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Environmental Persistence and Genotypic and Phenotypic Characterization of Salmonella Minnesota in Poultry
Larissa Justino1,2, Ana Angelita Sampaio Baptista2, Rafael Humberto de Carvalho3
1Laboratory of Animal Nutrition, Department of Zootechny, Agricultural Sciences Center, State University of Londrina, Londrina 86057-970, Brazil.
Abstract:
Salmonella Minnesota (SM) is considered an emerging serovar, adapted to the poultry production chain, frequently associated with antimicrobial resistance, biofilm formation, and environmental persistence. This study aimed to characterize SM isolates from a poultry slaughterhouse regarding phenotypic and genotypic profiles of antimicrobial resistance, biofilm-forming capacity, thermal tolerance, genotypic virulence profile, and clonal relatedness. Strains obtained from carcasses (n = 26), cecal contents (n = 25), and chiller water (n = 11) from the slaughterhouse were evaluated. A high frequency of resistance to β-lactams, multidrug-resistant phenotypes, and extended-spectrum β-lactamase-producing isolates were observed. All isolates harbored genes associated with virulence and biofilm formation (invA, csgD, and adrA). Biofilm formation was influenced by temperature, with greater intensity at refrigeration temperatures, especially on stainless steel surfaces. In thermal tolerance assays, a negative correlation between temperature and bacterial viability was observed. Genetically related lineages circulating among cecum, carcass, and slaughterhouse chiller water over time were observed. These findings indicate that the persistence of SM in poultry slaughterhouses is sustained by the interaction between antimicrobial resistance, adaptive capacity associated with biofilm formation, and the circulation of genetically related lineages, representing a relevant challenge for food safety and public health.
Insights
Salmonella Minnesota in poultry slaughterhouses shows high antimicrobial resistance and biofilm formation, persisting through genetically related lineages. This poses a significant food safety and public health challenge.
Area of Science:
- Food Microbiology
- Bacterial Pathogenesis
- Antimicrobial Resistance
Background:
- Salmonella Minnesota (SM) is an emerging serovar prevalent in poultry production.
- SM exhibits antimicrobial resistance, biofilm formation, and environmental persistence.
- Understanding SM's characteristics is crucial for food safety.
Purpose of the Study:
- To characterize Salmonella Minnesota isolates from a poultry slaughterhouse.
- To evaluate antimicrobial resistance, biofilm formation, thermal tolerance, virulence, and clonal relatedness.
- To identify factors contributing to SM persistence in poultry processing environments.
Main Methods:
- Phenotypic and genotypic characterization of SM isolates from carcasses, cecal contents, and chiller water.
- Antimicrobial resistance profiling, including extended-spectrum β-lactamase (ESBL) detection.
- Biofilm formation assays at different temperatures, thermal tolerance tests, and genotypic virulence profiling.
- Analysis of clonal relatedness using molecular methods.
Main Results:
- High prevalence of resistance to β-lactams and multidrug-resistant phenotypes, including ESBL producers.
- All isolates possessed virulence and biofilm formation genes (invA, csgD, adrA).
- Enhanced biofilm formation at refrigeration temperatures, particularly on stainless steel; inverse correlation between temperature and bacterial viability.
- Detection of genetically related SM lineages across different sample types and over time.
Conclusions:
- Salmonella Minnesota persistence in poultry slaughterhouses is driven by antimicrobial resistance, biofilm formation, and circulating related lineages.
- SM's adaptive capacity, especially biofilm formation under refrigeration, contributes to its environmental persistence.
- These factors present a significant challenge to food safety and public health, necessitating improved control strategies.
