Researchers at Penn state have discovered that some bacteria can carry ancient dormant viruses called cryptic prophases in their genomes. These dormant viral sequences can become a part of bacteria's defense system. They found that recombinase can modify bacterial DNA in response to viral threats only if a prophage is already embedded in the genome. This specific recombinase is known as PinQ. When a virus goes near the bacterial ell, PinQ triggers DNA inversion flipping a section of genetic code inside the chromosome.
In experiments with E. coli the proteins were overexpressed, and viruses could not land on the bacterial surface. After repeated exposure the virus evolved a new attachment mechanism and overcame the barrier. Researchers suggest that this kind of ancient viral defense could be helpful for antiviral strategies especially those showing antibiotics resistance.
Benefits to this research helps understand how antivirus systems operate. This can lead to a better understanding of how to effectively cultivate bacteria used to ferment foods like cheese and yogurt. This could also help improve how bacterial infections are managed in health care settings.
Sources: Ancient viruses hidden inside bacteria could help defeat modern infections. (2025, November 25). ScienceDaily. https://www.sciencedaily.com/releases/2025/11/251102205009.htm
Putol, R. (2025, November 1). Ancient viruses inside bacteria may help fight infections. Earth.com. https://www.earth.com/news/ancient-viruses-inside-bacteria-may-help-fight-infections/
