An update on eukaryotic viruses revived from ancient permafrost

Abstract

One quarter of the Northern hemisphere is underlain by permanently frozen ground, referred to as permafrost. Due to climate warming, irreversibly thawing permafrost is releasing organic matter frozen for up to a million years, most of which decomposes into carbon dioxide and methane, further enhancing the greenhouse effect. Part of this organic matter also consists of revived cellular microbes (prokaryotes, unicellular eukaryotes) as well as viruses that remained dormant since prehistorical times. While the literature abounds on descriptions of the rich and diverse prokaryotic microbiomes found in permafrost, no additional report about live viruses have been published since the two original studies describing pithovirus (in 2014) and mollivirus (in 2015). This wrongly suggests that such occurrences are rare and that zombie viruses are not a public health threat. To restore an appreciation closer to reality, we report the preliminary characterizations of 13 new viruses isolated from 7 different ancient Siberian permafrost samples, 1 from the Lena river and 1 from Kamchatka cryosol. As expected from the host specificity imposed by our protocol, these viruses belong to 5 different clades infecting Acanthamoeba spp. but not previously revived from permafrost: pandoravirus, cedratvirus, megavirus, and pacmanvirus, in addition to a new pithovirus strain.

‘Zombie virus’ and the social media: A social media analysis and call for action

“…Not only patients, but also their family caregivers, were shown to be significantly affected by their exposure to the news and social media during the epidemic, with negative effects on their mood and sleep quality. While the world worked tirelessly to contain the pandemic, the spread of misinformation about newly emerging viruses and mutants continued to raise public concern about the re-emergence of other epidemics [ 1 , 2 ].…”

“…On November 10, 2022, a preprint article entitled “An update on eukaryotic viruses derived from ancient permafrost” was published, reporting the isolation of viruses that dated 48,500 years back and were still capable of causing an infection [ 1 ]. The media reacted quickly to this new development, with several articles describing the newly discovered ‘zombie virus'.…”

“…Social media was quick to pick up on this ‘catchy’ information and responded with several posts on the topic that spread like wildfire, with people panicking about the potential global spread [ 2 ]. Even though the researchers acknowledged that global warming affects the melting of glaciers and consequentially the release of these bacteria into the environment, they emphasized that it is currently impossible to determine their infectivity in the environment [ 1 ].…”

“…Pandoravirus, Pithovirus, Megavirus, and Pacmanvirus were among those identified. Characterization of the isolated viruses is in its infancy, and genetic analysis of further viruses that could be isolated is ongoing [ 1 ]. A metagenomic study on Siberian permafrost samples by the same university revealed that Pithoviridae and Orpheoviridae-like viruses contributed the most to the gene pool.…”

“…But it's important to note here that only a small number of viruses were found, and we cannot ignore the possible effects of global warming-caused thawing on biodiversity. The evolutionary gap of Acanthamoeba with humans and other mammals was one of the protective mechanisms employed by the researchers to prevent possible contamination and spread to laboratory workers, thus preventing a potential cascade [ 1 ]. Previous metagenomic analysis on similar permafrost samples also showed a high content of beta-lactamase producing organisms, possibly because of their evolutionary advantage, further indicating a possible threat to the population in terms of antibiotic resistance [ 4 ].…”