New virus on the horizon: How Arctic melting is releasing ancient bacteria and why it’s a concern

youngest virus It was cheerfully 27,000 years old to be revived. And the oldest Pandoravirus was about 48,500 years old. This is the oldest virus ever revived.

As the world continues to warm, thawing permafrost is releasing frozen organic matter. a thousand yearsinclude bacteria and viruses – some can still reproduce.

This latest study was by a group of French scientists. Germany and Russia. They managed to revive 13 viruses with exotic names, including the Pandora virus and the Pac-Man virus, extracted from seven samples of Siberian permafrost. Assuming the samples were not contaminated during extraction (which is always difficult to guarantee), these actually represent viable viruses that only replicated tens of thousands of years ago.

This is not the first time viable viruses have been detected in permafrost samples. Previous studies have reported the detection of Pitovirus and morivirus.

In their preprint (study not yet reviewed by other scientists), the authors write, “It is justifiable to contemplate the risk that ancient viral particles remain infectious and return to circulation by thawing ancient permafrost. So what do we know so far about the risks of these so-called ‘zombie viruses’?

All viruses cultured so far from such samples are large DNA viruses that affect only amoebas. They are far from viruses that affect mammals, let alone humans, and are very unlikely to pose a danger to humans.

However, one such large amoeba-infecting virus, called Acanthamoeba polyphaga mimivirus, has been associated with pneumonia in humans. However, this association has not yet been proven. Therefore, viruses cultured from permafrost samples are not expected to pose a threat to public health.

A more relevant concern is that as the permafrost melts, it releases the bodies of deceased people who may have died from an infectious disease, which could be released into the world.

The only human infection that has been eradicated globally is smallpox, and the reintroduction of smallpox, especially in hard-to-reach areas, could be a global disaster. , found in bodies from permafrost burials, but they were fragments of a broken virus that could never infect anyone because they were “only partial gene sequences”. , survives well when frozen at -20°C, but only for decades, not hundreds of years.

In the last few decades, scientists have unearthed the bodies of people who died from the Spanish flu and were buried in permafrost-affected ground in Alaska and Svalbard. NorwayAlthough we were able to sequence the influenza virus, we were unable to culture it from the tissues of these deceased persons. I can’t live ten years.

Bacteria can be more of a problem

However, other types of pathogens such as bacteria can be a problem. Over the years, there have been several outbreaks of anthrax, a bacterial disease that affects livestock and humans, affecting reindeer. Siberia.

2016 saw a particularly large outbreak, killing 2,350 reindeer. This outbreak coincided with a particularly hot summer, leading to suggestions that anthrax bacteria released from thawing permafrost may have triggered the outbreak.

identified An outbreak of anthrax affecting reindeer in Siberia dates back to 1848. In these outbreaks, people who ate dead reindeer were also often affected. However, some emphasize alternative theories of these outbreaks that do not necessarily rely on thawing permafrost, such as anthrax vaccination or stopping reindeer overpopulation.

Even if thawing permafrost caused anthrax outbreaks that severely impacted local populations, herbivore anthrax infections are widespread worldwide, and such localized outbreaks could lead to pandemics. sex is low.

Another concern is whether thawing permafrost could release antibiotic-resistant organisms into the environment. There is good evidence from multiple studies that antimicrobial resistance genes can be detected in permafrost samples.

Resistance genes are genetic material that allows bacteria to become resistant to antibiotics and can spread from one bacterium to another. This is not surprising, as many antimicrobial resistance genes evolved from soil organisms that predated the antimicrobial age.

However, the environment, especially rivers, is already heavily contaminated with antibiotic-resistant bacteria and resistant genes. Therefore, it is doubtful whether antimicrobial-resistant bacteria thawed from permafrost significantly contribute to the large number of antimicrobial resistance genes already present in our environment.

(This is a PTI story syndicated via The Conversation)