Microbiota Dynamics: A Key Factor in Hirudotherapy-Related Infections?

Microbiome study published in Microorganisms (2025)

Última actualización: 18 de junio de 2026Revisado por: ASH Editorial Board

Artículo de investigación — revisión de evidenciaReferencia del artículo

Evidence: Research reportSeguridad y control de infeccionesGenómica y proteómicaKarasartova D et al. · Microorganisms, 2025

Abstract

The gastrointestinal microbiota of medicinal leeches is particularly interesting due to their blood-feeding habits, increasing medical use, and risk of pathogen transmission. Three groups of Hirudo verbana were used to study the leech microbiota: farmed leeches fasting for a long time, farmed leeches recently fed with bovine blood, and wild specimens fed with amphibian blood. The microbiota of the leeches' mouth, pharynx, crop, and intestine was analyzed. Metasequencing analyses were performed using amplification of the 16S rRNA V3-V4 region on a NovaSeq Illumina platform. The relative abundance of bacterial microbiota included environmental bacteria from the families Rhizobiaceae, Comamonadaceae, Sphingobacteriaceae, Phreatobacteraceae, Myxococcaceae, Chitinophagaceae, Rhodospirillaceae, and Bdellovibrionaceae, as well as symbiotic/probiotic bacteria such as Mucinivorans, Aeromonas, Vagococcus, Lactobacillales, and Morganella. Significant differences were found in the different regions of the digestive system among the three groups of leeches, and environmental bacteria were present in all groups to varying degrees. A negative correlation was found between the dominant environmental and the symbiotic/probiotic bacteria. In contrast, a positive correlation was found between environmental and symbiotic/probiotic bacteria, indicating their association with host factors. Microbiota diversity, abundance, and bacterial correlations may be influenced by factors such as the leech's fasting state, blood meal source, and environmental conditions. The identified opportunistic pathogens, such as Rickettsia, Anaplasma, and Treponema, identified for the first time in H. verbana, should be taken into consideration when using this leech in hirudotherapy. Our results show that extensive screening for opportunistic and pathogenic agents should be performed on leeches intended for medical use. Long-fasting leeches and leeches cultured in specialized farms are recommended for hirudotherapy.

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

Publication typeJournal Article

Resumen

16S rRNA metagenomic study of leech gastrointestinal microbiota across mouth, pharynx, crop and intestine in farmed (fed/fasting) versus wild leeches. Identifies opportunistic pathogens and recommends long-fasting farm-raised leeches for hirudotherapy.

Por qué esto importa para la hirudoterapia

Este estudio de metasecuenciación del ARNr 16S (V3–V4) caracterizó la microbiota del tracto digestivo de Hirudo verbana en tres grupos: sanguijuelas de granja en ayuno prolongado, sanguijuelas de granja alimentadas recientemente con sangre bovina y ejemplares silvestres alimentados con sangre de anfibios. Encontró diferencias taxonómicas específicas a lo largo de la boca/faringe, el buche y el intestino, con bacterias ambientales y simbióticas/probióticas que variaron según el estado de ayuno, la fuente de la comida de sangre y las condiciones ambientales, e identificó Rickettsia, Anaplasma y Treponema por primera vez en H. verbana. Para la ASH y la hirudoterapia, esto es directamente relevante porque los patógenos oportunistas asociados a sanguijuelas pueden afectar la seguridad del paciente y pueden fundamentar las prácticas de cribado microbiológico y aprovisionamiento. Una advertencia honesta es que el estudio caracteriza únicamente comunidades microbianas y correlaciones; no demuestra tasas de infección clínica, no prueba que los taxones detectados causen infección, ni establece que algún protocolo particular de cribado o ayuno elimine el riesgo.