Heat acclimation and the role of RpoS in prolonged heat shock of Escherichia coli O157

Vidović, Sinisa; Mangalappalli-Illathu, Anil K.; Xiong, Hua; Korber, Darren R.

doi:10.1016/j.fm.2011.12.029

Cited by 15 publications

(8 citation statements)

References 30 publications

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“…While many bacterial gene regulation studies have employed exponential phase cultures, examining bacterial adaptation to stationary phase in laboratory culture may be a useful proxy for understanding how bacteria transition to suboptimal growth conditions in the natural environment. During stationary phase adaptation, the E. coli cell undergoes morphological remodeling (Lange and Hengge-Aronis, 1991), becomes resistant to specific stresses (e.g., heat and oxidative stress; Vidovic et al, 2012;Mata et al, 2017), and substantially reduces overall macromolecule biosynthesis (Yoshida et al, 2018). Translation is down-regulated by the dimerization of ribosomes from the active 70S form to a quiescent 100S form (Yoshida et al, 2019).…”

Section: Rpos Evolutionmentioning

confidence: 99%

Function, Evolution, and Composition of the RpoS Regulon in Escherichia coli

Schellhorn

2020

Front. Microbiol.

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For many bacteria, successful growth and survival depends on efficient adaptation to rapidly changing conditions. In Escherichia coli, the RpoS alternative sigma factor plays a central role in the adaptation to many suboptimal growth conditions by controlling the expression of many genes that protect the cell from stress and help the cell scavenge nutrients. Neither RpoS or the genes it controls are essential for growth and, as a result, the composition of the regulon and the nature of RpoS control in E. coli strains can be variable. RpoS controls many genetic systems, including those affecting pathogenesis, phenotypic traits including metabolic pathways and biofilm formation, and the expression of genes needed to survive nutrient deprivation. In this review, I review the origin of RpoS and assess recent transcriptomic and proteomic studies to identify features of the RpoS regulon in specific clades of E. coli to identify core functions of the regulon and to identify more specialized potential roles for the regulon in E. coli subgroups.

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Section: Rpos Evolutionmentioning

confidence: 99%

Function, Evolution, and Composition of the RpoS Regulon in Escherichia coli

Schellhorn

2020

Front. Microbiol.

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“…To investigate the possible mechanism of resuscitation, several researchers have used proteomic analysis to examine the influence of environmental stress on genome-wide translational expression in foodborne pathogens. Vidovic et al (2011 , 2012 ) analyzed wild-type Escherichia coli O157 and the rpoS mutant strain at low temperatures through comparative proteomics. Their results showed that the differentially expressed protein (DEP) RpoS could regulate related protein expression under cold stimulation.…”

Section: Introductionmentioning

confidence: 99%

Comparative Proteomic and Morphological Change Analyses of Staphylococcus aureus During Resuscitation From Prolonged Freezing

Suo

Yang

Wang³

et al. 2018

Front. Microbiol.

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When frozen, Staphylococcus aureus survives in a sublethally injured state. However, S. aureus can recover at a suitable temperature, which poses a threat to food safety. To elucidate the resuscitation mechanism of freezing survived S. aureus, we used cells stored at -18°C for 90 days as controls. After resuscitating the survived cells at 37°C, the viable cell numbers were determined on tryptic soy agar with 0.6% yeast extract (TSAYE), and the non-injured-cell numbers were determined on TSAYE supplemented with 10% NaCl. The results showed that the total viable cell number did not increase within the first 3 h of resuscitation, but the osmotic regulation ability of freezing survived cells gradually recovered to the level of healthy cells, which was evidenced by the lack of difference between the two samples seen by differential cell enumeration. Scanning electron microscopy (SEM) showed that, compared to late exponential stage cells, some frozen survived cells underwent splitting and cell lysis due to deep distortion and membrane rupture. Transmission electron microscopy (TEM) showed that, in most of the frozen survived cells, the nucleoids (low electronic density area) were loose, and the cytoplasmic matrices (high electronic density area) were sparse. Additionally, a gap was seen to form between the cytoplasmic membranes and the cell walls in the frozen survived cells. The morphological changes were restored when the survived cells were resuscitated at 37°C. We also analyzed the differential proteome after resuscitation using non-labeled high-performance liquid chromatography–mass spectrometry (HPLC-MS). The results showed that, compared with freezing survived S. aureus cells, the cells resuscitated for 1 h had 45 upregulated and 73 downregulated proteins. The differentially expressed proteins were functionally categorized by gene ontology enrichment, KEGG pathway, and STRING analyses. Cell membrane synthesis-related proteins, oxidative stress resistance-related proteins, metabolism-related proteins, and virulence factors exhibited distinct expression patterns during resuscitation. These findings have implications in the understanding of the resuscitation mechanism of freezing survived S. aureus, which may facilitate the development of novel technologies for improved detection and control of foodborne pathogens in frozen food.

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“…Food-related bacteria have developed strategies to overcome a wide variety of unfavorable environmental conditions encountered during food processing or storage: extremely low or high temperatures (Vidovic et al, 2011 , 2012 ), acid pH and a high amount of salts (McMahon et al, 2007 ), pulsed electric fields (PEF; Sagarzazu et al, 2013 ), high hydrostatic pressure (HHP; Hauben et al, 1997 ), and chemical preservatives (Patrignani et al, 2008 ; Dubois-Brissonnet et al, 2011 ). These strategies can lead to an increase in bacterial resistance to the homologous stress agent (direct resistance) as well as to heterologous environmental stresses (cross-resistance; Hengge-Aronis, 2011 ).…”

Section: Introductionmentioning

confidence: 99%

Emergence of Hyper-Resistant Escherichia coli MG1655 Derivative Strains after Applying Sub-Inhibitory Doses of Individual Constituents of Essential Oils

et al. 2016

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The improvement of food preservation by using essential oils (EOs) and their individual constituents (ICs) is attracting enormous interest worldwide. Until now, researchers considered that treatments with such antimicrobial compounds did not induce bacterial resistance via a phenotypic (i.e., transient) response. Nevertheless, the emergence of genotypic (i.e., stable) resistance after treatment with these compounds had not been previously tested. Our results confirm that growth of Escherichia coli MG1655 in presence of sub-inhibitory concentrations of the ICs carvacrol, citral, and (+)-limonene oxide do not increase resistance to further treatments with either the same IC (direct resistance) or with other preservation treatments (cross-resistance) such as heat or pulsed electric fields (PEF). Bacterial mutation frequency was likewise lower when those IC's were applied; however, after 10 days of re-culturing cells in presence of sub-inhibitory concentrations of the ICs, we were able to isolate several derivative strains (i.e., mutants) displaying an increased minimum inhibitory concentration to those ICs. Furthermore, when compared to the wild type (WT) strain, they also displayed direct resistance and cross-resistance. Derivative strains selected with carvacrol and citral also displayed morphological changes involving filamentation along with cell counts at late-stationary growth phase that were lower than the WT strain. In addition, co-cultures of each derivative strain with the WT strain resulted in a predominance of the original strain in absence of ICs, indicating that mutants would not out-compete WT cells under optimal growth conditions. Nevertheless, growth in the presence of ICs facilitated the selection of these resistant mutants. Thus, as a result, subsequent food preservation treatments of these bacterial cultures might be less effective than expected for WT cultures. In conclusion, this study recommends that treatment with ICs at sub-inhibitory concentrations should be generally avoided, since it could favor the emergence of hyper-resistant strains. To ascertain the true value of EOs and their ICs in the field of food preservation, further research thus needs to be conducted on the induction of increased transient and stable bacterial resistance via such antimicrobial compounds, as revealed in this study.

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Heat acclimation and the role of RpoS in prolonged heat shock of Escherichia coli O157

Cited by 15 publications

References 30 publications

Function, Evolution, and Composition of the RpoS Regulon in Escherichia coli

Function, Evolution, and Composition of the RpoS Regulon in Escherichia coli

Comparative Proteomic and Morphological Change Analyses of Staphylococcus aureus During Resuscitation From Prolonged Freezing

Emergence of Hyper-Resistant Escherichia coli MG1655 Derivative Strains after Applying Sub-Inhibitory Doses of Individual Constituents of Essential Oils

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