Phylogenic analysis of the sheep Orf virus in Iraq

Abstract

Orf disease is a highly contagious, zoonotic viral skin disease affects sheep, goats and some other domesticated and wild ruminants, therefore this study is designed to evaluate predominant genotypes circulating Orf virus of sheep in Al-Qadisiyah Province in Iraq as the first time by using the sequencing and phylogenic analysis of isolates Orf virus strains. The study was carried out on (94) skin samples of affected sheep animals diagnosed previously by RT-PCR technique in different ages and sexes between September /2013– March/ 2014. PCR assay was performed for amplification of 408bp GM_CSF/IL-2 inhibition factor (GIF) gene Orf virus in positive samples of the real-time PCR assay. Eight purified DNA products isolated from different areas of Al-Qadisiyah Province (one sample for each area) were analyzed by using a sequencing method to obtain the nucleotide sets of GIF gene. DNA sequencing technique was performed for Phylogenic relationship analysis study of local Orf virus-positive samples isolates with NCBI-GenBank Global Orf virus isolates. The results of endpoint polymerase chain reaction for detection of specific GIF gene (408 bp) of Orf virus showed positive results for all collected examined samples. Sequencing analysis of our isolates in the present study recorded and published under accession numbers was (KJ508895.1, KJ634611.1, KJ634842.1, KJ648451.1, KJ653445.1, KJ653446.1, KJ659373.1 and KJ697772.1). The results of phylogeny tree construction showed that five of our published isolates of this study (KJ508895.1, KJ648451.1, KJ653445.1, KJ653446.1, and KJ697772.1) are located in the same first tree branch, which shared highest and closed relationship with AF192803.1, DQ184476.1 Orf virus strain NZ2 isolated from New Zealand. The KJ659373.1 our published Iraqi Orf virus isolates of this study showed high homology and closed relationship with AY605973.1 Orf virus isolated from reindeer in Norway. Phylogenic analysis of KJ634611.1 and KJ634842.1 our published Iraqi Orf isolates of the present study showed high homology with AY605977.1 Orf virus isolated from a goat in Norway. Sequencing study and phylogenic analysis have been considered useful in understanding Orf virus scenario in Iraqi endemic area and which important in the application of control measures and selective efficient vaccines to use in vaccination programs in Iraq.