Comparative homology and complete B2L gene-based sequence analysis of ORF virus from sheep and goats in Pakistan

Contagious Ecthyma (CE), also known as scabby mouth disease, is caused by an epitheliotropic parapoxvirus that primarily affects the goat and sheep populations worldwide.This study focused on investigating 12 outbreaks of CE in sheep and goat herds across various regions of Punjab, Pakistan.A total of 35 samples were collected between March 2021 and May 2022, with 34 out of 35 samples testing positive for parapoxvirus through PCR.Subsequently, 24 complete sequences of the major envelope protein B2L gene were successfully obtained.The nucleotide and amino acid sequences of the ORF virus B2L gene were analyzed.The 1206bp amplicons, after Sanger sequencing revealed an open reading frame of 1137bp encoding 378 amino acids.The minimum and maximum nucleotide differences of 0 and 34, respectively, were observed, while the percentage similarity at the nucleotide level and amino acid level ranged from 97.98% to 100% and 97.62% to 100%, respectively, among the ORF strains in this research study.The results of the phylogenetic analysis revealed that all 24 ORF virus isolates from Pakistan belonged to Group-I ORF viruses.The comparative homology of Pakistani ORF virus strains with Indian, Chinese, and Turkish isolates was 99.03%, 98.59%, and 98.15%, respectively.This study contributes to understanding the circulation of Group I ORF viruses in Pakistan and their relationship with strains from neighbouring countries.Furthermore, these findings may offer insights into the genotype of the causative agent responsible for the contagious pustular dermatitis (CPD) outbreak in Punjab, Pakistan.