Genome analysis of orf virus isolates from goats in the Fujian Province of southern China.

Xuelin Chi,Ming Li,Shuhong Luo,Wenbo Hao,Xiancheng Zeng,Yifan Huang,Shihua Wang,Wei Li,Daniel L Rock,Xiaohong Huang

doi:10.3389/fmicb.2015.01135

Abstract

Orf virus (ORFV), a species of the genus Parapoxvirus of the family Poxviridae, causes non-systemic, highly contagious, and eruptive disease in sheep, goat, and other wild and domestic ruminants. Our previous work shows orf to be ubiquitous in the Fujian Province of China, a region where there is considerable heterogeneity among ORFVs. In this study, we sequenced full genomes of four Fujian goat ORFV strains (OV-GO, OV-YX, OV-NP, and OV-SJ1). The four strains were 132–139 kb in length, with each containing 124–132 genes and about 64% G+C content. The most notable differences between the four strains were found near the genome termini. OV-NP lacked seven and OV-SJ1 lacked three genes near the right terminus when compared against other ORFVs. We also investigated the skin-virulence of the four Fujian ORFVs in goats. The ORFVs with gene deletions showed low virulence while the ORFVs without gene deletions showed high virulence in goats suggesting gene deletion possibly leads to attenuation of ORFVs. Gene 134 was disrupted in OV-NP genome due to the lack of initial code. The phylogenetic tree based on complete Parapoxviruse genomes showed that sheep originated and goat originated ORFVs formed distinctly separate branches with 100% bootstrap. Based on the single gene phylogenetic tree of 132 genes of ORFVs, 47 genes can be easily distinguished as having originated from sheep or goats. In order to further reveal genetic variation presented in goat ORFVs and sheep ORFVs, we analyzed the deduced amino acid sequences of gene 008, multiple alignment of amino acid sequences of gene 008 from the genome of five goat ORFVs and four sheep ORFVs revealed 33 unique amino acids differentiating it as having sheep or goats as host. The availability of genomic sequences of four Fujian goat ORFVs aids in our understanding of the diversity of orf virus isolates in this region and can assist in distinguishing between orf strains that originate in sheep and goats.

Highlights

Orf, known as contagious ecthyma, is a non-systemic cutaneous and debilitating disease with worldwide distribution
Orf virus (ORFV) strains were successfully isolated from goats in different areas within the Fujian Province (China) and phylogenetic analysis based on ORFV011 and ORF059 genes revealed that these isolates are highly divergent
The four Fujian goat ORFV genome length varied from 132,111 bp (OV-NP) to 139,886 bp (OV-GO) with 124–132 predicted genes

Summary

Introduction

Known as contagious ecthyma, is a non-systemic cutaneous and debilitating disease with worldwide distribution. Sheep and goats are the most infected. Camels, deer, reindeer, musk ox, Japanese serows can become infected (Kummeneje and Krogsrud, 1978, 1979; Inoshima et al, 2002). The lesions of the disease tend to proliferate on the mouth and oral mucosa as well as around the nostrils. Lesions follow a characteristic development pattern: erythema followed by the formation of papules, vesicles, pustules, and scabs. Humans, especially those working with animals (veterinarians, farmers, butchers), can be infected by orf (Kumar et al, 2014). The most common lesions are self-limiting with painful pustules on the hands, face, and arms (Mazur et al, 2000; Al-Salam et al, 2008)

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Results

Conclusion