Heat injury in Staphylococcus aureus 196E: protection by metabolizable and non-metabolizable sugars and polyols

Smith, James L.; Benedict, Robert C.; Haas, Melanie; Palumbo, Samuel A.

doi:10.1128/aem.46.6.1417-1419.1983

Cited by 15 publications

(3 citation statements)

References 17 publications

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“…As shown in Figure 1, cells grown in TSB medium and subsequently heated in TSB medium containing either 10% NaCl or 15% KCl had a greater thermal tolerance than cells heated in TSB medium containing no added solutes. These results are consistent with those re-ported previously by other investigators who have demonstrated that the a w of the heating menstruum can have an important influence on the thermal tolerance of bacterial cells (7,9,16,(32)(33)(34)38).…”

Section: Resultssupporting

confidence: 93%

Effects of Growth at Low Water Activity on the Thermal Tolerance of Staphylococcus aureus

Shebuski

Vilhelmsson

Miller

2000

Journal of Food Protection

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Staphylococcus aureus is the most osmotolerant foodborne pathogen, and outbreaks of staphylococcal food poisoning are often linked to foods of reduced water activity (a(w)) values. While it is generally known that the thermal tolerance of microorganisms increases as the a(w) of the heating menstruum is decreased, surprisingly little research has examined the influence of growth medium a(w) on microbial thermal tolerance. In the present study, we show that growth of S. aureus at an a(w) value of 0.94 leads to the development of dramatically enhanced thermal tolerance (i.e., less than 1 log reduction after heating for 20 min at 60 degrees C). We further show that the identity of the accumulated compatible solute within cells grown at low a(w) can also influence the overall level of thermal tolerance of S. aureus. Finally, we provide evidence that the synthesis of general stress and/or osmotic stress proteins is required for the development of enhanced thermal tolerance of S. aureus at low a(w).

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Section: Resultssupporting

confidence: 93%

Effects of Growth at Low Water Activity on the Thermal Tolerance of Staphylococcus aureus

Shebuski

Vilhelmsson

Miller

2000

Journal of Food Protection

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“…Whether this represents differences between gram-negative and grampositive bacteria or differences in the mechanism(s) of heat damage in the two organisms is not known. The exact mechanism by which these solutes prevent heat injury in S. aureus is not known (15)(16)(17).…”

Section: Resultsmentioning

confidence: 99%

Heat injury and repair in Campylobacter jejuni

Palumbo¹

1984

Appl Environ Microbiol

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A procedure for detecting and quantitating heat injury in Campylobacterjejuni was developed. Washed cells of C. jejuni A7455 were heated in potassium phosphate buffer (0.1 M, pH 7.3) at 46°C. Samples were plated on brucella agar supplemented with Na2S203, FeSO4 7H20, and sodium pyruvate and on a medium containing brilliant green, bile, Na2S203, FeSO4-7H20, and sodium pyruvate. Colonies were counted after 5 days of incubation at 37°C in an atmosphere containing 5% 02, 10% C02, and 85% N2. After 45 min at 46°C, there was virtually no killing and ca. two log cycles of injury. Cells grown at 42°C were more susceptible to injury than cells grown at 37°C. The addition to brucella agar supplemented with Na2S203, FeSO4 * 7H20, and sodium pyruvate of three different antibiotic mixtures used in the isolation of C. jejuni from foods or clinical specimens did not prevent recovery of heat-injured C. jejuni. Cells lost 260 nm of absorbing materials during heat injury. The addition of 5% NaCl or 40% sucrose to the heating buffer prevented leakage but did not prevent injury. Of the additional salts, sugars, and amino acids tested for protection, only NH4CI, KCI, and LiCl2 prevented injury. Heat-injured C. jejuni repaired (regained dye and bile tolerance) in brucella broth supplemented with Na2S203, FeSO4 * 7H20, and sodium pyruvate within 4 h. Increasing the NaCl in this medium to 1.25% inhibited repair, and increasing it to 2% was lethal. Heat-injured C. jejuni will repair at 42°C but not at 5°C. Campylobacter jejuni is emerging as a bacterium of considerable importance as an agent of human diarrhea (1, 4). Some reports have even indicated that C. jejuni may be isolated from human diarrhea cases as frequently as Salmonella spp. (1, 8). The mode of transmission is currently unknown, although food has been suggested as a vehicle (2, 4). C. jejuni has been isolated from poultry (9, 12) as well as from various other foods, such as raw milk, beef, and pork (2, 4, 6, 19). Many foodborne microorganisms, including pathogens, may be stressed (sublethally injured) by food processing unit operations such as heating, freezing, drying, fermentation, and acidification (3, 18). Heat injury has been demonstrated in organisms such as Staphylococcus aureus, salmonellae, streptococci, pseudomonads, yeasts, molds, and spores (3,

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“…The mechanism involved in this protection is not fully clear. It is well known that cells suspended in a high-osmolarity medium suffer from a rapid loss of intracellular water (this phenomenon is called plasmolysis), and that the heat stability of proteins increases in media of low a w [ 72 , 120 ]. It has also been suggested that sucrose could interact with membrane phospholipids, increasing the membrane’s heat stability [ 121 ].…”

Section: Factors Affecting Bacterial Inactivationmentioning

confidence: 99%

Physiology of the Inactivation of Vegetative Bacteria by Thermal Treatments: Mode of Action, Influence of Environmental Factors and Inactivation Kinetics

Cebrián

Condón

Mañas

2017

Foods

131

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Heat has been used extensively in the food industry as a preservation method, especially due to its ability to inactivate microorganisms present in foods. However, many aspects regarding the mechanisms of bacterial inactivation by heat and the factors affecting this process are still not fully understood. The purpose of this review is to offer a general overview of the most important aspects of the physiology of the inactivation or survival of microorganisms, particularly vegetative bacteria, submitted to heat treatments. This could help improve the design of current heat processes methods in order to apply milder and/or more effective treatments that could fulfill consumer requirements for fresh-like foods while maintaining the advantages of traditional heat treatments.

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Heat injury in Staphylococcus aureus 196E: protection by metabolizable and non-metabolizable sugars and polyols

Cited by 15 publications

References 17 publications

Effects of Growth at Low Water Activity on the Thermal Tolerance of Staphylococcus aureus

Effects of Growth at Low Water Activity on the Thermal Tolerance of Staphylococcus aureus

Heat injury and repair in Campylobacter jejuni

Physiology of the Inactivation of Vegetative Bacteria by Thermal Treatments: Mode of Action, Influence of Environmental Factors and Inactivation Kinetics

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