Viruses ‘eavesdrop’ on each other – but it can backfire

A colony of Bacillus subtilis grown on solid medium. These structured communities reflect how bacteria can organise & grow collectively.
Image Credit Elvina Smith

Scientific Frontline: Extended "At a Glance" Summary: Viral Eavesdropping and Arbitrium Systems

The Core Concept: Phages (viruses that infect bacteria) utilize chemical signals to communicate and can "eavesdrop" on the signals of other viral species, a process that can manipulate the eavesdropping virus into adopting a disadvantageous infection strategy.

Key Distinction/Mechanism: When infecting a host cell, phages must decide whether to replicate and kill the host (lysis) or remain dormant (lysogeny). They use chemical signals called peptides (part of the "arbitrium" system) to assess host availability; high peptide levels indicate scarce hosts (favoring dormancy), while low levels indicate abundant hosts (favoring lysis). However, cross-species eavesdropping can cause a listening virus to mistakenly choose dormancy, ultimately benefiting the signaling virus by eliminating competition.

Major Frameworks/Components:

• Arbitrium Communication Systems: The specific peptide-based chemical signaling networks used by phages to coordinate infection strategies.
• Lysis-Lysogeny Decision: The fundamental biological choice a virus makes upon infecting a cell, determining whether it will actively replicate and destroy the cell or integrate and lie dormant.
• Inter-Species Cross-Talk: The phenomenon where signals intended for intra-species coordination are intercepted by unrelated viral species.
• Viral Manipulation: The evolutionary dynamic where communication serves not just as cooperation, but as a mechanism for one species to suppress the competitive reproduction of another.

Branch of Science: Virology, Microbiology, Microbial Ecology, and Evolutionary Biology.

Future Application: Deciphering the chemical language of viruses paves the way for advanced biotechnological interventions. In the future, scientists could potentially manipulate these arbitrium signals to control viral behaviors or develop novel phage therapies to combat antibiotic-resistant bacterial infections.

Why It Matters: This discovery shifts the paradigm of viral interaction, demonstrating that microbial communication involves active manipulation rather than mere cooperation. Understanding the complex evolutionary dynamics of soil-dwelling phages provides critical foundational knowledge with far-reaching implications for human health and disease management.

A 24-hour-old Bacillus subtilis biofilm. Green fluorescence shows living cells, while red shows dead or damaged cells.
Image Credit Elvina Smith

Viruses can “eavesdrop” on each other using chemical signals – but it can backfire for the eavesdropper, new research shows. 

University of Exeter scientists studied chemical communication by phages (viruses that infect bacteria). 

The phages assessed in this study have two choices when they enter a cell: lie dormant or kill the cell and release new virus particles to infect other cells nearby. 

It was recently discovered that some phages use chemical communication systems to optimize this decision. 

The new study reveals that these signals do not pass solely between phages of the same species. Instead, other species – some of them barely related to the signaler – can eavesdrop. 

But the signal may prompt the eavesdropper to make the wrong decision. 

“The decision to kill (called lysis) or lie dormant (called lysogeny) depends on the specific situation,” said PhD student Rebecca Woodhams, from the Centre for Ecology and Conservation at Exeter’s Penryn Campus in Cornwall. 

“When many bacteria are available, a phage should choose lysis and look to infect these potential hosts. 

“When many hosts have already been killed and few remain, lying low and waiting for better times (lysogeny) is safer.” 

The signal chemicals are called peptides and are produced by the phage during infection. High peptide concentrations signal a lack of susceptible hosts, while low concentrations signal an abundance of uninfected hosts. 

The existence of these signaling systems (called “arbitrium” systems) suggests they provide an evolutionary benefit – at least for in-species communication. 

But the new study shows that “crosstalk” between species does not help the “listener”. 

Dr Robyn Manley, also from Exeter’s Centre for Ecology and Conservation, explained: “When a phage detects signals from another species, it is more likely to stay dormant instead of killing the cell and releasing more viruses, even when the message was not meant for it and does not reflect its own situation. 

“This can benefit the virus that sent the signal, as it prevents another virus killing cells, but it can come at a cost to the virus that responds. 

“In other words, viral communication is not just cooperation. Sometimes, it is manipulation.” 

The bacteria and phages in the study are commonly found in soil, but the findings pave the way for further research on how viruses communicate and decide when to kill cells – with far-reaching implications for areas including human health. 

Funding: This project received funding from a UK Research and Innovation grant under the UK Government’s Horizon Europe funding guarantee. 

Published in journal: University of Exeter

Title: Arbitrium phages can manipulate each other’s lysis/lysogeny decisions

Authors: R. Manley, R. Woodhams, T.J. Arrowsmith, E. Smith, J. Bruce, T.R. Blower, B. Temperton, and E.R. Westra

Source/Credit: University of Exeter | Alex Morrison

Reference Number: vi033126_01

Privacy Policy | Terms of Service | Contact Us