title: "Marseilleviridae", a new family of giant viruses infecting amoebae.
abstract: The family "Marseilleviridae" is a new proposed taxon for giant viruses that infect amoebae. Its first member, Acanthamoeba polyphaga marseillevirus (APMaV), was isolated in 2007 by culturing on amoebae a water sample collected from a cooling tower in Paris, France. APMaV has an icosahedral shape with a diameter of ≈250 nm. Its genome is a double-stranded circular DNA that is 368,454 base pairs (bp) in length. The genome has a GC content of 44.7 % and is predicted to encode 457 proteins. Phylogenetic reconstructions showed that APMaV belongs to a new viral family among nucleocytoplasmic large DNA viruses, a group of viruses that also includes Acanthamoeba polyphaga mimivirus (APMV) and the other members of the family Mimiviridae as well as the members of the families Poxviridae, Phycodnaviridae, Iridoviridae, Ascoviridae, and Asfarviridae. In 2011, Acanthamoeba castellanii lausannevirus (ACLaV), another close relative of APMaV, was isolated from river water in France. The ACLaV genome is 346,754 bp in size and encodes 450 genes, among which 320 have an APMaV protein as the closest homolog. Two other giant viruses closely related to APMaV and ACLaV have been recovered in our laboratory from a freshwater sample and a human stool sample using an amoebal co-culture method. The only currently identified hosts for "marseilleviruses" are Acanthamoeba spp. The prevalence of these viruses in the environment and in animals and humans remains to be determined.
authors.affiliation: URMITE UM63 CNRS 7278 IRD 198 INSERM U1905, Aix-Marseille Université, Facultés de Médecine et de Pharmacie, 27 boulevard Jean Moulin, 13385, Marseille Cedex 05, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Colson
authors.forename: Isabelle
authors.initials: I
authors.lastname: Pagnier
authors.forename: Niyaz
authors.initials: N
authors.lastname: Yoosuf
authors.forename: Ghislain
authors.initials: G
authors.lastname: Fournous
authors.forename: Bernard
authors.initials: B
authors.lastname: La Scola
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
mesh_terms: D000048:Acanthamoeba / Q000821:virology*; D000818:Animals; D005243:Feces / Q000821:virology; D015967:Gene Expression Regulation, Viral; D016679:Genome, Viral; D006801:Humans; D008854:Microscopy, Electron; D056686:Mimiviridae / Q000145:classification* / Q000235:genetics* / Q000648:ultrastructure; D010802:Phylogeny; D014776:Virus Cultivation; D014871:Water Microbiology