Cohabiting microbes can impact one another's mutation rates creating a mutational eco-evo feedback loop

In co-cultures with Enterococcus faecalis or Pseudomonas aeruginosa, a stronger ROS degrader lowers mutation rates in the weaker degrader, while higher density of the weaker increases mutation rates in the stronger.

• Why it matters: Eco-evolutionary feedbacks are usually framed as requiring ecological changes that drive selection, but ecology may also reshape other evolutionary mechanisms like mutation supply, affecting evolutionary rescue.
• What they did: Using Escherichia coli as the focal species, the study estimated mutation rates in both co-cultured partners across co-culture systems with different ROS-degrading abilities, addressing challenges in simultaneous estimation.
• The result: The findings support a mutational eco-evo feedback loop where cross-species effects alter mutational variation supply, potentially changing the chance of evolutionary rescue during later environmental change and influencing resistance evolution in polymicrobial infections.

AI summary of the abstract · may contain errors · not medical advice · read the paper.