Sukrit Silas and his team at the Gladstone Institutes and the University of California, San Francisco, have made a significant discovery regarding bacterial defenses against viral attacks. Their research illustrates how formidable a defense system can be. This system can activate the self-destruction of bacteria as a last resort when they face viral dangers. This groundbreaking study not only sheds light on bacterial survival mechanisms but offers new perspectives on the intricate battle between viruses and bacteria that has persisted for billions of years.
In the work they published in the journal Molecular Cell, Silas and his colleagues stumbled upon something thrilling. They discovered more than 10,000 new accessory genes in more than 1,000 phage genomes targeting bacteria from the Enterobacteria family. Unfortunately, many scientists have historically ignored such accessory genes as non-essential, dispensable genes. In fact, they are deeply important to the ways phages form relationships with their bacterial hosts. The researchers took advantage of a new research platform equipped with an impressive discovery algorithm. This new innovation allowed them to rapidly profile thousands of accessory genes simultaneously across phage genome families within the same experiment.
Silas envisions that this research platform will allow us to accelerate our understanding of accessory genes in phages. This discovery has the potential to shed new light on a trove of other microbial organisms. The research team discovered that some of these accessory genes can neutralize bacterial restriction-modification systems, thus enabling phages to successfully infect bacterial cells. To do so, they activated or deactivated some 200 novel genes in different strains of E. coli. This enabled them to see how these genes directly affected the bacteria’s resistance to lethal viral infection.
These findings shed light on how key bacterial virulence and pathogenicity defense mechanisms are coming together. In other words, their defense system functions as a joint first and second line of defense. This exciting finding paves the way towards expanding our knowledge on how bacteria overcome obstacles. It might just help identify new approaches to successfully fighting bacterial infections.
The study’s co-lead, UCSF’s Joe Bondy-Denomy, Ph.D., worked closely with Silas to explain this complicated dance of interactions. Their initiative has revealed the treasure trove of genetic data that most researchers had long ignored. This exciting finding indicates that accessory genes could be in the tens of thousands, widely dispersed among phage genomes and their hosts.
Sukrit Silas’s continuing work at Gladstone is focused on addressing the large knowledge gap that currently exists on accessory genes in phages. This new knowledge now equips scientists to explore deeper into the nuanced interactions between viruses and their bacterial hosts. It invites fresh perspectives in how we teach and engage with microbiology.