Differences in resistance to different environmental stresses and non-thermal food preservation technologies among Salmonella enterica subsp. enterica strains.

In this work the resistance of 15 strains belonging to 11 serovars of Salmonella enterica subsp. enterica to several different environmental stresses (acid, hydrogen peroxide, NaCl and heat) and non-thermal food preservation technologies (HHP, PEF, UV) was determined and compared. Results obtained showed that differences in resistance among strains, quantified as 2D-values, varied less than 2.4-fold for all agents, including heat if S. senftenberg 775W is excluded from the analysis. These results also indicate that variability in resistance among strains of the same serovar was comparable to inter-serovar variability. Salmonella strains that were the most resistant to a given stress were not more resistant to other types of stress. Nevertheless, a positive correlation was observed between the resistance of Salmonella strains to oxidative and osmotic stress, as well as between UV and PEF resistance. These results would be especially helpful in defining safe food preservation processes and might be very useful for improving quantitative microbiological risk assessments of Salmonella in food products.