Israeli researchers have deciphered a complex decision-making process that helps viruses choose to kill their host bacteria or stay friendly with them, Tel Aviv University (TAU) said in a statement on Wednesday.

Published in the journal Nature Microbiology, the study revealed how phage viruses leverage the bacterial immune system, typically designed to combat them, to make this decision, potentially resulting in the death of the host bacteria.

Phages usually tend to remain in a "sleep" mode within their host bacteria when they detect high concentrations of signals from other phages outside. During this dormant phase, phages integrate into the bacterial genome, aiding the host's growth symbiotically.

However, when no external phage signals are detected, the phages deactivate the host's defense system, become active and violent, rapidly replicate, kill the host and move on to the next target.

This discovery holds significance, particularly because certain bacteria, such as those causing cholera in humans, can become more harmful if they harbor dormant phages within them.

Additionally, phages have potential as alternatives to antibiotics against pathogenic bacteria, and further research on phages may enhance the understanding of viruses in general.