Evidence for evolution of canine parvovirus type 2 in Italy

Two isolates of canine parvovirus (CPV) were obtained from dogs affected wi th severe haemorrhagic diarrhoea. Type 2b antigenic specificity was predict ed by both antigenic analysis with monoclonal antibodies and PCR characteri zation with type-specific primers. Nevertheless, sequence analysis of the c apsid protein-encoding gene revealed two amino acid changes. One of the cha nges affected position 426 (Asp to Glu), in a major antigenic site of the v iral capsid, determining the replacement of a residue unique to CPV type 2b . The failure of established typing methods to distinguish this antigenic v ariant was overcome by the development of an RFLP assay.