CONCLUSION

This study demonstrated the occurrence of ARB harboring clinically important β-lactamase resistance genes in giant freshwater prawn aquaculture ponds in Kalasin Province, Thailand. A total of 20 bacterial isolates representing eight species and five genera were identified, with _A. _veronii being the predominant species. Fourteen isolates (70.0%; 95% CI: 45.7–88.1%) exhibited MDR phenotypes, and molecular analyses revealed the presence of clinically relevant resistance genes, particularly blaSHV and blaKPC-2. Notably, the co-occurrence of blaSHV and blaKPC-2 in _A. _veronii isolate MSS1 and the detection of blaKPC-2-positive isolates in multiple bacterial species represent important findings and provide the first evidence of blaKPC-2-carrying bacteria associated with freshwater prawn aquaculture ponds in Thailand.

These findings highlight the potential role of freshwater aquaculture systems as environmental reservoirs and dissemination pathways for AMR determinants. The results emphasize the importance of implementing prudent antimicrobial use practices, strengthening biosecurity measures, and incorporating routine molecular surveillance into disease management programs. Furthermore, the integration of aquaculture-associated AMR monitoring within a One Health framework may contribute to more sustainable aquaculture production and help mitigate the spread of clinically important resistance determinants.

A major strength of this study was the integrated approach that combined culture-based isolation, molecular identification, antimicrobial susceptibility profiling, and targeted detection of β-lactamase genes, thereby generating valuable baseline data for freshwater aquaculture systems in Northeastern Thailand.

Future studies should incorporate metagenomics, quantitative PCR, whole-genome sequencing, and resistome analyses to better elucidate the ecology, transmission dynamics, and persistence of ARGs in aquaculture ecosystems. Additional investigations involving environmental exposure pathways and food-chain transmission are also warranted to clarify the public health significance of resistant bacteria associated with freshwater aquaculture.

In conclusion, the present findings provide important baseline information for AMR surveillance in freshwater prawn farming and underscore the need for integrated antimicrobial stewardship and sustainable disease management strategies. Strengthening surveillance and adopting preventive approaches will be essential for safeguarding aquaculture productivity, environmental health, and public health under the One Health paradigm.