Laboratory Diagnosis of a NZ7-like Orf Virus Infection and Pathogen Genetic Characterization, Particularly in the VEGF Gene.

Yongzhong Yu,Yuanyuan Liu,Xuyang Duan,Zhengxing Lian,Baifen Song,Yudong Cui,Jinzhu Ma

doi:10.3389/fvets.2020.00538

Yongzhong Yu, Yuanyuan Liu + Show 5 more

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https://doi.org/10.3389/fvets.2020.00538

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Abstract

Orf is a widespread contagious epithelial viral disease found particularly in most sheep breeding countries in the world. Recently, an orf virus (ORFV) strain OV-HLJ05 was isolated from an outbreak in northeast China. Three genes of interest including ORFV011 (B2L), ORFV059 (F1L), and ORFV132 (VEGF) of ORFV, were recruited to identify and genetically characterize this newly isolated virus. Amino acid (aa) sequence compared with the ORFV references listed in GenBank, both B2L and F1L of OV-HLJ05 showed less microheterogeneity from their references. In contrast, the VEGF gene was included in the NZ7-VEGF like group as previously considered by Mercer in 2002. Unexpectedly, further multiple VEGF matches were made, using 34 published sequences from China and India, resulting in 27 strains of the NZ7 members. Based on Karki's report in 2020, NZ7-VEGF like viruses are emerging more and more frequently in these two countries, damaging the Asian sheep industry. Obvious heterogeneity with the NZ2, insertion of two oligopeptides TATI(L)QVVVAI(L) and SSSS(S) motif were found in the NZ7-like VEGF protein. These VEGFs are divided mainly into two types and a significant increase in the number of hydrogen bonds within the NZ7-like VEGF dimers was observed. The NZ7-like ORFV apparently favors the goat as a host and an emphasis on this in future epidemiological and pathological studies should be considered, focusing on the NZ7-like virus.

Highlights

Orf is an animal pustular dermatitis and an epitheliotrophic contagious disease directly caused by the orf virus (ORFV) with a worldwide distribution [1, 2]
The F13L is purportedly required for the efficient formation of enveloped Vaccinia virus (VACV) virions [39] and contains the variant HKD (His-Lys-Asp) motif of phospholipases and phospholipid synthases [40, 41], leading to a report of associated lipase activity [42]
The B2L protein owns the same HKD variant as in F13L which has an NKD pattern, where the His in HKD is substituted by the Asn both in F13L and B2L, while the detailed biochemical lipase function of B2L protein remains unclear

Summary

Introduction

Orf is an animal pustular dermatitis and an epitheliotrophic contagious disease directly caused by the orf virus (ORFV) with a worldwide distribution [1, 2]. This viral skin disease commonly affects sheep, goats, and some other ruminants and has a zoonotic potential in humans who are exposed to a contaminated workplace [3,4,5,6]. Prolonged infection and increased severity are associated with often severe secondary bacterial infection. Minor staphylococcal infection is a frequent occurrence, but mortality rates can be over 5% in infected herds [8]. Higher mortality occurs frequently in lambs or kids during the lactation period due to dehydration and starvation, as the pain and distortion of the lips and mouth reduces

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