Genetic Phylocomparative Analysis of B2L, F1L Genes in Orf Virus Isolated from Felid Infected Sheep

Abstract

Contagious ecthyma virus Large, oval, double-stranded DNA viruses from the family Poxviridae they are distinct from other poxviruses due to their unusual spiral coat. Orf virus encoded highly conserved F1L gene, B2L gene, which codes for highly immunogenic envelope protein. Orf lesions were observed on the upper and lower lips, upper and/or lower eyelids, and around the mouth and nose of sheep. This study evaluated the histology and genetics of Orf virus in AL-Qadisyah sheep infected with infectious ecthyma. Positive histology is defined by the presence of subcorneal pustules, hydropic degeneration of necrotic keratinocytes, and epidermal hyperplasia with pronounced rete ridges. Samples were fixed in paraffin and sectioned into 5m slices. PCR on DNA-extracted samples was positive for both the B2L and F1L genes. Four positive samples were sequenced and recorded in GeneBank, and phylogenetic analysis was performed. Histopathology and clinical symptoms can aid in the diagnosis of infectious ecthyma rapidly and affordably, whereas PCR distinguishes between identical diseases in endemic regions. Analyzing the divergence between the inferred amino acid sequences of the incomplete B2L gene in different strains from Iraq OK336711.1, OK336710.1, and other Indians, we found that two locations contain different amino acid changes, resulting in a nucleotide and amino acid identity of 97.8% and 97.6%, respectively. The F1L envelope protein of the Iraqi strain OK330734.1 was comparable to those of China and India, while the envelope protein of the Italian strain OK330733.1 was identical to that of Italy.