Molecular characterization of Brazilian isolates of orf virus

Outbreaks of an epidermic disease suggesting parapox virus infections have been observed in all major herds of sheep and goats from different geograph ical areas of Brazil. Clinical samples (dried scabs) were collected and orf virus was isolated and characterized by electron microscopy in previous wo rk. In order to characterize these viruses at the molecular level, a modifi ed methodology for genomic DNA extraction directly from scabs was used and such DNA was used to derive the restriction enzyme digestion patterns for c linical samples from three distinct geographic origins. Pulsed held gel ele ctrophoresis was used to separate restriction enzyme DNA fragments and hete rogeneity among isolates from different geographic areas could be observed on stained gels. The HindIII-G DNA fragment from orf-A virus genome was clo ned and hybridized to DNA of other orf virus isolates. Further heterogeneit y was confirmed by these hybridizations. (C) 2000 Elsevier Science B.V. All rights reserved.