The importance of RpoS in the survival of bacteria through food processing

Dodd, C.E.R.; Aldsworth, Timothy G.

doi:10.1016/s0168-1605(01)00679-1

Cited by 83 publications

(50 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This hypothesis is consistent with the suicide response model of Aldsworth and Dodd (1,21), which postulates that when actively growing cells are subjected to environmental stress, they produce an excess of free radicals inside cells. The model is supported by two recent studies which demonstrated that a set of common environmental response genes, which were up-regulated under a variety of stressful conditions, included representatives involved in defense against oxidative damage (11,27).…”

supporting

confidence: 86%

Genome-Wide Transcriptional Responses ofEscherichia coliK-12 to Continuous Osmotic and Heat Stresses

2008

View full text Add to dashboard Cite

Osmotic stress is known to increase the thermotolerance and oxidative-stress resistance of bacteria by a mechanism that is not adequately understood. We probed the cross-regulation of continuous osmotic and heat stress responses by characterizing the effects of external osmolarity (0.3 M versus 0.0 M NaCl) and temperature (43°C versus 30°C) on the transcriptome of Escherichia coli K-12. Our most important discovery was that a number of genes in the SoxRS and OxyR oxidative-stress regulons were up-regulated by high osmolarity, high temperature, or a combination of both stresses. This result can explain the previously noted cross-protection of osmotic stress against oxidative and heat stresses. Most of the genes shown in previous studies to be induced during the early phase of adaptation to hyperosmotic shock were found to be also overexpressed under continuous osmotic stress. However, there was a poorer overlap between the heat shock genes that are induced transiently after high temperature shifts and the genes that we found to be chronically up-regulated at 43°C. Supplementation of the high-osmolarity medium with the osmoprotectant glycine betaine, which reduces the cytoplasmic K ؉ pool, did not lead to a universal reduction in the expression of osmotically induced genes. This finding does not support the hypothesis that K ؉ is the central osmoregulatory signal in Enterobacteriaceae.

show abstract

supporting

confidence: 86%

Genome-Wide Transcriptional Responses ofEscherichia coliK-12 to Continuous Osmotic and Heat Stresses

2008

View full text Add to dashboard Cite

show abstract

“…Consistent with this notion, E. coli strains with high endogenous RpoS levels accumulated rpoS mutations at a higher rate during growth under nutrient limitation and disruption of rpoS indeed improves nutritional capability with many poor substrates of E. coli (King et al 2004). Of course, the trade-off in losing RpoS function is that rpoS mutants exhibit reduced resistance to encountered stresses such as prolonged starvation, high pressure, high osmolarity, and low pH (Cheville et al 1996;Waterman and Small 1996;Robey et al 2001;Dodd and Aldsworth 2002). Survival in the gastrointestinal 1 tract is reduced (Price et al 2000) and rpoS mutants also exhibit a reduced virulence potential in organisms in which virulence gene expression is under RpoS control (Wiedmann et al 1998;Nadon et al 2002).…”

Section: Utations Sweep Through Bacterial Populationsmentioning

confidence: 93%

Genotype-by-Environment Interactions Influencing the Emergence of rpoS Mutations in Escherichia coli Populations

2006

View full text Add to dashboard Cite

Polymorphisms in rpoS are common in Escherichia coli. rpoS status influences a trade-off between nutrition and stress resistance and hence fitness across different environments. To analyze the selective pressures acting on rpoS, measurement of glucose transport rates in rpoS 1 and rpoS bacteria was used to estimate the role of F nc , the fitness gain due to improved nutrient uptake, in the emergence of rpoS mutations in nutrient-limited chemostat cultures. Chemostats with set atmospheres, temperatures, pH's, antibiotics, and levels of osmotic stress were followed. F nc was reduced under anaerobiosis, high osmolarity, and with chloramphenicol, consistent with a reduced rate of rpoS enrichment in these conditions. F nc remained high, however, with alkaline pH and low temperature but rpoS sweeps were diminished. Under these conditions, F sp , the fitness reduction due to lowered stress protection, became significant. We also estimated whether the fitness need for the gene was related to its regulation. No consistent pattern emerged between the level of RpoS and the loss of rpoS function in particular environments. This dissection allows an unprecedented view of the genotype-by-environment interactions controlling a mutational sweep and shows that both F nc and F sp are influenced by individual stresses and that additional factors contribute to selection pressure in some environments.

show abstract

“…Their synthesis is dependent on several regulatory genes: the alternative sigma factor  S encoded by rpoS, the iron regulator Fur and the two-component signal transduction system PhoPQ (Baik et al, 1996;Bearson et al, 1997;Foster, 1991;Foster, 1999). The alternative sigma factor  S has been recognized as a key factor in increasing the stress resistance of Salmonella cells in stationary phase but it can also be induced by stresses that bacteria may encounter during processing, such as acid stress (Dodd & Aldsworth, 2002). It controls the expression of about 40 genes/operons involved in generating the physiological changes associated with survival processes, among them ASP synthesis.…”

Section: Atr Mechanismmentioning

confidence: 99%

Adaptation of Salmonella to Antimicrobials in Food-Processing Environments

Dubois‐Brissonnet¹

2012

Salmonella - Distribution, Adaptation, Control Measures and Molecular Technologies

View full text Add to dashboard Cite

The importance of RpoS in the survival of bacteria through food processing

Cited by 83 publications

References 26 publications

Genome-Wide Transcriptional Responses ofEscherichia coliK-12 to Continuous Osmotic and Heat Stresses

Genome-Wide Transcriptional Responses ofEscherichia coliK-12 to Continuous Osmotic and Heat Stresses

Genotype-by-Environment Interactions Influencing the Emergence of rpoS Mutations in Escherichia coli Populations

Adaptation of Salmonella to Antimicrobials in Food-Processing Environments

Contact Info

Product

Resources

About