Antibacterial Activity of Stenotrophomonas maltophilia Endolysin P28 against both Gram-positive and Gram-negative...

Area of Science:

• Microbiology
• Biochemistry
• Molecular Biology

Background:

• Maltocin P28 is a bacteriocin from Stenotrophomonas maltophilia P28.
• The ORF8 gene in the maltocin P28 cluster encodes endolysin P28, featuring a lysozyme-like domain and conserved motifs similar to E. coli phage lambda gpR's endolysin.

Purpose of the Study:

• To express, purify, and characterize endolysin P28.
• To evaluate the antibacterial activity and stability of endolysin P28.
• To assess its potential as a therapeutic agent against multi-drug-resistant pathogens.

Main Methods:

• Endolysin P28 was expressed in E. coli BL21 (DE3) and purified using a C-terminal oligo-histidine tag.
• Antibacterial activity was tested across a temperature range (25-70°C) and under varying pH and salinity conditions.
• Thermostability was assessed by measuring residual activity after heat treatment.
• The lytic spectrum against Gram-positive and Gram-negative bacteria was determined.

Main Results:

• Endolysin P28 activity increased with temperature up to 45°C and remained stable up to 50°C.
• Acidity and high salinity enhanced its antibacterial efficacy.
• It demonstrated broad-spectrum activity against 14 of 16 tested bacterial species, including Gram-negative and Gram-positive bacteria.
• Endolysin P28 effectively lysed intact Gram-negative bacteria without requiring ethylenediaminetetraacetic acid.

Conclusions:

• Endolysin P28 exhibits significant antibacterial properties, including broad-spectrum activity and stability under specific conditions.
• Its ability to lyse Gram-negative bacteria without permeabilizers highlights its potential.
• Endolysin P28 is a promising candidate for developing novel therapeutic strategies against multi-drug-resistant bacteria.