Bacteriophages limit the existence conditions for conjugative plasmids

Area of Science:

• Microbiology
• Evolutionary Biology
• Genetics

Background:

• Bacteriophages are major drivers of bacterial mortality and evolution.
• Conjugative plasmids carry adaptive genes but their dynamics are poorly understood in phage-rich environments.
• Understanding plasmid-bacterium-phage interactions is crucial for bacterial evolution and combating resistance.

Purpose of the Study:

• To investigate how bacteriophages influence the ecological and evolutionary dynamics of conjugative plasmids.
• To determine the conditions under which bacteriophages limit or promote plasmid persistence.
• To explore the potential of using bacteriophages to control plasmids carrying undesirable traits.

Main Methods:

• Experimental evolution of bacterial populations under phage pressure.
• Mathematical modeling of plasmid and phage dynamics.
• Individual-based simulations to explore population genetics effects.

Main Results:

• Bacteriophages limit the conditions for plasmid existence, especially when plasmids offer no benefit.
• Phages can cause temporary plasmid maintenance followed by rapid loss.
• Conjugative plasmids can hitchhike with bacterial phage resistance mutations.

Conclusions:

• Bacteriophages significantly impact conjugative plasmid dynamics through ecological and evolutionary mechanisms.
• Phage-driven selection for resistance can lead to indirect plasmid persistence.
• Bacteriophages may offer a strategy to eliminate plasmids with harmful genes, like antibiotic resistance.