Researchers at the University of Pittsburgh have made a breakthrough in understanding bacteriophages, viruses that target bacteria. By using cryo-electron microscopy and imaging techniques, they were able to see phages in unprecedented detail, revealing their structural makeup for the first time.
The team, led by Graham Hatfull, has produced high-resolution images of phage capsids, which are composed of 60 symmetrical parts that can be averaged together. This allowed them to visualize the tail tube and tip of the phage, where it binds to its target Mycobacterium cell.
With this new information, scientists can now design phages to bind to different kinds of cells, making them a potential game-changer in the fight against bacterial infections. Phages are particularly useful because they can target specific strains of bacteria, but their ability to recognize and attack bacteria is still not fully understood.
The researchers used cryo-electron tomography to visualize phages bound to bacterial cells, highlighting the entire phage and where it attaches to the cell surface. This work has provided new insights into the mechanism by which phage DNA is triggered to leave the capsid and transported through the tail tube.
While there are still many questions remaining, this breakthrough has opened up new possibilities for engineers to design phages that can recognize different bacteria. As Hatfull said, “Before, we wouldn’t have stood a chance. And now, doing this is going to become completely routine.”
The study was published in the journal Cell and provides a significant step forward in understanding these important viruses.
Source: https://phys.org/news/2025-04-imaging-techniques-phages-unprecedented.html