An Update on Eukaryotic Viruses Revived from Ancient Permafrost

Area of Science:

• Virology
• Microbiology
• Climate Science

Background:

• Permafrost covers a quarter of the Northern Hemisphere and contains ancient organic matter, including dormant microbes and viruses.
• Thawing permafrost due to climate change releases this ancient organic matter, potentially reanimating microbes and viruses.
• Previous research on revived viruses from permafrost is limited, leading to an underestimation of their prevalence and potential risks.

Purpose of the Study:

• To characterize new viruses revived from ancient Siberian permafrost samples.
• To assess the diversity of viable viruses present in thawing permafrost.
• To address the misconception that revived viruses from permafrost are rare and not a public health concern.

Main Methods:

• Isolation and preliminary characterization of viruses from seven Siberian permafrost samples.
• Infection of Acanthamoeba spp. cultures to revive and identify viable viruses.
• Phylogenetic analysis to determine viral clades and relationships.

Main Results:

• 13 new viruses were successfully revived and characterized from ancient permafrost.
• The revived viruses belong to five distinct clades (Pandoravirus, Cedratvirus, Megavirus, Pacmanvirus, and a new Pithovirus strain) infecting Acanthamoeba.
• These viral types had not been previously reported as revived from permafrost.

Conclusions:

• Ancient Siberian permafrost harbors a diverse range of viable viruses, challenging previous assumptions about their rarity.
• The revival of these viruses underscores a potential, yet underestimated, public health risk associated with thawing permafrost.
• Further research is crucial to fully understand the virome of permafrost and its implications in a warming climate.