK) cells, and confirmed by immunoperoxidase monolayer assay (IPMA). Histopathology and immunohistochemistry (IHC) of a skin lesion showed inclusion bodies in keratinocytes and skin epithelial cells. Phylogenetic analyses of RPO30 and GPCR genes, and the whole genome revealed that Thai viruses were closely related to the vaccine-derived recombinant LSDV strains found previously in China and Vietnam. Recombination analysis confirmed that the Thai LSDV possesses a mosaic hybrid genome containing the vaccine virus DNA as the backbone and a field strain DNA as the minor donor. This is an inclusive report on the disease distributions, complete diagnoses, and genetic characterisation of LSDV during the first wave of LSD outbreaks in Thailand.

Lumpy Skin Disease: An Economically Significant Emerging Disease

“…The author claimed that the recent emergence of vaccine-like LSDV strains in large parts of Asia is likely the result of a spillover from animals vaccinated with the Lumpivax vaccine. Furthermore, Suwankitwa et al [12], in Thailand, by genetic analysis, detected a recombinant LSDV derived from a vaccine strain previously appearing in China and Vietnam. Investigation revealed that the Thailand LSDV possesses a mosaic hybrid genome containing the vaccine virus DNA as the backbone and a field strain DNA as the minor donor.…”

Long-term monitoring of immune response to recombinant lumpy skin disease virus in dairy cattle from small-household farms in western Thailand

“…Thus, the external parasite prevention is recommended. On 19 April 2021, an o cial index case of dairy cattle in Nakhon Pathom province obtained sperm from Ratchaburi province, which had previously had an LSD epidemic on 5 April 2021 14 . There were six investigated farms collected sperm from prior LSD epidemic areas.…”

“…The GPCR and RPO30 genes demonstrated that the viruses in Nakhon Pathom, Ratchaburi, and Kanchanaburi were same and clustered in recombinant vaccination strains, which was consistent with prior results in Thailand. [12][13][14] . Furthermore, this nding suggests that both genes are still helpful for con rming LSDV and classifying viral strains.…”

“…The disease was rstly reported in Zambia in 1929 5 and spread to other continentals [6][7][8] . Recently, the disease was reported in several Asian countries including Thailand [9][10][11][12][13][14] . Immunity in animals infected with LSDV is lifelong and can neutralize the virus by up to three-log TCID 50 /mL 15 .…”

In-silico characterization of LSDV132 protein divulged its BCL-2-like nature

“…LSDV entails 156 ORFs as putative genes, having a coding density of 95% and about 53–2025 amino acid sequences that encode their respective proteins [ 4 ]. The functions of most of the proteins are known which include the involvement in nucleic acid biogenesis, virion assembly, and formation of the virion structure [ 5 ]. Although all such putative genes have well-known functions but there are exceptions as well [ 6 ].…”