American Society of Hirudotherapy

The Hirudo medicinalis microbiome is a source of new antimicrobial peptides

Basic science / drug discovery published in Int J Mol Sci (2020)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: In vitro / laboratoryAntimicrobial ResistanceDrug DevelopmentGenomics & ProteomicsGrafskaia E et al. · International journal of molecular sciences, 2020

Abstract

Antimicrobial peptides (AMPs) are considered a promising new class of anti-infectious agents. This study reports new antimicrobial peptides derived from the Hirudo medicinalis microbiome identified by a computational analysis method applied to the H. medicinalis metagenome. The identified AMPs possess a strong antimicrobial activity against Gram-positive and Gram-negative bacteria (MIC range: 5.3 to 22.4 μM), including Staphylococcus haemolyticus, an opportunistic coagulase-negative pathogen. The secondary structure analysis of peptides via CD spectroscopy showed that all the AMPs except pept_352 have mostly disordered structures that do not change under different conditions. For peptide pept_352, the α-helical content increases in the membrane environment. The examination of the mechanism of action of peptides suggests that peptide pept_352 exhibits a direct membranolytic activity. Furthermore, the cytotoxicity assay demonstrated that the nontoxic peptide pept_1545 is a promising candidate for drug development. Overall, the analysis method implemented in the study may serve as an effective tool for the identification of new AMPs.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal Article
Indexed MeSH termsAmino Acid SequenceAnimalsAnti-Bacterial AgentsAntimicrobial Cationic PeptidesCell LineCell SurvivalCircular DichroismDrug DiscoveryFibroblastsGram-Negative BacteriaGram-Positive BacteriaHirudo medicinalis

Summary

Computational metagenomic mining of Hirudo medicinalis microbiome identifying novel antimicrobial peptides with strong activity (MIC 5.3-22.4 uM) against Gram-positive and Gram-negative bacteria including coagulase-negative pathogens.

Why This Matters for Hirudotherapy

This study used a computational analysis of the Hirudo medicinalis metagenome to identify new antimicrobial peptides (AMPs) derived from the medicinal leech microbiome, finding strong activity against both Gram-positive and Gram-negative bacteria (MIC range 5.3–22.4 μM) including the opportunistic pathogen Staphylococcus haemolyticus. One peptide (pept_352) exhibited direct membranolytic activity, while another (pept_1545) was found nontoxic in a cytotoxicity assay and identified as a promising candidate for drug development. This work is relevant to ASH's domain as it characterizes antimicrobial compounds associated with Hirudo medicinalis, the medicinal leech. The caveat is that the study is preclinical and in-vitro in nature; no animal or human testing is described, and clinical efficacy remains unestablished.

Citation

The Hirudo medicinalis microbiome is a source of new antimicrobial peptides.

Grafskaia E et al. · International journal of molecular sciences, 2020

Added to ASH library: May 27, 2026 · Site last updated: June 18, 2026

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