First molecular diagnosis and partial characterization of the nucleoprotein gene of Canine Distemper Virus in Uruguay

Abstract

Canine Distemper Virus (CDV) is the etiologic agent of a severe infectious disease, known as Distemper or Carré, which affects dogs and various families of carnivores. The disease is characterized by clinical symptoms associated with lesions in the respiratory, digestive and/or central nervous system. The diversity of the symptoms makes it difficult to establish a clinical ante-mortem diagnosis. In this work we implemented for the first time in Uruguay, an ante-mortem diagnostic method using RT-PCR (reverse transcription - polymerase chain reaction) to amplify a conserved fragment of 287 bp of the nucleocapsid gene from samples belonging to dogs with symptoms of Distemper. Amplicons were obtained in 44 out of the 51 samples tested. The analysis of nucleotide sequences of three field samples revealed that they were 100% identical. The comparison of these sequences with the vaccine strain (Onderstepoort) revealed numerous nucleotide variations. These differences allowed us to design a method of RFLP (Restriction Fragment Length Polymorphism) to discriminate between the vaccine strain to field cases.