Modifications in membrane fatty acid composition of Salmonella typhimurium in response to growth conditions and their effect on heat resistance

Álvarez‐Ordóñez, Avelino; Fernández, Antonio José Díaz; López, Mercedes; Arenas, Ricardo León Sánchez; Bernardo, Ana

doi:10.1016/j.ijfoodmicro.2008.01.015

Cited by 187 publications

(122 citation statements)

References 58 publications

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“…Values were obtained by shifting cells from 25°C to a desired temperature for 15 min. Within this period of time cells do not modify their lipid/ protein profile since the process of homeoviscous adaptation (the ability to modulate the fluidity of their constituent membrane components to compensate for the direct effects of altered environmental temperature [12]) requires a much longer time (1). It is worth noting that such an effect is very significant in the physiological temperature range of 25°to 40°C while it is not present at higher temperatures.…”

Section: Resultsmentioning

confidence: 99%

Genetic Modification of theSalmonellaMembrane Physical State Alters the Pattern of Heat Shock Response

et al. 2010

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It is now recognized that membranes are not simple physical barriers but represent a complex and dynamic environment that affects membrane protein structures and their functions. Recent data emphasize the role of membranes in sensing temperature changes, and it has been shown that the physical state of the plasma membrane influences the expression of a variety of genes such as heat shock genes. It has been widely shown that minor alterations in lipid membranes are critically involved in the conversion of signals from the environment to the transcriptional activation of heat shock genes. Previously, we have proposed that the composition, molecular arrangement, and physical state of lipid membranes and their organization have crucial roles in cellular responses during stress caused by physical and chemical factors as well as in pathological states. Here, we show that transformation of Salmonella enterica serovar Typhimurium LT2 (Salmonella Typhimurium) with a heterologous ⌬ 12 -desaturase (or with its trans-membrane regions) causes major changes in the pathogen's membrane dynamic. In addition, this pathogen is strongly impaired in the synthesis of major stress proteins (heat shock proteins) under heat shock. These data support the hypothesis that the perception of temperature in Salmonella is strictly controlled by membrane order and by a specific membrane lipid/protein ratio that ultimately causes transcriptional activation of heat shock genes. These results represent a previously unrecognized mode of sensing temperature variation used by this pathogen at the onset of infection.The heat shock response, one of the most studied cellular homeostatic mechanisms, is involved in the maintenance of cell functionality during stress (25, 60). The heat shock response is also elicited by pathogens at the onset of infection as a result of exposure to environmental stresses such as a heat shock or during macrophage infection (25,55). In addition, the heat shock response is severely altered as a result of several chronic diseases, cancer, apoptosis, and the aging process (3, 27, 45). The resulting protection from different types of stresses is due to the transcriptional activation of heat shock genes (29, 54). Further, moderate heat (or stress) treatment induces transient acquisition of thermotolerance, even in the absence of denatured proteins (40, 51), due to the accumulation of heat shock proteins (HSPs) (35). These proteins are not only essential under a variety of stress conditions, such as heat, drought, salinity, osmotic shock, membrane shearing, ischemia, etc. (11,23,55,67), but are also crucial under physiological conditions for protein folding, translocation, mRNA splicing, nucleic acid and protein syntheses, mitochondrial electron transport, and photosynthesis, for example (4,24,25,39). Members of the group of small HSPs (sHSPs) have also been shown to antagonize heat-induced membrane hyperfluidization and to stabilize the bilayer state under stress conditions (40,54,59).According to the conventional model, during s...

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Section: Resultsmentioning

confidence: 99%

Genetic Modification of theSalmonellaMembrane Physical State Alters the Pattern of Heat Shock Response

et al. 2010

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“…Heated, acidified organic acid salt treatments were applied as previously reported and with the following modifications (36). For each treatment, 50 l of stationary-phase S. Typhimurium (approximately 10 5 CFU) was exposed to 450 l of one of the following solutions: 1.25% or 2.5% sodium lactate (SL), sodium acetate (SA), or sodium propionate (SP) (all prepared in deionized H 2 O [dH 2 O] and adjusted to pH 4 or 7) or sterile dH 2 O adjusted to pH 4. The two pH levels were selected to evaluate the effect of the proportion of undissociated weak organic acid ( Table 1).…”

Section: Methodsmentioning

confidence: 99%

Immediate Reduction of Salmonella enterica Serotype Typhimurium Viability via Membrane Destabilization following Exposure to Multiple-Hurdle Treatments with Heated, Acidified Organic Acid Salt Solutions

Milillo

Martin

Muthaiyan

et al. 2011

Appl Environ Microbiol

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The antimicrobial activity of organic acids in combination with nonchemical treatments was evaluated for inactivation of Salmonella enterica serotype Typhimurium within 1 min. It was observed that the effectiveness of the multiple-hurdle treatments was temperature (P < 0.05) and pH (P < 0.05) dependent and corresponded to the degree of organic acid lipophilicity (sodium acetate being least effective and sodium propionate being the most effective). This led to the hypothesis that the loss in viability was due at least in part to cell membrane disruption. Evaluation of osmotic response, potassium ion leakage, and transmission electron micrographs confirmed treatment effects on the cell membrane. Interestingly, all treatments, even those with no effect on viability, such as with sodium acetate, resulted in measurable cellular stress. Microarray experiments explored the specific response of S. Typhimurium to sodium acetate and sodium propionate, the most similar of the tested treatments in terms of pK a and ionic strength, and found little difference in the changes in gene expression following exposure to either, despite their very different effects on viability. Taken together, the results reported support our hypothesis that treatment with heated, acidified, organic acid salt solutions for 1 min causes loss of S. Typhimurium viability at least in part by membrane damage and that the degree of effectiveness can be correlated with lipophilicity of the organic acid. Overall, the data presented here indicate that a combined thermal, acidified sodium propionate treatment can provide an effective antimicrobial treatment against Salmonella.

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“…The proportions of membrane cyclopropane fatty acid (CFA) in S. Typhimurium were found to be higher at a pH lower than 6 when compared with those of cells grown at pH 7.5 (de Jonge et al, 2003). CFA levels were also found to be 1.5-fold higher in acid-adapted cells (grown in the presence of acids at pH values of 6.4, 5.4, or 4.5 in BHI) than in non-adapted cells (Alvarez-Ordonez et al, 2008). It could be speculated that acid-induced RpoS in the exponential phase might increase CFA synthase activity in S. Typhimurium (Kim et al, 2005).…”

Section: Atr Mechanismmentioning

confidence: 93%

Adaptation of Salmonella to Antimicrobials in Food-Processing Environments

Dubois‐Brissonnet¹

2012

Salmonella - Distribution, Adaptation, Control Measures and Molecular Technologies

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Modifications in membrane fatty acid composition of Salmonella typhimurium in response to growth conditions and their effect on heat resistance

Cited by 187 publications

References 58 publications

Genetic Modification of theSalmonellaMembrane Physical State Alters the Pattern of Heat Shock Response

Genetic Modification of theSalmonellaMembrane Physical State Alters the Pattern of Heat Shock Response

Immediate Reduction of Salmonella enterica Serotype Typhimurium Viability via Membrane Destabilization following Exposure to Multiple-Hurdle Treatments with Heated, Acidified Organic Acid Salt Solutions

Adaptation of Salmonella to Antimicrobials in Food-Processing Environments

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