The study evaluated the antimicrobial susceptibility of 55 Salmonella isolates from tambaqui hybrid fish farms in Mato Grosso, Brazil, finding all strains fully susceptible to 14 commonly used antibiotics and no clinically significant serotypes detected. The results emphasize the necessity of continuous monitoring in aquaculture systems to ensure food safety.
Literature Overview
This study, titled 'Microbiological Monitoring and Microbial Susceptibility of Salmonella from Aquacultured Tambaqui Hybrids (Colossoma macropomum): Implications for Food Safety', published in the journal Antibiotics, reviews the distribution and antimicrobial susceptibility of Salmonella strains in tambaqui fish farms in Mato Grosso, Brazil. The research utilized the VITEK®2 Compact system to assess minimum inhibitory concentrations (MICs) of 14 antimicrobial agents and classified results according to the Brazilian Committee on Antimicrobial Susceptibility (BrCAST) standards. Findings revealed all isolates exhibited susceptibility to tested antibiotics, with no detection of clinically significant serotypes such as S. Typhi or S. Paratyphi.
Background Knowledge
Salmonella is a globally significant foodborne pathogen, with potential transmission risks in fish and aquaculture systems. While fish are not natural hosts for Salmonella, its presence in aquaculture environments has raised food safety concerns. In recent years, multidrug-resistant (MDR) Salmonella strains have emerged as priority pathogens for the World Health Organization (WHO) due to associations with treatment failure, prolonged hospitalization, and increased mortality. This study investigates Salmonella serotypes and antimicrobial resistance in tambaqui hybrids from Mato Grosso, Brazil, providing scientific evidence for food safety and public health policies.
Research Methods and Experiments
Seventy-two tambaqui hybrid fish samples were collected from 25 aquaculture farms across eight municipalities in the Cerrado and Pantanal biomes of Mato Grosso, Brazil. Salmonella isolation and identification followed ISO 6579-1 standards, with strain confirmation via PCR amplification of the hilA gene. Serotyping and antimicrobial susceptibility testing (covering 14 antibiotics including β-lactams, carbapenems, aminoglycosides, fluoroquinolones, and sulfonamides) were conducted using the VITEK®2 Compact system, with results categorized according to BrCAST guidelines.
Key Conclusions and Perspectives
Research Significance and Prospects
Results indicate that Salmonella strains from tambaqui hybrids under current management practices remain susceptible to common antibiotics, suggesting low public health risk. However, continuous surveillance is critical due to potential cross-contamination with livestock systems and the evolutionary dynamics of antimicrobial resistance. Future studies should integrate serotyping with resistance gene profiling to comprehensively assess Salmonella's transmission potential and public health impact in aquaculture. Implementing One Health frameworks could further optimize antimicrobial stewardship by integrating data across human, animal, and environmental health domains.
Conclusion
Through systematic monitoring of Salmonella in aquacultured tambaqui hybrids in Mato Grosso, Brazil, this study demonstrated full susceptibility to 14 common antimicrobials and absence of clinically relevant serotypes. Despite these findings, Salmonella's persistent presence in aquaculture systems highlights the need for sustained surveillance, particularly under changing environmental and management conditions. The potential for antimicrobial use to drive resistance selection necessitates future research on microbial diversity and resistance evolution across production stages. These data reinforce Brazil's current zero-tolerance policy for Salmonella in fish products and provide evidence-based support for food safety and public health management.
