title: High-throughput isolation of giant viruses of the Mimiviridae and Marseilleviridae families in the Tunisian environment.
abstract: Giant viruses of the Megavirales order have been recently isolated from aquatic environments and have long been neglected because they are removed from samples during viral purification for viral metagenomic studies. Due to bacterial overgrowth and susceptibility to high concentrations of antibiotics, isolation by amoeba co-culture has a low efficiency and is highly time-consuming. Thus, few environments have been exhaustively investigated to date, although the ubiquitous distribution of the Acanthamoeba sp. suggests that these viruses could also be ubiquitous. In this work, we have implemented a high-throughput method to detect amoebae lysis on agar plates that allows the testing of hundreds of samples in a few days. Using this procedure, a total of 11 new Marseilleviridae strains and four new Mimiviridae strains, including a virus infected with a virophage, were isolated from 1000 environmental samples from Tunisia. Of these, four corresponded to new genotypic variants. These isolates are the first African environmental isolates identified from these two families, and several samples were obtained from a hypersaline aquatic environment. These results demonstrate that this technique can be used for the evaluation and characterization of large collections of giant viruses to provide insight into understanding their ecology.
authors.affiliation: URMITE, UM63, CNRS 7278, IRD 198, INSERM 1095, Aix Marseille Universite, Marseille, France.
authors.forename: Mondher
authors.initials: M
authors.lastname: Boughalmi
authors.forename: Hanene
authors.initials: H
authors.lastname: Saadi
authors.forename: Isabelle
authors.initials: I
authors.lastname: Pagnier
authors.forename: Philippe
authors.initials: P
authors.lastname: Colson
authors.forename: Ghislain
authors.initials: G
authors.lastname: Fournous
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
authors.forename: Bernard
authors.initials: B
authors.lastname: La Scola
mesh_terms: D000048:Acanthamoeba / Q000821:virology; D036022:Capsid Proteins / Q000235:genetics; D004267:DNA Viruses / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D004783:Environmental Microbiology; D005838:Genotype; D056686:Mimiviridae / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D010802:Phylogeny; D014416:Tunisia; D014773:Virology / Q000379:methods*
chemical_list: D036022:Capsid Proteins