Genetic analysis of canine parvovirus isolates (CPV-2) from dogs in Italy.

Genetic and antigenic properties of 62 field isolates of canine parvovirus (CPV-2) collected from 1994 to 2001 in Italy were investigated. Antigenic characterisation was conducted using specific monoclonal antibodies (Mabs). The VP1\VP2 gene was amplified by PCR and characterised with restriction endonucleases to detect the 297 and 265 variant. The VP2 gene of 16 isolates was sequenced and molecular genetic analysis was conducted. The antigenic type prevalent among our isolates is type 2a as well as the 297 variant, which is also prevalent in the rest of Europe. Only the 9.7% of the isolates have the T265P mutation. The VP2 sequences of CPV-2 isolates were very similar to recent Asian isolates. In the threefold spike of CPV-699 a coding change was detected in the 440 residue where threonine was substituted by alanine: the same mutation has been found in two Asian CPV-2 isolates from leopard cats [Virology 278 (2000) 13]. Phylogenetic analysis revealed that the Italian CPV-2 strains followed the same evolution as observed in other countries and they gave no indication of a separate lineage.