Molecular biology characteristics of Canine distemper virus (CDV) isolated in dog in Tra Vinh province

Abstract

Carreù disease (CD) caused by Canine distemper virus (CDV) is a disease having the high mortality and infection rate in the ornamental/pet dogs in Viet Nam. The result of analyzing gene sequences of the CDV strains in the different geographical areas showed that the genome of CDV had a lot of
variations, especially in the H gene. In this study, H gene was isolated from 5 positive dog samples with CDV by using rapid test kit (Gemc Technology - China). The H gene was amplified by the specific primers, amplifying a H gene fragment with 1.642 bp. The PCR products after amplifying were
determined by electrophoresis on 2.00% agarose gel. The positive PCR products were continuously purified and sent to the laboratory of Phu Sa Biochemical Company for DNA sequencing by using Sanger method. The result of analyzing the gene fragments showed that similarity level on amino acid sequence of H gene fragment among the CDV field virus strains was very high (87.74 - 100%); the amino acid similarity level of the CDV field virus strains compared to the amino acid similarity level of CDV strains in GenBank was 78.82 - 98.64%. The result of analyzing phylogenetic tree showed that
the CDV strains isolated in Tra Vinh province belonged to genotypes Asia 1 and America 1blood cells (42.86%), white blood cells decreased (9.53%).