Mucinivorans hirudinis gen. nov., sp. nov., an anaerobic, mucin-degrading bacterium isolated from the digestive tract of the medicinal leech Hirudo verbana
Taxonomy paper published in International Journal of Systematic and Evolutionary Microbiology (2015)
Abstract
Three anaerobic bacterial strains were isolated from the digestive tract of the medicinal leech Hirudo verbana, using mucin as the primary carbon and energy source. These strains, designated M3(T), M4 and M6, were Gram-stain-negative, non-spore-forming and non-motile. Cells were elongated bacilli approximately 2.4 µm long and 0.6 µm wide. Growth only occurred anaerobically under mesophilic and neutral pH conditions. All three strains could utilize multiple simple and complex sugars as carbon sources, with glucose fermented to acid by-products. The DNA G+C contents of strains M3(T), M4 and M6 were 44.9, 44.8 and 44.8 mol%, respectively. The major cellular fatty acid of strain M3(T) was iso-C15 : 0. Phylogenetic analysis of full-length 16S rRNA gene sequences revealed that the three strains shared >99 % similarity with each other and represent a new lineage within the family Rikenellaceae of the order Bacteroidales, phylum Bacteroidetes. The most closely related bacteria to strain M3(T) based on 16S rRNA gene sequences were Rikenella microfusus DSM 15922(T) (87.3 % similarity) and Alistipes finegoldii AHN 2437(T) (87.4 %). On the basis of phenotypic, genotypic and physiological evidence, strains M3(T), M4 and M6 are proposed as representing a novel species of a new genus within the family Rikenellaceae, for which the name Mucinivorans hirudinis gen. nov., sp. nov. is proposed. The type strain of Mucinivorans hirudinis is M3(T) ( = ATCC BAA-2553(T) = DSM 27344(T)).
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Summary
Description of Mucinivorans hirudinis gen. nov., sp. nov., the first cultured representative of the previously known Rikenella-like dominant symbiont of the medicinal leech crop, marking a major advance after 20+ years of culture attempts.
Why This Matters for Hirudotherapy
This study describes the isolation and taxonomic characterization of three anaerobic, mucin-degrading bacterial strains (M3(T), M4, M6) from the digestive tract of the medicinal leech Hirudo verbana. Based on phenotypic, genotypic, and physiological evidence—including 16S rRNA gene sequencing, DNA G+C content (~44.9 mol%), and fatty acid analysis—the authors propose these strains as a novel species and genus, Mucinivorans hirudinis gen. nov., sp. nov., within the family Rikenellaceae (phylum Bacteroidetes). This work is indirectly relevant to the leech research domain, as characterizing the leech gut microbiota contributes to understanding the microbial ecology of medicinal leeches and may inform future studies on symbiont-host relationships or infection risk. However, this is purely a taxonomy and physiology paper with no clinical, therapeutic, or direct hirudotherapy data, and no pathogenicity or antibiotic resistance findings are reported.
Citation
Mucinivorans hirudinis gen. nov., sp. nov., an anaerobic, mucin-degrading bacterium isolated from the digestive tract of the medicinal leech Hirudo verbana.
Nelson MC, Bomar L, Maltz M, Graf J · International journal of systematic and evolutionary microbiology, 2015
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