Engineered Peptides Harboring Cation Motifs Against Multidrug-Resistant Bacteria

Area of Science:

• Biochemistry
• Microbiology
• Pharmacology

Background:

• Multidrug-resistant (MDR) pathogens present a significant global health threat.
• There is an urgent need for novel antimicrobial agents to combat resistant bacterial infections.

Purpose of the Study:

• To develop and characterize novel short antimicrobial peptides (AMPs) with a cation end motif.
• To evaluate the efficacy of these peptides against MDR bacteria, biofilms, and in an animal sepsis model.

Main Methods:

• Synthesis and characterization of nine amino acid peptides.
• Bioactivity assays against MDR planktonic bacteria and mature biofilms.
• Mechanistic studies involving reactive oxygen species accumulation and membrane disruption.
• In vivo efficacy testing in a murine model of sepsis.

Main Results:

• A peptide with a central "RWWWR" motif and "KXR" unit (KLR) demonstrated high activity against MDR planktonic bacteria.
• The peptide KLR achieved a 92.33% clearance rate against mature bacterial biofilms.
• Mechanistic studies revealed KLR induces excessive reactive oxygen species and disrupts bacterial membranes.
• KLR showed significant therapeutic effects in an animal model of sepsis caused by MDR bacteria.

Conclusions:

• The study identified a dominant structural motif for potent short antimicrobial peptides.
• The peptide KLR exhibits broad-spectrum activity and a dual mechanism of action against MDR bacteria.
• KLR represents a promising candidate for development as a new therapeutic agent against drug-resistant bacterial infections.