A tiny viral switch discovered by Israeli and American scientists could open a new front in the fight against antibiotic-resistant infections, a global health threat projected to kill up to 10 million people annually by 2050. Scientists at the Hebrew University of Jerusalem have revealed that bacteriophages—viruses that infect bacteria—use a small RNA molecule to hijack bacterial cells, a mechanism that had never been described before, offering fresh insights for future phage-based therapies.

The study, led by Dr. Sahar Melamed and her team, including PhD student Aviezer Silverman, MSc student Raneem Nashef, and computational biologist Reut Wasserman, in collaboration with Prof. Ido Golding from the University of Illinois Urbana-Champaign, focused on a tiny viral RNA called PreS. Unlike most prior research, which concentrated on viral proteins, this study showed that even one of the most studied phages, lambda, uses RNA to directly manipulate bacterial gene expression.

“This small RNA gives the phage another layer of control,” Melamed said. “By regulating essential bacterial genes at exactly the right moment, the virus improves its chances of successful replication. What astonished us most is that phage lambda, studied for more than 75 years, still hides secrets. Discovering an unexpected RNA regulator in such a classic system suggests we have only grasped a single thread of what may be a much richer network of RNA-mediated control in phages.”