Diversity of stress responses in dairy thermophilic streptococci

Zotta, Teresa; Ricciardi, Annamaria; Ciocia, Felicia; Rossano, Rocco; Parente, Eugenio

doi:10.1016/j.ijfoodmicro.2008.02.024

Cited by 46 publications

(36 citation statements)

References 39 publications

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“…Those stressors could explain a pressure for a subset of genotypes to survive and consequently cause human infections. In Listeria monocytogenes and lactic acid bacteria, relationships between stress resistance patterns and their environmental niches have been shown (3,29,46). It is plausible that a similar selective pressure exists for STEC O157.…”

Section: Figmentioning

confidence: 99%

Variation in Stress Resistance Patterns among stx Genotypes and Genetic Lineages of Shiga Toxin-Producing Escherichia coli O157

Lee

French

Jones

et al. 2012

Appl Environ Microbiol

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ABSTRACTTo evaluate the relationship between bacterial genotypes and stress resistance patterns, we exposed 57 strains of Shiga toxin-producingEscherichia coli(STEC) O157 to acid, freeze-thaw, heat, osmotic, oxidative, and starvation stresses. Inactivation rates were calculated in each assay and subjected to univariate and multivariate analyses, including principal component analysis (PCA) and cluster analysis. Thestxgenotype was determined for each strain as was the lineage-specific polymorphism assay (LSPA6) genotype. In univariate analyses, strains of thestx1stx2genotype showed greater resistance to heat than strains of thestx1stx2cgenotype; moreover, strains of thestx1stx2genotype showed greater resistance to starvation than strains of thestx2orstx2cgenotypes. LSPA6 lineage I (LI) strains showed greater resistance to heat and starvation than LSPA6 lineage II (LII) strains. PCA revealed a general trend that a strain with greater resistance to one type of stress tended to have greater resistance to other types of stresses. In cluster analysis, STEC O157 strains were grouped into stress-resistant, stress-sensitive, and intermediate clusters. Instxgenotypes, all strains of thestx1stx2genotype were grouped with the stress-resistant cluster, whereas 72.7% (8/11) of strains of thestx1stx2cgenotype grouped with the stress-sensitive cluster. In LI strains, 77.8% (14/18) of the strains were grouped with the stress-resistant cluster, whereas 64.7% (11/17) of LII strains were grouped with the stress-sensitive cluster. These results indicate that the genotypes of STEC O157 that are frequently associated with human illness, i.e., LI or thestx1stx2genotype, have greater multiple stress resistance than do strains of other genotypes.

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Section: Figmentioning

confidence: 99%

Variation in Stress Resistance Patterns among stx Genotypes and Genetic Lineages of Shiga Toxin-Producing Escherichia coli O157

Lee

French

Jones

et al. 2012

Appl Environ Microbiol

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“…The acid, bile and temperature stresses were studied extensively in some microorganisms, such as Bacillus subtilis, Corynebacterium glutamicum, Escherichia coli, Lactobacillus plantarum, Lactococcus lactis, Listeria monocytogenes, and Salmonella typhimurium [10][11][12][13][14][15]. But the information of physiological and metabolic responses of L. salivarius to osmotic stress remains unavailable now.…”

Section: Introductionmentioning

confidence: 99%

Cell surface properties of Lactobacillus salivarius under osmotic stress

Gong

Chen

et al. 2012

Eur Food Res Technol

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The modifications of cell morphology and surface properties of Lactobacillus salivarius under osmotic stress were investigated. When deMan-RogosaSharpe (MRS) medium was supplemented with NaCl (0.8 mol l -1 ), changes in cell size and shape of L. salivarius cells occurred. A higher autoaggregation percentage and a lower hydrophobicity of L. salivarius determined by microbial adhesion to hydrocarbons were observed under osmotic stress. Moreover, coaggregation was strain specific and depended on incubation time as well as growth medium. On the other hand, fatty acid analysis by gas chromatograph-mass spectrometer revealed increases in the ratio of saturated/unsaturated fatty acids and cyclopropaneoctanoic acid, which is a useful way to enhance their osmotic resistance for maintaining the structural and functional integrity of cell membranes.

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“…In two previous papers we compared the effect of growth phase (exponential or stationary phase cells) and adaptation (heat, acid) on the SDS-PAGE and stress resistance patterns of wild-type strains of S. thermophilus (Zotta et al 2008) and mutants of S. thermophilus Sfi39 (Zotta et al 2009) and we found that strain, mutations, adaptation and growth phase significantly affected the protein expression pattern and tolerance to various stresses (acid, heat, osmotic, oxidative). Although single mutations or specific stress treatments may alter the expression of a single protein which can be easily visualized on SDS-PAGE (Castaldo et al 2006;Fiocco et al 2007;Gonzàlez-Màrquez et al 1997;Varcamonti et al 2006) or 2D-E gels (Gonzàlez-Màrquez et al 1997Zotta et al 2009), adaptation to stress or entry in the stationary growth phase is likely to alter the expression of a large number of proteins, only some of which are specific to a given stress or directly related to stress tolerance (Hörmann et al 2006;Gonzàlez-Màrquez et al 1997;Svensäter et al 2000;van de Guchte et al 2002).…”

Section: Introductionmentioning

confidence: 95%

“…Cells were harvested by centrifugation (12,000 9g, 5 min) and washed twice with 10 mmol/l sterile phosphate buffer pH 7.0 (PB7). For acid and heat adaptation, exponential growth phase cells were suspended in LM17 pH 5.0 or in LM17 pH 6.8 and incubated for 60 min at 42 or 50°C, respectively (Zotta et al 2008(Zotta et al , 2009). …”

Section: Strains and Culture Conditionsmentioning

confidence: 99%

“…As for other lactic acid bacteria (van de Guchte et al 2002), adaptation to stress or entry in the stationary growth phase (Arena et al 2006;Salzano et al 2007) significantly change protein expression. Moreover, strain to strain differences have been found after SDS-PAGE (Zotta et al 2008;Zotta et al 2009) or 2DE (Perrin et al 2000) of whole-cell proteins.…”

Section: Introductionmentioning

confidence: 99%

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SDS–PAGE patterns of whole cell proteins of Streptococcus thermophilus: impact of strain, growth phase and adaptation and relationship with stress response

Zotta

Parente

Piraino³

et al. 2011

World J Microbiol Biotechnol

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In previous studies we demonstrated that a relatively large diversity of stress response patterns (acid, osmotic, oxidative, heat) exists among Streptococcus thermophilus strains. Changes in protein expression, evaluated by SDS-PAGE in 4 wild strains (CNBL7035, TH681, Y3, Sfi39) and in three Sfi39 mutants in which hrcA, ctsR and rr01 genes were inactivated showed that significant variations of proteins involved in general stress response (GSR) occur as a function of growth phase, adaptation and inactivation of stress response regulators. In this work we re-evaluate the previous results comparing two unsupervised (Hierarchical Cluster Analysis, HCA, and Principal Component Analysis, PCA) and one supervised (Partial Least Square Regression, PLSR) statistical techniques for the ability to extract information from SDS-PAGE patterns of wild type and mutant strains of S. thermophilus and to uncover relationships between protein patterns and stress tolerance. HCA and PCA are two purely descriptive techniques. The HCA showed that SDS-PAGE is an efficient tool to differentiate strains but did not shed any light on the relationships between band intensity and strain, growth phase or adaptation treatment. PCA helped to identify group of bands which covaried with the stress input factors but also not allow to find a relationship between protein expression and stress tolerance. The PLS regression, even with the limitations due to the data set used in this study, appears as an extremely promising tools for the identification of complex relationships between design and response variables in the analysis of SDS-PAGE patterns of whole cell proteins.

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Diversity of stress responses in dairy thermophilic streptococci

Cited by 46 publications

References 39 publications

Variation in Stress Resistance Patterns among stx Genotypes and Genetic Lineages of Shiga Toxin-Producing Escherichia coli O157

Variation in Stress Resistance Patterns among stx Genotypes and Genetic Lineages of Shiga Toxin-Producing Escherichia coli O157

Cell surface properties of Lactobacillus salivarius under osmotic stress

SDS–PAGE patterns of whole cell proteins of Streptococcus thermophilus: impact of strain, growth phase and adaptation and relationship with stress response

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