Role of Sigma B Factor in the Alkaline Tolerance Response of Listeria monocytogenes 10403S and Cross-Protection against Subsequent Ethanol and Osmotic Stress

2008 ◽  
Vol 71 (7) ◽  
pp. 1481-1485 ◽  
Author(s):  
EFSTATHIOS S. GIOTIS ◽  
MUDCHAREE JULOTOK ◽  
BRIAN J. WILKINSON ◽  
IAN S. BLAIR ◽  
DAVID A. MCDOWELL
Keyword(s):  
Listeria Monocytogenes ◽  
Osmotic Stress ◽  
Surface Cleaning ◽  
Cross Protection ◽  
Ethanol Stress ◽  
Alkaline Ph ◽  
Alkaline Tolerance ◽  
Wide Range ◽  
Type Strains

Many of the considerable abilities of Listeria monocytogenes to persist and grow in a wide range of adverse environmental conditions are thought to be at least partly under the control of the alternative sigma factor (σB), encoded by the sigB gene. However, little is known about the role of this master regulon in the impressive ability of Listeria to persist and grow under conditions of alkaline pH. In this study, Northern blot analysis of parent Listeria mRNA revealed that alkali adaptation (pH 9.5 for 1 h) significantly increased the expression of sigB-derived mRNA. The study included a comparison of the relative survival of mid-exponential populations of adapted and nonadapted parent type (σB expressing) and mutant (not σB expressing, ΔsigB) Listeria strains during subsequent alkaline (pH 12.0), osmotic (25% NaCl, wt/vol), or ethanol (16.5%) stress. Alkali-adapted parent strains were more resistant to pH 12.0 than were adapted ΔsigB type strains, but both alkali-adapted parent and ΔsigB strains were more resistant to pH 12.0 than were nonadapted strains. Alkali-adapted parent strains were more resistant to osmotic stress than were adapted ΔsigB type strains. No significant differences in viability were observed between alkali-adapted parent and ΔsigB strains after ethanol stress, suggesting that cross-protection against osmotic stress is mediated by σB whereas cross-protection against ethanol is σB independent. Overall, alkali-induced cross-protection against osmotic and ethanol challenges may have serious implications for food safety and human health because such stress conditions are routinely used as part of food preservation and surface cleaning processes.

scholarly journals The RNA-Binding Protein Hfq of Listeria monocytogenes: Role in Stress Tolerance and Virulence

2004 ◽  
Vol 186 (11) ◽  
pp. 3355-3362 ◽  
Author(s):  
Janne K. Christiansen ◽  
Marianne H. Larsen ◽  
Hanne Ingmer ◽  
Lotte Søgaard-Andersen ◽  
Birgitte H. Kallipolitis
Keyword(s):  
Listeria Monocytogenes ◽  
Stress Tolerance ◽  
Rna Binding ◽  
Binding Protein ◽  
Rna Binding Protein ◽  
Stationary Growth Phase ◽  
Ethanol Stress ◽  
Gram Positive ◽  
Term Survival

ABSTRACT In gram-negative bacteria, the RNA-binding protein Hfq has emerged as an important regulatory factor in a variety of physiological processes, including stress resistance and virulence. In Escherichia coli, Hfq modulates the stability or the translation of mRNAs and interacts with numerous small regulatory RNAs. Here, we studied the role of Hfq in the stress tolerance and virulence of the gram-positive food-borne human pathogen Listeria monocytogenes. We present evidence that Hfq is involved in the ability of L. monocytogenes to tolerate osmotic and ethanol stress and contributes to long-term survival under amino acid-limiting conditions. However, Hfq is not required for resistance to acid and oxidative stress. Transcription of hfq is induced under various stress conditions, including osmotic and ethanol stress and at the entry into the stationary growth phase, thus supporting the view that Hfq is important for the growth and survival of L. monocytogenes in harsh environments. The stress-inducible transcription of hfq depends on the alternative sigma factor σB, which controls the expression of numerous stress- and virulence-associated genes in L. monocytogenes. Infection studies showed that Hfq contributes to pathogenesis in mice, yet plays no role in the infection of cultured cell lines. This study provides, for the first time, information on the role of Hfq in the stress tolerance and virulence of a gram-positive pathogen.

scholarly journals Identification of Listeria monocytogenes Genes Involved in Salt and Alkaline-pH Tolerance

2003 ◽  
Vol 69 (6) ◽  
pp. 3137-3143 ◽  
Author(s):  
Rozenn Gardan ◽  
Pascale Cossart ◽  
Jean Labadie
Keyword(s):  
Salt Stress ◽  
Listeria Monocytogenes ◽  
Food Processing ◽  
Food Preservation ◽  
Alkaline Ph ◽  
Sequence Comparisons ◽  
Insertional Mutants ◽  
Ph Tolerance ◽  
Alkaline Tolerance ◽  
Intergenic Regions

ABSTRACT The capacity of Listeria monocytogenes to tolerate salt and alkaline stresses is of particular importance, as this pathogen is often exposed to such environments during food processing and food preservation. We screened a library of Tn917-lacZ insertional mutants in order to identify genes involved in salt and/or alkaline tolerance. We isolated six mutants sensitive to salt stress and 12 mutants sensitive to salt and alkaline stresses. The position of the insertion of the transposon was located in 15 of these mutants. In six mutants the transposon was inserted in intergenic regions, and in nine mutants it was inserted in genes. Most of the genes have unknown functions, but sequence comparisons indicated that they encode putative transporters.

scholarly journals Role of ctc from Listeria monocytogenes in Osmotolerance

2003 ◽  
Vol 69 (1) ◽  
pp. 154-161 ◽  
Author(s):  
Rozenn Gardan ◽  
Ophélie Duché ◽  
Sabine Leroy-Sétrin ◽  
Jean Labadie
Keyword(s):  
Salt Stress ◽  
Heat Stress ◽  
Listeria Monocytogenes ◽  
Osmotic Stress ◽  
Minimal Medium ◽  
Stress Protein ◽  
Transcriptional Level ◽  
Osmotic Stress Tolerance ◽  
Electron Microscopy Analysis

ABSTRACT Listeria monocytogenes is a food-borne pathogen with the ability to grow under conditions of high osmolarity. In a previous study, we reported the identification of 12 proteins showing high induction after salt stress. One of these proteins is highly similar to the general stress protein Ctc of Bacillus subtilis. In this study, induction of Ctc after salt stress was confirmed at the transcriptional level by using RNA slot blot experiments. To explore the role of the ctc gene product in resistance to stresses, we constructed a ctc insertional mutant. No difference in growth was observed between the wild-type strain LO28 and the ctc mutant either in rich medium after osmotic or heat stress or in minimal medium after heat stress. However, in minimal medium after osmotic stress, the growth rate of the mutant was increased by a factor of 2. Moreover, electron microscopy analysis showed impaired morphology of the mutant grown under osmotic stress conditions in minimal medium. Addition of the osmoprotectant glycine betaine to the medium completely abolished the osmotic sensitivity phenotype of the ctc mutant. Altogether, these results suggest that the Ctc protein of L. monocytogenes is involved in osmotic stress tolerance in the absence of any osmoprotectant in the medium.

scholarly journals Listeria monocytogenes Shows Temperature-Dependent and -Independent Responses to Salt Stress, Including Responses That Induce Cross-Protection against Other Stresses

2012 ◽  
Vol 78 (8) ◽  
pp. 2602-2612 ◽  
Author(s):  
Teresa M. Bergholz ◽  
Barbara Bowen ◽  
Martin Wiedmann ◽  
Kathryn J. Boor
Keyword(s):  
Salt Stress ◽  
Listeria Monocytogenes ◽  
Osmotic Stress ◽  
Parent Strain ◽  
Cross Protection ◽  
Temperature Dependent ◽  
Short Term ◽  
Transcript Levels ◽  
Content Type ◽  
Short Term Adaptation

ABSTRACTThe food-borne pathogenListeria monocytogenesexperiences osmotic stress in many habitats, including foods and the gastrointestinal tract of the host. During transmission,L. monocytogenesis likely to experience osmotic stress at different temperatures and may adapt to osmotic stress in a temperature-dependent manner. To understand the impact of temperature on the responses this pathogen uses to adapt to osmotic stress, we assessed genome-wide changes in theL. monocytogenesH7858 transcriptome during short-term and long-term adaptation to salt stress at 7°C and 37°C. At both temperatures, the short-term response to salt stress included increased transcript levels ofsigBand SigB-regulated genes, as well asmrpABCDEFG, encoding a sodium/proton antiporter. This antiporter was found to play a role in adaptation to salt stress at both temperatures; ΔmrpABCDEFGhad a significantly longer lag phase than the parent strain in BHI plus 6% NaCl at 7°C and 37°C. The short-term adaptation to salt stress at 7°C included increased transcript levels of two genes encoding carboxypeptidases that modify peptidoglycan. These carboxypeptidases play a role in the short-term adaptation to salt stress only at 7°C, where the deletion mutants had significantly different lag phases than the parent strain. Changes in the transcriptome at both temperatures suggested that exposure to salt stress could provide cross-protection to other stresses, including peroxide stress. Short-term exposure to salt stress significantly increased H2O2resistance at both temperatures. These results provide information for the development of knowledge-based intervention methods against this pathogen, as well as provide insight into potential mechanisms of cross-protection.

The Problem of Identifying and Modeling the Relationship between Monetary Factor and Inflation in the Russian Economy

2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko
Keyword(s):  
Money Supply ◽  
Money Demand ◽  
Russian Economy ◽  
Long Run ◽  
Complex Approach ◽  
Wide Range ◽  
Long Time ◽  
The Relationship ◽  
Supply Side Factors

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.

Introduction: Emotion, History and the Arts

2018 ◽  
Vol 7 (2) ◽  
pp. 117-128 ◽  
Author(s):  
Erin Sullivan ◽  
Marie Louise Herzfeld-Schild
Keyword(s):  
Historical Change ◽  
Carson Mccullers ◽  
Emotional Life ◽  
Review Section ◽  
The Arts ◽  
Wide Range ◽  
War Correspondents ◽  
History Of ◽  
Johan Huizinga

This introduction surveys the rise of the history of emotions as a field and the role of the arts in such developments. Reflecting on the foundational role of the arts in the early emotion-oriented histories of Johan Huizinga and Jacob Burkhardt, as well as the concerns about methodological impressionism that have sometimes arisen in response to such studies, the introduction considers how intensive engagements with the arts can open up new insights into past emotions while still being historically and theoretically rigorous. Drawing on a wide range of emotionally charged art works from different times and places—including the novels of Carson McCullers and Harriet Beecher-Stowe, the private poetry of neo-Confucian Chinese civil servants, the photojournalism of twentieth-century war correspondents, and music from Igor Stravinsky to the Beatles—the introduction proposes five ways in which art in all its forms contributes to emotional life and consequently to emotional histories: first, by incubating deep emotional experiences that contribute to formations of identity; second, by acting as a place for the expression of private or deviant emotions; third, by functioning as a barometer of wider cultural and attitudinal change; fourth, by serving as an engine of momentous historical change; and fifth, by working as a tool for emotional connection across communities, both within specific time periods but also across them. The introduction finishes by outlining how the special issue's five articles and review section address each of these categories, while also illustrating new methodological possibilities for the field.

Short Films from a Small Nation

2018 ◽  
Author(s):  
C. Claire Thomson
Keyword(s):  
Public Information ◽  
Industrial Process ◽  
Actor Network Theory ◽  
Documentary Films ◽  
Wide Range ◽  
Short Films ◽  
Post War ◽  
The 1960S ◽  
Art And Architecture

The first book-length study in English of a national corpus of state-sponsored informational film, this book traces how Danish shorts on topics including social welfare, industry, art and architecture were commissioned, funded, produced and reviewed from the inter-war period to the 1960s. For three decades, state-sponsored short filmmaking educated Danish citizens, promoted Denmark to the world, and shaped the careers of renowned directors like Carl Th. Dreyer. Examining the life cycle of a representative selection of films, and discussing their preservation and mediation in the digital age, this book presents a detailed case study of how informational cinema is shaped by, and indeed shapes, its cultural, political and technological contexts.The book combines close textual analysis of a broad range of films with detailed accounts of their commissioning, production, distribution and reception in Denmark and abroad, drawing on Actor-Network Theory to emphasise the role of a wide range of entities in these processes. It considers a broad range of genres and sub-genres, including industrial process films, public information films, art films, the city symphony, the essay film, and many more. It also maps international networks of informational and documentary films in the post-war period, and explores the role of informational film in Danish cultural and political history.

Quantitative and Qualitative Methods of Studying the Processes of Socialization of a Modern Teenager

2020 ◽  
pp. 102-109
Author(s):  
Svetlana Alekseevna Raschetina ◽  
Keyword(s):  
Research Methods ◽  
Interpersonal Relations ◽  
Internet Communication ◽  
Socialization Process ◽  
Wide Range ◽  
The Family ◽  
Modern Family ◽  
Making Friends ◽  
Main Support

Relevance and problem statement. Modern unstable society is characterized by narrowing the boundaries of controlled socialization and expanding the boundaries of spontaneous socialization of a teenager based on his immersion in the question arises about the importance of the family in the process of socialization of a teenager in the conditions of expanding the space of socialization. There is a need to study the role of the family in this process, to search, develop and test research methods that allow us to reveal the phenomenon of socialization from the side of its value characteristics. The purpose and methodology of the study: to identify the possibilities of a systematic and anthropological methodology for studying the role of the family in the process of socialization of adolescents in modern conditions, testing research methods: photo research on the topic “Ego – I” (author of the German sociologist H. Abels), profile update reflexive processes (by S. A. Raschetina). Materials and results of the study. The study showed that for all the problems that exist in the family of the perestroika era and in the modern family, it acts for a teenager as a value and the first (main) support in the processes of socialization. The positions well known in psychology about the importance of interpersonal relations in adolescence for the formation of attitudes towards oneself as the basis of socialization are confirmed. Today, the frontiers of making friends have expanded enormously on the basis of Internet communication. The types of activities of interest to a teenager (traditional and new ones related to digitalization) are the third pillar of socialization. Conclusion. The “Ego – I” method of photo research has a wide range of possibilities for quantitative and qualitative analysis of the socialization process to identify the value Pillars of this process.

Victorian Culture and Classical Antiquity

2011 ◽  
Author(s):  
Simon Goldhill
Keyword(s):  
Nineteenth Century ◽  
Roman Empire ◽  
Classical Antiquity ◽  
Victorian Culture ◽  
Wide Range ◽  
Victorian Art ◽  
Victorian Science ◽  
Role Of Religion ◽  
Nineteenth Century Novels

How did the Victorians engage with the ancient world? This book is an exploration of how ancient Greece and Rome influenced Victorian culture. Through Victorian art, opera, and novels, the book examines how sexuality and desire, the politics of culture, and the role of religion in society were considered and debated through the Victorian obsession with antiquity. Looking at Victorian art, it demonstrates how desire and sexuality, particularly anxieties about male desire, were represented and communicated through classical imagery. Probing into operas of the period, the book addresses ideas of citizenship, nationalism, and cultural politics. And through fiction—specifically nineteenth-century novels about the Roman Empire—it discusses religion and the fierce battles over the church as Christianity began to lose dominance over the progressive stance of Victorian science and investigation. Rediscovering some great forgotten works and reframing some more familiar ones, the book offers extraordinary insights into how the Victorian sense of antiquity and our sense of the Victorians came into being. With a wide range of examples and stories, it demonstrates how interest in the classical past shaped nineteenth-century self-expression, giving antiquity a unique place in Victorian culture.

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