American Society of Hirudotherapy

First identification of beta-lactamases in antibiotic-resistant bacteria isolated in stream macroinvertebrates in a central Italian region

Basic science / microbiology published in Microb Drug Resist (2020)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Safety & Infection ControlSegatore B et al. · Microbial drug resistance, 2020

Abstract

Antibiotic-resistant bacteria (ARB) are widespread in nature and represent a serious public and environmental problem. In the present study, we report for the first time the presence of bacterial β-lactamases in two macroinvertebrate species with different feeding traits. The class A β-lactamases, SHV-1 and TEM-1, were found in Citrobacter freundii isolated from Gammarus elvirae and Escherichia coli from water samples, respectively. The metallo-β-lactamase CphA was found in Aeromonas veronii and Aeromonas hydrophila strains isolated from the predator Dina lineata. The presence of a large plasmid was ascertained only in E. coli strains isolated from water. In all strains studied, an integrase I typical of class I integrin was found. In contaminated freshwater habitats, ARB and antibiotic resistance genes could be disseminated through trophic links with important ecological implications. Transmission through the food chain may contribute to spreading and transferring antibiotic resistance not only in freshwater ecosystems but also outside the aquatic habitat.

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

Publication typeJournal Article
Indexed MeSH termsAeromonasAnimalsAnti-Bacterial AgentsBacterial ProteinsCitrobacter freundiiCrustaceaDrug Resistance, MicrobialEscherichia coliIntegronsInvertebratesItalyLeeches

Summary

First identification of SHV-1 and TEM-1 beta-lactamases in stream-macroinvertebrate-isolated bacteria including leech-associated strains. Class I integrase detected in all strains, suggesting horizontal antibiotic-resistance gene transfer.

Why This Matters for Hirudotherapy

This study reports the first identification of beta-lactamase genes in bacteria isolated from stream macroinvertebrates, including the metallo-beta-lactamase CphA in Aeromonas veronii and Aeromonas hydrophila strains from the predator Dina lineata, and class A beta-lactamases (SHV-1, TEM-1) in Citrobacter freundii from Gammarus elvirae and Escherichia coli from water samples. All strains carried class I integrase, suggesting potential for horizontal resistance gene transfer through trophic links in freshwater ecosystems. The abstract does not identify Dina lineata as a leech, nor does it mention medicinal leech therapy, hirudotherapy, or Hirudo medicinalis. Consequently, no defensible connection to ASH's domain can be established from the abstract alone; the study is an environmental microbiology investigation of antibiotic resistance dissemination in freshwater habitats.

Citation

First identification of beta-lactamases in antibiotic-resistant bacteria isolated in stream macroinvertebrates in a central Italian region.

Segatore B et al. · Microbial drug resistance, 2020

DOI

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