Culture-independent characterization of the digestive-tract microbiota of the medicinal leech reveals a tripartite symbiosis

Culture-based studies of the microbial community within the gut of the medicinal leech have typically been focused on various Aeromonas species, which were believed to be the sole symbiont of the leech digestive tract. In this study, analysis of 16S rRNA gene clone libraries confirmed the presence of Aeromonas veronii and revealed a second symbiont, clone PW3, a novel member of the Rikenellaceae, within the crop, a large compartment where ingested blood is stored prior to digestion. The diversity of the bacterial community in the leech intestinum was determined, and additional symbionts were detected, including members of the alpha-, gamma-, and delta-Proteobacteria, Fusobacteria, Firmicutes, and Bacteroidetes. The relative abundances of the clones suggested that A. veronii and the novel clone, PW3, also dominate the intestinum community, while other clones, representing transient organisms, were typically present in low numbers. The identities of these transients varied greatly between individual leeches. Neither time after feeding nor feeding on defibrinated blood caused a change in identity of the dominant members of the microbial communities. Terminal restriction fragment length polymorphism analysis was used to verify that the results from the clone libraries were representative of a larger data set. The presence of a two-member bacterial community in the crop provides a unique opportunity to investigate both symbiont-symbiont and symbiont-host interactions in a natural model of digestive-tract associations.

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

16S rRNA gene clone libraries reveal a tripartite symbiosis dominated by Aeromonas veronii and a novel Rikenella-like bacterium (PW3) in the crop, with diverse low-abundance transient organisms in the intestinum.

Erfahren Sie, wie diese Forschung mit der klinischen Praxis verknüpft ist

More peer-reviewed studies in Genomik & Proteomik.

• 434 Salivary Proteins — Integrated Proteomics of Hirudo medicinalis — Liu et al. (2019)
• Medicinal Leech Genome Assembly — Anticoagulant Gene Catalog — Kvist et al. (2020)
• Effects of hirudotherapy on liver functions, lipid profile, and insulin sensitivity in rats with metabolic syndrome — Bilden A et al. (2026)
• Efficacy and Safety of Hirudotherapy for Improving Sperm Quality Parameters in Male Infertility: A Randomized Controlled Trial — Abtahi-Forooshani M et al. (2026)
• Hirudotherapy in Wound Healing — Nair H et al. (2022)
• [Medicinal leeches and hirudotherapy] — Gödekmerdan A et al. (2011)
• [Cutaneous pseudolymphoma after hirudotherapy : Case report and review] — Hanner S et al. (2022)
• HIRUDOTHERAPY IN PRESBYACUZIS PRAECOX IN CLEAN-UP WORKERS AFTER THE CHORNOBYL ACCIDENT DURING THE POST-CATASTROPHE YEARS — Zabolotnyi D, Mishchanchuk N (2019)
• Hirudotherapy (medicinal leeches) for treatment of upper airway obstruction in a dog — Trenholme H, Masseau I, Reinero C (2021)
• Leech therapy — Yantis M, O'Toole K, Ring P (2009)

Browse all ASH-analysed research →