Molecular Characterisation of Orf Virus in Goats From Eastern Türkiye

Orf virus (ORFV) is the etiologic agent of infectious ecthyma, a common worldwide disease that occasionally causes zoonotic infections. In this study, we aimed to detect and molecularly characterise circulating ORFV strains in goats from different provinces in eastern Türkiye.

Skin lesion samples collected during ORFV outbreaks between 2022 and 2024 were analysed. Following DNA extraction, positive samples identified by real-time PCR were analysed using a multi-locus phylogenetic approach targeting the structural F1L, the major envelope protein B2L, and the virulence-related VIR gene regions. Sequencing was performed using the Sanger method, followed by phylogenetic analysis using the Maximum Likelihood method in MEGA X.

Phylogenetic analysis revealed high genetic similarity (95.63% to 99.48%) between the Turkish strains and global isolates from countries such as China, India, Iran, and Malaysia. Notably, while most isolates shared 100% similarity, the isolate from one specific province (Tunceli) exhibited significant nucleotide substitutions and a separate clustering pattern, particularly in the VIR gene.

The results demonstrate that ORFV strains circulating in Türkiye display close phylogenetic clustering with Asian strains. The study highlights that multi-locus analyses, especially utilising the highly variable VIR gene, are essential for identifying regional genetic heterogeneity and monitoring microbial evolution. These findings provide a pilot reference for future epidemiological surveillance and vaccine development strategies in the region.