Previously unseen microbes trapped in Tibetan glaciers could trigger a wave of new pandemics

While the UK and US have just emerged from the “pandemic phase” for COVID-19scientists already foresee the next global health crisis and say it could be caused by a microbe trapped in a Tibetan glacier.

Researchers from Lanzhou University studied 21 glaciers in the Tibetan Plateau and found evidence of 968 microbes, most of which have never been seen before.

Worryingly, the team has also identified more than 25 million protein-coding genes, including some that may influence the ability to cause disease.

“Captured by ice, modern and ancient pathogenic microbes can lead to local epidemics and even pandemics,” the researchers write in their study, published in the journal Nature Biotechnology.

Researchers from Lanzhou University studied 21 glaciers in the Tibetan Plateau and found evidence of 968 microbes, most of which have never been seen before.

The researchers sequenced 883 bacterial genomes from cultivated glacial bacteria and 85 metagenomes from 21 Tibetan glaciers spanning a variety of habitats including snow (lower left map), ice (top left map) and cryoconite (top right map).

The researchers sequenced 883 bacterial genomes from cultivated glacial bacteria and 85 metagenomes from 21 Tibetan glaciers spanning a variety of habitats including snow (lower left map), ice (top left map) and cryoconite (top right map).

Tibetan plateau

The Tibetan Plateau is a key source of water for some of the world’s largest rivers, meaning that any dangerous microbes can quickly reach large numbers of people.

“The Tibetan Plateau, known as the water tower of Asia, is the source of several of the world’s largest rivers, including the Yangtze, the Yellow River, the Ganges and the Yarlung Tsangpo (Brahmaputra River),” the researchers explained.

“The release of potentially dangerous bacteria could affect two of the world’s most populous countries: China and India.”

In the study, the team collected bacteria and microscopic life forms called archaea from 21 glaciers on the Tibetan Plateau between 2016 and 2020.

Using genetic sequencing, the researchers found evidence for the existence of 968 microbial species.

Some microbes are widespread, such as Pseudomonas aeruginosa, which is found in soil and water.

However, the vast majority (82 percent) were found to have little genetic similarity to microbes found in other environments.

Eleven percent of the species were found in only one glacier, and 10 percent were found in almost all glaciers studied.

The team also found more than 25 million protein-coding genes, including some that may affect the ability to cause disease.

“Here we present the first, to our knowledge, specialized catalog of genomes and genes for glacial ecosystems, including 3,241 genomes and genomes assembled from metagenomes, as well as 25 million non-repeating proteins from 85 Tibetan glacier metagenomes and 883 cultured isolates,” the researchers write.

The findings suggest that many microbes have evolved to withstand extreme conditions, the scientists said.

“The surfaces of glaciers support a variety of life including bacteria, algae, archaea, fungi and other microeukaryotes,” they explained.

“Microorganisms have demonstrated the ability to adapt to these extreme conditions and contribute to vital ecological processes.

Some microbes are widespread, such as Pseudomonas aeruginosa, which is found in soil and water.  However, the vast majority (82 percent) were found to have little genetic similarity to microbes found in other environments.

Some microbes are widespread, such as Pseudomonas aeruginosa, which is found in soil and water. However, the vast majority (82 percent) were found to have little genetic similarity to microbes found in other environments.

“Glacial ice can also act as a record of microorganisms from the past, with ancient (over 10,000 years old) airborne microorganisms successfully resurrecting.

“Therefore, the glacial microbiome also represents an invaluable chronology of microbial life on our planet.”

The Tibetan Plateau is a key source of water for some of the world’s largest rivers, meaning that any dangerous microbes could quickly reach large numbers of people if released.

“The Tibetan Plateau, known as the water tower of Asia, is the source of several of the world’s largest rivers, including the Yangtze, the Yellow River, the Ganges and the Yarlung Tsangpo (Brahmaputra River),” the researchers explained.

“The release of potentially dangerous bacteria could affect two of the world’s most populous countries: China and India.”

Unfortunately, report for 2019 The Intergovernmental Panel on Climate Change (IPCC) has warned that up to two-thirds of the remaining glaciers in the Tibetan Plateau could disappear by the end of the century.

A third of the ice is expected to be lost in that time, even if global warming is limited to 2.7F (1.5C) above pre-industrial levels.

The team hopes that the project, which they will call the Tibetan Glacier Genome and Gene Catalog (TG2G), will be of use to researchers in the future.

“The TG2G catalog offers a database and platform for archiving, analyzing and comparing glacier microbiomes at the genomic and gene levels. This is especially timely as the glacier ecosystem is threatened by global warming and glaciers are retreating at an unprecedented rate,” they concluded.

“We anticipate that the catalog will form the basis of a comprehensive global repository of data on the glacial microbiome.”

The study was published in natural biotechnology.

HOW DO VIRUSES WORK?

A virus particle, or virion, consists of three parts: a set of genetic instructions, DNA or RNA; a protein shell that surrounds DNA or RNA to protect it; lipid membrane surrounding a protein coat.

Unlike human cells or bacteria, viruses do not contain the chemical machinery called enzymes needed to carry out the chemical reactions of division and propagation.

They only carry one or two enzymes that decipher their genetic instructions and need a host cell such as a bacterium, plant or animal in which to live and produce more viruses.

When a virus infects a living cell, it takes over and reprograms the cell, turning it into a virus factory.

Virus proteins interact with specific receptors on the target cell.

The virus then inserts its genetic code into the target cell while the cell’s own DNA is degraded.

The target cell is then “taken over”, using the virus’s genetic code as a blueprint to produce more viruses.

Eventually the cell ruptures to release new, intact viruses, which then infect other cells and start the process all over again.

Once freed from the host cell, new viruses can attack other cells.

Because a single virus can reproduce thousands of new viruses, viral infections can quickly spread throughout the body.