Scientists discover ancient bacteria that could help stop modern viruses

An ancient bacterial defense system dating back billions of years may hold the key to combating modern viral threats.

Scientists led by Professor Thomas Wood of Penn State University have revealed how bacteria use long-dormant viruses, known as cryptic prophages, embedded in their DNA to fend off new viral invaders.

Their study, published in Nucleic acids Research, reveals how this ancient mechanism could inspire new antiviral treatments and help fight antibiotic resistance.

“These bacteria carry fossil viruses in their genomes, and we found that these fossils actually help protect them from infection,” Wood explained.

“It is a finely tuned defense system that has evolved over millions of years.”

The team discovered that a bacterial enzyme called recombinase, triggered by embedded prophage DNA, translates a section of the genome to produce two new “chimeric” proteins.

These proteins prevent incoming viruses (or phages) from binding to the bacterial surface and injecting their genetic material.

When the researchers increased the production of these proteins in E. coli, they found that the bacteria temporarily became immune to viral attacks.

But after a few generations, viruses evolved new attachment methods, demonstrating the dynamic arms race between microbes and their viral enemies.

With antibiotic resistance on the rise, Wood believes the discovery could offer safer alternatives to traditional medicines.

He said: “Before we start using viruses to treat bacterial infections, we need to understand how bacteria naturally defend themselves, and this system is a big part of that picture.”

The findings could also benefit the food industry by improving bacterial health in fermentation processes such as cheese and yogurt production.

“This is a story about how ancient viral fossils still protect their hosts, and we are only just beginning to unlock their potential,” Wood added.