Ectromelia virus

Species of virus

Ectromelia virus (ECTV) is a virus of the family Poxviridae and the genus Orthopoxvirus that causes mousepox, a disease of mice. It has only been seen in mouse colonies kept for research purposes but believed that wild populations of mice and other rodents in Europe are naturally infected with ECTV. The original Hampstead strain of ECTV was discovered in 1930 in a laboratory mouse colony. Since then, other ECTV strains and outbreaks have been seen in Europe and the USA with differences in the severity of the disease.

Ectromelia virus belongs to the genus Orthopoxvirus of the family Poxviridae. It is a large virus with a complex structure. It has block shape, size 250 300 150 200 nm. The virus is covered by an outer shell with the villi. Virion contains a two chain DNA and protein checks. The virus is resistant to ether and phenol, long preserved in glycerin. But even a relatively low temperature (55 °C) kills it during 30 min.

The study of poxviruses is of great interest due to the proteins that they encode to formulate the response of the host, this makes it possible to more deeply study the relationship of the virus host. The genomic sequence of ECTV in mice allows us to understand the mechanisms of the disease and the interaction of cells and mediators that represent host protection. The similarity of the ECTV genome with the genome of other pox viruses, of which there are 40 genomes of various genera, species and strains of poxviruses, was determined by determining their amino acid or nucleotide sequence. A study of the influence of poxviruses on human and animal health underlines the value of the ECTV mouse model. ECTV strain Moscow (Mos) the most virulent, it was isolated by V. Sololiev and first described by Andrewes & Elford. It is important to note that the genetic background of the mouse can affect the infection, which means that host factors are involved in the regulation of susceptibility and resistance to the virus. For example, wild mice exhibit variable susceptibility, while laboratory strains were useful for determining host resistance factors. It is believed that the natural route of infection occurs through abrasions on the skin, which means that the transmission of the virus occurs from animal to animal or through fomites, such as infected bedding in the place for keeping mice. There are several named strains of ectromelia virus that vary in virulence, including NIH 79, Wash U, Moscow, Hampstead, St. Louis 69, Beijing 70, and Ishibashi I–III. The mousepox model presents an opportunity to study the components of the immune system that are required for an efficient immunological response to a natural poxvirus infection in a well understood animal model that can be further manipulated by targeted inactivation or expression of genes.