Abstract
Porcine circovirus (PCV) genes were detected in formalin-fixed pig-tissue samples embedded in paraffin. The tissues came from pigs affected by the postweaning multisystemic wasting syndrome and demonstrating pathological evidence of PCV infection. The samples were collected between 1993 to 1998 from farms B, C, and D in Hokkaido, Japan, and were examined by polymerase chain reaction (PCR). Among primers, detection rate of the Nlf and N2r primer set was highest. Of the 35 (85.7%) samples examined 30 were PCR positive. The cleavage sites recognized by restriction enzymes (Ava II andNsp I) in these amplified PCR fragments were missing in the fragment amplified from PCV-1. The Sac I site was present in fragments amplified from the 4 samples from farm D but absent in the 7 fragments from farm C. Although 15 of the 19 samples from farm B had the Sac I site, the remaining 4 samples lacked it. These results suggest that at least 2 types of genetically different PCV-2 exist in Hokkaido.
