A Comparative Study on Global Genetic Diversity and Population Genetic Analysis of Orf Virus Isolates from Outbreaks and it’s Implications for the Vaccine Development

Saeed Nazeri

doi:10.34297/ajbsr.2020.08.001281

Abstract

The nucleotide sequence analysis of Iranian B2L showed the occurrence of 71 SNPs. In total, 17 amino acid substitutions were detected with 2 unique mutations, resulting in 9 haplo types that 6 of them were not reported in any other geographic regions. Tests for departure from neutral evolution showed purifying selection. Phylogenetic analysis of the B2L gene suggests that the Iranian isolates were closely related to Turkey, India, China, Taiwan, Finland and Brazil isolates.

Highlights

Orf virus envelope gene (B2L) encodes a highly immunogenic protein that exhibits lipase activity
24 mouth scab samples were collected from two outbreaks of Orf virus which occurred in sheep and goats of Northwest (Taleqan in Alborz province; Mehdi Abad in Qazvin province; Firuzkuh in Tehran province) and Southeast (Qaleh Ganj, Kerman province) Iran during 2018-2019 (Figure 1, & Table 1)
A PCR product of 1,210 bp was visualized on 1% agarose gel (Figure 2) from all samples. This result confirmed the presence of infectious Orf virus in all attended herds

Summary

Introduction

Orf virus envelope gene (B2L) encodes a highly immunogenic protein that exhibits lipase activity. Since Orf virus strains change genetically, it is essential to have adequate information on geospatial genetic diversity of global B2L to design an appropriate contagious ecthyma vaccine. Contagious ecthyma (Orf, contagious pustular dermatitis, infectious labial dermatitis, scabby mouth, sore mouth) is a viral disease that is caused by the epitheliotropic Orf virus and it primarily causes disease in goats, sheep, and other ruminants globally [1,2,3]. The disease is transmissible to humans (zoonotic) due to direct or indirect contact to people working with animals [4] and infections are manifested by painful lesions in hand and can spread to other organs [5]. The disease in sheep and goats are characterized by inflammatory, proliferative and scabby lesions in the lips, oral and nasal mucosa and muzzle.

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Discussion

Conclusion