Phylogenetic Characterization of Canine Distemper Viruses Detected in Naturally Infected Dogs in North America

Abstract

In 2004, six puppies and one adult dog from a total of four premises were subjected to necropsy evaluation. For five of the seven dogs, disease caused by canine distemper virus (CDV) infection was suspected based on clinical signs. In all of the dogs, a diagnosis of CDV infection was established by the presence of compatible gross and histologic lesions, immunohistochemical labeling for CDV antigen, and detection of CDV RNA by reverse transcription-PCR. To further characterize the CDV strains detected in the four cases, complete gene sequences were determined for the hemagglutinin (H) and fusion (F) protein genes, while partial gene sequencing was performed for the phosphoprotein gene. A total of 4,508 bases were sequenced for the CDV strains detected from each of the four cases. Two cases were found to have identical sequences except for 2 bases in the intergenic region of the F and H genes. Phylogenetic analysis strongly suggested an evolutionary relationship between sequences detected in these two cases and those of phocine distemper virus 2 and two other strains of CDV not previously detected in the continental United States. Clear phylogenetic relationships were not established for viruses detected in the two additional cases; however, one strain showed similarity to CDV strains detected in a panda from China. Importantly, the three CDV strains detected were demonstrated to be genetically distinct from known vaccine strains and strains previously reported in the continental United States.Canine distemper virus (CDV) is the etiological agent of one the most important viral diseases of wild and domestic Canidae (dog, dingo, fox, coyote, jackal, and wolf) (2). It occurs worldwide and produces high morbidity and mortality in immunologically naïve populations (22,29). This virus also infects a broad range of other animals, such as Mustelidae (ferrets, minks, skunks, weasels, and badgers), Procyonidae (raccoons and pandas), Ursidae (bears), Viverridae (civets, genets, and linsangs), hyaenidae (hyenas), and Felidae (lions and tigers) (2,3,4,10,12,16,36). Canine distemper virus is classified in the genus Morbillivirus within the family Paramyxoviridae and has an unsegmented, negative-sense, single-stranded, ϳ15.7-kb RNA genome and an enveloped virus particle that is 150 to 300 nm in diameter (29). The pathogenesis of CDV infection in dogs has been well characterized (2,22,29,35). The genome of CDV encodes the following virion proteins: matrix (M), fusion (F), hemagglutinin (H), nucleocapsid (N), polymerase (L), and phosphoprotein (P). The H gene protein is responsible for viral attachment to the cell host (38) and may also play a role in induction of protective immunity (11). The H protein is one of the most variable morbillivirus proteins and thus has often been used to assess genetic changes between CDV isolates (8,9,17,18,20,21,23,26,28,30).In this study, postmortem findings, immunohistochemical labeling, and reverse transcription (RT)-PCR specific for CDV genomic RNA established a definitive diagnosis of diseas...

Importance of canine distemper virus (CDV) infection in free-ranging Iberian lynxes (Lynx pardinus)

“…To obtain information about the origin and the relationship to other strains the entire H gene and a part of the P gene from the CDV of the lynx and the stone marten were sequenced. For phylogenetic analysis the H gene was used as it shows the highest antigenic variation in morbilliviruses (Harder et al, 1996;Mochizuki et al, 1999;Pardo et al, 2005;Martella et al, 2006). The H genes of lynx and marten were identical and showed a very close relationship to the European dog lineage of CDV, however they formed a cluster separate from the sequences identified as "Europe-wildlife" (Martella et al, 2006) as well as from CDV isolates from other continents.…”

“…To characterize the CDV strains of the Iberian lynx and the stone marten, the complete hemagglutinin (H) gene (1824 bp), and the partial transcriptase-associated phosphoprotein (P) gene (633 bp) were sequenced as described (Mochizuki et al, 1999;Pardo et al, 2005). PCR products were cloned into the pCRII vector using the TOPO TA cloning® Kit (Invitrogen).…”

“…It is the etiological agent of one of the most important viral diseases of wild and domestic carnivores (Pardo et al, 2005). Interspecies transmission frequently occurs, often leading to devastating epizootics in highly susceptible or immunologically naïve populations, such as in the Serengeti lions (Panthera leo) (Roelke-Parker et al, 1996).…”

Epidemiology, Pathology, and Genetic Analysis of a Canine Distemper Epidemic in Namibia

“…Canine distemper virus is highly contagious and has been responsible for severe population declines in both terrestrial (Murray et al, 1999) and aquatic wildlife (Kennedy et al, 2000). Canine distemper continues to be a major disease of domestic dogs (Canis familiaris), re-occurring despite vaccination efforts (Pardo et al, 2005;Norris et al, 2006). …”

Broadly Reactive Pan-Paramyxovirus Reverse Transcription Polymerase Chain Reaction and Sequence Analysis for the Detection of Canine Distemper Virus in a Case of Canine Meningoencephalitis of Unknown Etiology

“…6). 12,13,16 Sequence alignment revealed significant disparity in the CDV strain detected from the current case when compared with the Onderstepoort and Rockborn vaccine strains, with a total of 22 nucleotide differences. Seventeen of these nucleotide differences were mutual among all of the aligned wild CDV strains.…”