Detection and phylogenetic analysis of Orf virus from sheep in Brazil: a case report

BACKGROUND: Orf virus (ORFV), the prototype of the genus Parapoxvirus (PPV), is the etiological agent of contagious ecthyma, a severe exanthematic dermatitis that afflicts domestic and wild small ruminants. Although South American ORFV outbreaks have occurred and diagnosed there are no South American PPV major membrane glycoprotein B2L gene nucleotide sequences available. CASE PRESENTATION: an outbreak of ovine contagious ecthyma in Midwest Brazil was investigated. The diagnosis was based on clinical examinations and molecular biology techniques. The molecular characterization of the virus was done using PCR amplification, cloning and DNA sequencing of the B2L gene. The phylogenetic analysis demonstrated a high degree of identity with ORFV strains, and the isolate was closest to the ORFV-India 82/04 isolate. Another Brazilian ORFV isolate, NE1, was sequenced for comparative analysis and also showed a high degree of identity with an Asian ORFV strain. CONCLUSION: Distinct ORFV strains are circulating in Brazil. This is the first report on the phylogenetic analysis of an ORFV in South America.