Biological characteristics and anti-biofilm activity of a lytic phage against vancomycin-resistant Enterococcus...

Area of Science:

• Microbiology
• Bacteriophage Therapy
• Antimicrobial Resistance

Background:

• Antibiotic resistance in enterococci, particularly vancomycin-resistant Enterococcus faecium (VREfm), poses a significant global health threat.
• The inefficiency of current antibiotics necessitates the exploration of alternative therapeutic strategies to combat drug-resistant pathogens.
• Bacteriophages represent a promising alternative due to their specificity and ability to target resistant bacteria.

Purpose of the Study:

• To isolate and characterize a bacteriophage effective against vancomycin-resistant Enterococcus faecium.
• To evaluate the biological properties and efficacy of the isolated bacteriophage (vB-EfmS-S2) against VREfm.
• To assess the phage's impact on VREfm biofilm formation and structure.

Main Methods:

• Isolation of bacteriophage vB-EfmS-S2 from hospital sewage.
• Determination of biological properties including host range, optimal pH and temperature, stability in bile, and Mg2+ requirement.
• Assessment of phage S2's lytic activity and its effect on VREfm biofilm disruption using electron microscopy.

Main Results:

• Phage S2 demonstrated specific lysis against a broad range of clinical VREfm isolates.
• Electron microscopy confirmed phage S2 belongs to the Siphoviridae family.
• Optimal conditions for phage S2 activity included pH 5-11 and temperatures of 30-45°C (peak at 37°C), with a latent period of 14 min and burst size of 200 PFU/ml. It tolerated 1-2% bile and required Mg2+.
• Phage S2 significantly inhibited and disrupted VREfm biofilms.

Conclusions:

• Bacteriophage S2 exhibits potent lytic activity against vancomycin-resistant Enterococcus faecium.
• Phage S2 effectively inhibits and disrupts VREfm biofilms.
• Phage S2 holds significant potential as an alternative therapeutic agent for controlling VREfm infections, particularly those involving biofilms.