Antibacterial Activity of a Lytic Enzyme Encoded by Pseudomonas aeruginosa Double Stranded RNA Bacteriophage phiYY

Area of Science:

• Microbiology
• Biotechnology
• Antimicrobial Research

Background:

• Multidrug-resistant *Pseudomonas aeruginosa* poses a significant global health threat.
• Phage-encoded lytic proteins, such as endolysins and VAPGH, are explored as antimicrobial agents.
• Unlike dsDNA phages, dsRNA phages encode a single lytic protein with dual functions.

Purpose of the Study:

• To clone, purify, and characterize the dsRNA phage phiYY encoded lysin, Ply17.
• To evaluate the antibacterial activity and lytic potential of Ply17 against Gram-negative and Gram-positive bacteria.
• To assess the optimal conditions for Ply17's lytic activity.

Main Methods:

• Cloning and purification of the dsRNA phage phiYY encoded lysin (Ply17).
• Assessment of Ply17's antibacterial spectrum against Gram-negative bacteria treated with an outer membrane permeabilizer.
• Determination of optimal conditions (temperature, pH, EDTA concentration) for Ply17's lytic activity.
• Evaluation of Ply17's direct lytic activity against Gram-positive bacteria.

Main Results:

• Ply17 was successfully cloned and purified, revealing a PG-binding domain and a lysozyme-like-family domain.
• Ply17 demonstrated broad antibacterial activity against Gram-negative bacteria and direct lysis of Gram-positive bacteria, including *Staphylococcus aureus*.
• Optimal lytic activity for Ply17 was observed at 37°C, pH 7.5, with 0.5 mM EDTA.

Conclusions:

• The dsRNA phage encoded lysin, Ply17, exhibits significant antibacterial properties.
• Ply17 shows potential as a novel therapeutic agent against multidrug-resistant Gram-negative and Gram-positive pathogens.
• Further investigation into Ply17 as an antimicrobial agent is warranted.