Parapoxvirus in goats: experimental infection and genomic analysis

Parapoxvirus are DNA viruses belonging to the family Poxviridae, subfamily Chordopox- virinae. The genus encompasses four species: the bovine papular stomatitis virus (BPSV) and the pseudocowpox virus (PCPV) both of which infect cattle; the type species, Orf virus (OV) that causes contagious ectyma in sheep and goats and the parapoxvirus of New Zealand red deer (PVNZ), all the species can be transmitted to man. Current knowledge of the molecular biology of Parapoxvirus, and in particular of genes that affect the host range and virulence, is still limited and is mainly based on that of the other Poxviruses. Genomic analysis of Parapoxvirus demonstrated that the right terminal region of the genome is characterized by during co-infection of the same host (Mercer et al. 2006). Sequence analysis performed on the VEGF gene of several viral strains isolated from goats has shown that this gene has genetic features similar to the VEGF variant of OV strains isolated from sheep and of PCPV, suggesting possible events of recombination (Mercer et al. 2002). Outbreaks of malignant OV infections have recently been reported in goat flocks. Furthermore, during outbreaks of disease it is not uncommon to observe the appearance of clinical orf in goats but not in sheep raised on the same farm, suggesting that there may be some fundamental differences between the viruses that cause disease in sheep as compared to goats (de la Concha-Bermejillo et al. 2003). The aim of the experimental infection was to study the clinical course of the OV infection in sheep and goats and to perform a genetic characterisation of OV isolates after infection furthermore, to evaluate the susceptibility of the two animal species to PCPV infection. a high degree of variability and could be subjected to recombination