Intra-species competition combats vancomycin-resistant enterococci

Area of Science:

• Microbiology
• Microbiome Therapeutics
• Infectious Diseases

Background:

• Vancomycin-resistant Enterococcus (VRE) is a major cause of hospital-acquired infections.
• Existing treatments lack reproducible microbiota therapies to selectively eliminate VRE.
• Developing targeted interventions against VRE is crucial for public health.

Purpose of the Study:

• To identify a specific bacterial strain capable of suppressing VRE colonization.
• To explore the use of intra-species competition for developing VRE microbiota therapies.
• To investigate phage-driven evolution for enhancing VRE antagonism.

Main Methods:

• Conducted in vitro screening and mouse colonization models to identify VRE-suppressing strains.
• Utilized phage selection on a vancomycin-sensitive Enterococcus strain.
• Analyzed genetic mutations and secreted factors responsible for VRE antagonism.

Main Results:

• A single antibiotic-susceptible strain, E. faecalis X98, significantly reduced VRE burden in vitro and in vivo.
• Multi-strain consortia were less effective due to competitive interference.
• Phage-selected E. faecalis OG1RF derivatives exhibited enhanced VRE antagonism via secreted factors.

Conclusions:

• Intra-species competition can be harnessed to select effective VRE-suppressing strains.
• Phage-driven evolution offers a strategy to enhance microbial therapeutics.
• This framework provides a practical approach for developing targeted microbiome interventions against antibiotic-resistant pathogens with minimal collateral damage.