Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Survival stress”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2006

A quantitative trait locus analysis of natural genetic variation for Drosophila melanogaster oxidative stress survival.

Little is known about natural genetic variation for survival under oxidative stress conditions or whether genetic variation for oxidative stress survival is associated with that for life-history traits. We have investigated survival in a high-oxygen environment at 2 adult densities using a set of recombinant inbred lines (RILs) isolated from a natural population of Drosophila melanogaster. Female and male oxidative stress survival was highly correlated. Quantitative trait loci (QTLs) for oxidative stress survival were identified on both autosomes. These QTLs were sometimes sex or density specific but were most often not. QTLs were identified that colocalize to the same region of the genome as longevity in other studies using the same set of RILs. We also determined early-age egg production and found QTLs for this trait, but there was no support for an association between oxidative stress survival and egg production.

Age Factors↗
PubMed2005

Recovery from long-term stationary phase and stress survival in Escherichia coli require the L-isoaspartyl protein carboxyl methyltransferase at alkaline pH.

The L-isoaspartyl protein carboxyl methyltransferase (pcm) can stimulate repair of isoaspartyl residues arising spontaneously in proteins to normal L-aspartyl residues. PCM is needed in Escherichia coli for maximal long-term survival when exposed to oxidative stress, osmotic stress, repeated heat stress or methanol. The effect of pH on a pcm mutant during long-term stationary phase was examined. PCM was not required for long-term survival of E. coli subjected to pH stress alone; however, PCM-deficient cells showed impaired resistance to paraquat and methanol only at elevated pH. The mutant also showed stress-survival phenotypes in minimal medium buffered to pH 9.0. Accumulation of isoaspartyl residues was accelerated at pH 8.0 or 9.0 in vivo, though PCM-deficient cells did not show higher levels of damage. However, the pcm mutant displayed an extended lag phase in recovering from stationary phase at pH 9.0. Protein repair by PCM thus plays a key role in long-term stress survival only at alkaline pH in E. coli, and it may function primarily to repair damage in cells that are recovering from nutrient limitation and in those cells that are able to divide during long-term stationary phase.

Aspartic Acid↗
PubMed2004

Influence of the sigB gene on the cold stress survival and subsequent recovery of two Listeria monocytogenes serotypes.

The influence of serotype and the role of the sigB gene of Listeria monocytogenes during the survival and recovery on different substrates were determined. Wild-type and sigB mutants of two serotypes of L. monocytogenes were inoculated into buffer and onto beef steaks, and incubated at 4 degrees C for 8 weeks during which samples were removed and Listeria numbers determined. Growth kinetics of stationary phase wild-type and sigB mutant cells were compared, without prechilling and after prechilling at 4 degrees C. The two serotypes had similar survival capabilities under the conditions examined, and the sigB gene was influential in survival of chill stress, but was dependent upon additional nutritional factors. Prechilling cells prior to growth extended the lag phase of both strains, and this lag phase extension was compounded by the absence of a functional sigB gene. In conclusion, the sigB gene is involved in the survival and recovery from chill stress by the two serotypes tested. Additional factors such as previous growth conditions, nutritional requirements and serotype susceptibility are also contributory. This study adds relevant information regarding the influence of the sigB gene, in conjunction with the historical growth conditions and serotype differences. Understanding the significance of these factors may be useful in creating improved recovery systems for the detection of L. monocytogenes from at-risk foods.

Adaptation, Physiological↗
PubMed1993

A portion of RNA polymerase II molecules has a component essential for stress responses and stress survival.

Cells respond to stress by altering gene expression, and these adjustments facilitate stress tolerance. Although transcriptional changes are integral to most stress responses, little is known about the mechanisms that permit the transcription apparatus itself to tolerate stress. Here we report that a major role of the RNA polymerase II subunit RPB4 is to permit appropriate transcriptional responses during stress. Yeast cells lacking RPB4 have essentially wild-type growth rates at moderate temperatures (18 to 22 degrees C), but their growth rates are substantially reduced at temperatures outside this range. When subjected to a heat shock, cells lacking RPB4 rapidly lose the ability to transcribe genes and experience a dramatic loss in viability. When cells lacking RPB4 are subjected to the nutrient stress that accompanies entry into stationary phase, they also exhibit a substantial decline in mRNA synthesis and in viability relative to wild-type cells. Interestingly, the portion of RNA polymerase II molecules that contain RPB4 is small in log phase but increases substantially as cells enter stationary phase. We propose that the association of RPB4 with the other RNA polymerase II subunits increases the tolerance of the enzyme to stress.

Blotting, Western↗
PubMed1998

Role of rpoS in stress survival and virulence of Vibrio cholerae.

Vibrio cholerae is known to persist in aquatic environments under nutrient-limiting conditions. To analyze the possible involvement of the alternative sigma factor encoded by rpoS, which is shown to be important for survival during nutrient deprivation in several other bacterial species, a V. cholerae rpoS homolog was cloned by functional complementation of an Escherichia coli mutant by using a wild-type genomic library. Sequence analysis of the complementing clone revealed an 1.008-bp open reading frame which is predicted to encode a 336-amino-acid protein with 71 to 63% overall identity to other reported rpoS gene products. To determine the functional role of rpoS in V. cholerae, we inactivated rpoS by homologous recombination. V. cholerae strains lacking rpoS are impaired in the ability to survive diverse environmental stresses, including exposure to hydrogen peroxide, hyperosmolarity, and carbon starvation. These results suggest that rpoS may be required for the persistence of V. cholerae in aquatic habitats. In addition, the rpoS mutation led to reduced production or secretion of hemagglutinin/protease. However, rpoS is not critical for in vivo survival, as determined by an infant mouse intestinal competition assay.

Amino Acid Sequence↗
PubMed2006

Analytical assays of human HSP27 and thermal-stress survival of Escherichia coli cells that overexpress it.

HSP27 is a small heat-shock protein (sHSP). Such proteins are produced in all organisms. These small HSPs exhibit chaperone-like activity that can bind to unfolded polypeptides and prevent uncontrolled protein aggregation in vitro. Cellular anti-apoptosis function and enhanced cell survival are correlated with increased expression of HSPs. This study presents a thermal-stress survival model for cells using the Escherichia coli expression system for which human HSP27, a recombinant protein, is inducible. Results show that E. coli cells overexpressing human HSP27 have enhanced tolerance to 50 degrees C thermal stress.

Amino Acid Sequence↗
PubMed1992

Survival, stress resistance, and alterations in protein expression in the marine vibrio sp. strain S14 during starvation for different individual nutrients.

The response of the marine Vibrio sp. strain S14 to starvation for carbon, nitrogen, or phosphorus and to simultaneous depletion of all these nutrients (multiple-nutrient starvation) was examined with respect to survival, stress resistance, quantitative and qualitative alterations in protein and RNA synthesis, and the induction of the stringent control. Of the conditions tested, carbon starvation and multiple-nutrient starvation both promoted long-term starvation resistance and a rapid induction of the stringent control, as deduced from the kinetics of RNA synthesis. Carbon- and multiple-nutrient-starved cells were also found to become increasingly resistant to heat, UV, near-UV, and CdCl2 stress. Nitrogen- and phosphorus-starved cells demonstrated a poor ability to survive in the presence of carbon and did not develop a marked resistance to the stresses examined. The carbon, nitrogen, and phosphorus starvation stimulons consisted of about 20 proteins each, while simultaneous starvation for all the nutrients elicited an increased synthesis of 42 polypeptides. Nine common proteins were found to be induced regardless of the starvation condition used and were tentatively termed general starvation proteins. It was also demonstrated that the total number of proteins induced in response to multiple-nutrient starvation was not a predictable sum of the different individual starvation stimulons. Multiple-nutrient starvation induced 14 proteins which were not detected at increased levels of expression in response to individual starvation conditions. Furthermore, four out of five phosphorus starvation-specific polypeptides were not induced during simultaneous starvation for phosphorus, nitrogen, and carbon. The results are discussed in light of the physiological alterations previously described for Vibrio sp. strain S14 cells starved for carbon, nitrogen, and phosphorus simultaneously.

Bacterial Proteins↗
PubMed1998

Mutations in the Escherichia coli surE gene increase isoaspartyl accumulation in a strain lacking the pcm repair methyltransferase but suppress stress-survival phenotypes.

The Escherichia coli surE gene is co-transcribed with pcm, encoding the L-isoaspartyl protein repair methyltransferase, and is highly conserved among both the Eubacteria and the Archaea; however, no biochemical function has yet been identified for this gene. Isoaspartyl accumulation during stationary phase was much higher in a pcm surE double mutant than in either single mutant, suggesting that the two genes may represent two parallel pathways by which E. coli can respond to protein damage. A null mutation in surE also suppressed stress-survival defects previously observed in a pcm mutant strain, providing further evidence for an interaction between the two gene products.

Acid Phosphatase↗
PubMed1996

The relationship between heat stress, survivability and blood composition of the domestic chicken.

In order to better understand the metabolic changes leading to death which take place in the chicken during acute heat stress, the blood composition was determined in surviving and non-surviving chickens. The following blood analytes were determined: glucose, uric acid, serum total proteins, inorganic phosphate, total and ionized calcium, sodium, potassium, triiodothyronine, thyroxine. The haematocrit, erythrocyte creatine kinase (total and the isoenzymes) and haemoglobin fractions were also measured. Blood was taken from the wing vein before and after heat stress. Eight-week-old "Anak 2000" broilers were kept in a climate chamber at 24 degrees C/40% relative humidity during a 14-hour day, and at 20 degrees C/40% relative humidity during a 10-hour night. The birds were subjected to heat stress by exposing them to 40 degrees C/30% relative humidity for 3 hours. Significant differences between heat-stressed surviving and non-surviving chickens were seen in the blood levels of glucose, uric acid, total and ionized calcium, potassium, triiodothyronine, erythrocyte creatine kinase (total and isoenzymes). Differences were also seen in the levels and ratio of the 2 haemoglobin fractions. The significance of these changes, and their potential use as markers for heat resistance is discussed.

Animals↗
PubMed2001

The limits to genomic predictions: role of sigma(N) in environmental stress survival of Pseudomonas putida.

Based on genomic data and on the phenotypes of an FlhF mutant of Pseudomonas putida, the alternative sigma factor sigma(N) (sigma(54)) has been proposed to play a key role in survival to various nutritional and environmental stresses in this bacterium. Quite in contrast, we show that unlike sigma(S) (sigma(38)) the loss of sigma(N) does not impair to any significant extent the ability of P. putida to survive long-term starvation. rpoN mutants (lacking sigma(N)) are indistinguishable from the wild-type with respect to solvent tolerance, resistance to heat shock or sensitivity to hydrogen peroxide. These data suggest that while sigma(N) is a key component of expression of alternative biodegradative pathways for unusual carbon sources (i.e. m-xylene or dimethylphenols), its loss does not compromise bacterial endurance to gross types of environmental stress. Moreover, these results point out the limitations, if not the deception, of genomic predictions when confronted with experimental data.

Journal Article↗
PubMed1999

Characterization of the major superoxide dismutase of Staphylococcus aureus and its role in starvation survival, stress resistance, and pathogenicity.

A Staphylococcus aureus mutant (SPW1) which is unable to survive long-term starvation was shown to have a transposon insertion within a gene homologous to the sodA family of manganese-dependent superoxide dismutases (SOD). Whole-cell lysates of the parental 8325-4 strain demonstrated three zones of SOD activity by nondenaturing gel electrophoresis. The activities of two of these zones were dependent on manganese for activity and were absent in SPW1. The levels of SOD activity and sodA expression were growth-phase dependent, occurring most during postexponential phase. This response was also dependent on the level of aeration of the culture, with highest activity and expression occurring only under high aeration. Expression of sodA and, consequently, SOD activity could be induced by methyl viologen but only during the transition from exponential- to postexponential-phase growth. SPW1 was less able to survive amino acid limitation and acid stress but showed no alteration in pathogenicity in a mouse abscess model of infection compared to the parental strain 8325-4.

Acids↗
PubMed1999

Stress Survival of a Genetically Engineered Pseudomonas in Soil Slurries: Cytochrome P-450cam-Catalyzed Dehalogenation of Chlorinated Hydrocarbons.

Biological treatment of hazardous chemical wastes has potential as an effective, practical, and economically viable process in above the ground treatment systems that consist of both genetically engineered microorganisms (GEMs) and bioreactors with process control instruments to create ideal conditions for biodegradation. A strain of Pseudomonas putida coexpressing cytochrome P-450cam and luciferase (lux) that provides both the reductive detoxification potential of the hemoprotein and a mechanism for its reduction in the absence of "normal" P-450 redox partners was evaluated for its ability to survive and remain metabolically competent under nutrient stress in soil slurry microcosms. More than 74% of the cells of engineered Pseudomonas were culturable after 7 days of multiple nutrient (C,N,P) starvation. The diagnostic luminescence and carbon monoxide-difference spectra for the two engineered traits could be detected in a significant fraction of the surviving population. The GEM could be revived after repeated desiccation and starvation using Luria broth, benzoate, or citrate as nutrients. Soil slurries inoculated with the GEM transformed hexachloroethane (HCE) to tetrachloroethylene (tetraCE) 8-10-fold faster than uninoculated slurries. The GEM also transformed the insecticide, gamma-HCH (gamma-3,4,5,6-hexachlorocyclhexene), to gamma-3,4,5,6-tetrachlorocyclohexene (gammatetraCH) in soil slurries under subatmospheric conditions. These results indicate that GEMs can be constructed with broad substrate range detoxification catalysts such as cytochrome P-450 for remediation.

Journal Article↗
PubMed2002

Partial depletion of intracellular ATP mediates the stress-survival function of the PCPH oncoprotein.

Promotion of cellular resistance to stressful stimuli, including ionizing radiation and chemotherapeutic drugs, contributes to the transforming activity of the PCPH oncogene. The mechanism of this action, however, has remained unknown. Consistent with its intrinsic ATP diphosphohydrolase activity, expression of the PCPH oncoprotein in cultured cells has now been shown to result in partial depletion of intracellular ATP and consequent inhibition of the c-JUN NH2-terminal kinase-mediated stress signaling pathway. Supplementation of cells expressing the PCPH oncoprotein with exogenous ATP restored both stress-response signaling and sensitivity to cisplatin-induced apoptosis. In contrast, overexpression of the wild-type PCPH protein had a minimal effect on stress-induced signaling and on the cellular ATP content and did not protect cells from apoptosis. These results suggest that the PCPH oncoprotein confers resistance to stressors by reducing the cellular ATP concentration to levels below those required for optimal stress-induced signaling and apoptosis. Treatment with adenosine or nucleoside analogues may thus enhance the response to radiation or chemotherapy of tumors that express the PCPH oncogene.

3T3 Cells↗
PubMed1997

A mutation in the ftsK gene of Escherichia coli affects cell-cell separation, stationary-phase survival, stress adaptation, and expression of the gene encoding the stress protein UspA.

An insertional mutation in ftsK, encoding an Escherichia coli product similar to the sporulation protein SpoIIIE of Bacillus subtilis, results in uspA overexpression in stationary phase and impairs cell division. The ftsK1::cat insertion mutant forms chains which are the result of inhibited cell-cell separation, while chromosome synthesis and partitioning appear to be normal as judged by flow cytometry and electron and light microscopy in combination with DNA staining. The cells of the chains are attached to each other by a small envelope structure, and unlike in a spoIIIE mutant of B. subtilis, there is no DNA trapped in the division plane. In addition, plasmids harboring a truncated ftsK allele lacking the last 195 bp of the gene cause chain formation in wild-type cells. While the mutant cells grow at essentially the same rate as the parent in complex and defined minimal media, they are sensitive to stresses. Specifically, the mutant failed to grow at elevated salt concentrations and survived stationary phase poorly. The phenotypes of the ftsK1::cat mutant are complemented by the 3' end (spoIIIE-like half) of the ftsK locus. In contrast, the 5' end of the ftsK locus reported to complement ftsK44(Ts) phenotypes does not complement the phenotypes of the ftsK1::cat mutant.

Bacterial Proteins↗
PubMed2005

Stress-survival responses of a carbon-starved p-nitrophenol-mineralizing Moraxella strain in river water.

The effect of carbon starvation on the stress-resistant responses of a p-nitrophenol-mineralizing Moraxella strain was examined in both buffer and river water samples. The Moraxella strain showed optimal stress-resistant responses in a minimal salt buffer when carbon-starved for 1-2 d. In the buffer system, the 1- and 2-day carbon-starved Moraxella cultures survived about 150-, 200-, and 100-fold better than the non-starved cultures when exposed to 43.5 degrees C, 2.7 mol/L NaCl, and 500 micromol/L H2O2 for 4 h, respectively. A green fluorescent protein gene- (gfp) labelled derivative of the Moraxella strain was used to examine the stress-resistant responses of the bacterium in natural river water microcosms. The carbon-starved gfp-labelled Moraxella strain also showed stress-resistant responses against heat, osmotic, and oxidative stresses in the river water samples. Despite the stress-tolerant capability of the carbon-starved gfp-labelled Moraxella cells, they did not exhibit any survival advantage over their non-starved counterparts when inoculated into river water microcosms and incubated at 10 and 22 degrees C for 14 d.

Biodegradation, Environmental↗
PubMed2005

The Campylobacter jejuni stringent response controls specific stress survival and virulence-associated phenotypes.

Campylobacter jejuni is a highly prevalent food-borne pathogen that causes diarrhoeal disease in humans. A natural zoonotic, it must overcome significant stresses both in vivo and during transmission despite the absence of several traditional stress response genes. Although relatively little is understood about its mechanisms of pathogenesis, its ability to interact with and invade human intestinal epithelial cells closely correlates with virulence. A C. jejuni microarray-based screen revealed that several known virulence genes and several uncharacterized genes, including spoT, were rapidly upregulated during infection of human epithelial cells. spoT and its homologue relA have been shown in other bacteria to regulate the stringent response, an important stress response that to date had not been demonstrated for C. jejuni or any other epsilon-proteobacteria. We have found that C. jejuni mounts a stringent response that is regulated by spoT. Detailed analyses of a C. jejuni delta spoT mutant revealed that the stringent response is required for several specific stress, transmission and antibiotic resistance-related phenotypes. These include stationary phase survival, growth and survival under low CO2/high O2 conditions, and rifampicin resistance. A secondary suppressor strain that specifically rescues the low CO2 growth defect of the delta spoT mutant was also isolated. The stringent response additionally proved to be required for the virulence-related phenotypes of adherence, invasion, and intracellular survival in two human epithelial cell culture models of infection; spoT is the first C. jejuni gene shown to participate in longer term survival in epithelial cells. Microarray analyses comparing wild-type to the delta spoT mutant also revealed a strong correlation between gene expression profiles and phenotype differences observed. Together, these data demonstrate a critical role for the C. jejuni stringent response in multiple aspects of C. jejuni biology and pathogenesis and, further, may lend novel insight into unexplored features of the stringent response in other prokaryotic organisms.

Bacterial Proteins↗
PubMed1997

Adaptation to nutrient starvation in Rhizobium leguminosarum bv. phaseoli: analysis of survival, stress resistance, and changes in macromolecular synthesis during entry to and exit from stationary phase.

The nitrogen-fixing bacterium Rhizobium leguminosarum bv. phaseoli often has to survive long periods of starvation in the soil, when not in a useful symbiotic relationship with leguminous plants. We report that it can survive carbon, nitrogen, and phosphorus starvation for at least 2 months with little loss of viability. Upon carbon starvation, R. leguminosarum cells were found to undergo reductive cell division. During this period, they acquired the potential for long-term starvation-survival, levels of protein, DNA, and RNA synthesis were decreased to base levels, and pool mRNA was stabilized. The starved cells are ready to rapidly restart growth when nutrients become available. Upon addition of fresh nutrients, there is an immediate increase in the levels of macromolecular synthesis, pool mRNA destabilizes, and the cultures enter exponential growth within 5 to 8 h. The starved cells were cross-protected against pH, heat, osmotic, and oxidative shock. These results provide evidence for a general starvation response in R. leguminosarum similar to that previously found in other bacteria such as Escherichia coli and Vibrio sp.

Bacterial Proteins↗
PubMed2003

A research agenda for the black middle class: work stress, survival strategies, and mental health.

In this article we discuss the social position of the black middle class and two forms of work stress that appear unique to this group: token stress and social rejection. We outline a research agenda for studying: (1) the relationship between these stressors and mental health in the context of the work environment, and (2) the type of strategies that appear especially efficacious (or problematic) with regard to these problems. We begin the paper with a contextual discussion of the black middle class. We then offer a set of theoretical predictions about the relationship between work stress and mental health among middle class African Americans. We conclude the article with recommendations for future research, and we identify the implications of the research agenda for social policy efforts to diversify the workplace.

Adaptation, Psychological↗