scholarly journals Escherichia coli stress response systems and their reaction to terahertz radiation

2016 ◽  
Vol 20 (6) ◽  
pp. 876-886
Author(s):  
S. E. Peltek ◽  
E. V. Demidova ◽  
V. M. Popik ◽  
T. N. Goryachkovskaya
Keyword(s):  
Escherichia Coli ◽  
Stress Response ◽  
Terahertz Radiation ◽  
Response Systems

scholarly journals UV Light Induces IS10 Transposition in Escherichia coli

Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1173-1181
Author(s):  
Zehava Eichenbaum ◽  
Zvi Livneh
Keyword(s):  
Escherichia Coli ◽  
Stress Response ◽  
Target Gene ◽  
Uv Light ◽  
Insertion Site ◽  
Donor Plasmid ◽  
Donor And Acceptor ◽  
Low Copy Number ◽  
Uv Induction ◽  
Target Plasmid

Abstract A new mutagenesis assay system based on the phage 434 cI gene carried on a low-copy number plasmid was used to investigate the effect of UV light on intermolecular transposition of IS10. Inactivation of the target gene by IS10 insertion was detected by the expression of the tet gene from the phage 434 PR promoter, followed by Southern blot analysis of plasmids isolated from TetR colonies. UV irradiation of cells harboring the target plasmid and a donor plasmid carrying an IS10 element led to an increase of up to 28-fold in IS10 transposition. Each UV-induced transposition of IS10 was accompanied by fusion of the donor and acceptor plasmid into a cointegrate structure, due to coupled homologous recombination at the insertion site, similar to the situation in spontaneous IS10 transposition. UV radiation also induced transposition of IS10 from the chromosome to the target plasmid, leading almost exclusively to the integration of the target plasmid into the chromosome. UV induction of IS10 transposition did not depend on the umuC and uvrA gene product, but it was not observed in lexA3 and ΔrecA strains, indicating that the SOS stress response is involved in regulating UV-induced transposition. IS10 transposition, known to increase the fitness of Escherichia coli, may have been recruited under the SOS response to assist in increasing cell survival under hostile environmental conditions. To our knowledge, this is the first report on the induction of transposition by a DNA-damaging agent and the SOS stress response in bacteria.

Thermal and Starvation Stress Response of Escherichia coli O157:H7 Isolates Selected from Agricultural Environments

2016 ◽  
Vol 79 (10) ◽  
pp. 1673-1679 ◽  
Author(s):  
ACHYUT ADHIKARI ◽  
ANDY BARY ◽  
CRAIG COGGER ◽  
CALEB JAMES ◽  
GÜLHAN ÜNLÜ ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Heat Stress ◽  
Stress Response ◽  
Weibull Model ◽  
Stress Conditions ◽  
Inactivation Kinetics ◽  
Escherichia Coli O157 ◽  
Starvation Stress ◽  
E Coli ◽  
Response To Stress

ABSTRACT Pathogens exposed to agricultural production environments are subject to multiple stresses that may alter their survival under subsequent stress conditions. The objective of this study was to examine heat and starvation stress response of Escherichia coli O157:H7 strains isolated from agricultural matrices. Seven E. coli O157:H7 isolates from different agricultural matrices—soil, compost, irrigation water, and sheep manure—were selected, and two ATCC strains were used as controls. The E. coli O157:H7 isolates were exposed to heat stress (56°C in 0.1% peptone water for up to 1 h) and starvation (in phosphate-buffered saline at 37°C for 15 days), and their survival was examined. GInaFiT freeware tool was used to perform regression analyses of the surviving populations. The Weibull model was identified as the most appropriate model for response of the isolates to heat stress, whereas the biphasic survival curves during starvation were fitted using the double Weibull model, indicating the adaptation to starvation or a resistant subpopulation. The inactivation time during heating to achieve the first decimal reduction time (δ) calculated with the Weibull parameters was the highest (45 min) for a compost isolate (Comp60A) and the lowest (28 min) for ATCC strain 43895. Two of the nine isolates (ATCC 43895 and a manure isolate) had β < 1, indicating that surviving populations adapted to heat stress, and six strains demonstrated downward concavity (β > 1), indicating decreasing heat resistance over time. The ATCC strains displayed the longest δ2 (>1,250 h) in response to starvation stress, compared with from 328 to 812 h for the environmental strains. The considerable variation in inactivation kinetics of E. coli O157:H7 highlights the importance of evaluating response to stress conditions among individual strains of a specific pathogen. Environmental isolates did not exhibit more robust response to stress conditions in this study compared with ATCC strains.

scholarly journals The Small Noncoding DsrA RNA Is an Acid Resistance Regulator in Escherichia coli

2004 ◽  
Vol 186 (18) ◽  
pp. 6179-6185 ◽  
Author(s):  
Richard A. Lease ◽  
Dorie Smith ◽  
Kathleen McDonough ◽  
Marlene Belfort
Keyword(s):  
Escherichia Coli ◽  
Stress Response ◽  
Resistance Genes ◽  
Acid Resistance ◽  
Dna Arrays ◽  
E Coli ◽  
Specific Mrnas ◽  
Steady State Levels ◽  
Control Translation ◽  
K 12

ABSTRACT DsrA RNA is a small (87-nucleotide) regulatory RNA of Escherichia coli that acts by RNA-RNA interactions to control translation and turnover of specific mRNAs. Two targets of DsrA regulation are RpoS, the stationary-phase and stress response sigma factor (σs), and H-NS, a histone-like nucleoid protein and global transcription repressor. Genes regulated globally by RpoS and H-NS include stress response proteins and virulence factors for pathogenic E. coli. Here, by using transcription profiling via DNA arrays, we have identified genes induced by DsrA. Steady-state levels of mRNAs from many genes increased with DsrA overproduction, including multiple acid resistance genes of E. coli. Quantitative primer extension analysis verified the induction of individual acid resistance genes in the hdeAB, gadAX, and gadBC operons. E. coli K-12 strains, as well as pathogenic E. coli O157:H7, exhibited compromised acid resistance in dsrA mutants. Conversely, overproduction of DsrA from a plasmid rendered the acid-sensitive dsrA mutant extremely acid resistant. Thus, DsrA RNA plays a regulatory role in acid resistance. Whether DsrA targets acid resistance genes directly by base pairing or indirectly via perturbation of RpoS and/or H-NS is not known, but in either event, our results suggest that DsrA RNA may enhance the virulence of pathogenic E. coli.

scholarly journals Dephosphorylated NPr is involved in an envelope stress response of Escherichia coli

Microbiology ◽  
2015 ◽  
Vol 161 (5) ◽  
pp. 1113-1123 ◽  
Author(s):  
Jaeseop Lee ◽  
Young-Ha Park ◽  
Yeon-Ran Kim ◽  
Yeong-Jae Seok ◽  
Chang-Ro Lee
Keyword(s):  
Escherichia Coli ◽  
Stress Response ◽  
Envelope Stress

Impact of stress response systems on forced choice recognition in an experimental trauma film paradigm

2018 ◽  
Vol 156 ◽  
pp. 45-52
Author(s):  
Felicitas Rombold-Bruehl ◽  
Christian Otte ◽  
Babette Renneberg ◽  
Julian Hellmann-Regen ◽  
Linda Bruch ◽  
...  
Keyword(s):  
Stress Response ◽  
Forced Choice ◽  
Experimental Trauma ◽  
Response Systems ◽  
Trauma Film Paradigm

scholarly journals Cell-to-cell heterogeneity in Escherichia coli stress response originates from pulsatile expression and growth

2020 ◽  
Author(s):  
Nadia M. V. Sampaio ◽  
Caroline M. Blassick ◽  
Jean-Baptiste Lugagne ◽  
Mary J. Dunlop
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Stress Response ◽  
Single Cell ◽  
Phenotypic Variability ◽  
Growth Dynamics ◽  
Time Lapse ◽  
Cell Heterogeneity ◽  
Temporal Expression ◽  
Functional Consequences

AbstractCell-to-cell heterogeneity in gene expression and growth can have critical functional consequences, such as determining whether individual bacteria survive or die following stress. Although phenotypic variability is well documented, the dynamics that underlie it are often unknown. This information is critical because dramatically different outcomes can arise from gradual versus rapid changes in expression and growth. Using single-cell time-lapse microscopy, we measured the temporal expression of a suite of stress response reporters in Escherichia coli, while simultaneously monitoring growth rate. In conditions without stress, we found widespread examples of pulsatile expression. Single-cell growth rates were often anti-correlated with gene expression, with changes in growth preceding changes in expression. These pulsatile dynamics have functional consequences, which we demonstrate by measuring survival after challenging cells with the antibiotic ciprofloxacin. Our results suggest that pulsatile expression and growth dynamics are common in stress response networks and can have direct consequences for survival.

scholarly journals Study on the effects of terahertz radiation on gene networks of Escherichia coli by means of fluorescent biosensors

2020 ◽  
Vol 11 (9) ◽  
pp. 5258 ◽  
Author(s):  
Danil S. Serdyukov ◽  
Tatiana N. Goryachkovskaya ◽  
Irina A. Mescheryakova ◽  
Svetlana V. Bannikova ◽  
Sergei A. Kuznetsov ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Terahertz Radiation ◽  
Gene Networks ◽  
Fluorescent Biosensors
Sign in / Sign up

Export Citation Format

Share Document