From 1999 to 2002, a genetically characterized strain of Salmonella Enteritidis was involved in more than 90% of foodborne salmonellosis in the state of Rio Grande do Sul, southern Brazil. This work aimed to evaluate the growth kinetics of this strain in comparison with that of other Salmonella serovar strains (S. Typhimurium and S. Bredeney) which were not involved in salmonellosis outbreaks. Each strain was inoculated separately in nutrient broth (NB) and in potato salad prepared with homemade mayonnaise (MS), and incubated at 30 and 9.5 °C. The experimental results were compared with results obtained by the Pathogen Modeling Program, USDA. All the strains showed similar growth characteristics in NB at 30 °C, reaching approximately 8 log CFU.mL-1. In MS, the S. Enteritidis strain showed higher counts in the first 6 hours when cultivated at 30 °C. Only after 12 hours of incubation did all the microorganisms reach similar counts (approximately 6 log CFU g-1). No growth of any strain was detected in the first 24 hours in NB and MS at 9.5 °C, suggesting that this temperature was adequate to control the multiplication of the tested Salmonella strains. The bacterial modeling confirmed most of the experimental results.
Salmonella; RS; growth kinetics; homemade mayonnaise
