Elucidating environmental reservoir of antimicrobial resistance - a phenotypic characterization of gut microbiota from aquatic coleoptera in a low-anthropogenic impact zone.
Research article published in Annals of agricultural and environmental medicine : AAEM (2025)
Abstract
INTRODUCTION AND OBJECTIVE: This study investigated the antibiotic resistance of bacterial isolates obtained from the gut microbiota of certain insects (Coleoptera: Hydrophilidae and Helophoridae), which were collected from aquatic areas in Erzurum Province, Türkiye. This area is characterised by a low level of human impact, thereby providing a unique opportunity to investigate the baseline microbial diversity and ecological roles within relatively pristine aquatic environments. MATERIAL AND METHODS: The antimicrobial susceptibility of the isolates was assessed using disc diffusion and minimum inhibitory concentration (MIC) methods. The analysis encompassed 30 Gram-negative bacteria belonging to the genera Aeromonas, Acinetobacter, Vibrio, Pseudomonas, Escherichia and Yersinia. RESULTS: The results indicated that the most resistant bacteria were Aeromonas, Pseudomonas and Acinetobacter, while enteric bacteria demonstrated greater sensitivity. It is noteworthy that nitrofurantoin, a commonly used antibiotic for treating urinary tract infections, exhibited the highest level of resistance among the antibiotics tested by disc diffusion, followed by cephalosporins and penicillins. CONCLUSIONS: The MIC testing with DKGM and NF kits demonstrated high resistance to cephalosporins, sulfonamides, polymyxins and monobactams. Furthermore, two multidrug-resistant (MDR) isolates exhibited resistance to at least two antibiotic classes. These findings underscore the necessity for expanded antimicrobial resistance surveillance beyond clinical settings, extending into environmental samples, and contributing to ongoing research on resistance mechanisms.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Summary
This study investigated the antibiotic resistance of bacterial isolates obtained from the gut microbiota of certain insects (Coleoptera: Hydrophilidae and Helophoridae), which were collected from aquatic areas in Erzurum Province, Türkiye.
Why This Matters for Hirudotherapy
This study phenotypically characterized the gut microbiota of aquatic beetles (Coleoptera) from a low-human-impact zone in Erzurum Province, Turkiye, testing 30 Gram-negative isolates and finding that Aeromonas, Pseudomonas and Acinetobacter were the most antibiotic-resistant genera, with two multidrug-resistant isolates and notably high resistance to nitrofurantoin, cephalosporins, sulfonamides, polymyxins and monobactams. For hirudotherapy this is relevant context because Aeromonas is the principal gut symbiont of the medicinal leech and the main organism behind post-leech-application wound infections; finding environmentally derived, sometimes multidrug-resistant Aeromonas in pristine aquatic insects reinforces why antibiotic prophylaxis around leech therapy must account for possible resistance rather than assuming standard susceptibility. The caveat is that this is an environmental phenotyping study of beetle (not leech) microbiota and does not test leech-associated isolates or any clinical outcome, so it informs surveillance and prophylaxis thinking by analogy only and should not be read as data on leech-therapy infection rates.
Citation
Elucidating environmental reservoir of antimicrobial resistance - a phenotypic characterization of gut microbiota from aquatic coleoptera in a low-anthropogenic impact zone.
Orhan F et al. · Annals of agricultural and environmental medicine : AAEM, 2025
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