Peptide extract from Hexaplex trunculus: A promising antimicrobial agent with inhibitory effects on quorum sensing and biofilm formation

Purpose

Infectious diseases are a global concern and antimicrobial resistance is a major cause of their prevalence. Antimicrobial peptides (AMPs), which are key components of the innate immune system of marine invertebrates, provide a rapid and immediate response against invading microbes. They possess remarkable antimicrobial activities and slower rates of resistance acquisition, making them an attractive target for new antimicrobial therapeutics. This work seeks to extract peptides from the marine mollusc, Hexaplex trunculus, and explore their antimicrobial activity.

Methods

Peptides were precipitated from the body tissue of H. trunculus, and the peptides were characterized using spectroscopic methods such as FTIR and UV. The broth dilution technique was used to determine the peptides' minimum inhibitory concentrations (MICs). The peptide extract was tested against Escherichia coli, Enterococcus faecalis, Staphylococcus aureus, Candida albicans, and Pseudomonas aeruginosa. The study also evaluated the effect of the peptide extracts on quorum sensing-mediated processes in Pseudomonas aeruginosa.

Results

The MIC values obtained against the various microorganisms ranged between 0.50 mg/mL and 0.25 mg/mL. Minimum bactericidal concentration (MBC) determination showed that the peptide extract at 0.50 mg/mL and 0.25 mg/mL had bacteriostatic effects. The results showed that the crude peptide extract inhibited biofilm formation in Pseudomonas aeruginosa. The expression of pyocyanin and pyoverdine, which are mediated by cell-to-cell communication, was inhibited by 88% and 66%, respectively, at 1/2 MIC of the peptide extract.

Conclusion

These findings suggest that crude peptide extract from Hexaplex trunculus may serve as a potential source of new antimicrobial agents to combat infectious diseases.