Molecular characterization of SG33 and Borghi vaccines used against myxomatosis.

Myxoma virus is a poxvirus responsible for myxomatosis in European Rabbits (Oryctolagus cuniculus). The entire genome of the myxoma virus has been sequenced, allowing a systemic survey of the functions of a large number of putative pathogenic factors that this virus expresses to subvert the immune and inflammatory pathways of infected rabbit hosts. In Italy, industrial rabbits are mostly vaccinated against myxomatosis using the attenuated myxoma virus strains Borghi or SG33. We have identified genetic markers specific for Borghi or SG33 vaccine strains and established a PCR-based assay that could be used to: (a) rapidly diagnose the presence of myxoma virus in infected organs; (b) discriminate between field strain-infected and vaccinated rabbits and (c) differentiate between Borghi or SG33 vaccine strain.