Genes of
            <i>Escherichia coli</i>
            O157:H7 That Are Involved in High-Pressure Resistance

Malone, Aaron S.; Chung, Yoon Kyung; Yousef, Ahmed E.

doi:10.1128/aem.72.4.2661-2671.2006

Cited by 104 publications

(110 citation statements)

References 68 publications

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“…A number of previous studies have analyzed the transcriptomes of foodborne pathogens under stress conditions commonly present on/in food matrices (including hyperosmotic stress, cold stress, hydrostatic pressure stress, antimicrobial stress, acid stress, and alkali stress), using laboratory media modified to simulate these conditions as a model (15)(16)(17)(18)(19)(20)(21)(22)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59)(60)(61)(62)(63). These laboratory media include BHI broth (18,20,21,59), BHI agar (19), Luria-Bertani broth (60,61), tryptic soy broth (62), M9-glucose (63), and Listeria minimal medium (22) as reference conditions.…”

Section: Discussionmentioning

confidence: 99%

Transcriptomic Analysis of the Adaptation of Listeria monocytogenes to Growth on Vacuum-Packed Cold Smoked Salmon

Tang

Orsi

Bakker

et al. 2015

Appl Environ Microbiol

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The foodborne pathogen Listeria monocytogenes is able to survive and grow in ready-to-eat foods, in which it is likely to experience a number of environmental stresses due to refrigerated storage and the physicochemical properties of the food. Little is known about the specific molecular mechanisms underlying survival and growth of L. monocytogenes under different complex conditions on/in specific food matrices. Transcriptome sequencing (RNA-seq) was used to understand the transcriptional landscape of L. monocytogenes strain H7858 grown on cold smoked salmon (CSS; water phase salt, 4.65%; pH 6.1) relative to that in modified brain heart infusion broth (MBHIB; water phase salt, 4.65%; pH 6.1) at 7°C. Significant differential transcription of 149 genes was observed (false-discovery rate [FDR], <0.05; fold change, >2.5), and 88 and 61 genes were up-and downregulated, respectively, in H7858 grown on CSS relative to the genes in H7858 grown in MBHIB. In spite of these differences in transcriptomes under these two conditions, growth parameters for L. monocytogenes were not significantly different between CSS and MBHIB, indicating that the transcriptomic differences reflect how L. monocytogenes is able to facilitate growth under these different conditions. Differential expression analysis and Gene Ontology enrichment analysis indicated that genes encoding proteins involved in cobalamin biosynthesis as well as ethanolamine and 1,2-propanediol utilization have significantly higher transcript levels in H7858 grown on CSS than in that grown in MBHIB. Our data identify specific transcriptional profiles of L. monocytogenes growing on vacuum-packaged CSS, which may provide targets for the development of novel and improved strategies to control L. monocytogenes growth on this ready-to-eat food.L isteria monocytogenes is a psychrotolerant foodborne pathogen that causes a potentially severe disease, listeriosis. This pathogen is of particular concern to the ready-to-eat (RTE) meat and seafood industries due to its ability to grow at temperatures as low as Ϫ0.4°C and under conditions of salt content as high as 25% (at 4°C) (1-3). Cold smoked salmon (CSS), an RTE seafood, represents a typical food product that can support the growth of L. monocytogenes from low numbers to potentially hazardous levels (4-9). The heat treatment applied during processing of CSS is not sufficient to inactivate microbes present on the raw material, including L. monocytogenes (10, 11). In addition, RTE food products, including CSS, can be contaminated with L. monocytogenes from environmental sources in processing facilities (10-13). Importantly, typical product characteristics of CSS, including pH, water activity (a w ), salt, and phenolic components, do not seem to be sufficient to control the growth of L. monocytogenes if it is present (8, 9).With the aim of developing control strategies that prevent or reduce growth of this pathogen in RTE seafood products, there is a need for a better understanding of the mechanisms that L. monocytogenes uses to sur...

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Section: Discussionmentioning

confidence: 99%

Transcriptomic Analysis of the Adaptation of Listeria monocytogenes to Growth on Vacuum-Packed Cold Smoked Salmon

Tang

Orsi

Bakker

et al. 2015

Appl Environ Microbiol

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“…For example, in Escherichia coli, stationary-phase cells are very much more resistant to pressure than those in the exponential phase of growth (8,44). This is due to the operation of the general stress response, since mutations in the rpoS gene encoding the RpoS sigma factor ( S ) lead to a considerable loss of pressure resistance in stationary phase (35,47). Natural isolates of E. coli O157 vary widely in their resistance to HHP, and this is due largely to heterogeneity in the rpoS genes and consequent differences in RpoS activity (8,44,47).…”

mentioning

confidence: 99%

Role of rpoS in the Development of Cell Envelope Resilience and Pressure Resistance in Stationary-Phase Escherichia coli

Charoenwong

Andrews

Mackey

2011

Appl Environ Microbiol

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This work investigated the role of rpoS in the development of increased cell envelope resilience and enhanced pressure resistance in stationary-phase cells of Escherichia coli. Loss of both colony-forming ability and membrane integrity, measured as uptake of propidium iodide (PI), occurred at lower pressures in E. coli BW3709 (rpoS) than in the parental strain (BW2952). The rpoS mutant also released much higher concentrations of protein under pressure than the parent. We propose that RpoS-regulated functions are responsible for the increase in membrane resilience as cells enter stationary phase and that this plays a major role in the development of pressure resistance. Strains from the Keio collection with mutations in two RpoS-regulated genes, cfa (cyclopropane fatty acyl phospholipid synthase) and osmB (outer membrane lipoprotein), were significantly more pressure sensitive and took up more PI than the parent strain, with cfa having the greatest effect. Mutations in the bolA morphogene and other RpoS-regulated lipoprotein genes (osmC, osmE, osmY, and ybaY) had no effect on pressure resistance. The cytoplasmic membranes of the rpoS mutant failed to reseal after pressure treatment, and strains with mutations in osmB and nlpI (new lipoprotein) were also somewhat impaired in the ability to reseal their membranes. The cfa mutant, though pressure sensitive, was unaffected in membrane resealing, implying that the initial transient permeabilization event is critical for loss of viability rather than the failure to reseal. The enhanced pressure sensitivity of polA, recA, and xthA mutants suggested that DNA may be a target of oxidative stress in pressure-treated cells.Consumer demand for minimally processed, additive-free foods that have a long shelf life has stimulated research into new nonthermal methods of food preservation. High hydrostatic pressure (HHP) can inactivate nonsporing food-borne pathogens and spoilage organisms with minimal effects on food quality and is thus regarded as one of the more promising of the new technologies. The operation of HHP machinery requires relatively low energy consumption, produces little waste, and therefore, has a low impact on the environment (13,37,46). The use of HHP in the food industry is gradually increasing and is now being applied to a wide range of food products, including oysters, crabs and other crustaceans, cured hams, guacamole, salsas, fruit juices, desserts, and prepared meals (50).In order to ensure the safety of pressure-treated foods, it is important not only to have quantitative information on the intrinsic pressure resistance of different microorganisms but also to understand the basis of cellular pressure resistance and how this is affected by conditions during growth, pressure treatment, and recovery. Three main processes are currently believed to contribute to the inactivation of pressure-treated cells. These are protein denaturation, oxidative damage, and loss of membrane integrity (34).In all bacteria examined so far, pressure resistance is highly depende...

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“…This novel strategy of combining signature-tagged transposon mutagenesis and microarrays could identify mutants deficient in survival in cultured macrophages and identify components of SPI 2. The results were in conformity with Baro resistant/sensitive strains Identified factors that promote barotolerance [66] Mutants and varying O 2 concentrations Gene regulation during anaerobic growth [75,98] Zinc stress Transcriptional response of E. coli to zinc [61] Attachment to eukaryotic membrane Induction of stress associated transcripts in E. coli O157:H7 and down-regulation of genes involved in TTSS [31] Intraneutrophil Induction of genes regulated by OxyR [93] Deletion of fim gene cluster Expression of surface protein antigen 43 [90] P. multocida…”

Section: Pathogenesismentioning

confidence: 59%

“…During processing, the meat is subject to varying degrees of pressure in order to get rid of the contaminating pathogen. In a study, DNA array analysis of pressure resistant and sensitive E. coli O157:H7 strains subjected to various degrees of pressure showed an effect on transcription of many genes involved in the physiology of the pathogen [66]. The genes affected included the ones involved in stress response, the thioldisulfide redox system, Fe-S cluster assembly, and spontaneous mutation.…”

Section: Intra-macrophage Gene Expressionmentioning

confidence: 99%

Examination of animal and zoonotic pathogens using microarrays

Ojha¹,

Kostrzynska²

2007

Vet. Res.

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-The advancement in functional genomics, such as DNA microarrays along with the genome availability of important pathogens as well as of human and livestock species has allowed scientists to study the expression of thousands of genes in a single step. In the past decade, DNA arrays have been employed to study infectious processes of pathogens, in diagnostics, and to study host-pathogen interactions. The generation of enormous data sets by microarray experiments also stimulated the growth of a new generation of analytical software. The information provided by microarray experiments has been useful in generating new hypotheses for future research. The concept of DNA array technology has been utilized in the development of novel diagnostic methods. This review highlights the application of microarrays in the field of veterinary research.

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Genes of Escherichia coli O157:H7 That Are Involved in High-Pressure Resistance

Cited by 104 publications

References 68 publications

Transcriptomic Analysis of the Adaptation of Listeria monocytogenes to Growth on Vacuum-Packed Cold Smoked Salmon

Transcriptomic Analysis of the Adaptation of Listeria monocytogenes to Growth on Vacuum-Packed Cold Smoked Salmon

Role of rpoS in the Development of Cell Envelope Resilience and Pressure Resistance in Stationary-Phase Escherichia coli

Examination of animal and zoonotic pathogens using microarrays

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