Bacterial symbiont and salivary peptide evolution in the context of leech phylogeny

The evolutionary history of leeches is employed as a general framework for understanding more than merely the systematics of this charismatic group of annelid worms, and serves as a basis for understanding blood-feeding related correlates ranging from the specifics of gut-associated bacterial symbionts to salivary anticoagulant peptides. A variety of medicinal leech families were examined for intraluminal crop bacterial symbionts. Species of Aeromonas and Bacteroidetes were characterized with DNA gyrase B and 16S rDNA. Bacteroidetes isolates were found to be much more phylogenetically diverse and suggested stronger evidence of phylogenetic correlation than the gammaproteobacteria. Patterns that look like co-speciation with limited taxon sampling do not in the full context of phylogeny. Bioactive compounds that are expressed as gene products, like those in leech salivary glands, have 'passed the test' of evolutionary selection. We produced and bioinformatically mined salivary gland EST libraries across medicinal leech lineages to experimentally and statistically evaluate whether evolutionary selection on peptides can identify structure-function activities of known therapeutically relevant bioactive compounds like antithrombin, hirudin and antistasin. The combined information content of a well corroborated leech phylogeny and broad taxonomic coverage of expressed proteins leads to a rich understanding of evolution and function in leech history.

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

The evolutionary history of leeches is employed as a general framework for understanding more than merely the systematics of this charismatic group of annelid worms, and serves as a basis for understanding blood-feeding related correlates ranging from the specifics of gut-associated bacterial symbionts to salivary a...

Leech-derived molecules this paper discusses, each with a full profile in the ASH compound registry:

Explore how this research connects to clinical practice

More peer-reviewed studies in Antimicrobial Resistance.

• Novel Leech Antimicrobial Peptides — Hirunipins — Kumar et al. (2025)
• Leech therapy (Hirudo medicinalis) attenuates testicular damages induced by testicular ischemia/reperfusion in an animal model — Davoodi F et al. (2021)
• AIF-1 and RNASET2 Play Complementary Roles in the Innate Immune Response of Medicinal Leech — Baranzini N et al. (2019)
• Medicinal leech antimicrobial peptides lacking toxicity represent a promising alternative strategy to combat antibiotic-resistant pathogens — Grafskaia E et al. (2019)
• Antimicrobial Role of RNASET2 Protein During Innate Immune Response in the Medicinal Leech — Baranzini N et al. (2020)
• Morganella Morganii Infection in Hirudo Medicinalis (Iran): A Case Report — Rahmati Holasoo H et al. (2022)
• Clinical efficacy of Jalaukawacharana (leech application) in Thrombosed piles — Bhagat P, Raut S, Lakhapati A (2012)
• Determination of disulfide linkages in antimicrobial peptides of the macin family by combination of top-down and bottom-up proteomics — Hung CW, Jung S, Grötzinger J, Gelhaus C, Leippe M, Tholey A (2014)
• Molecular characterization of two novel antibacterial peptides inducible upon bacterial challenge in an annelid, the leech Theromyzon tessulatum — Tasiemski A, Vandenbulcke F, Mitta G, Lemoine J, Lefebvre C, Sautière PE, Salzet M (2004)
• Macin family of antimicrobial proteins combines antimicrobial and nerve repair activities — Jung S, Sönnichsen FD, Hung CW et al. (2012)

Browse all ASH-analysed research →