# Environmental Persistence and Genotypic and Phenotypic Characterization of Salmonella Minnesota in Poultry Slaughterhouses

## TL;DR

This study explores how Salmonella Minnesota persists in poultry slaughterhouses through resistance, biofilm formation, and genetic similarities.

## Contribution

The study identifies genetic and phenotypic traits of Salmonella Minnesota that contribute to its persistence in poultry slaughterhouses.

## Key findings

- Salmonella Minnesota isolates showed high resistance to β-lactams and multidrug resistance.
- Biofilm formation was more intense at refrigeration temperatures on stainless steel surfaces.
- Genetically related lineages were found in different parts of the slaughterhouse environment.

## 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.