Changes in the heat resistance of Salmonella typhimurium during heating at rising temperatures

Abstract

The heat resistance of Salmonella typhimurium, measured as survival following a standard heat challenge at 55°C for 25 min, increased progressively as cells were heated up at linearly rising temperatures. The amount by which heat resistance increased depended on the rate of temperature rise; the slower the temperature rise, the greater the increase in resistance.

Escherichia coli Heat Shock Protein DnaK: Production and Consequences in Terms of Monitoring Cooking

“…Greater heat resistance by a prior exposure to a sublethal heat stress has been reported for E. coli (14) and other gramnegative (11,12) and gram-positive (3) bacteria. In Salmonella enterica serovar Typhimurium, this elevated heat resistance was shown to persist for at least 10 h of exposure at preincubation temperatures of 42, 45, and 48°C for cells in a stationary phase (11).…”

“…It was elaborated before the discovery of bacterial sensitivity and resistance and/or adaptation to stress, in particular heat stress. In several species, prior exposure to a sublethal heat treatment was shown to increase bacterial resistance to a subsequent and severer treatment (3,11,12,14), and this knowledge challenges the predictions of classical bacteriology during heating at lowto-moderate temperatures (50 to 65°C).…”

Heat Adaptation Alters Escherichia coli O157:H7 Membrane Lipid Composition and Verotoxin Production

“…Results indicate that heat-adapted HEC and HEC-VM at Others have demonstrated that heat-adapted bacteria exposed to temperatures above their optimum for growth had higher heat resistance than those grown at lower temperatures (17,18). It is known that stationary phase or starvation induces production of protective proteins that impart resistance to chemical and physical challenges and these proteins are regulated by rpoS in E. coli (2).…”

Salmonella typhimuriumphage type 141 infections in Sheffield during 1984 and 1985: association with hens' eggs

“…Our work, and that of others (Clarenburg & Burger, 1950) has shown that normal cooking procedures applied to eggs may not destroy all salmonellae. Recently the thermal resistance of S. typhimurium has been shown to be greater if temperature is increased gradually (Mackey & Derrick, 1987), as is true of most light cooking procedures applied to eggs. The infective dose of salmonellae is usually high (DuPont & Hornick, 1973).…”