Molecular Components of Physiological Stress Responses in Escherichia coli

2004 ◽  
pp. 1-45 ◽  
Author(s):  
Lukas M. Wick ◽  
Thomas Egli
Keyword(s):  
Escherichia Coli ◽  
Stress Responses ◽  
Physiological Stress ◽  
Molecular Components

pH-Dependent Stationary-Phase Acid Resistance Response of Enterohemorrhagic Escherichia coli in the Presence of Various Acidulants†

1999 ◽  
Vol 62 (3) ◽  
pp. 211-218 ◽  
Author(s):  
ROBERT L. BUCHANAN ◽  
SHARON G. EDELSON
Keyword(s):  
Escherichia Coli ◽  
Stationary Phase ◽  
Stress Responses ◽  
Physiological Stress ◽  
Accurate Determination ◽  
Acid Resistance ◽  
Enterohemorrhagic Escherichia Coli ◽  
Resistance Response ◽  
E Coli ◽  
Ph Dependent

The effect of acidulant identity on the pH-dependent stationary-phase acid resistance response of enterohemorrhagic Escherichia coli was studied. Nine strains of E. coli (seven O157:H7, one O111:H-, and one biotype 1 reference strain) were cultured individually for 18 h at 37°C in tryptic soy broth (TSB) plus 1% dextrose and in TSB without dextrose to yield acid resistance induced and noninduced stationary-phase cells, respectively. These cultures were then inoculated into brain heart infusion broth (BHI) supplemented with 0.5% citric, malic, lactic, or acetic acid and adjusted to pH 3.0 with HCl. The BHI tubes were incubated at 37°C for up to 7 h and samples were removed after 0, 2, 5, and 7 h and plated for counting CFU on BHI agar and MacConkey agar (MA). The results were compared to data previously obtained with HCl only. Acid resistance varied substantially among the isolates, being dependent on the strain, the acidulant, and the induction of pH-dependent acid resistance. Hydrochloric acid was consistently the least damaging to cells; lactic acid was the most detrimental. The relative activity of the other acids was strain dependent. Inducing pH-dependent acid resistance increased the already substantial acid tolerance of stationary-phase E. coli. The extent of injury also varied with acid and strain, with as much as a 5-log-cycle differential between BHI agar and MA CFU counts. The accurate determination of the survival of enterohemorrhagic E. coli in acidic foods must take into account the biological variability of the microorganism with respect to its acid resistance and its ability to enhance survival through the induction of physiological stress responses.

Emotions and health: The impact of emotions, emotions regulation, music, and acculturation on health

2008 ◽  
Vol 16 (3) ◽  
pp. 112-115 ◽  
Author(s):  
Stephan Bongard ◽  
Volker Hodapp ◽  
Sonja Rohrmann
Keyword(s):  
Stress Responses ◽  
Physiological Stress ◽  
Anger Expression ◽  
Domain Specific ◽  
Cardiovascular Stress ◽  
Expression Behavior ◽  
Cardio Vascular ◽  
And Coping ◽  
Relationship Of ◽  
The Impact

Abstract. Our unit investigates the relationship of emotional processes (experience, expression, and coping), their physiological correlates and possible health outcomes. We study domain specific anger expression behavior and associated cardio-vascular loads and found e.g. that particularly an open anger expression at work is associated with greater blood pressure. Furthermore, we demonstrated that women may be predisposed for the development of certain mental disorders because of their higher disgust sensitivity. We also pointed out that the suppression of negative emotions leads to increased physiological stress responses which results in a higher risk for cardiovascular diseases. We could show that relaxation as well as music activity like singing in a choir causes increases in the local immune parameter immunoglobuline A. Finally, we are investigating connections between migrants’ strategy of acculturation and health and found e.g. elevated cardiovascular stress responses in migrants when they where highly adapted to the German culture.

scholarly journals Genome-scale target identification in Escherichia coli for high-titer production of free fatty acids

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lixia Fang ◽  
Jie Fan ◽  
Shulei Luo ◽  
Yaru Chen ◽  
Congya Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Free Fatty Acids ◽  
Stress Responses ◽  
Metabolic Networks ◽  
Target Identification ◽  
High Titer ◽  
Cell Factory ◽  
Microbial Cell Factory ◽  
Ffa Metabolism

AbstractTo construct a superior microbial cell factory for chemical synthesis, a major challenge is to fully exploit cellular potential by identifying and engineering beneficial gene targets in sophisticated metabolic networks. Here, we take advantage of CRISPR interference (CRISPRi) and omics analyses to systematically identify beneficial genes that can be engineered to promote free fatty acids (FFAs) production in Escherichia coli. CRISPRi-mediated genetic perturbation enables the identification of 30 beneficial genes from 108 targets related to FFA metabolism. Then, omics analyses of the FFAs-overproducing strains and a control strain enable the identification of another 26 beneficial genes that are seemingly irrelevant to FFA metabolism. Combinatorial perturbation of four beneficial genes involving cellular stress responses results in a recombinant strain ihfAL−-aidB+-ryfAM−-gadAH−, producing 30.0 g L−1 FFAs in fed-batch fermentation, the maximum titer in E. coli reported to date. Our findings are of help in rewiring cellular metabolism and interwoven intracellular processes to facilitate high-titer production of biochemicals.

Associations between multisystem stress reactivity and peer nominated aggression in early childhood vary by sex

2020 ◽  
Vol 32 (5) ◽  
pp. 1888-1898
Author(s):  
Melissa J. Hagan ◽  
Danielle S. Roubinov ◽  
W. Thomas Boyce ◽  
Nicole R. Bush
Keyword(s):  
Early Childhood ◽  
Relational Aggression ◽  
Stress Responses ◽  
Physical Aggression ◽  
Stress Reactivity ◽  
Physiological Stress ◽  
Kindergarten Children ◽  
Peer Ratings ◽  
Cortisol Reactivity ◽  
Physiological Stress Response

AbstractThere is emerging evidence that the development of problematic aggression in childhood may be associated with specific physiological stress response patterns, with both biological overactivation and underactivation implicated. This study tested associations between sex-specific patterns of stress responses across the sympathetic nervous system (SNS) and hypothalamic–pituitary–adrenal (HPA) axis and peer nominations of aggression among 271 kindergarten children (Mean age = 5.32 years; 52% Female; 44% White). Upon entry to kindergarten, children participated in a multidomain standardized stress paradigm. Changes in pre-ejection period (PEP) and salivary cortisol were assessed. On a separate day, children provided peer ratings of physical and relational aggression in a standardized interview. As expected, there was a significant three-way interaction between PEP, cortisol reactivity, and sex, but only for physical aggression. Among boys, cortisol reactivity was positively associated with physical aggression only for those with higher SNS reactivity. Findings suggest that for boys, asymmetrical and symmetrical HPA/SNS reactivity may be associated with lower and higher risk for peer-directed physical aggression, respectively. Understanding the complex associations between multisystem physiology, child sex and peer-directed aggression in early childhood may offer insight into individual differences underlying the emergence of behavioral dysregulation in early peer contexts.

Social isolation of goats: significance of visual contact with conspecifics on behavioral and physiological responses

2021 ◽  
Author(s):  
Govind Kannan ◽  
Zaira M Estrada-Reyes ◽  
Phaneendra Batchu ◽  
Brou Kouakou ◽  
Thomas H Terrill ◽  
...  
Keyword(s):  
Social Isolation ◽  
Stress Responses ◽  
Repeated Measures ◽  
Physiological Stress ◽  
Physiological Responses ◽  
Average Weight ◽  
Median Frequency ◽  
Visual Contact ◽  
Time Interaction ◽  
Rank Score

Abstract Social isolation can increase distress in goats, particularly when they cannot maintain visual contact with conspecifics. This experiment was conducted to determine the behavioral and physiological responses in goats during isolation with or without visual contact with conspecifics. Male Spanish goats (uncastrated, 8-mo old, average weight 29.4 ± 0.59 kg) were randomly assigned to a control (CO) group with no isolation or to one of four isolation treatment (TRT) pens (1.5 × 1.5 m) with: (1) open grill panels but with no visual contact with conspecifics (IO), (2) covered grill to prevent visual contact (IC), (3) open grill with visual contact (IV), or (3) covered grill with a 30 × 30 cm window to allow visual contact (IW) for 90 min of social isolation (n = 12 goats/TRT). Blood samples were collected at 0, 30, 60, and 90 min (Time) from isolated and control goats. The experiment was repeated one week later using the same animals, with each goat being subjected to the same isolation treatment the second time to study the effect of prior exposure to isolation. Friedman’s Two-Way ANOVA by Ranks Test in SAS showed that the median frequency of vocalization (rank score) in goats was high in IO group, low in IV and IW groups, and intermediate in IC group (P < 0.01). Vocalization rank score was also higher (P < 0.01) during the first 30 min of isolation in goats. Median frequency of visual contact was higher in the IW group than in the IV group (P < 0.01). Frequency of climbing behavior was high in IC and IO groups, low in IV group, and intermediate in IW group (P < 0.01). Repeated Measures Analysis using GLM procedures in SAS revealed that plasma cortisol and glucose concentrations tended (P < 0.1) to be the highest in IO group than in CO, IC, IV, and IW groups. Cortisol levels were also higher (Time; P < 0.05) at 0 and 90 min compared to 30 and 60 min. Norepinephrine concentrations decreased (P < 0.05) with Time, and plasma non-esterified fatty acid (NEFA) levels were affected by TRT × Time interaction (P < 0.01). Overall, epinephrine, norepinephrine, glucose, and NEFA concentrations were lower (P < 0.01) and cortisol concentrations and lymphocyte counts higher (P < 0.01) when goats were exposed to isolation the second time. The results showed that goats with no visual contact with conspecifics during social isolation had greater physiological stress responses and spent more time vocalizing or trying to escape the pen, which may indicate distress.

Responses to social evaluative stress in regular cannabis smokers

2021 ◽  
pp. 026988112097233
Author(s):  
Richard J Xia ◽  
Thomas Chao ◽  
Divya Patel ◽  
Gillinder Bedi
Keyword(s):  
Heart Rate ◽  
Stress Responses ◽  
Social Stress ◽  
Physiological Stress ◽  
Negative Mood ◽  
Mood States ◽  
Residual Effects ◽  
Subjective Response ◽  
Negative Mood States ◽  
Stress Responding

Background: Aspects of the canonical stress response differ in stimulant, opioid, and alcohol users relative to controls, and dysregulated responses to stress may contribute to continued use of these drugs. Little prior research has focused on stress responses in regular cannabis smokers. We assessed responses to a standardized laboratory social stress assay (the Trier Social Stress Task; TSST) in regular cannabis smokers (CANs) compared with controls (CONs). Methods: Healthy, non-treatment-seeking adult CANs (⩾4×/week; smoking cannabis as usual) and demographically matched CONs completed the TSST. Outcome measures were subjective mood, heart rate, and salivary cortisol. Results: Nineteen CANs (1 female) and 20 CONs (2 female) participated; groups were matched on trauma exposure, sex, race, and age. CANs smoked cannabis 6.4 ± 1.1 days/week. Eight CANs and one CON smoked tobacco cigarettes daily. Overall, the TSST produced expected increases in anxiety, negative mood states, cortisol, and heart rate. CANs had blunted subjective response to stress relative to CONs, but they did not differ in physiological (cortisol and cardiovascular) stress responding. Conclusion: These results indicate that CANs have blunted mood responses to social stress, but normative physiological stress responding. Observed differences could be due to residual effects of cannabis, reluctance to endorse negative mood states, or to issues related to identifying (i.e., emotional identification) or feeling (i.e., interoception) stress-related affective states. Further research is warranted to characterize the mechanisms of these differences and assess implications for daily functioning and treatment outcomes.

scholarly journals Effects of Cage and Floor Pen Management on Behavior, Production, and Physiological Stress Responses of Laying Hens

1986 ◽  
Vol 65 (6) ◽  
pp. 1058-1069 ◽  
Author(s):  
J.A. MENCH ◽  
A. van TIENHOVEN ◽  
J.A. MARSH ◽  
C.C. McCORMICK ◽  
D.L. CUNNINGHAM ◽  
...  
Keyword(s):  
Stress Responses ◽  
Laying Hens ◽  
Physiological Stress

scholarly journals Non-medical prescription opioid users exhibit dysfunctional physiological stress responses to social rejection

2019 ◽  
Vol 100 ◽  
pp. 264-275 ◽  
Author(s):  
Sara L. Kroll ◽  
DeWayne P. Williams ◽  
Martina Thoma ◽  
Matthias Staib ◽  
Tina M. Binz ◽  
...  
Keyword(s):  
Stress Responses ◽  
Physiological Stress ◽  
Social Rejection ◽  
Prescription Opioid ◽  
Medical Prescription ◽  
Opioid Users
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