Use of PCR-ribotyping, RAPD, and antimicrobial resistance for typing of Salmonella enteritidis involved in food-borne outbreaks in Southern Brazil

Background: Salmonella is one of the principal causes of food-borne diseases transmitted all over the world and in the state of Rio Grande do Sul, Southern Brazil, this microorganism has been identified as the principal agent of food-borne outbreaks in the last years. The objective of this study was to characterize Salmonella enteritidis strains involved in food-borne outbreaks usingantimicrobial resistance and rapid genotyping methods.Methodology: Strains of Salmonella isolated from foods involved in salmonellosis occurring in the state of Rio Grande do Sul, in the period from 2001 to 2002 were characterized by antimicrobial resistance, PCR-ribotyping and RAPD.Results: Among the 79 S. enteritidis analysed by antibiotic resistance, 62.1% were susceptible to all drugs tested. The predominant resistance observed was to nalidixic acid (21.5%), gentamicin (12.7%), and streptomycin (11.4%). Resistance was demonstrated in 30 strains (30.9%), which were grouped in 14 different patterns. The strains submitted to PCR-ribotyping were grouped in two profiles (R1 and R2). The profile R1 comprised 92.4% of the strains. The same strains were also analyzed by RAPD, making it possible to identify four banding profiles (A to D). The profile A comprised 81% of the strains, while the profiles B, C, and D comprised 9%, 5%, and 5% of the strains, respectively.Conclusions: Our results suggested that a S. enteritidis strain was isolated from different foods involved in several food-borne outbreaks which occurred in Rio Grande do Sul, Southern Brazil