Detection by RT-PCR and genetic characterization of canine distemper virus from vaccinated and

GALLO CALDERON, MARINA; REMORINI, PATRICIA; PERIOLO, OSVALDO; IGLESIAS, MARCELA; MATTION, NORA; LA TORRE, JOSE

VETERINARY MICROBIOLOGY

Elsevier

Año: 2006

0378-1135

Reverse transcription-PCR (RT-PCR) was used to detect a 287-nucleotide (nt) fragment in canine distemper virus (CDV) nucleocapsid protein (NP) RNA from Argentine domestic dogs, with clinical symptoms of CDV disease. Of the 99 blood samples analyzed, 73 were positive, suggesting that the animals were infected with wild-type CDV. The deduced amino acid sequence of this gene fragment showed 100% identity with the sequence of other wild-type and vaccine strains. On the other hand, the presence of an 871-nt fragment in the viral hemagglutinin gene was detected in all the vaccine strains analyzed, but only in 24  (35%) of the 68 NP-RNA-positive clinical specimens. The DNA fragments amplified from H- RNA-positive samples were further analyzed by restriction fragment length polymorphism (RFLP) and sequencing. A single NdeI site was detected in all 24 wild-type strains but was absent in the vaccine strains. Phylogenetic analysis of the partial hemagglutinin amino acid sequences showed close clustering for local strains, clearly distinct from vaccine strains and other wild-type foreign CDV strains. One of the local strains, Arg23, branched out of the root  of the Argentine clade, close to the European strains, suggesting that two different pathogenic 41 CDV genotypes are currently circulating in Argentina, one of them clearly predominant