American Society of Hirudotherapy

First Identification of β-Lactamases in Antibiotic-Resistant Escherichia coli, Citrobacter freundii, and Aeromonas spp. 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 coliIntegronsInvertebratesItalyLeechesMicrobial Sensitivity TestsPlasmidsRiversbeta-Lactamases

Summary

First report of β-lactamases in stream macroinvertebrates: SHV-1 in Citrobacter freundii from Gammarus elvirae, TEM-1 in Escherichia coli from water samples, and CphA in Aeromonas strains from the predator Dina lineata, with a class 1 integron-associated integrase found in all strains studied.

Context

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. The study is an environmental microbiology investigation of antibiotic resistance dissemination in freshwater habitats.

Citation

Reference (Vancouver style)

Segatore B, Piccirilli A, Setacci D, Cicolani B, Di Sabatino A, Miccoli FP, et al. First Identification of β-Lactamases in Antibiotic-Resistant Escherichia coli, Citrobacter freundii, and Aeromonas spp. Isolated in Stream Macroinvertebrates in a Central Italian Region. Microb Drug Resist. 2020;26(8):976-981. doi:10.1089/mdr.2019.0258. PMID: 32101080

Bibliographic details (authors, volume, pages, DOI) are taken from the PubMed record.

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