Antimicrobial Resistance in Pathogenic Bacteria from Endangered Fish: A One Health Approach to Emerging Zoonotic Threats

Introduction:
Emerging antimicrobial resistance (AMR) in aquatic ecosystems poses significant threats to biodiversity, particularly for endangered fish species. Pathogenic bacteria, such as Aeromonas, are increasingly recognized as reservoirs of resistance, yet their role in the context of endangered species remains underexplored. Understanding the pathogenic potential and resistance profiles of Aeromonas is critical for the development of effective conservation strategies and the protection of both animal and human health. This study aims to investigate the occurrence and antimicrobial resistance of Aeromonas in endangered fish species, with a focus on the zoonotic potential and implications for One Health.

Methods:
Aeromonas was isolated from various organs of endangered fish species from the Tarim River and identified using molecular techniques. The isolates were evaluated for antimicrobial susceptibility, focusing on tetracyclines and fluoroquinolones. Genomic analyses were performed to identify resistance genes and virulence factors linked to pathogenicity and zoonotic transmission.

Results:
All isolates were confirmed as Aeromonas. The bacteria exhibited significant multidrug resistance, particularly to tetracyclines (38 genes) and fluoroquinolones (28 genes). Other antibiotic classes, including macrolides, peptide antibiotics, and cephalosporins, also showed notable resistance. Genomic analysis revealed the presence of virulence genes related to bacterial adherence, motility, and host invasion, suggesting zoonotic potential.

Conclusions:
This study highlights the emerging threat of AMR in Aeromonas species from endangered fish, emphasizing the need for a One Health approach to monitor and manage resistance in aquatic environments. The findings underscore the importance of integrating AMR surveillance into conservation efforts to mitigate risks to both wildlife and human health.