AUTHOR=Andreani Julien , Khalil Jacques Y. B. , Baptiste Emeline , Hasni Issam , Michelle Caroline , Raoult Didier , Levasseur Anthony , La Scola Bernard 

TITLE=Orpheovirus IHUMI-LCC2: A New Virus among the Giant Viruses

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.02643

DOI=10.3389/fmicb.2017.02643

ISSN=1664-302X

ABSTRACT=<p>Giant viruses continue to invade the world of virology, in gigantic genome sizes and various particles shapes. Strains discoveries and metagenomic studies make it possible to reveal the complexity of these microorganisms, their origins, ecosystems and putative roles. We isolated from a rat stool sample a new giant virus “Orpheovirus IHUMI-LCC2,” using <italic>Vermamoeba vermiformis</italic> as host cell. In this paper, we describe the main genomic features and replicative cycle of Orpheovirus IHUMI-LCC2. It possesses a circular genome exceeding 1.4 Megabases with 25% G+C content and ovoidal-shaped particles ranging from 900 to 1300 nm. Particles are closed by at least one thick membrane in a single ostiole-like shape in their apex. Phylogenetic analysis and the reciprocal best hit for Orpheovirus show a connection to the proposed <italic>Pithoviridae</italic> family. However, some genomic characteristics bear witness to a completely divergent evolution for Orpheovirus IHUMI-LCC2 when compared to Cedratviruses or Pithoviruses.</p>