Project description:Canine distemper virus causes a severe infectious disease in carnivores worldwide. Herein, we sequenced and analyzed the genome of a new strain (Uy251/2012) isolated from a dog in Uruguay. The Uy251/2012 strain belongs to the Europe1/South America1 lineage, and constitutes the first report of a genomic sequence in South America.
Project description:In the year 1994, the Serengeti lion population was decimated by a canine distemper disease outbreak. Retrospective investigations showed that this host population had already been in contact with the pathogen in 1981 without any detected sign of disease. As an alternative to the virus mutation hypothesis to explain this difference in virulences observed in 1981 and 1994, we propose a novel mechanism of disease emergence based on variation in population immunity. We use a stochastic model to show that stochastic fluctuations in pathogen circulation, owing to a low probability of virus transmission from its reservoir to the target host and thereby resulting in variations in the global immunity level of the target host population, can explain the observations made in Serengeti. This mechanism may also be involved in other infectious disease emergences or re-emergences.
Project description:RNA viruses adapt rapidly to new host environments by generating highly diverse genome sets, so-called “quasispecies”. Minor genetic variants promote their rapid adaptation allowing for emergence of drug-resistance or immune-escape mutants. Understanding these adaptation processes is highly relevant to assess the risk of cross-species transmission, and safety and efficacy of vaccines and antivirals. We hypothesized that genetic memory within a viral genome population facilitates rapid adaptation.
Project description:Canine distemper virus (CDV)-induced demyelinating leukoencephalitis (CDV-DL) in dogs is a translational animal model for human demyelinating diseases such as multiple sclerosis. The aim of this study was to perform an assumption-free microarray analysis of gene expression in different subgroups of CDV-DL as compared to normal controls. Dogs were classified into normal controls (group 1), acute CDV-DL lesions with CDV within the brain but without demyelination and inflammation (group 2), subacute lesions with demyelination but without inflammation (group 3), and subacute to chronic lesions with demyelination and inflammation (group 4).
Project description:One of the greatest threats to the conservation of wild cat populations may be dogs or, at least, one of their viruses. Canine distemper virus (CDV), a single-stranded RNA virus in the Paramyxoviridae family and genus Morbillivirus, infects and causes disease in a variety of species, not just canids. An outbreak of CDV in wild lions in the Serengeti, Tanzania, in 1994 was a wake-up call for conservationists, as it demonstrated that an infectious disease could swiftly impact a previously healthy felid population. To understand how this virus causes disease in noncanid hosts, researchers have focused on specific mutations in the binding site of the CDV hemagglutinin gene. Now, Seimon et al. provide information on CDV in its latest feline victim, the endangered wild Amur tiger (Panthera tigris altaica) [T. A. Seimon et al., mBio 4(4):e00410-13, 2013, doi:10.1128/mBio.00410-13]. Their findings of CDV strains infecting tigers, in combination with recent information from other felids, paints a different picture, one in which CDV strains from a variety of geographic lineages and with a variety of amino acid residues in the hemagglutinin gene binding site can infect cats and cause disease. Although CDV has been known as a multihost disease since its discovery in domestic dogs in 1905, perhaps it is time to reconsider whether these noncanid species are not just incidental or "spillover" hosts but, rather, a normal part of the complex ecology of this infectious disease.
