Acid stress, starvation, and cold stress affect poststress behavior of Escherichia coli O157:H7 and nonpathogenic Escherichia coli

• Published in: Journal of food protection Vol. 64; no. 7; pp. 970 - 974
• Main Authors: LEENANON, B, DRAKE, M. A
• Format: Journal Article
• Language: English
• Published: Des Moines, IA International Association of Milk, Food and Environmental Sanitarians 01.07.2001
• Subjects: Adaptation, Physiological; Biological and medical sciences; Colony Count, Microbial; Escherichia coli - growth & development; Escherichia coli - physiology; Escherichia coli O157 - growth & development; Escherichia coli O157 - physiology; Food Handling - methods; Food industries; Food Microbiology; Freezing; Fundamental and applied biological sciences. Psychology; Hot Temperature; Hydrogen-Ion Concentration; Starvation; Temperature; Time Factors; Escherichia coli; Environmental factor; Acidity; Thawing; Nutrient starvation; Freezing; Stress; Pathogenicity; Sensitivity resistance; Thermal shock; pH; Bacteria; Thermotolerance; Enterobacteriaceae; Adaptation
• ISSN: 0362-028X; 1944-9097
• DOI: 10.4315/0362-028x-64.7.970

The effects of acid shock, acid adaptation, starvation, and cold stress of Escherichia coli O157:H7 (ATCC 43895), an rpoS mutant (FRIK 816-3), and nonpathogenic E. coli (ATCC 25922) on poststress heat resistance and freeze-thaw resistance were investigated. Following stress, heat tolerance at 56 degrees C and freeze-thaw resistance at -20 to 21 degrees C were determined. Heat and freeze-thaw resistance of E. coli O157:H7 and nonpathogenic E. coli was enhanced after acid adaptation and starvation. Following cold stress, heat resistance of E. coli O157:H7 and nonpathogenic E. coli was decreased, while freeze-thaw resistance was increased. Heat and freeze-thaw resistance of the rpoS mutant was enhanced only after acid adaptation. Increased or decreased tolerance of acid-adapted, starved, or cold-stressed E. coli O157:H7 cells to heat or freeze-thaw processes should be considered when processing minimally processed or extended shelf-life foods.