Different Multidrug-Resistant Salmonella spp. Serovars Isolated from Slaughter Calves in Southern Brazil

Area of Science:

• Veterinary Microbiology
• Food Safety
• Antimicrobial Resistance

Background:

• Bovines are reservoirs for Salmonella spp., a significant foodborne pathogen.
• Calves are susceptible to Salmonella infections, with potential for antimicrobial resistance development.
• Slaughterhouse contamination poses risks to food safety and public health.

Purpose of the Study:

• To determine the prevalence of Salmonella spp. in calves from Rio Grande do Sul, Brazil.
• To identify virulence factors and antimicrobial resistance profiles of recovered Salmonella isolates.
• To assess the food safety implications of Salmonella contamination in calf carcasses.

Main Methods:

• Analysis of 85 calf carcasses (leather and veal meat) for Salmonella spp. isolation.
• Serotyping of Salmonella isolates to identify specific serovars.
• Detection of virulence-related genes and antimicrobial resistance genes (e.g., blaOXA-48).

Main Results:

• Salmonella spp. were detected in 13% of animals (11/85), exclusively from the leather.
• Identified serotypes included S. Minnesota, S. Abony, S. Cerro, and S. Gafsa.
• All isolates were multidrug-resistant and possessed at least 19 virulence genes, with blaOXA-48 found in 23%.

Conclusions:

• Calf hide contamination with multidrug-resistant Salmonella occurs before slaughter.
• The identified Salmonella strains harbor significant virulence determinants.
• Antimicrobial treatment challenges and potential public health risks are highlighted.