The restriction fragment length polymorphism (RFLP) assay of a 721 bp fragment from hemagglutinin (H) gene of canine distemper virus (CDV) amplified by RT-PCR was analyzed with Hinf I and Rsa I enzymes. Clinical samples from 27 dogs with natural canine distemper infection, and three vaccine (Snyder Hill, Onderstepoort and Rockborn) CDV strains were analyzed. All RT-PCR amplified product from CDV wild-type and vaccine-strains had the same RFLP pattern with Hinf I enzyme showing the amplicon specificity. The RFLP pattern for CDV vaccine-strains generated with Rsa I enzyme was the expected by in silico analysis. All 27 wild-type CDV strains present the same Rsa I enzyme RFLP pattern that was different from vaccine-strains pattern, suggesting molecular differences between vaccine-strains and wild-type of CDV from dogs population in North region of Paraná State/Brazil. These results open the perspectives of the accomplishment of comparative molecular analysis, such as sequencing of the whole gene H, of CDV wild-type strains identified in different Brazilian regions.
dog; canine distemper; canine distemper virus; H gene; RT-PCR; RFLP
