Scientists have taken a major step toward tackling antibiotic-resistant infections by designing bacteria-killing viruses entirely in the laboratory. The breakthrough could speed up the development of precision treatments against deadly superbugs, at a time when conventional antibiotics are steadily losing their power.
Bacteriophages, viruses that infect and kill bacteria, have been known for more than a century. Their medical use, however, has remained limited because engineering them is slow, complex, and heavily dependent on naturally occurring viruses. As drug-resistant infections rise worldwide, researchers have been searching for faster and safer ways to create tailor-made phages.
Synthetic DNA Turns Phage Engineering on Its Head
In a study published in the journal Proceedings of the National Academy of Sciences, researchers from New England Biolabs and Yale University report the first fully synthetic system for building bacteriophages that attack Pseudomonas aeruginosa a dangerous antibiotic-resistant bacterium. Instead of modifying existing viruses, the team assembled a complete phage genome from scratch using only digital DNA sequence information.
The researchers constructed the virus from 28 synthetic DNA fragments and introduced precise genetic changes, including insertions, deletions, and mutations. These edits allowed them to control which bacteria the virus could infect and to add fluorescent markers that made infections visible in real time. The approach dramatically reduces the time and labor traditionally required to engineer therapeutic phages.
From Digital Blueprint to Living Virus
The technique relies on a high-complexity Golden Gate Assembly platform, which enables scientists to assemble large viral genomes outside living cells. Once complete, the synthetic genome is introduced into a safe laboratory strain, where it becomes an active bacteriophage capable of infecting bacteria.
By bypassing the need for fragile virus collections and specialized host bacteria, the method removes long-standing bottlenecks in phage research. It also avoids repeated trial-and-error genetic editing inside cells, making the process faster, more flexible, and potentially safer.
Researchers say the advance could transform efforts to combat antibiotic resistance, allowing doctors to one day deploy custom-designed viruses against specific bacterial infections. The same technology may also support new applications, such as biosensors for detecting harmful bacteria in water supplies.
At the same time, the idea of fully synthetic viruses has sparked public concern, with some questioning the risks of creating living viruses in the lab. Scientists involved in the work stress that bacteriophages infect only bacteria, not humans, and that the new system actually improves safety by eliminating the need to work with dangerous pathogens directly.
As antibiotic resistance continues to spread globally, the study highlights both the promise and the responsibility that come with powerful new tools. Whether lab-designed viruses become a mainstream medical solution will depend not only on scientific success, but also on careful regulation and public trust.