In vitro activity of the antimicrobial peptides h-Lf1-11, MSI-78, LL-37, fengycin 2B, and magainin-2 against...

Area of Science:

• Microbiology
• Pharmacology
• Biochemistry

Background:

• Antibiotic resistance is a growing global health threat.
• Antimicrobial peptides (AMPs) are a promising alternative to conventional antibiotics.
• Several AMPs, including h-Lf1-11, MSI-78, LL-37, fengycin 2B, and magainin-2, were evaluated for their efficacy.

Purpose of the Study:

• To assess and compare the antibacterial activity of five selected antimicrobial peptides.
• To determine the minimum inhibitory concentration (MIC) of these peptides against key pathogenic bacteria.
• To identify potent AMPs for potential development against antibiotic-resistant infections.

Main Methods:

• Minimum inhibitory concentration (MIC) determination using the microdilution technique.
• Standardized protocols (CLSI M07-A9, 2012) were followed.
• Testing was conducted against a panel of clinically relevant bacterial strains: Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, carbapenem-resistant Klebsiella pneumoniae (CRKP), and Acinetobacter baumannii.

Main Results:

• MSI-78 exhibited potent bactericidal activity with MIC values ranging from 1.25 to 40 mg/L against all tested bacterial strains.
• h-Lf1-11, magainin-2, and LL-37 displayed moderate antibacterial activity, with MIC ranges of 40-160 mg/L, 80-160 mg/L, and 40-160 mg/L, respectively.
• Fengycin 2B showed no significant antibacterial activity against the tested bacterial panel.

Conclusions:

• MSI-78 is a highly promising antibacterial agent with broad-spectrum activity against resistant bacteria.
• h-Lf1-11, magainin-2, and LL-37 also possess significant antibacterial potential and warrant further investigation.
• These findings support the exploration of these AMPs as novel therapeutic strategies to combat antibiotic-resistant infections.