Prevalence of Salmonella in cucumbers, antibiotic and acid resistances and description of the kinetic behavior with dynamic model during storage

Abstract

This study isolated Salmonella from cucumbers, analyzed the antibiotic resistance and acid resistance for the isolates and developed a dynamic model. Salmonella prevalence in cucumbers and their resistances were determined. To describe the kinetic behavior of Salmonella isolates, the isolates were inoculated into cucumbers, and Salmonella cell counts were enumerated during storage at 10-30 degrees C. The Baranyi model was fitted to the cell count data to calculate kinetic parameters (lag phase duration [LPD] and maximum specific growth rate (mu(max))], and a polynomial model was fitted to the kinetic parameters as a function of temperature. The model performance was evaluated with root mean square error (RMSE). Using these models, a dynamic model was developed. Salmonella were detected in 3 of 24 cucumbers, all of which were multidrug-resistant and one was acid-resistant. As storage temperature increased, LPD decreased and mu(max) increased. These models were appropriate with 0.367 of RMSE. These results suggest that cross-contaminated Salmonella could increase during transportation, and it may lead to human infection.