The antimicrobial peptide LI14 combats multidrug-resistant bacterial infections

Area of Science:

• Microbiology
• Biochemistry
• Drug Discovery

Background:

• Multidrug-resistant (MDR) pathogens pose a significant global health threat, necessitating novel antimicrobial strategies.
• Antimicrobial peptides (AMPs) are explored as potential antibiotic alternatives due to their unique mechanisms and low resistance development potential.

Purpose of the Study:

• To develop and evaluate novel synthetic peptide compounds as potential agents against drug-resistant bacterial infections.
• To characterize the antibacterial activity, resistance potential, stability, and mechanism of action of lead peptide LI14.

Main Methods:

• Database filters technology (DFT) was employed to design and synthesize a panel of peptide compounds.
• Antibacterial activity, biofilm inhibition, persister cell eradication, stability, toxicity, and mechanism of action (membrane damage, PMF dissipation) were assessed.
• In vivo efficacy was evaluated in animal infection models.

Main Results:

• The lead peptide LI14 demonstrated potent bactericidal activity against multidrug-resistant bacteria, with rapid action and low resistance propensity.
• LI14 exhibited strong anti-biofilm and anti-persister activity, alongside stability against pH, temperature, and pepsin.
• Mechanistic studies revealed LI14 targets bacterial membranes, dissipates proton motive force, and sensitizes bacteria to existing antibiotics.
• LI14 showed no detectable in vitro or in vivo toxicity and proved effective in animal models.

Conclusions:

• The synthetic peptide LI14 is a promising antibiotic candidate for combating multidrug-resistant bacterial infections.
• LI14's multifaceted mechanism, stability, and safety profile support its potential clinical application.
• LI14 can also enhance the efficacy of existing antibiotics against resistant strains.