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Sample records for live escherchia coli

  1. Escherchia coli ribose binding protein based bioreporters revisited

    PubMed Central

    Reimer, Artur; Yagur-Kroll, Sharon; Belkin, Shimshon; Roy, Shantanu; van der Meer, Jan Roelof

    2014-01-01

    Bioreporter bacteria, i.e., strains engineered to respond to chemical exposure by production of reporter proteins, have attracted wide interest because of their potential to offer cheap and simple alternative analytics for specified compounds or conditions. Bioreporter construction has mostly exploited the natural variation of sensory proteins, but it has been proposed that computational design of new substrate binding properties could lead to completely novel detection specificities at very low affinities. Here we reconstruct a bioreporter system based on the native Escherichia coli ribose binding protein RbsB and one of its computationally designed variants, reported to be capable of binding 2,4,6-trinitrotoluene (TNT). Our results show in vivo reporter induction at 50 nM ribose, and a 125 nM affinity constant for in vitro ribose binding to RbsB. In contrast, the purified published TNT-binding variant did not bind TNT nor did TNT cause induction of the E. coli reporter system. PMID:25005019

  2. Homology of the 3' terminal sequences of the 18S rRNA of Bombyx mori and the 16S rRNA of Escherchia coli.

    PubMed Central

    Samols, D R; Hagenbuchle, O; Gage, L P

    1979-01-01

    The terminal 220 base pairs (bp) of the gene for 18S rRNA and 18 bp of the adjoining spacer rDNA of the silkworm Bombyx mori have been sequenced. Comparison with the sequence of the 16S rRNA gene of Escherichia coli has shown that a region including 45 bp of the B. mori sequence at the 3' end is remarkably homologous with the 3' terminal E. coli sequence. Other homologies occur in the terminal regions of the 18S and 16S rRNAs, including a perfectly conserved stretch of 13 bp within a longer homology located 150--200 bp from the 3' termini. These homologies are the most extensive so far reported between prokaryotic and eukaryotic genomic DNA. Images PMID:390496

  3. Enhanced host immune recognition of E.coli causing mastitis in CD-14 transgenic mice.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Escherchia coli causes mastitis, an economically significant disease in dairy animals. E. coli endotoxin (lipopolysaccharide, LPS) when bound by host membrane proteins such as CD-14, causes release of pro-inflammatory cytokines recruiting neutrophils as a early innate immune response. Excessive pr...

  4. Detection and Classification of Live and Dead Escherichia coli by Laser-Induced Breakdown Spectroscopy

    PubMed Central

    Sivakumar, P.; Fernández-Bravo, A.; Taleh, L.; Biddle, J.F.

    2015-01-01

    Abstract A common goal for astrobiology is to detect organic materials that may indicate the presence of life. However, organic materials alone may not be representative of currently living systems. Thus, it would be valuable to have a method with which to determine the health of living materials. Here, we present progress toward this goal by reporting on the application of laser-induced breakdown spectroscopy (LIBS) to study characteristics of live and dead cells using Escherichia coli (E. coli) strain K12 cells as a model organism since its growth and death in the laboratory are well understood. Our goal is to determine whether LIBS, in its femto- and/or nanosecond forms, could ascertain the state of a living organism. E. coli strain K12 cells were grown, collected, and exposed to one of two types of inactivation treatments: autoclaving and sonication. Cells were also kept alive as a control. We found that LIBS yields key information that allows for the discrimination of live and dead E. coli bacteria based on ionic shifts reflective of cell membrane integrity. Key Words: E. coli—Trace elements—Live and dead cells—Laser-induced breakdown spectroscopy—Atomic force microscopy. Astrobiology 15, 144–153. PMID:25683088

  5. Detection and classification of live and dead Escherichia coli by laser-induced breakdown spectroscopy.

    PubMed

    Sivakumar, P; Fernández-Bravo, A; Taleh, L; Biddle, J F; Melikechi, N

    2015-02-01

    A common goal for astrobiology is to detect organic materials that may indicate the presence of life. However, organic materials alone may not be representative of currently living systems. Thus, it would be valuable to have a method with which to determine the health of living materials. Here, we present progress toward this goal by reporting on the application of laser-induced breakdown spectroscopy (LIBS) to study characteristics of live and dead cells using Escherichia coli (E. coli) strain K12 cells as a model organism since its growth and death in the laboratory are well understood. Our goal is to determine whether LIBS, in its femto- and/or nanosecond forms, could ascertain the state of a living organism. E. coli strain K12 cells were grown, collected, and exposed to one of two types of inactivation treatments: autoclaving and sonication. Cells were also kept alive as a control. We found that LIBS yields key information that allows for the discrimination of live and dead E. coli bacteria based on ionic shifts reflective of cell membrane integrity. PMID:25683088

  6. Dissecting the stochastic transcription initiation process in live Escherichia coli

    PubMed Central

    Lloyd-Price, Jason; Startceva, Sofia; Kandavalli, Vinodh; Chandraseelan, Jerome G.; Goncalves, Nadia; Oliveira, Samuel M. D.; Häkkinen, Antti; Ribeiro, Andre S.

    2016-01-01

    We investigate the hypothesis that, in Escherichia coli, while the concentration of RNA polymerases differs in different growth conditions, the fraction of RNA polymerases free for transcription remains approximately constant within a certain range of these conditions. After establishing this, we apply a standard model-fitting procedure to fully characterize the in vivo kinetics of the rate-limiting steps in transcription initiation of the Plac/ara-1 promoter from distributions of intervals between transcription events in cells with different RNA polymerase concentrations. We find that, under full induction, the closed complex lasts ∼788 s while subsequent steps last ∼193 s, on average. We then establish that the closed complex formation usually occurs multiple times prior to each successful initiation event. Furthermore, the promoter intermittently switches to an inactive state that, on average, lasts ∼87 s. This is shown to arise from the intermittent repression of the promoter by LacI. The methods employed here should be of use to resolve the rate-limiting steps governing the in vivo dynamics of initiation of prokaryotic promoters, similar to established steady-state assays to resolve the in vitro dynamics. PMID:27026687

  7. Dissecting the stochastic transcription initiation process in live Escherichia coli.

    PubMed

    Lloyd-Price, Jason; Startceva, Sofia; Kandavalli, Vinodh; Chandraseelan, Jerome G; Goncalves, Nadia; Oliveira, Samuel M D; Häkkinen, Antti; Ribeiro, Andre S

    2016-06-01

    We investigate the hypothesis that, in Escherichia coli, while the concentration of RNA polymerases differs in different growth conditions, the fraction of RNA polymerases free for transcription remains approximately constant within a certain range of these conditions. After establishing this, we apply a standard model-fitting procedure to fully characterize the in vivo kinetics of the rate-limiting steps in transcription initiation of the Plac/ara-1 promoter from distributions of intervals between transcription events in cells with different RNA polymerase concentrations. We find that, under full induction, the closed complex lasts ∼788 s while subsequent steps last ∼193 s, on average. We then establish that the closed complex formation usually occurs multiple times prior to each successful initiation event. Furthermore, the promoter intermittently switches to an inactive state that, on average, lasts ∼87 s. This is shown to arise from the intermittent repression of the promoter by LacI. The methods employed here should be of use to resolve the rate-limiting steps governing the in vivo dynamics of initiation of prokaryotic promoters, similar to established steady-state assays to resolve the in vitro dynamics. PMID:27026687

  8. Monitoring Dynamic Protein Expression in Single Living E. Coli. Bacterial Cells by Laser Tweezers Raman Spectroscopy

    SciTech Connect

    Chan, J W; Winhold, H; Corzett, M H; Ulloa, J M; Cosman, M; Balhorn, R; Huser, T

    2007-01-09

    Laser tweezers Raman spectroscopy (LTRS) is a novel, nondestructive, and label-free method that can be used to quantitatively measure changes in cellular activity in single living cells. Here, we demonstrate its use to monitor changes in a population of E. coli cells that occur during overexpression of a protein, the extracellular domain of myelin oligodendrocyte glycoprotein (MOG(1-120)) Raman spectra were acquired of individual E. coli cells suspended in solution and trapped by a single tightly focused laser beam. Overexpression of MOG(1-120) in transformed E. coli Rosetta-Gami (DE3)pLysS cells was induced by addition of isopropyl thiogalactoside (IPTG). Changes in the peak intensities of the Raman spectra from a population of cells were monitored and analyzed over a total duration of three hours. Data was also collected for concentrated purified MOG(1-120) protein in solution, and the spectra compared with that obtained for the MOG(1-120) expressing cells. Raman spectra of individual, living E. coli cells exhibit signatures due to DNA and protein molecular vibrations. Characteristic Raman markers associated with protein vibrations, such as 1257 cm{sup -1}, 1340 cm{sup -1}, 1453 cm{sup -1} and 1660 cm{sup -1}, are shown to increase as a function of time following the addition of IPTG. Comparison of these spectra and the spectra of purified MOG protein indicates that the changes are predominantly due to the induction of MOG protein expression. Protein expression was found to occur mostly within the second hour, with a 470% increase relative to the protein expressed in the first hour. A 230% relative increase between the second and third hour indicates that protein expression begins to level off within the third hour. It is demonstrated that LTRS has sufficient sensitivity for real-time, nondestructive, and quantitative monitoring of biological processes, such as protein expression, in single living cells. Such capabilities, which are not currently available in

  9. A model for chromosome organization during the cell cycle in live E. coli

    PubMed Central

    Liu, Yuru; Xie, Ping; Wang, Pengye; Li, Ming; Li, Hui; Li, Wei; Dou, Shuoxing

    2015-01-01

    Bacterial chromosomal DNA is a highly compact nucleoid. The organization of this nucleoid is poorly understood due to limitations in the methods used to monitor the complexities of DNA organization in live bacteria. Here, we report that circular plasmid DNA is auto-packaged into a uniform dual-toroidal-spool conformation in response to mechanical stress stemming from sharp bending and un-winding by atomic force microscopic analysis. The mechanism underlying this phenomenon was deduced with basic physical principles to explain the auto-packaging behaviour of circular DNA. Based on our observations and previous studies, we propose a dynamic model of how chromosomal DNA in E. coli may be organized during a cell division cycle. Next, we test the model by monitoring the development of HNS clusters in live E. coli during a cell cycle. The results were in close agreement with the model. Furthermore, the model accommodates a majority of the thus-far-discovered remarkable features of nucleoids in vivo. PMID:26597953

  10. Tumor-specific colonization, tissue distribution, and gene induction by probiotic Escherichia coli Nissle 1917 in live mice.

    PubMed

    Stritzker, Jochen; Weibel, Stephanie; Hill, Philip J; Oelschlaeger, Tobias A; Goebel, Werner; Szalay, Aladar A

    2007-06-01

    Systemic administration of microorganisms into tumor-bearing mice revealed preferential accumulation in tumors in comparison to clearance in organs such as spleen and liver. Here we compared the efficiency of tumor-specific colonization of pathogenic Salmonella typhimurium strains 14028 and SL1344 to the enteroinvasive Escherichia coli 4608-58 strain and to the attenuated Salmonella flexneri 2a SC602 strain, as well as to the uropathogenic E. coli CFT073, the non-pathogenic E. coli Top10, and the probiotic E. coli Nissle 1917 strain. All strains colonized and replicated in tumors efficiently each resulting in more than 1 x 10(8) colony-forming units per gram tumor tissue. Colonization of spleen and liver were significantly lower when E. coli strains were used in comparison to S. typhimurium and the non-pathogenic strains did not colonize those organs at all. Further investigation of E. coli Nissle 1917 showed that no drastic differences in colonization and amplification were seen when immunocompetent and immunocompromised animals were used, and we were able to show that E. coli Nissle 1917 replicates at the border of live and necrotic tumor tissue. We also demonstrated exogenously applied L-arabinose-dependent gene activation in colonized tumors in live mice. These findings will prepare the way for bacterium-mediated controlled protein delivery to solid tumors. PMID:17448724

  11. Green biosynthesis of biocompatible CdSe quantum dots in living Escherichia coli cells

    NASA Astrophysics Data System (ADS)

    Yan, Zhengyu; Qian, Jing; Gu, Yueqing; Su, Yilong; Ai, Xiaoxia; Wu, Shengmei

    2014-03-01

    A green and efficient biosynthesis method to prepare fluorescence-tunable biocompatible cadmium selenide quantum dots using Escherichia coli cells as biological matrix was proposed. Decisive factors in biosynthesis of cadmium selenide quantum dots in a designed route in Escherichia coli cells were elaborately investigated, including the influence of the biological matrix growth stage, the working concentration of inorganic reactants, and the co-incubation duration of inorganic metals to biomatrix. Ultraviolet-visible, photoluminescence, and inverted fluorescence microscope analysis confirmed the unique optical properties of the biosynthesized cadmium selenide quantum dots. The size distribution of the nanocrystals extracted from cells and the location of nanocrystals foci in vivo were also detected seriously by transmission electron microscopy. A surface protein capping layer outside the nanocrystals was confirmed by Fourier transform infrared spectroscopy measurements, which were supposed to contribute to reducing cytotoxicity and maintain a high viability of cells when incubating with quantum dots at concentrations as high as 2 μM. Cell morphology observation indicated an effective labeling of living cells by the biosynthesized quantum dots after a 48 h co-incubation. The present work demonstrated an economical and environmentally friendly approach to fabricating highly fluorescent quantum dots which were expected to be an excellent fluorescent dye for broad bio-imaging and labeling.

  12. RNA-Based Detection Does not Accurately Enumerate Living Escherichia coli O157:H7 Cells on Plants

    PubMed Central

    Ju, Wenting; Moyne, Anne-Laure; Marco, Maria L.

    2016-01-01

    The capacity to distinguish between living and dead cells is an important, but often unrealized, attribute of rapid detection methods for foodborne pathogens. In this study, the numbers of enterohemorrhagic Escherichia coli O157:H7 after inoculation onto Romaine lettuce plants and on plastic (abiotic) surfaces were measured over time by culturing, and quantitative PCR (qPCR), propidium monoazide (PMA)-qPCR, and reverse transcriptase (RT)-qPCR targeting E. coli O157:H7 gapA, rfbE, eae, and lpfA genes and gene transcripts. On Romaine lettuce plants incubated at low relative humidity, E. coli O157:H7 cell numbers declined 107-fold within 96 h according to culture-based assessments. In contrast, there were no reductions in E. coli levels according to qPCR and only 100- and 1000-fold lower numbers per leaf by RT-qPCR and PMA-qPCR, respectively. Similar results were obtained upon exposure of E. coli O157:H7 to desiccation conditions on a sterile plastic surface. Subsequent investigation of mixtures of living and dead E. coli O157:H7 cells strongly indicated that PMA-qPCR detection was subject to false-positive enumerations of viable targets when in the presence of 100-fold higher numbers of dead cells. RT-qPCR measurements of killed E. coli O157:H7 as well as for RNaseA-treated E. coli RNA confirmed that transcripts from dead cells and highly degraded RNA were also amplified by RT-qPCR. These findings show that neither PMA-qPCR nor RT-qPCR provide accurate estimates of bacterial viability in environments where growth and survival is limited. PMID:26955370

  13. RNA-Based Detection Does not Accurately Enumerate Living Escherichia coli O157:H7 Cells on Plants.

    PubMed

    Ju, Wenting; Moyne, Anne-Laure; Marco, Maria L

    2016-01-01

    The capacity to distinguish between living and dead cells is an important, but often unrealized, attribute of rapid detection methods for foodborne pathogens. In this study, the numbers of enterohemorrhagic Escherichia coli O157:H7 after inoculation onto Romaine lettuce plants and on plastic (abiotic) surfaces were measured over time by culturing, and quantitative PCR (qPCR), propidium monoazide (PMA)-qPCR, and reverse transcriptase (RT)-qPCR targeting E. coli O157:H7 gapA, rfbE, eae, and lpfA genes and gene transcripts. On Romaine lettuce plants incubated at low relative humidity, E. coli O157:H7 cell numbers declined 10(7)-fold within 96 h according to culture-based assessments. In contrast, there were no reductions in E. coli levels according to qPCR and only 100- and 1000-fold lower numbers per leaf by RT-qPCR and PMA-qPCR, respectively. Similar results were obtained upon exposure of E. coli O157:H7 to desiccation conditions on a sterile plastic surface. Subsequent investigation of mixtures of living and dead E. coli O157:H7 cells strongly indicated that PMA-qPCR detection was subject to false-positive enumerations of viable targets when in the presence of 100-fold higher numbers of dead cells. RT-qPCR measurements of killed E. coli O157:H7 as well as for RNaseA-treated E. coli RNA confirmed that transcripts from dead cells and highly degraded RNA were also amplified by RT-qPCR. These findings show that neither PMA-qPCR nor RT-qPCR provide accurate estimates of bacterial viability in environments where growth and survival is limited. PMID:26955370

  14. Substrate-Dependent Assembly of the Tat Translocase as Observed in Live Escherichia coli Cells

    PubMed Central

    Rose, Patrick; Fröbel, Julia; Graumann, Peter L.; Müller, Matthias

    2013-01-01

    The twin-arginine translocation (Tat) pathway guides fully folded proteins across membranes of bacteria, archaea and plant chloroplasts. In Escherichia coli, Tat-specific transport is executed in a still largely unknown manner by three functionally diverse membrane proteins, termed TatA, TatB, and TatC. In order to follow the intracellular distribution of the TatABC proteins in live E. coli cells, we have individually expressed fluorophore-tagged versions of each Tat protein in addition to a set of chromosomally encoded TatABC proteins. In this way, a Tat translocase could form from the native TatABC proteins and be visualized via the association of a fluorescent Tat variant. A functionally active TatA-green fluorescent protein fusion was found to re-locate from a uniform distribution in the membrane into a few clusters preferentially located at the cell poles. Clustering was absolutely dependent on the co-expression of functional Tat substrates, the proton-motive force, and the cognate TatBC subunits. Likewise, polar cluster formation of a functional TatB-mCherry fusion required TatA and TatC and that of a functional TatC-mCherry fusion a functional Tat substrate. Furthermore we directly demonstrate the co-localization of TatA and TatB in the same fluorescent clusters. Our collective results are consistent with distinct Tat translocation sites dynamically forming in vivo in response to newly synthesized Tat substrates. PMID:23936332

  15. Diarrheagenic Escherichia coli pathotypes investigation revealed atypical enteropathogenic E. coli as putative emerging diarrheal agents in children living in Botucatu, São Paulo State, Brazil.

    PubMed

    Dias, Regiane C B; Dos Santos, Bruna C; Dos Santos, Luis F; Vieira, Melissa A; Yamatogi, Ricardo S; Mondelli, Alessandro L; Sadatsune, Terue; Sforcin, José M; Gomes, Tânia A T; Hernandes, Rodrigo T

    2016-04-01

    The aim of the present study was to investigate the prevalence of Diarrheagenic Escherichia coli (DEC) pathotypes, a leading cause of diarrhea worldwide, among diarrheal and healthy children, up to 5 years of age, living in the city of Botucatu, São Paulo, Brazil. DEC, investigated by PCR detection of virulence factor-encoding genes associated with the distinct pathotypes, was isolated from 18.0% of the patients, and 19.0% of the controls, with enteroaggregative E. coli (EAEC), the most frequent pathotype, being detected in equal proportion between patients and controls (10.0%). Among the enteropathogenic E. coli (EPEC) isolates, only one isolate was able to produce the localized adherence pattern to HeLa cells, being thus the only typical EPEC identified. All the remaining EPEC were classified as atypical (aEPEC), and detected in 8.0% and 8.5% of the patients and controls, respectively. Regarding the serotypes, 26.5% of the analyzed EPEC isolates belonged to classical EPEC-serogroups, and the only two STEC found were serotyped as O26:H11 (patient) and O119:H7 (control). Antimicrobial susceptibility tests revealed that 43.6%, 29.5% and 2.6% of the DEC isolates were resistant to ampicillin, cotrimoxazole and gentamicin, respectively. Our data indicate that EAEC remains prevalent among children living in Botucatu, and revealed atypical EPEC as emerging putative diarrheal agents in this geographical region. PMID:26752102

  16. Subdiffraction-Limit Study of Kaede Diffusion and Spatial Distribution in Live Escherichia coli

    PubMed Central

    Bakshi, Somenath; Bratton, Benjamin P.; Weisshaar, James C.

    2011-01-01

    Photoactivation localization microscopy (PALM) is used to study the spatial distribution and diffusion of single copies of the protein Kaede in the cytoplasm of live Escherichia coli under moderate growth conditions (67 min doubling time). The spatial distribution of Kaede is uniform within the cytoplasm. The cytoplasmic radius of 380 ± 30 nm varies little from cell to cell. Single-particle tracking using 4 ms exposure times reveals negatively curved plots of mean-square displacement versus time. A detailed comparison with Monte Carlo simulations in a spherocylindrical volume shows that the curvature can be quantitatively understood in terms of free diffusion within a confining volume. The mean diffusion coefficient across cells is  = 7.3 ± 1.1 μm2·s−1, consistent with a homotetrameric form of Kaede. The distribution of squared displacements along the long axis for individual Kaede molecules is consistent with homogeneous diffusion. However, for longer cells, a spatial map of one-step estimates of the diffusion coefficient along x suggests that diffusion is ∼20–40% faster within nucleoids than in the ribosome-rich region lying between nucleoid lobes at the cell mid-plane. Fluorescence recovery after photobleaching yielded  = 8.3 ± 1.6 μm2·s−1, in agreement with the single-particle tracking results. PMID:22098753

  17. Slow unloading leads to DNA-bound β2-sliding clamp accumulation in live Escherichia coli cells

    NASA Astrophysics Data System (ADS)

    Moolman, M. Charl; Krishnan, Sriram Tiruvadi; Kerssemakers, Jacob W. J.; van den Berg, Aafke; Tulinski, Pawel; Depken, Martin; Reyes-Lamothe, Rodrigo; Sherratt, David J.; Dekker, Nynke H.

    2014-12-01

    The ubiquitous sliding clamp facilitates processivity of the replicative polymerase and acts as a platform to recruit proteins involved in replication, recombination and repair. While the dynamics of the E. coli β2-sliding clamp have been characterized in vitro, its in vivo stoichiometry and dynamics remain unclear. To probe both β2-clamp dynamics and stoichiometry in live E. coli cells, we use custom-built microfluidics in combination with single-molecule fluorescence microscopy and photoactivated fluorescence microscopy. We quantify the recruitment, binding and turnover of β2-sliding clamps on DNA during replication. These quantitative in vivo results demonstrate that numerous β2-clamps in E. coli remain on the DNA behind the replication fork for a protracted period of time, allowing them to form a docking platform for other enzymes involved in DNA metabolism.

  18. Slow unloading leads to DNA-bound β2-sliding clamp accumulation in live Escherichia coli cells

    PubMed Central

    Moolman, M. Charl; Krishnan, Sriram Tiruvadi; Kerssemakers, Jacob W. J.; van den Berg, Aafke; Tulinski, Pawel; Depken, Martin; Reyes-Lamothe, Rodrigo; Sherratt, David J.; Dekker, Nynke H.

    2014-01-01

    The ubiquitous sliding clamp facilitates processivity of the replicative polymerase and acts as a platform to recruit proteins involved in replication, recombination and repair. While the dynamics of the E. coli β2-sliding clamp have been characterized in vitro, its in vivo stoichiometry and dynamics remain unclear. To probe both β2-clamp dynamics and stoichiometry in live E. coli cells, we use custom-built microfluidics in combination with single-molecule fluorescence microscopy and photoactivated fluorescence microscopy. We quantify the recruitment, binding and turnover of β2-sliding clamps on DNA during replication. These quantitative in vivo results demonstrate that numerous β2-clamps in E. coli remain on the DNA behind the replication fork for a protracted period of time, allowing them to form a docking platform for other enzymes involved in DNA metabolism. PMID:25520215

  19. E. Coli and Pregnancy

    MedlinePlus

    ... care provider. What is E. coli? E. coli (Escherichia coli) is a bacterium that lives in your colon ( ... 10):1411-1413. Jones B, et al. 2004. Escherichia coli: a growing problem in early onset neonatal sepsis. ...

  20. Proton NMR spectral study of UV treated live Escherichia coli Bacteria

    NASA Astrophysics Data System (ADS)

    Sorokopud, Michael

    The lethal effects of ultraviolet radiation on microorganisms have been known and utilized for many years. In sufficiently high photon fluences, light and in particular, UV light, is an effective and subtle means of killing or at least immobilizing most, if not all cells and micro-organisms. Because of their small size, light can penetrate the enclosing protective walls and enter the inner volumes where it can break organic bonds in components that are vital to cell function. Despite the fact that a very low dose of UV light (1-9 mJ/cm2) has been shown to inactivate many micro-organisms, there remains a dearth of biological information about light induced effects in molecules and their interactions within living microbial systems. The use of 1H NMR as a spectroscopic tool was chosen to undertake an examination of the possible effects resulting from exposing E. coli to lethal fluencies of UV radiation. Once sample preparation, treatment, and NMR mounting methods were optimized, the high sensitivity and high resolution capabilities of the method produced reproducible results for a series of experiments. These results reveal significant changes in the ratio of the 1H NMR spectra of the treated to untreated E.coli samples when the treated sample was exposed to a lethal fluence of 275nm light. Photons at the 275nm wavelength, used in this study, have enough energy to break all of the principle bonds in an organic molecule. The difference spectrum between treated to untreated samples appears to be fitted well using specific component spectra from these groups of compounds. Increases in NMR peak amplitudes are observed and appear to be correlated with the spectral locations of several amino acids, membrane components and several sugars/saccharides. Increases in peak intensities of 4-8% were observed in the 0.8-1.1 ppm chemical shift region, characteristic of lipid and amino acid groups. A 3.5-4% increase was observed in the 2 ppm and 3.4-4 ppm region characteristic of

  1. Correction: A versatile two-photon fluorescent probe for ratiometric imaging E. coliβ-galactosidase in live cells and in vivo.

    PubMed

    Zhang, Xue-Xiang; Wu, Hao; Li, Peng; Qu, Zong-Jin; Tan, Ming-Qian; Han, Ke-Li

    2016-08-01

    Correction for 'A versatile two-photon fluorescent probe for ratiometric imaging E. coliβ-galactosidase in live cells and in vivo' by Xue-Xiang Zhang et al., Chem. Commun., 2016, 52, 8283-8286. PMID:27388438

  2. Avian pathogenic Escherichia coli ΔtonB mutants are safe and protective live-attenuated vaccine candidates.

    PubMed

    Holden, Karen M; Browning, Glenn F; Noormohammadi, Amir H; Markham, Philip; Marenda, Marc S

    2014-10-10

    Avian pathogenic Escherichia coli (APEC) cause colibacillosis, a serious respiratory disease in poultry. Most APEC strains possess TonB-dependent outer membrane transporters for the siderophores salmochelin and aerobactin, which both contribute to their capacity to cause disease. To assess the potential of iron transport deficient mutants as vaccine candidates, the tonB gene was deleted in the APEC wild type strain E956 and a Δfur (ferric uptake repressor) mutant of E956. The growth of the ΔtonB and ΔtonB/Δfur mutants was impaired in iron-restricted conditions, but not in iron-replete media. Day old chicks were exposed to aerosols of the mutants to assess their efficacy as live attenuated vaccines. At day 18, the birds were challenged with aerosols of the virulent parent strain E956. Both mutants conferred protection against colibacillosis; weight gains and lesion scores were significantly different between the vaccinated groups and an unvaccinated challenged control group. Thus mutation of iron uptake systems can be used as a platform technology to generate protective live attenuated vaccines against extraintestinal E. coli infections, and potentially a range of Gram negative pathogens of importance in veterinary medicine. PMID:25205199

  3. Living on the edge: transfer and traffic of E. coli in a confined flow

    NASA Astrophysics Data System (ADS)

    Figueroa-Morales, Nuris; Miño, Gaston; Rivera, Aramis; Caballero, Rogelio; Altshuler, Ernesto; Clément, Eric; Lindner, Anke

    2015-11-01

    We quantitatively study the transport of E. coli near the walls of confined microfluidic channels, and in more detail along the edges formed by the interception of two perpendicular walls. Our experiments establish the connection between bacteria motion at the flat surface and at the edges and demonstrate the robustness of the upstream motion at the edges. Upstream migration of E. coli at the edges is possible at much larger flow rates compared to motion at the flat surfaces. Interestingly, the bacteria speed at the edges mainly results from collisions between bacteria moving along this single line. We show that upstream motion not only takes place at the edge but also in an ``edge boundary layer'' whose size varies with the applied flow rate. We quantify the bacteria fluxes along the bottom walls and the edges and show that the result from both the transport velocity of bacteria and the decrease of surface concentration with increasing flow rate due to erosion processes. We rationalize our findings as a function of the local variations of the shear rate in the rectangular channels and hydrodynamic attractive forces between bacteria and walls.

  4. Transcription-Factor-Mediated DNA Looping Probed by High-Resolution, Single-Molecule Imaging in Live E. coli Cells

    PubMed Central

    Hensel, Zach; Xiao, Jie

    2013-01-01

    DNA looping mediated by transcription factors plays critical roles in prokaryotic gene regulation. The “genetic switch” of bacteriophage λ determines whether a prophage stays incorporated in the E. coli chromosome or enters the lytic cycle of phage propagation and cell lysis. Past studies have shown that long-range DNA interactions between the operator sequences OR and OL (separated by 2.3 kb), mediated by the λ repressor CI (accession number P03034), play key roles in regulating the λ switch. In vitro, it was demonstrated that DNA segments harboring the operator sequences formed loops in the presence of CI, but CI-mediated DNA looping has not been directly visualized in vivo, hindering a deep understanding of the corresponding dynamics in realistic cellular environments. We report a high-resolution, single-molecule imaging method to probe CI-mediated DNA looping in live E. coli cells. We labeled two DNA loci with differently colored fluorescent fusion proteins and tracked their separations in real time with ∼40 nm accuracy, enabling the first direct analysis of transcription-factor-mediated DNA looping in live cells. Combining looping measurements with measurements of CI expression levels in different operator mutants, we show quantitatively that DNA looping activates transcription and enhances repression. Further, we estimated the upper bound of the rate of conformational change from the unlooped to the looped state, and discuss how chromosome compaction may impact looping kinetics. Our results provide insights into transcription-factor-mediated DNA looping in a variety of operator and CI mutant backgrounds in vivo, and our methodology can be applied to a broad range of questions regarding chromosome conformations in prokaryotes and higher organisms. PMID:23853547

  5. A versatile two-photon fluorescent probe for ratiometric imaging E. coliβ-galactosidase in live cells and in vivo.

    PubMed

    Zhang, Xue-Xiang; Wu, Hao; Li, Peng; Qu, Zong-Jin; Tan, Ming-Qian; Han, Ke-Li

    2016-07-01

    We have described the design, synthesis, spectroscopy and biological applications of NI-βGal, a versatile fluorescent probe to detect E. coliβ-galactosidase in live cells and mice sensitively and directly, which holds great promise for its application in biomedical research such as gene therapy for cancer in the future. PMID:27291508

  6. N-Chlorotaurine, a Long-Lived Oxidant Produced by Human Leukocytes, Inactivates Shiga Toxin of Enterohemorrhagic Escherichia coli

    PubMed Central

    Eitzinger, Christian; Ehrlenbach, Silvia; Lindner, Herbert; Kremser, Leopold; Gottardi, Waldemar; Debabov, Dmitri; Anderson, Mark

    2012-01-01

    N-chlorotaurine (NCT), the main representative of long-lived oxidants produced by granulocytes and monocytes, is known to exert broad-spectrum microbicidal activity. Here we show that NCT directly inactivates Shiga toxin 2 (Stx2), used as a model toxin secreted by enterohemorrhagic Escherichia coli (EHEC). Bacterial growth and Stx2 production were both inhibited by 2 mM NCT. The cytotoxic effect of Stx2 on Vero cells was removed by ≥5.5 mM NCT. Confocal microscopy and FACS analyses showed that the binding of Stx2 to human kidney glomerular endothelial cells was inhibited, and no NCT-treated Stx2 entered the cytosol. Mass spectrometry displayed oxidation of thio groups and aromatic amino acids of Stx2 by NCT. Therefore, long-lived oxidants may act as powerful tools of innate immunity against soluble virulence factors of pathogens. Moreover, inactivation of virulence factors may contribute to therapeutic success of NCT and novel analogs, which are in development as topical antiinfectives. PMID:23139739

  7. Effects of amino acid starvation on RelA diffusive behavior in live Escherichia coli

    PubMed Central

    Li, Wenting; Bouveret, Emmanuelle; Zhang, Yan; Liu, Kuanqing; Wang, Jue D.; Weisshaar, James C.

    2016-01-01

    Summary During amino acid starvation, bacterial cells rapidly synthesize the nucleotides (p)ppGpp, causing a massive re-programming of the transcriptional profile known as the stringent response. The (p)ppGpp synthase RelA is activated by ribosomes harboring an uncharged tRNA at the A site. It is unclear whether synthesis occurs while RelA is bound to the ribosome or free in the cytoplasm. We present a study of three E. coli strains, each expressing a different RelA-fluorescent protein (RelA-FP) construct: RelA-YFP, RelA-mEos2, and RelA-Dendra2. Single-molecule localization and tracking studies were carried out under normal growth conditions and during amino acid starvation. Study of three labeling schemes enabled us to assess potential problems with FP labeling of RelA. The diffusive trajectories and axial spatial distributions indicate that amino acid starvation induces net binding of all three RelA-FP constructs to 70S ribosomes. The data are most consistent with a model in which RelA synthesizes (p)ppGpp while bound to the 70S ribosome. We suggest a “short hopping time” model of RelA activity during starvation. Our results contradict an earlier study of RelA-Dendra2 diffusion that inferred off-ribosome synthesis of (p)ppGpp. The reasons for the discrepancy remain unclear. PMID:26480956

  8. Single-Cell, Time-Resolved Antimicrobial Effects of a Highly Cationic, Random Nylon-3 Copolymer on Live Escherichia coli.

    PubMed

    Choi, Heejun; Chakraborty, Saswata; Liu, Runhui; Gellman, Samuel H; Weisshaar, James C

    2016-01-15

    Synthetic random copolymers based on the nylon-3 (β-peptide) backbone show promise as inexpensive antimicrobial agents resistant to proteolysis. We present a time-resolved observational study of the attack of a particular copolymer MM63:CHx37 on single, live Escherichia coli cells. The composition and chain length of MM63:CHx37 (63% cationic subunits, 37% hydrophobic subunits, 35-subunit average length) were optimized to enhance antibacterial activity while minimizing lysis of human red blood cells. For E. coli cells that export GFP to the periplasm, we obtain alternating phase-contrast and green fluorescence images with a time resolution of 12 s over 60 min following initiation of copolymer flow. Within seconds, cells shrink and exhibit the same plasmolysis spaces that occur following abrupt external osmotic upshift. The osmoprotection machinery attempts to replenish cytoplasmic water, but recovery is interrupted by permeabilization of the cytoplasmic membrane (CM) to GFP. Evidently, the highly cationic copolymer and its counterions rapidly translocate across the outer membrane without permeabilizing it to GFP. The CM permeabilization event is spatially localized. Cells whose CM has been permeabilized never recover growth. The minimum inhibitory concentration (MIC) for cells lacking the osmolyte importer ProP is 4-fold smaller than for normal cells, suggesting that osmoprotection is an important survival strategy. In addition, at the time of CM permeabilization, we observe evidence of oxidative stress. The MIC under anaerobic conditions is at least 8-fold larger than under aerobic conditions, further implicating oxidative damage as an important bacteriostatic effect. Once the copolymer reaches the periplasm, multiple growth-halting mechanisms proceed in parallel. PMID:26493221

  9. Effects of volume resuscitation on splanchnic perfusion in canine model of severe sepsis induced by live Escherichia coli infusion

    PubMed Central

    Lagoa, Claudio Esteves; de Figueiredo, Luiz Francisco Poli; Cruz, Ruy Jorge; Silva, Eliézer; Rocha e Silva, Maurício

    2004-01-01

    Introduction We conducted the present study to investigate whether early large-volume crystalloid infusion can restore gut mucosal blood flow and mesenteric oxygen metabolism in severe sepsis. Methods Anesthetized and mechanically ventilated male mongrel dogs were challenged with intravenous injection of live Escherichia coli (6 × 109 colony-forming units/ml per kg over 15 min). After 90 min they were randomly assigned to one of two groups – control (no fluids; n = 13) or lactated Ringer's solution (32 ml/kg per hour; n = 14) – and followed for 60 min. Cardiac index, mesenteric blood flow, mean arterial pressure, systemic and mesenteric oxygen-derived variables, blood lactate and gastric carbon dioxide tension (PCO2; by gas tonometry) were assessed throughout the study. Results E. coli infusion significantly decreased arterial pressure, cardiac index, mesenteric blood flow, and systemic and mesenteric oxygen delivery, and increased arterial and portal lactate, intramucosal PCO2, PCO2 gap (the difference between gastric mucosal and arterial PCO2), and systemic and mesenteric oxygen extraction ratio in both groups. The Ringer's solution group had significantly higher cardiac index and systemic oxygen delivery, and lower oxygen extraction ratio and PCO2 gap at 165 min as compared with control animals. However, infusion of lactated Ringer's solution was unable to restore the PCO2 gap. There were no significant differences between groups in mesenteric oxygen delivery, oxygen extraction ratio, or portal lactate at the end of study. Conclusion Significant disturbances occur in the systemic and mesenteric beds during bacteremic severe sepsis. Although large-volume infusion of lactated Ringer's solution restored systemic hemodynamic parameters, it was unable to correct gut mucosal PCO2 gap. PMID:15312221

  10. Development of a novel live vaccine delivering enterotoxigenic Escherichia coli fimbrial antigens to prevent post-weaning diarrhea in piglets.

    PubMed

    Hur, Jin; Lee, John Hwa

    2012-05-15

    The efficacy of a novel, live delivery vaccine was examined for protection against post-weaning diarrhea in pigs. An expression/secretion plasmid harboring genes encoding enterotoxigenic Escherichia coli K88ab, K88ac, FedA and FedF fimbriae was constructed and harbored in an attenuated Salmonella, which was used as the vaccine candidate. Groups A (n=3) and B (n=3) sows were orally immunized with the candidate vaccine and PBS as a control, respectively, at 8 and 11 weeks of pregnancy. All group piglets were challenged with two challenge strains at 5-week-old. All immunized sows had significantly increased IgG and IgA levels in both serum and colostrum to individual adhesins compared to the control (p ≤ 0.05). Immune response in Group A piglets were significantly increased (p ≤ 0.05). Furthermore, no clinical signs were observed in Group A piglets after the challenge and no challenge strains were detected in rectal swabs, while diarrhea was observed in 47.8% control piglets and challenge strains were isolated from all the diarrheic piglets. These results show that immune response of sucking piglets can maintain at higher levels through the milk of the immunized sows and vaccination of sows with the candidate may protect colibacillosis in weaned piglets. PMID:22417986

  11. Single-molecule imaging of UvrA and UvrB recruitment to DNA lesions in living Escherichia coli.

    PubMed

    Stracy, Mathew; Jaciuk, Marcin; Uphoff, Stephan; Kapanidis, Achillefs N; Nowotny, Marcin; Sherratt, David J; Zawadzki, Pawel

    2016-01-01

    Nucleotide excision repair (NER) removes chemically diverse DNA lesions in all domains of life. In Escherichia coli, UvrA and UvrB initiate NER, although the mechanistic details of how this occurs in vivo remain to be established. Here, we use single-molecule fluorescence imaging to provide a comprehensive characterization of the lesion search, recognition and verification process in living cells. We show that NER initiation involves a two-step mechanism in which UvrA scans the genome and locates DNA damage independently of UvrB. Then UvrA recruits UvrB from solution to the lesion. These steps are coordinated by ATP binding and hydrolysis in the 'proximal' and 'distal' UvrA ATP-binding sites. We show that initial UvrB-independent damage recognition by UvrA requires ATPase activity in the distal site only. Subsequent UvrB recruitment requires ATP hydrolysis in the proximal site. Finally, UvrA dissociates from the lesion complex, allowing UvrB to orchestrate the downstream NER reactions. PMID:27562541

  12. Single-molecule imaging of UvrA and UvrB recruitment to DNA lesions in living Escherichia coli

    PubMed Central

    Stracy, Mathew; Jaciuk, Marcin; Uphoff, Stephan; Kapanidis, Achillefs N.; Nowotny, Marcin; Sherratt, David J.; Zawadzki, Pawel

    2016-01-01

    Nucleotide excision repair (NER) removes chemically diverse DNA lesions in all domains of life. In Escherichia coli, UvrA and UvrB initiate NER, although the mechanistic details of how this occurs in vivo remain to be established. Here, we use single-molecule fluorescence imaging to provide a comprehensive characterization of the lesion search, recognition and verification process in living cells. We show that NER initiation involves a two-step mechanism in which UvrA scans the genome and locates DNA damage independently of UvrB. Then UvrA recruits UvrB from solution to the lesion. These steps are coordinated by ATP binding and hydrolysis in the ‘proximal' and ‘distal' UvrA ATP-binding sites. We show that initial UvrB-independent damage recognition by UvrA requires ATPase activity in the distal site only. Subsequent UvrB recruitment requires ATP hydrolysis in the proximal site. Finally, UvrA dissociates from the lesion complex, allowing UvrB to orchestrate the downstream NER reactions. PMID:27562541

  13. Simultaneous oral immunization of mice with live attenuated Escherichia coli expressing LT192-STa 13 and LT 192-STb fusion immunogen, respectively, for polyvalent vaccine candidate.

    PubMed

    Liu, Wenxin; Li, Jinping; Bao, Jun; Li, Xingyue; Guan, Weikun; Yuan, Chaowen; Tang, Jie; Zhao, Zhiteng; Shi, Dongfang

    2015-05-01

    Previous epidemiological study showed that most of the porcine enterotoxin Escherichia coli (ETEC) strains harbor multiple enterotoxins but lack any of the fimbriae or non-fimbrial adhesion genes. Therefore, effective ETEC vaccines need to aim directly at all the enterotoxin antigens. The objective of this study was to evaluate the simultaneous immune effect of two live attenuated E. coli strains expressing LTR192G-STaA13Q and LTR192G-STb fusion immunogen, respectively. The results showed that both local mucosal and systemic immune responses against LT, STa, STb, and F41 were induced in BALB/c mice immunized orally with the recombinant E. coli strains ER-A and ER-B simultaneously. In addition, results of cellular immune responses showed that stimulation index (SI) values of immunized mice were significantly higher than control mice (P < 0.05) and a marked shift toward type-2 helper T lymphocyte (Th 2) immunity. Moreover, the induced antibodies demonstrated neutralizing effects on LT, STa, and STb producing E. coli infection. These data indicated that the use of recombinant E. coli ER-A and ER-B could be a valuable strategy for future polyvalent vaccine development of ETEC. PMID:25549617

  14. Typing of Campylobacter jejuni and Campylobacter coli isolated from live broilers and retail broiler meat by flaA-RFLP, MLST, PFGE and REP-PCR.

    PubMed

    Behringer, Megan; Miller, William G; Oyarzabal, Omar A

    2011-02-01

    We analyzed 100 Campylobacter spp. isolates (C. jejuni and C. coli) from Grenada, Puerto Rico and Alabama, which were collected from live broilers or retail broiler meat. We analyzed these isolates with four molecular typing methods: restriction fragment length polymorphism of the flaA gene (flaA-RFLP), multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and automated repetitive extragenic palindromic polymerase chain reaction (REP-PCR) using the DiversiLab system. All methods performed similarly for the typing of C. jejuni and C. coli. The DNA extraction method appears to influence the results obtained with REP-PCR. This method was better for the typing of C. jejuni than C. coli, however both REP-PCR and flaA-RFLP generated types that were indistinguishable between C. jejuni and C. coli and appeared to be random, without any relationship to species, location, or source of isolates. PFGE and MLST generated typing results that had a better correlation with the geographic location of the isolates and showed higher concordance with the Wallace coefficient. The adjusted Rand coefficient did not show higher concordance among the methods, although the PFGE/MLST combination exhibited the highest concordance. PFGE and MLST revealed a better discriminatory power for C. coli isolates than REP-PCR or flaA-RFLP. The use of readily available online tools to calculate the confidence interval of the Simpson's index of diversity and the adjusted Rand and Wallace coefficients helped estimate the discriminatory power of typing methods. Further studies using different C. jejuni and C. coli strains may expand our understanding of the benefits and limitations of each of these typing methods for epidemiological studies of Campylobacter spp. PMID:21130125

  15. Antimicrobial Resistance in Generic Escherichia coli Isolates from Wild Small Mammals Living in Swine Farm, Residential, Landfill, and Natural Environments in Southern Ontario, Canada▿

    PubMed Central

    Allen, Samantha E.; Boerlin, Patrick; Janecko, Nicol; Lumsden, John S.; Barker, Ian K.; Pearl, David L.; Reid-Smith, Richard J.; Jardine, Claire

    2011-01-01

    To assess the impacts of different types of human activity on the development of resistant bacteria in the feces of wild small mammals, we compared the prevalences and patterns of antimicrobial resistance and resistance genes in generic Escherichia coli and Salmonella enterica isolates from fecal samples collected from wild small mammals living in four environments: swine farms, residential areas, landfills, and natural habitats. Resistance to antimicrobials was observed in E. coli isolates from animals in all environments: 25/52 (48%) animals trapped at swine farms, 6/69 (9%) animals trapped in residential areas, 3/20 (15%) animals trapped at landfills, and 1/22 (5%) animals trapped in natural habitats. Animals trapped on farms were significantly more likely to carry E. coli isolates with resistance to tetracycline, ampicillin, sulfisoxazole, and streptomycin than animals trapped in residential areas. The resistance genes sul2, aadA, and tet(A) were significantly more likely to be detected in E. coli isolates from animals trapped on farms than from those trapped in residential areas. Three S. enterica serotypes (Give, Typhimurium, and Newport) were recovered from the feces of 4/302 (1%) wild small mammals. All Salmonella isolates were pansusceptible. Our results show that swine farm origin is significantly associated with the presence of resistant bacteria and resistance genes in wild small mammals in southern Ontario, Canada. However, resistant fecal bacteria were found in small mammals living in all environments studied, indicating that environmental exposure to antimicrobials, antimicrobial residues, resistant bacteria, or resistance genes is widespread. PMID:21131524

  16. A carAB mutant of avian pathogenic Escherichia coli serogroup O2 is attenuated and effective as a live oral vaccine against colibacillosis in turkeys.

    PubMed Central

    Kwaga, J K; Allan, B J; van der Hurk, J V; Seida, H; Potter, A A

    1994-01-01

    Colibacillosis is a serious and economically important disease of the respiratory tract of chickens and turkeys. The serogroups of Escherichia coli commonly associated with colibacillosis in poultry are O1, O2, and O78. Although previous attempts to develop a vaccine have not been very successful, vaccination is still considered the most effective way of controlling the disease. Therefore, our laboratory has been involved in the development of an attenuated live vaccine that will be effective in the prevention of colibacillosis. The carAB operon coding for carbamoyl-phosphate synthetase, an essential enzyme in arginine and pyrimidine metabolism, was selected for study. Generalized transduction was used to transfer a Tn10-generated mutation from a laboratory strain to virulent avian field isolates of E. coli. Molecular techniques were used to determine the point of Tn10 insertion within the carAB operon. The insertion mutants were then cured of the tetracycline resistance gene of the transposon to select for antibiotic-sensitive and stable carAB mutants. The degree of attenuation obtained by the mutation was determined in day-old chickens. Typically, when 100-fold the 50% lethal dose (for the wild type) was given, no more than 50% mortality in the day-old chickens was observed. The deletion mutant of serotype O2 was also found to be avirulent in turkeys rendered susceptible to infection with hemorrhagic enteritis virus A. Turkey poults vaccinated orally at 4 weeks old with either the wild-type E. coli EC317 strain or its carAB mutant EC751 were completely protected from infection following challenge with the homologous wild-type strain. Our data indicate that carAB mutants of virulent avian strains of E. coli will be effective and safe as live oral vaccines for prevention of colibacillosis in poultry. Images PMID:8063392

  17. A microbiological hazard of rural living: Clostridium septicum brain abscess in a child with E coli 0157 associated haemolytic uraemic syndrome.

    PubMed

    Williams, Eleri J; Mitchell, Patrick; Mitra, Dipayan; Clark, Julia E

    2012-01-01

    Clostridium septicum infection in humans is rare and this is the second case report of focal C septicum brain abscesses associated with Escherichia coli 0157 haemolytic uraemic syndrome (HUS). The case presented in a child who lived on a rural farm. The abscesses initially progressed despite 7 months of appropriate antibiotic therapy and repeated image-guided aspiration. After definitive resection and prolonged antibiotic therapy, there was no recurrence. This case reminds us of this rare but important neurological complication of HUS and supports consideration of early definitive neurosurgical intervention in similar unusual cases. PMID:22736786

  18. Survival characteristics of diarrheagenic Escherichia coli pathotypes and Helicobacter pylori during passage through the free-living ciliate, Tetrahymena sp.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ciliates prey on bacteria in water and waste water systems. Compartmentalization of ingested material (including bacteria) in the food vacuoles of Tetrahymena and its egestion in the fecal pellet has been described and the survival of Salmonella enterica and E. coli O157:H7 in such fecal pellets ha...

  19. E. coli

    MedlinePlus

    ... sure that ground beef has reached a safe internal temperature of 160° F. Wash hands before preparing food, after diapering infants, and after contact with cows, sheep, or goats, their food or treats, or their living environment . General Information E. coli Infections (NIH MedlinePlus) Trusted ...

  20. Colony-live —a high-throughput method for measuring microbial colony growth kinetics— reveals diverse growth effects of gene knockouts in Escherichia coli

    PubMed Central

    2014-01-01

    Background Precise quantitative growth measurements and detection of small growth changes in high-throughput manner is essential for fundamental studies of bacterial cell. However, an inherent tradeoff for measurement quality in high-throughput methods sacrifices some measurement quality. A key challenge has been how to enhance measurement quality without sacrificing throughput. Results We developed a new high-throughput measurement system, termed Colony-live. Here we show that Colony-live provides accurate measurement of three growth values (lag time of growth (LTG), maximum growth rate (MGR), and saturation point growth (SPG)) by visualizing colony growth over time. By using a new normalization method for colony growth, Colony-live gives more precise and accurate growth values than the conventional method. We demonstrated the utility of Colony-live by measuring growth values for the entire Keio collection of Escherichia coli single-gene knockout mutants. By using Colony-live, we were able to identify subtle growth defects of single-gene knockout mutants that were undetectable by the conventional method quantified by fixed time-point camera imaging. Further, Colony-live can reveal genes that influence the length of the lag-phase and the saturation point of growth. Conclusions Measurement quality is critical to achieving the resolution required to identify unique phenotypes among a diverse range of phenotypes. Sharing high-quality genome-wide datasets should benefit many researchers who are interested in specific gene functions or the architecture of cellular systems. Our Colony-live system provides a new powerful tool to accelerate accumulation of knowledge of microbial growth phenotypes. PMID:24964927

  1. 17(R)-Resolvin D1 differentially regulates TLR4-mediated responses of primary human macrophages to purified LPS and live E. coli

    PubMed Central

    Palmer, Christine D.; Mancuso, Christy J.; Weiss, Jerrold P.; Serhan, Charles N.; Guinan, Eva C.; Levy, Ofer

    2011-01-01

    Detection and clearance of bacterial infection require balanced effector and resolution signals to avoid chronic inflammation. Detection of GNB LPS by TLR4 on mϕ induces inflammatory responses, contributing to chronic inflammation and tissue injury. LXs and Rvs are endogenous lipid mediators that enhance resolution of inflammation, and their actions on primary human mϕ responses toward GNB are largely uncharacterized. Here, we report that LXA4, LXB4, and RvD1, tested at 0.1–1 μM, inhibited LPS-induced TNF production from primary human mϕ, with ATL and 17(R)-RvD1, demonstrating potent inhibition at 0.1 μM. In addition, 17(R)-RvD1 inhibited LPS-induced primary human mϕ production of IL-7, IL-12p70, GM-CSF, IL-8, CCL2, and MIP-1α without reducing that of IL-6 or IL-10. Remarkably, when stimulated with live Escherichia coli, mϕ treated with 17(R)-RvD1 demonstrated increased TNF production and enhanced internalization and killing of the bacteria. 17(R)-RvD1-enhanced TNF, internalization, and killing were not evident for an lpxM mutant of E. coli expressing hypoacylated LPS with reduced inflammatory activity. Furthermore, 17(R)-RvD1-enhanced, E. coli-induced TNF production was evident in WT but not TLR4-deficient murine mϕ. Thus, Rvs differentially modulate primary human mϕ responses to E. coli in an LPS- and TLR4-dependent manner, such that this Rv could promote resolution of GNB/LPS-driven inflammation by reducing mϕ proinflammatory responses to isolated LPS and increasing mϕ responses important for clearance of infection. PMID:21653234

  2. Oral immunization of a live attenuated Escherichia coli strain expressing a holotoxin-structured adhesin-toxoid fusion (1FaeG-FedF-LTA₂:5LTB) protected young pigs against enterotoxigenic E. coli (ETEC) infection.

    PubMed

    Ruan, Xiaosai; Zhang, Weiping

    2013-03-01

    ETEC strains expressing K88 (F4) or F18 fimbriae and enterotoxins are the predominant cause of porcine post-weaning diarrhea (PWD). PWD continues causing significant economic losses to swine producers worldwide. Vaccines effectively protecting against PWD are needed. Our recent study revealed that a tripartite adhesin-toxin monomer (FaeG-FedF-LT(A2-B)) elicited protective antibodies. In this study, we constructed a new adhesin-toxoid fusion, expressed it as a 1A:5B holotoxin-structured antigen (1FaeG-FedF-LT(192A2):5LT(B)) in an avirulent Escherichia coli strain, and evaluated its vaccine potential in pig challenge studies. Piglets orally inoculated with this live strain showed no adverse effects but developed systemic and mucosal antibodies that neutralized cholera toxin and inhibited adherence of K88 and F18 fimbriae in vitro. Moreover, the immunized piglets, when were challenged with ETEC strain 3030-2 (K88ac/LT/STb), had significant fewer bacteria colonized at small intestines and did not develop diarrhea; whereas the control piglets developed severe diarrhea and died. These results indicated the 1FaeG-FedF-LT(192A2):5LT(B) fusion antigen induced protective antiadhesin and antitoxin immunity in pigs, and suggested a live attenuated vaccine can be potentially developed against porcine ETEC diarrhea. Additionally, presenting antigens in a holotoxin structure to target host local mucosal immunity can be used in vaccine development against other enteric diseases. PMID:23375979

  3. Improvement of the live vaccine strain Salmonella enterica serovar Typhi Ty21a for antigen delivery via the hemolysin secretion system of Escherichia coli.

    PubMed

    Hotz, Christian; Fensterle, Joachim; Goebel, Werner; Meyer, Susanne R; Kirchgraber, Gabriel; Heisig, Martin; Fürer, Andreas; Dietrich, Guido; Rapp, Ulf R; Gentschev, Ivaylo

    2009-02-01

    The attenuated Salmonella enterica serovar Typhi strain Ty21a (Ty21a) is the only attenuated live oral vaccine against typhoid fever. Ty21a is also an attractive carrier for the delivery of heterologous antigens. We have used Ty21a for antigen delivery via the hemolysin (HlyA) secretion system of Escherichia coli, the prototype of the type I secretion system (T1SS). In this study, we identified by genetic complementation that the specific mutation of rpoS correlated with the hemolysin production of strain Ty21a. We furthermore showed that complementation with a plasmid encoding rfaH, which is described to be a downstream target of rpoS, led to increased expression and secretion of hemolysin. Finally, we demonstrated a significant enhancement of antibody responses against the heterologous HlyA antigen of Ty21a after immunization of mice with rfaH complemented S. typhi strain secreting HlyA compared with the same strain without rfaH plasmid. PMID:18706861

  4. Escherichia coli (E. coli)

    MedlinePlus

    ... so you might hear about E. coli being found in drinking water, which are not themselves harmful, but indicate the ... at CDC Foodborne disease Travelers' Health: Safe Food & Water Healthy Swimming E. coli Infection & Farm ... Word file Microsoft Excel file Audio/Video file Apple ...

  5. Methicillin-resistant Staphylococcus aureus and extended-spectrum and AmpC β-lactamase-producing Escherichia coli in broilers and in people living and/or working on organic broiler farms.

    PubMed

    Huijbers, Patricia M C; van Hoek, Angela H A M; Graat, Elisabeth A M; Haenen, Anja P J; Florijn, Alice; Hengeveld, Paul D; van Duijkeren, Engeline

    2015-03-23

    The aim of this study was to estimate the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum and AmpC β-lactamase (ESBL/AmpC)-producing Escherichia coli among broilers, and humans living and/or working on organic broiler farms; further characterise isolates; and compare these results with those from conventional farms. In the Netherlands, only 9 certified organic broiler farms were present. On 8 of these farms, 60 throat swabs and 20 cloacal swabs were taken per farm for MRSA and ESBL/AmpC-E. coli detection, respectively, at an average age of both 34 (T1) and 68 (T2) days. Faecal swabs and questionnaires were returned by 27 out of 36 humans. For selected ESBL/AmpC-producing E. coli isolates, phylogenetic groups, β-lactamase genes, plasmid families, and sequence types were determined. MRSA was not detected in broiler and human samples. ESBL/AmpC-producing E. coli were isolated from broilers on 7/8 farms at T1 and on all farms at T2. Furthermore, 3 farmers at T1, and 2 farmers and 1 family member at T2 were positive. Genes found in broilers and humans were almost exclusively blaCTX-M-1 and blaCMY-2. Given the high overall human ESBL/AmpC-prevalence (18.5%), which is similar to conventional farms, contact with live broilers is assumed a risk factor for carriage. Farm and sample-level prevalence at T1 are consistent with those from conventional farms. At T2, just before slaughter, sample-level prevalence of ESBL/AmpC-E. coli appears to have decreased (94.3% vs. 80%), which could have important consequences for contamination of retail meat. PMID:25582613

  6. E. Coli

    MedlinePlus

    ... E. coli is short for the medical term Escherichia coli . The strange thing about these bacteria — and lots ... cause a very serious infection. Someone who has E. coli infection may have these symptoms: bad stomach cramps and ...

  7. Histomorphometric evaluation of intestinal cellular immune responses in pigs immunized with live oral F4ac+ non-enterotoxigenic E. coli vaccine against postweaning colibacillosis

    PubMed Central

    Kovšca Janjatović, A.; Lacković, G.; Božić, F.; Kezić, D.; Popović, M.; Valpotić, H.; Harapin, I.; Pavižić, Ž.; Njari, B.; Valpotić, I.

    2010-01-01

    Enterotoxigenic Escherichia coli (ETEC) infection is the most common type of porcine postweaning colibacillosis (PWC). Among fimbriae of porcine ETEC strains the best studied family of fimbriae are the members of F4 adhesins, existing in at least three variants: ab, ac, ad. Active immunization against porcine PWC is difficult due to: i) ETEC strains are only one of the essential predisposing factors, ii) the success of vaccinal antigen uptake depends on the presence of enterocyte receptors for F4 adhesins, iii) the intestinal immune system may react with tolerance or hypersensitivity to the same antigens depending on the dose and form of the vaccinal immunogen, and iv) kinetics of the specific immune responses may be different in the case of F4 (earlier) and the other ETEC adhesins, particularly F18 (later). The aim of this study was to test the effectiveness of a live attenuated F4ac+ non-ETEC vaccine against porcine PWC by analyzing quantitative differences in the small intestinal lymphoid and myeloid cell subsets of immunized (with or without levamisole given as an adjuvant) vs control non-immunized pigs. Four week-old pigs were intragastrically immunized with a vaccine candidate F4ac + non-ETEC strain 2407 at day 0, challenged 7 days later with a virulent F4ac+ strain ETEC 11-800/1/94, euthanatized at day 13 and sampled for immunohistology. Non-immunized pigs received saline at day 0 and were processed as the principals. Immunophenotypes of lymphoid and myeloid cell subsets were demonstrated within jejunal and ileal mucosa by immunohistochemical avidinbiotin complex method and corresponding morphometric data were analyzed using software program Lucia G for digital image analyses. Monoclonal antibodies reactive with surface molecules on porcine immune cells such as CD3, CD45RA, CD45RC, CD21 and SWC3 enabled clear insight into distribution patterns and amount of these cells within the gut-associated lymphoid tissues (GALT) examined. The numbers of jejunal and

  8. Absence of CTX-M Enzymes but High Prevalence of Clones, Including Clone ST131, among Fecal Escherichia coli Isolates from Healthy Subjects Living in the Area of Paris, France▿

    PubMed Central

    Leflon-Guibout, Véronique; Blanco, Jorge; Amaqdouf, Karim; Mora, Azucena; Guize, Louis; Nicolas-Chanoine, Marie-Hélène

    2008-01-01

    Quinolone-resistant and CTX-M-15-producing Escherichia coli isolates belonging to clone ST131 have been reported in the community. This study was designed to identify these E. coli isolates in the stools of 332 independent healthy subjects living in the area of Paris, France. Stools were plated on media without antibiotics, in order to obtain the dominant (Dm) fecal E. coli strain, and with nalidixic acid (NAL) and cefotaxime. Quinolone susceptibility, phylogenetic groups, and molecular profiles, including multilocus sequence types (ST), were determined for all NAL-resistant (NAL-R) isolates. Groups were also determined for the Dm strains from participants with NAL-R isolates and from a subgroup without NAL-R isolates. All B2 isolates were typed; pulsed-field gel electrophoresis was performed for the ST131 isolates, and the results were compared with those for intercontinental clone ST131. Two participants (0.6%) had extended-spectrum β-lactamase-producing (SHV-2, TEM-52) fecal E. coli isolates, and 51 (15%) had NAL-R isolates; 51% of NAL-R isolates belonged to phylogenetic group A, 31% to group D, 16% to group B2, and 2% to group B1. The Dm strain was NAL-R in 3.3% of the 332 subjects. Forty-nine percent of the NAL-R isolates belonged to clones: ST10 and ST606 for group A isolates, ST117 and ST393 for group D isolates. Of all B2 isolates studied from 100 subjects (8 NAL-R strains; 19 NAL-susceptible dominant strains), 52% belonged to three clones: ST131 (n = 7), ST95 (n = 4), and ST141 (n = 3). This is the first study to show the presence of fecal E. coli isolates of clone ST131 in 7% of independent healthy subjects not colonized by CTX-M-15-producing isolates. PMID:18842941

  9. Long-term feeding with Euglena gracilis cells modulates immune responses, oxidative balance and metabolic condition in Diplodon chilensis (Mollusca, Bivalvia, Hyriidae) exposed to living Escherichia coli.

    PubMed

    Bianchi, Virginia A; Castro, Juan M; Rocchetta, Iara; Nahabedian, Daniel E; Conforti, Visitación; Luquet, Carlos M

    2015-02-01

    We evaluated the modulating effect of long-term feeding with lyophilized Euglena gracilis cells on immune response, oxidative balance and metabolic condition of the freshwater mussel Diplodon chilensis. Mussels, previously fed with Scenedesmus vacuolatus (SV) or E. gracilis (EG) for 90 days, were challenged with an environmentally relevant concentration of Escherichia coli in water for 5 days, under feeding or starvation conditions. EG diet increased overall phagocytic activity and tissue hemocyte accumulation (gill and mantle), and favored hemocyte viability upon E. coli challenge. Tissular hemocyte accumulation, and humoral bacteriolytic activity and protein content were similarly stimulated by EG and E. coli, with no further effect when both stimuli were combined. Both, E. coli challenge and EG diet reduced gill bacteriolytic activity with respect to nonchallenged SV mussels, while no effect was observed in challenged EG mussels. Gill and digestive gland protein contents, along with digestive gland bacteriolytic activity were higher in EG than in SV mussels. Both SV and EG mussels showed increased gill mass upon E. coli challenge, while digestive gland mass was increased by bacterial challenge only in SV mussels. Bacterial challenge produced no effect on humoral reactive oxygen species levels of both groups. Total oxyradical scavenging capacity levels was reduced in challenged SV mussels but remained unaffected in EG ones. In general, EG diet decreased glutathione S-transferase and catalase activities in gill and digestive gland, compared with SV diet; but increased enzyme activity was evident in challenged mussels of both groups. Gill and digestive gland lipid peroxidation levels were higher in EG than in SV mussels but E. coli challenge had stronger effect on SV mussels. Adductor muscle RNA:DNA ratio was higher in EG mussels than in SV ones, and increased upon E. coli challenge in mussels of both groups. E. gracilis can be suggested as a nutritional and

  10. Analysis and molecular cloning of genes involved in thiophene and furan oxidation by Escherichia coli

    SciTech Connect

    Alam, K.Y.; Worland, M.J.; Clark, D.P.

    1989-01-01

    Alternative methods for the desulfurization of coal are currently needed. The microbial removal of organic sulfur from coal is addressed in this issue by attempting to construct by genetic means, strains of bacteria which can degrade thiophenes and related organic sulfur compounds. Our first attempts in this direction have resulted in the isolation of a series of mutant strains of Escherchia coli with successively increased oxidizing ability towards furan and thiophene compounds. Three novel genes involved in thiophene oxidation, thdA, thdC, and thdD, were identified and mapped on the E. coli chromosome. In addition, mutations in two previously known regulatory genes fadR and atoC were also required. Further work resulted in more accurate mapping of thdA and thdD relative to known chromosomal genes and the isolation of a further mutation, thdE, so far unmapped. This conference presentation reviews some more recent findings, including the cloning of several genes involved in thiophene metabolism. 23 refs., 2 figs., 5 tabs.

  11. One step affinity recovery of 3α-hydroxysteroid dehydrogenase from cloned Escherichia coli.

    PubMed

    Yang, Hailin; Fang, Yanan; Wang, Zhizhen; Zhang, Ling

    2015-06-01

    3α-Hydroxysteroid dehydrogenase (3α-HSD), from Comamonas Testosterone, catalyze reversibly the oxidoreduction of 3α-hydroxyl groups of the steroid hormones. The gene encoding 3α-HSD (hsdA) from Comamonas Testosterone was expressed in Escherchia coli BL21 (DE3). A protocol for recovering 3α-HSD based on affinity strategy was designed and employed. Deoxycholic acid was chosen as the affinity ligand, and it was linked to Sepharose 4B with the aid of the spacers as cyanuric chloride and ethanediamine. With this specific affinity medium, the enzyme recovery process consisted of only one chromatography step to capture 3α-HSD. The target protein, analyzed on HPLC Agilent SEC-5 column, was of 94% pure among the captured protein, and 98% with SDS-PAGE analysis. The yield of the expressed enzyme was 8.8% of crude extracted proteins; the recovery yield of 3α-HSD was 73.2%. 3α-HSD was revealed as a non-covalent homodimer with molecular mass of ∼56kDa by 15.0% SDS-PAGE analysis and SE-HPLC analysis. The desorption constant Kd and the theoretical maximum absorption Qmax on the affinity medium were 4.5μg/g medium and 21.3mg/g medium, respectively. PMID:25913427

  12. Mechanisms of toxicity of hydroxylated polybrominated diphenyl ethers (HO-PBDEs) determined by toxicogenomic analysis with a live cell array coupled with mutagenesis in Escherichia coli.

    PubMed

    Su, Guanyong; Yu, Hongxia; Lam, Michael H W; Giesy, John P; Zhang, Xiaowei

    2014-05-20

    Results of previous studies have indicated that 6-HO-BDE-47, the addition of the hydroxyl (HO) group to the backbone of BDE-47, significantly increased the toxicity of the chemical compared to its postulated precursor analogues, BDE-47 and 6-MeO-BDE-47. However, whether such a result is conserved across polybrominated diphenyl ether (PBDE) congeners was unknown. Here, cytotoxicity of 32 PBDE analogues (17 HO-PBDEs and 15 MeO-PBDEs) was further tested and the underlying molecular mechanism was investigated. A total of 14 of the 17 HO-PBDEs inhibited growth of Escherichia coli during 4 or 24 h durations of exposure, but none of the MeO-PBDEs was cytotoxic at the concentrations tested. 6-HO-BDE-47 and 2-HO-BDE-28 were most potent with 4 h median effect concentrations (EC50) of 12.13 and 6.25 mg/L, respectively, which trended to be lesser with a longer exposure time (24 h). Expression of 30 modulated and validated genes by 6-HO-BDE-47 in a previous study was also observed after exposure to other HO-PBDE analogues. For instance, uhpT was upregulated by 13 HO-PBDEs, and three rRNA operons (rrnA, rrnB, and rrnC) were downregulated by 8 HO-PBDEs. These unanimous responses suggested a potential common molecular signaling modulated by HO-PBDEs. To explore new information on mechanisms of action, this work was extended by testing the increased susceptibility of 182 mutations of transcriptional factors (TFs) and 22 mutations as genes modulated by 6-HO-BDE-47 after exposure to 6-HO-BDE-47 at the 4 h IC50 concentration. Although a unanimous upregulation of uhpT was observed after exposure to HO-PBDEs, no significant shift in sensitivity was observed in uhpT-defective mutants. The 54 genes, selected by cut-offs of 0.35 and 0.65, were determined to be responsible for "organic acid/oxoacid/carboxylic acid metabolic process" pathways, which supported a previous finding. PMID:24717064

  13. Comparison of a live attenuated Salmonella Enteritidis vaccine candidate secreting Escherichia coli heat-labile enterotoxin B subunit with a commercial vaccine for efficacy of protection against internal egg contamination by Salmonella in hens

    PubMed Central

    Nandre, Rahul M.; Eo, Seong Kug; Park, Sang Youel; Lee, John Hwa

    2015-01-01

    This study compared a new live attenuated Salmonella Enteritidis vaccine candidate secreting Escherichia coli heat-labile enterotoxin B subunit (SE-LTB) with a commercial Salmonella Enteritidis (SE) vaccine for efficacy of protection against SE infection in laying hens. Chickens were divided into 3 groups of 20 each. Group A chickens were inoculated orally with phosphate-buffered saline and served as controls, group B chickens were inoculated orally with the vaccine candidate, and group C chickens were inoculated intramuscularly with a commercial vaccine, the primary inoculation in groups B and C being at 10 wk of age and the booster at 16 wk. Groups B and C showed significantly higher titers of plasma immunoglobulin G, intestinal secretory immunoglobulin A, and egg yolk immunoglobulin Y antibodies compared with the control group, and both vaccinated groups showed a significantly elevated cellular immune response. After virulent challenge, group B had significantly lower production of thin-shelled and/or malformed eggs and a significantly lower rate of SE contamination of eggs compared with the control group. Furthermore, the challenge strain was detected significantly less in all of the examined organs of group B compared with the control group. Group C had lower gross lesion scores only in the spleen and had lower bacterial counts only in the spleen, ceca, and ovary. These findings indicate that vaccination with the SE-LTB vaccine candidate can efficiently reduce internal egg and internal organ contamination by Salmonella and has advantages over the commercial vaccine. PMID:26130857

  14. Distribution of virulence associated traits among urine Escherichia coli isolates from patients in onco-hematology.

    PubMed

    Safi, Mariem; Achour, Wafa; Baaboura, Rekaya; El Fatmi, Rym; Ben othmen, Tarek; Ben Hassen, Assia

    2016-04-01

    Escherchia coli is the most common etiological agent of urinary tract infections. In this study we had two goals: First of all, to find out if urine stains isolated from our patients--having the particularity of being immunocompromised--would have a virulence genes distribution different from the one observed in strains isolated from ordinary patients. Second, we wanted to identify a common virulence profile associated to these particular strains. The prevalence of virulence factors (VF)-encoding genes was analyzed by PCR. Of the tested VF-encoding genes, malX (80%), ompT (79%), fyuA (74%), usp (67%), chuA (66%), iroN (59%), iutA (56%), papC (36%), pap AH (30%), papEF (28%), hlyA (28%), papG allele II (25%), cnf1 (21%), focG (20%),cvaC (20%) and papG allele III (7%) were significantly associated to urinary strains. Virulence genes distribution of urinary strains isolated from onco-hematology patients and the one observed in strains isolated from ordinary patients are almost the same. The virulence profiles containing adhesins type 1, S and F1C fimbriae, siderophore genes and three individual genes ompT, usp and malX were present in half of the urinary strains and were significantly associated to them. Two virulence signatures occurred significantly in UTI-causing strains (12%). These findings provide first insight into the virulence of UTI-causing E. coli strains isolated in onco-hematology patients. PMID:26829995

  15. E. Coli Infection

    MedlinePlus

    ... is E. coli? E. coli is short for Escherichia coli -- bacteria (germs) that cause severe cramps and diarrhea. E. ... and especially in people who have another illness. E. coli infection is more common during the summer months and ...

  16. Engineering Living Functional Materials

    PubMed Central

    2016-01-01

    Natural materials, such as bone, integrate living cells composed of organic molecules together with inorganic components. This enables combinations of functionalities, such as mechanical strength and the ability to regenerate and remodel, which are not present in existing synthetic materials. Taking a cue from nature, we propose that engineered ‘living functional materials’ and ‘living materials synthesis platforms’ that incorporate both living systems and inorganic components could transform the performance and the manufacturing of materials. As a proof-of-concept, we recently demonstrated that synthetic gene circuits in Escherichia coli enabled biofilms to be both a functional material in its own right and a materials-synthesis platform. To demonstrate the former, we engineered E. coli biofilms into a chemical-inducer-responsive electrical switch. To demonstrate the latter, we engineered E. coli biofilms to dynamically organize biotic-abiotic materials across multiple length scales, template gold nanorods, gold nanowires, and metal/semiconductor heterostructures, and synthesize semiconductor nanoparticles (Chen, A. Y. et al. (2014) Synthesis and patterning of tunable multiscale materials with engineered cells. Nat. Mater.13, 515–523.). Thus, tools from synthetic biology, such as those for artificial gene regulation, can be used to engineer the spatiotemporal characteristics of living systems and to interface living systems with inorganic materials. Such hybrids can possess novel properties enabled by living cells while retaining desirable functionalities of inorganic systems. These systems, as living functional materials and as living materials foundries, would provide a radically different paradigm of materials performance and synthesis–materials possessing multifunctional, self-healing, adaptable, and evolvable properties that are created and organized in a distributed, bottom-up, autonomously assembled, and environmentally sustainable manner. PMID

  17. Engineering living functional materials.

    PubMed

    Chen, Allen Y; Zhong, Chao; Lu, Timothy K

    2015-01-16

    Natural materials, such as bone, integrate living cells composed of organic molecules together with inorganic components. This enables combinations of functionalities, such as mechanical strength and the ability to regenerate and remodel, which are not present in existing synthetic materials. Taking a cue from nature, we propose that engineered 'living functional materials' and 'living materials synthesis platforms' that incorporate both living systems and inorganic components could transform the performance and the manufacturing of materials. As a proof-of-concept, we recently demonstrated that synthetic gene circuits in Escherichia coli enabled biofilms to be both a functional material in its own right and a materials-synthesis platform. To demonstrate the former, we engineered E. coli biofilms into a chemical-inducer-responsive electrical switch. To demonstrate the latter, we engineered E. coli biofilms to dynamically organize biotic-abiotic materials across multiple length scales, template gold nanorods, gold nanowires, and metal/semiconductor heterostructures, and synthesize semiconductor nanoparticles (Chen, A. Y. et al. (2014) Synthesis and patterning of tunable multiscale materials with engineered cells. Nat. Mater. 13, 515-523.). Thus, tools from synthetic biology, such as those for artificial gene regulation, can be used to engineer the spatiotemporal characteristics of living systems and to interface living systems with inorganic materials. Such hybrids can possess novel properties enabled by living cells while retaining desirable functionalities of inorganic systems. These systems, as living functional materials and as living materials foundries, would provide a radically different paradigm of materials performance and synthesis-materials possessing multifunctional, self-healing, adaptable, and evolvable properties that are created and organized in a distributed, bottom-up, autonomously assembled, and environmentally sustainable manner. PMID:25592034

  18. Escherichia Coli

    ERIC Educational Resources Information Center

    Goodsell, David S.

    2009-01-01

    Diverse biological data may be used to create illustrations of molecules in their cellular context. I describe the scientific results that support a recent textbook illustration of an "Escherichia coli cell". The image magnifies a portion of the bacterium at one million times, showing the location and form of individual macromolecules. Results…

  19. Oral immunization with an attenuated Salmonella Gallinarum mutant as a fowl typhoid vaccine with a live adjuvant strain secreting the B subunit of Escherichia coli heat-labile enterotoxin

    PubMed Central

    2013-01-01

    Background The Salmonella Gallinarum (SG) lon/cpxR deletion mutant JOL916 was developed as a live vaccine candidate for fowl typhoid (FT), and a SG mutant secreting an Escherichia coli heat-labile enterotoxin B subunit (LTB), designated JOL1229, was recently constructed as an adjuvant strain for oral vaccination against FT. In this study, we evaluated the immunogenicity and protective properties of the SG mutant JOL916 and the LTB adjuvant strain JOL1229 in order to establish a prime and boost immunization strategy for each strain. In addition, we compared the increase in body weight, the immunogenicity, the egg production rates, and the bacteriological egg contamination of these strains with those of SG 9R, a widely used commercial vaccine. Results Plasma IgG, intestinal secretory IgA (sIgA), and cell-mediated responses were significantly induced after a boost inoculation with a mixture of JOL916 and JOL1229, and significant reductions in the mortality of chickens challenged with a wild-type SG strain were observed in the immunized groups. There were no significant differences in increases in body weight, cell-mediated immune responses, or systemic IgG responses between our vaccine mixture and the SG 9R vaccine groups. However, there was a significant elevation in intestinal sIgA in chickens immunized with our mixture at 3 weeks post-prime-immunization and at 3 weeks post-boost-immunization, while sIgA levels in SG 9R-immunized chickens were not significantly elevated compared to the control. In addition, the SG strain was not detected in the eggs of chickens immunized with our mixture. Conclusion Our results suggest that immunization with the LTB-adjuvant strain JOL1229 can significantly increase the immune response, and provide efficient protection against FT with no side effects on body weight, egg production, or egg contamination. PMID:23647814

  20. E. coli enteritis

    MedlinePlus

    Traveler's diarrhea - E. coli ; Food poisoning - E. coli ; E. coli diarrhea; Hamburger disease ... infected. The most common symptom is sudden, severe diarrhea that is often bloody. Other symptoms may include: ...

  1. Diarrheagenic Escherichia coli

    PubMed Central

    Nataro, James P.; Kaper, James B.

    1998-01-01

    Escherichia coli is the predominant nonpathogenic facultative flora of the human intestine. Some E. coli strains, however, have developed the ability to cause disease of the gastrointestinal, urinary, or central nervous system in even the most robust human hosts. Diarrheagenic strains of E. coli can be divided into at least six different categories with corresponding distinct pathogenic schemes. Taken together, these organisms probably represent the most common cause of pediatric diarrhea worldwide. Several distinct clinical syndromes accompany infection with diarrheagenic E. coli categories, including traveler’s diarrhea (enterotoxigenic E. coli), hemorrhagic colitis and hemolytic-uremic syndrome (enterohemorrhagic E. coli), persistent diarrhea (enteroaggregative E. coli), and watery diarrhea of infants (enteropathogenic E. coli). This review discusses the current level of understanding of the pathogenesis of the diarrheagenic E. coli strains and describes how their pathogenic schemes underlie the clinical manifestations, diagnostic approach, and epidemiologic investigation of these important pathogens. PMID:9457432

  2. E. Coli Infections

    MedlinePlus

    ... adults with weak immune systems. You can get E. coli infections by eating foods containing the bacteria. Symptoms of ... pool contaminated with human waste. Most cases of E. coli infection get better without treatment in 5 to 10 ...

  3. Assisted Living

    MedlinePlus

    ... but they don't need full-time nursing care. Some assisted living facilities are part of retirement ... change. Assisted living costs less than nursing home care. It is still fairly expensive. Older people or ...

  4. Biodegradation of Aromatic Compounds by Escherichia coli

    PubMed Central

    Díaz, Eduardo; Ferrández, Abel; Prieto, María A.; García, José L.

    2001-01-01

    Although Escherichia coli has long been recognized as the best-understood living organism, little was known about its abilities to use aromatic compounds as sole carbon and energy sources. This review gives an extensive overview of the current knowledge of the catabolism of aromatic compounds by E. coli. After giving a general overview of the aromatic compounds that E. coli strains encounter and mineralize in the different habitats that they colonize, we provide an up-to-date status report on the genes and proteins involved in the catabolism of such compounds, namely, several aromatic acids (phenylacetic acid, 3- and 4-hydroxyphenylacetic acid, phenylpropionic acid, 3-hydroxyphenylpropionic acid, and 3-hydroxycinnamic acid) and amines (phenylethylamine, tyramine, and dopamine). Other enzymatic activities acting on aromatic compounds in E. coli are also reviewed and evaluated. The review also reflects the present impact of genomic research and how the analysis of the whole E. coli genome reveals novel aromatic catabolic functions. Moreover, evolutionary considerations derived from sequence comparisons between the aromatic catabolic clusters of E. coli and homologous clusters from an increasing number of bacteria are also discussed. The recent progress in the understanding of the fundamentals that govern the degradation of aromatic compounds in E. coli makes this bacterium a very useful model system to decipher biochemical, genetic, evolutionary, and ecological aspects of the catabolism of such compounds. In the last part of the review, we discuss strategies and concepts to metabolically engineer E. coli to suit specific needs for biodegradation and biotransformation of aromatics and we provide several examples based on selected studies. Finally, conclusions derived from this review may serve as a lead for future research and applications. PMID:11729263

  5. Pathogenic Escherichia coli.

    PubMed

    Kaper, James B; Nataro, James P; Mobley, Harry L

    2004-02-01

    Few microorganisms are as versatile as Escherichia coli. An important member of the normal intestinal microflora of humans and other mammals, E. coli has also been widely exploited as a cloning host in recombinant DNA technology. But E. coli is more than just a laboratory workhorse or harmless intestinal inhabitant; it can also be a highly versatile, and frequently deadly, pathogen. Several different E. coli strains cause diverse intestinal and extraintestinal diseases by means of virulence factors that affect a wide range of cellular processes. PMID:15040260

  6. Construction of Bifidobacterium infantis as a live oral vaccine that expresses antigens of the major fimbrial subunit (CfaB) and the B subunit of heat-labile enterotoxin (LTB) from enterotoxigenic Escherichia coli.

    PubMed

    Ma, Yongping; Luo, Yaolin; Huang, Xueping; Song, Fangzhou; Liu, Geli

    2012-02-01

    We sought to develop Bifidobacterium infantis (BI) as a vehicle for the expression of heterologous antigens. Two proteins of enterotoxigenic Escherichia coli (ETEC) were expressed in BI: CfaB, a major fimbrial subunit protein, and LTB, the B subunit of heat-labile enterotoxin. The expression of CfaB and LTB in BI was verified by electrophoretic analysis. Sprague-Dawley rats were then subjected to intragastric immunization with BI-CfaB and BI-LTB systems both separately and together. ELISA was used to characterize the serum and mucosal immune responses against ETEC antigens. The immunized rats were intraperitoneally challenged with wild-type ETEC H10407 to study the immune response in vivo. The serum titres of IgG and faecal IgA antibodies in the BI-CfaB plus BI-LTB mixed vaccination group were significantly greater than those in the other two groups, which were immunized with a single vaccine (P<0.05). However, no significant difference was seen between the two groups that received a single immunization. These results suggest that expressing CfaB and LTB in BI provides a probiotic system with immunogenic properties. Furthermore, the expression of LTB in BI preserved its mucosal adjuvant effect. So this study confirms that BI can be used as a novel oral vaccine expression system for a heterologous antigen and BI-LTB can provide mucosal adjuvant properties. PMID:22053005

  7. A comprehensive library of fluorescent transcriptional reporters for Escherichia coli.

    PubMed

    Zaslaver, Alon; Bren, Anat; Ronen, Michal; Itzkovitz, Shalev; Kikoin, Ilya; Shavit, Seagull; Liebermeister, Wolfram; Surette, Michael G; Alon, Uri

    2006-08-01

    E. coli is widely used for systems biology research; there exists a need, however, for tools that can be used to accurately and comprehensively measure expression dynamics in individual living cells. To address this we present a library of transcriptional fusions of gfp to each of about 2,000 different promoters in E. coli K12, covering the great majority of the promoters in the organism. Each promoter fusion is expressed from a low-copy plasmid. We demonstrate that this library can be used to obtain highly accurate dynamic measurements of promoter activity on a genomic scale, in a glucose-lactose diauxic shift experiment. The library allowed detection of about 80 previously uncharacterized transcription units in E. coli, including putative internal promoters within previously known operons, such as the lac operon. This library can serve as a tool for accurate, high-resolution analysis of transcription networks in living E. coli cells. PMID:16862137

  8. Assisted Living

    MedlinePlus

    ... it, too. Back to top What is the Cost for Assisted Living? Although assisted living costs less than nursing home care, it is still ... of services an older person chooses, the price costs can range from less than $25,000 a ...

  9. Pathogenic Escherichia coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Escherichia coli, a member of the Enterobacteriaceae family, is a part of the normal flora of the intestinal tract of humans and a variety of animals. E. coli strains are classified on the basis of antigenic differences in two surface components (serotyping), the somatic antigen (O) of the lipopoly...

  10. PATHOGENIC ESCHERICHIA COLI

    EPA Science Inventory

    Escherichia coli is a bacterial species which inhabits the gastrointestinal tract of man and warm-blooded animals. Because of the ubiquity of this bacterium in the intestinal flora, it serves as an important indicator organism of fecal contamination. E. coli, aside from serving a...

  11. Assisted Living

    MedlinePlus

    ... are part of retirement communities. Others are near nursing homes, so a person can move easily if needs change. Assisted living costs less than nursing home care. It is still fairly expensive. Older people ...

  12. Assisted Living

    MedlinePlus

    ... Recreational activities Security Transportation How to Choose a Facility A good match between a facility and a resident's needs depends as much on the philosophy and services of the assisted living facility as it does on the quality of care. ...

  13. Assisted Living

    MedlinePlus

    ... a resident's needs depends as much on the philosophy and services of the assisted living facility as ... the facility provide a written statement of its philosophy of care? Visit each facility more than once, ...

  14. Assisted Living

    MedlinePlus

    ... premises. Adult foster care has the advantages of maintaining frail older adults in a more home-like ... pay to live in these communities, though some facilities have beds for skilled care that are funded ...

  15. Living Laboratories

    ERIC Educational Resources Information Center

    Mules, B. R.

    1976-01-01

    Presented is a review of various methods of keeping live animals, including scorpions, spiders, crabs, crayfish, shrimp, ants, fish, mice, and birds, as well as plants as a school science project/display. (SL)

  16. Healthy Living

    MedlinePlus

    ... Environment Kids Health Kids Environment Kids Health Topics Environment & Health Healthy Living Pollution Reduce, Reuse, Recycle Science – How It Works The Natural World Games Brainteasers Puzzles Riddles Songs Activities Be ...

  17. E. Coli Infections

    MedlinePlus

    ... You can also get the infection by swallowing water in a swimming pool contaminated with human waste. Most cases of E. coli infection get better without treatment in 5 to 10 days. NIH: National Institute ...

  18. [Enterohemorrhagic E. coli (EHEC)].

    PubMed

    Goto, Tetsushi; Shirano, Michinori

    2012-08-01

    Escherichia coli (E. coli) is a bacterium that is commonly found in the gut of humans and warm-blooded animals. Most strains of E. coli are harmless. Some strains however, such as enterohemorrhagic E. coli (EHEC), can cause severe foodborne disease. It is transmitted to humans primarily through consumption of contaminated foods, such as raw meal. EHEC produces toxins, known as verotoxins. EHEC that induces bloody diarrhea leads to HUS in 10% of cases. The clinical manifestations of post-diarrheal HUS include acute renal failure, microangiopathic hemolytic anemia, and thrombocytopenia. The verocytotoxin can directly damage renal and endothelial cells. Thrombocytopenia occurs as platelets are consumed by clotting. Hemolytic anemia results from intravascular fibrin deposition, increased fragility of red blood cells, and fragmentation. PMID:22894069

  19. Recurrent Escherichia coli bacteremia.

    PubMed Central

    Maslow, J N; Mulligan, M E; Arbeit, R D

    1994-01-01

    Escherichia coli is the most common gram-negative organism associated with bacteremia. While recurrent E. coli urinary tract infections are well-described, recurrent E. coli bacteremia appears to be uncommon, with no episodes noted in multiple series of patients with gram-negative bacteremias. We report on 5 patients with recurrent bloodstream infections identified from a series of 163 patients with E. coli bacteremia. For each patient, the isolates from each episode were analyzed by pulsed-field gel electrophoresis (PFGE) and ribotyping and for the presence of E. coli virulence factors. For each of four patients, the index and recurrent episodes of bacteremia represented the same strain as defined by PFGE, and the strains were found to carry one or more virulence factors. The remaining patient, with two episodes of bloodstream infection separated by a 4-year interval, was infected with two isolates that did not carry any virulence factors and that were clonally related by ribotype analysis but differed by PFGE. All five patients had either a local host defense defect (three patients) or impaired systemic defenses (one patient) or both (one patient). Thus, recurrent E. coli bacteremia is likely to represent a multifactorial process that occurs in patients with impaired host defenses who are infected with virulent isolates. Images PMID:7910828

  20. Survival of Escherichia coli O157:H7 on cattle hides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to determine the length of time that E. coli O157:H7 survives on the hides of cattle. Extensive research has been conducted and is on-going to identify and develop novel pre- and post-harvest intervention strategies to reduce E. coli O157:H7 from live cattle and proc...

  1. Rapid detection of E. coli on goat meat by electronic nose

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Much attention has been paid on the foodborne illness of food, which is easily contaminated with bacterial or pathogens. Escherichia coli (E. coli) is one of these bacterial that commonly live in the contaminated animal meat. There is a growing need in the food industry for pathogen detection syst...

  2. Healthy Living

    MedlinePlus

    ... health. Some you cannot control, such as your genetic makeup or your age. But you can make changes to your lifestyle. By taking steps toward healthy living, you can help reduce your risk of heart disease, cancer, stroke and other serious diseases: Get ...

  3. Retiring Lives

    ERIC Educational Resources Information Center

    Carnell, Eileen, Ed.; Lodge, Caroline, Ed.

    2009-01-01

    "Retiring Lives" presents fourteen personal real life stories from people at various stages of retiring. Each author recounts their own story about retiring, bringing together many aspects of the experiences: the social, psychological and practical. These inspirational and illustrated stories will encourage the reader to hold up these experiences…

  4. Learn & Live.

    ERIC Educational Resources Information Center

    Burness, Patty, Ed.; Snider, William, Ed.

    Along with a companion documentary video, "Learn & Live," this resource manual focuses on innovative schools around the country that are integrating technology and involving parents, business, and the community. Ten chapters are divided into four sections. In Section 1, "Students," two chapters look at learning and assessment. The two chapters in…

  5. Outdoor Living.

    ERIC Educational Resources Information Center

    Cotter, Kathy

    Course objectives and learning activities are contained in this curriculum guide for a 16-week home economics course which teaches cooking and sewing skills applicable to outdoor living. The course goals include increasing male enrollment in the home economics program, developing students' self-confidence and ability to work in groups, and…

  6. Triglyceride kinetics in fasted and fed E. coli septic rats

    SciTech Connect

    Lanza-Jacoby, S.; Tabares, A. )

    1990-02-26

    The mechanism for the development of hypertriglyceridemia during gram-negative sepsis was studies by examining the liver production and clearance of very-low-density lipoprotein (VLDL) triglyceride (TG). To assess the liver output and peripheral clearance the kinetics of VLDL-TG were determined by a constant intravenous infusion of (2-{sup 3}H) glycerol-labeled VLDL in fasted control, fasted E. coli-treated, fed control, and fed E.coli-treated rats. Lewis inbred rats, 275-300 g, were made septic with 8 {times} 10{sup 7} live E.coli colonies per 100 g body weight. Twenty-four hours following E.coli injection serum TG of fasted E.coli-treated rats was elevated by 170% which was attributed to a 67% decrease in the clearance rate of VLDL-TG in fasted E.coli-treated rats compared with their fasted controls. The secretion of VLDL-TG declined by 31% in the livers of the fasted E.coli-treated rats which was accompanied by a 2-fold increase in the composition of liver TG. In a second series of experiments control and E.coli-treated rats were fed intragastrically (IG) a balanced solution containing glucose plus fat as the sources of nonprotein calories. Serum TG were 26% lower in the fed E.coli-treated rats because the clearance rate increased by 86%. The secretion of TG in the fed septic rats increased by 40% but this difference was not significant. In the septic rat the ability to clear triglycerides from the plasma depends upon the nutritional state.

  7. Genetic recombination. [Escherichia coli

    SciTech Connect

    Stahl, F.W.

    1987-02-01

    The molecular pathways of gene recombination are explored and compared in studies of the model organisms, Escherichia coli and phase lambda. In the discussion of data from these studies it seems that recombination varies with the genetic idiosyncrasies of the organism and may also vary within a single organism.

  8. E. coli on the move

    NASA Astrophysics Data System (ADS)

    Calne, S.

    2012-04-01

    Lynn Grove High School in Great Yarmouth, UK has been awarded a Royal Society partnership grant. Lynn Grove pupils aged between 11 and 16 years will carry out an investigation collaborating with scientists at the John Innes Centre in Norwich, UK to investigate the distribution of E.coli and other coliform bacteria within a school. The information will be used as an evidence base to educate pupils about the transmission of microbes and about methods of control. Through this work pupils will gain an appreciation of the diversity of microbial biochemistry and the chemistry behind chromogenic detection methodologies for specific bacterial enzymes. Inferences from the use of diagnostic selective media will be confirmed by carrying out DNA isolation and PCR to identify the genes responsible for the biochemical reactions. PCR will also be used to identify species of coliforms by reference to genomic sequence databases. These techniques will allow pupils to look into an unseen world in a way which has direct relevance to their everyday lives. Furthermore this partnership study will demonstrate to pupils that solving scientific questions requires the integration of a variety of scientific disciplines. The project will run from January 2012 until June 2012. We will present our preliminary results from the investigation and outline our future plans.

  9. ISS Live!

    NASA Technical Reports Server (NTRS)

    Price, Jennifer; Harris, Philip; Hochstetler, Bruce; Guerra, Mark; Mendez, Israel; Healy, Matthew; Khan, Ahmed

    2013-01-01

    International Space Station Live! (ISSLive!) is a Web application that uses a proprietary commercial technology called Lightstreamer to push data across the Internet using the standard http port (port 80). ISSLive! uses the push technology to display real-time telemetry and mission timeline data from the space station in any common Web browser or Internet- enabled mobile device. ISSLive! is designed to fill a unique niche in the education and outreach areas by providing access to real-time space station data without a physical presence in the mission control center. The technology conforms to Internet standards, supports the throughput needed for real-time space station data, and is flexible enough to work on a large number of Internet-enabled devices. ISSLive! consists of two custom components: (1) a series of data adapters that resides server-side in the mission control center at Johnson Space Center, and (2) a set of public html that renders the data pushed from the data adapters. A third component, the Lightstreamer server, is commercially available from a third party and acts as an intermediary between custom components (1) and (2). Lightstreamer also provides proprietary software libraries that are required to use the custom components. At the time of this reporting, this is the first usage of Web-based, push streaming technology in the aerospace industry.

  10. Live Virus Smallpox Vaccine

    MedlinePlus

    ... Index SMALLPOX FACT SHEET The Live Virus Smallpox Vaccine The vaccinia virus is the "live virus" used ... cannot cause smallpox. What is a "live virus" vaccine? A "live virus" vaccine is a vaccine that ...

  11. Living Nanomachines

    NASA Astrophysics Data System (ADS)

    Carlier, M.-F.; Helfer, E.; Wade, R.; Haraux, F.

    The living cell is a kind of factory on the microscopic scale, in which an assembly of modular machines carries out, in a spatially and temporally coordinated way, a whole range of activities internal to the cell, including the synthesis of substances essential to its survival, intracellular traffic, waste disposal, and cell division, but also activities related to intercellular communication and exchanges with the outside world, i.e., the ability of the cell to change shape, to move within a tissue, or to organise its own defence against attack by pathogens, injury, and so on. These nanomachines are made up of macromolecular assemblies with varying degrees of complexity, forged by evolution, within which work is done as a result of changes in interactions between proteins, or between proteins and nucleic acids, or between proteins and membrane components. All these cell components measure a few nanometers across, so the mechanical activity of these nanomachines all happens on the nanometric scale. The directional nature of the work carried out by biological nanomachines is associated with a dissipation of energy. As examples of protein assemblies, one could mention the proteasome, which is responsible for the degradation of proteins, and linear molecular motors such as actomyosin, responsible for muscle contraction, the dynein-microtubule system, responsible for flagellar motility, and the kinesin-microtubule system, responsible for transport of vesicles, which transform chemical energy into motion. Nucleic acid-protein assemblies include the ribosome, responsible for synthesising proteins, polymerases, helicases, elongation factors, and the machinery of DNA replication and repair; the mitotic spindle is an integrated system involving several of these activities which drive chromosome segregation. The machinery coupling membranes and proteins includes systems involved in the energy metabolism, such as the ATP synthase rotary motor, signalling cascades, endocytosis

  12. Escherichia coli ghosts promote innate immune responses in human keratinocytes.

    PubMed

    Abtin, Arby; Kudela, Pavol; Mayr, Ulrike Beate; Koller, Verena Juliana; Mildner, Michael; Tschachler, Erwin; Lubitz, Werner

    2010-09-10

    Bacterial ghosts (BGs) as non-living bacterial envelopes devoid of cytoplasmic content with preserved and intact inner and outer membrane structures of their living counterparts have been used to study the ability of their surface components for the induction of antimicrobial peptides and pro-inflammatory cytokines in human primary keratinocytes (KCs). Quantitative real-time PCR analysis revealed that incubation of KCs with BGs generated from wild-type Escherichia coli induced the mRNA expression of antimicrobial psoriasin (S100A7c) in a BGs particle concentration-dependent manner. Using immunoblot analysis we showed that BGs generated from the flagellin-deficient (ΔFliC) E. coli strain NK9375 were as effective as its isogenic wild-type (wt) E. coli strain NK9373 to induce psoriasin expression when normalized to BG particles being taken up by KCs. However, results obtained from endocytic activity of KCs reflect that internalization of BGs is greatly dependent on the presence of flagellin on the surface of BGs. Moreover, BGs derived from wt E. coli NK9373 strongly induced the release of the pro-inflammatory cytokines IL-6 and IL-8, compared to ΔFliC E. coli NK9375 BGs. Taken together, obtained data demonstrate that non-living BGs possessing all bacterial bio-adhesive surface properties in their original state while not posing any infectious threat have the capacity to induce the expression of innate immune modulators and that these responses are partially dependent on the presence of flagellin. PMID:20696136

  13. "R"-living vaccine against colibacillosis. Communication I.

    PubMed

    Parnas, J; Dam, A; Jorgensen, J B

    1977-04-01

    After our estimation of the LD100 of enteropathogenic E. coli 0149 and 0138 (and their toxins) in rabbits and mice (intravenously and subcutaneously or intraperitoneally, respectively), rabbits and mice were vaccinated subcutaneously by the living "R" 0149 vaccine. All animals showed resistance against the LD100 of both E. coli serotypes; this state of resistance lasted 1-5 months in rabbits, and 1-3 months in mice. Sera of vaccinated rabbits showed bactericidal activity against both E. coli serotypes. The R-E-system of rabbits which were immunized by the endotoxin of "R" 0149 living vaccine, showed mobilization of immunocytes. The vaccine seems to be harmless to newborn piglets after oral vaccination; 2 colostrum deprived piglets, despite vaccination at once after birth, did not survive the big chalenge with 100 ml of broth culture of E. coli 0149 "S" (anapylactic shock). But in comparison to 1 not vaccinated control piglet, the two piglests showed only few E. coli colonies in the intestines, while the intestine of the control animal was very massively colonized by the virulent strain. As the immunizing potency of the "R" 0149 living vaccine was clearly shown in rabbits and mice, further investigations on piglets (newborns, weaning epriod, and after weaning) are needed, to state whether the value of this vaccine corresponds with the immunizing potency shown in our preliminary experiments. The "R"-vaccine seems to open some perspective in colibacillosis prevention of children and animals, and therefore it deserves our attention. PMID:325952

  14. Programming controlled adhesion of E. coli to target surfaces, cells, and tumors with synthetic adhesins.

    PubMed

    Piñero-Lambea, Carlos; Bodelón, Gustavo; Fernández-Periáñez, Rodrigo; Cuesta, Angel M; Álvarez-Vallina, Luis; Fernández, Luis Ángel

    2015-04-17

    In this work we report synthetic adhesins (SAs) enabling the rational design of the adhesion properties of E. coli. SAs have a modular structure comprising a stable β-domain for outer membrane anchoring and surface-exposed immunoglobulin domains with high affinity and specificity that can be selected from large repertoires. SAs are constitutively and stably expressed in an E. coli strain lacking a conserved set of natural adhesins, directing a robust, fast, and specific adhesion of bacteria to target antigenic surfaces and cells. We demonstrate the functionality of SAs in vivo, showing that, compared to wild type E. coli, lower doses of engineered E. coli are sufficient to colonize solid tumors expressing an antigen recognized by the SA. In addition, lower levels of engineered bacteria were found in non-target tissues. Therefore, SAs provide stable and specific adhesion capabilities to E. coli against target surfaces of interest for diverse applications using live bacteria. PMID:25045780

  15. Modulation of host cell signalling by enteropathogenic and Shiga toxin-producing Escherichia coli.

    PubMed

    Kresse, A U; Guzmán, C A; Ebel, F

    2001-09-01

    The majority of Escherichia coli strains are harmless symbionts in the intestinal tract. However, there are several pathogenic forms, which are responsible for various diseases in humans and live stock. In this review we discuss the interactions between Shiga toxin-producing E. coli and enteropathogenic E. coli and their target host cells, describing their strategies to activate specific cellular signalling pathways which lead to subversion of critical physiological functions. We mainly concentrate on those pathogenic mechanisms that are dependent on a functional type III secretion system, but we also briefly discuss additional factors that contribute to the specific pathogenic profiles of Shiga toxin-producing E. coli and enreropathogenic E. coli. PMID:11680788

  16. Programming Controlled Adhesion of E. coli to Target Surfaces, Cells, and Tumors with Synthetic Adhesins

    PubMed Central

    2014-01-01

    In this work we report synthetic adhesins (SAs) enabling the rational design of the adhesion properties of E. coli. SAs have a modular structure comprising a stable β-domain for outer membrane anchoring and surface-exposed immunoglobulin domains with high affinity and specificity that can be selected from large repertoires. SAs are constitutively and stably expressed in an E. coli strain lacking a conserved set of natural adhesins, directing a robust, fast, and specific adhesion of bacteria to target antigenic surfaces and cells. We demonstrate the functionality of SAs in vivo, showing that, compared to wild type E. coli, lower doses of engineered E. coli are sufficient to colonize solid tumors expressing an antigen recognized by the SA. In addition, lower levels of engineered bacteria were found in non-target tissues. Therefore, SAs provide stable and specific adhesion capabilities to E. coli against target surfaces of interest for diverse applications using live bacteria. PMID:25045780

  17. Emerging Enteropathogenic Escherichia coli Strains?

    PubMed Central

    Irino, Kinue; Girão, Dennys M.; Girão, Valéria B.C.; Guth, Beatriz E.C.; Vaz, Tânia M.I.; Moreira, Fabiana C.; Chinarelli, Silvia H.; Vieira, Mônica A.M.

    2004-01-01

    Escherichia coli strains of nonenteropathogenic serogroups carrying eae but lacking the enteropathogenic E. coli adherence factor plasmid and Shiga toxin DNA probe sequences were isolated from patients (children, adults, and AIDS patients) with and without diarrhea in Brazil. Although diverse in phenotype and genotype, some strains are potentially diarrheagenic. PMID:15504277

  18. Electric field induced bacterial flocculation of enteroaggregative Escherichia coli 042

    NASA Astrophysics Data System (ADS)

    Kumar, Aloke; Mortensen, Ninell P.; Mukherjee, Partha P.; Retterer, Scott T.; Doktycz, Mitchel J.

    2011-06-01

    A response of the aggregation dynamics of enteroaggregative Escherichia coli under low magnitude steady and oscillating electric fields is presented. The presence of uniform electric fields hampered microbial adhesion and biofilm formation on a transverse glass surface, but instead promoted the formation of flocs. Extremely heterogenous distribution of live and dead cells was observed among the flocs. Moreover, floc formation was largely observed to be independent of the frequency of alternating electric fields.

  19. Electric field induced bacterial flocculation of Enteroaggregative Escherichia coli 042

    SciTech Connect

    Kumar, Aloke; Mortensen, Ninell P; Mukherjee, Partha P; Retterer, Scott T; Doktycz, Mitchel John

    2011-01-01

    A response of the aggregation dynamics of enteroaggregative Escherichia coli under low magnitude steady and oscillating electric fields is presented. The presence of uniform electric fields hampered microbial adhesion and biofilm formation on a transverse glass surface, but instead promoted the formation of flocs. Extremely heterogeneous distribution of live and dead cells was observed among the flocs. Moreover, floc formation was largely observed to be independent of the frequency of alternating electric fields.

  20. Living with an Arrhythmia

    MedlinePlus

    ... from the NHLBI on Twitter. Living With an Arrhythmia Many arrhythmias are harmless. It's common to have an occasional ... heartbeat or mild palpitations . People who have harmless arrhythmias can live healthy lives. They usually don't ...

  1. Living with endometriosis

    MedlinePlus

    Pelvic pain - living with endometriosis; Endometrial implant - living with endometriosis; Endometrioma - living with endometriosis ... counter pain relievers can reduce the pain of endometriosis. These include: Ibuprofen (Advil) Naproxen (Aleve) Acetaminophen (Tylenol) ...

  2. Living Gluten Free

    MedlinePlus

    ... turn JavaScript on. Feature: Celiac Disease Living Gluten Free Past Issues / Spring 2015 Table of Contents Allowed ... to Live Well with Celiac Disease / Living Gluten-Free Spring 2015 Issue: Volume 10 Number 1 Page ...

  3. Meta-Analysis of Transcriptional Responses to Mastitis-Causing Escherichia coli

    PubMed Central

    Younis, Sidra; Javed, Qamar; Blumenberg, Miroslav

    2016-01-01

    Bovine mastitis is a widespread disease in dairy cows, and is often caused by bacterial mammary gland infection. Mastitis causes reduced milk production and leads to excessive use of antibiotics. We present meta-analysis of transcriptional profiles of bovine mastitis from 10 studies and 307 microarrays, allowing identification of much larger sets of affected genes than any individual study. Combining multiple studies provides insight into the molecular effects of Escherichia coli infection in vivo and uncovers differences between the consequences of E. coli vs. Staphylococcus aureus infection of primary mammary epithelial cells (PMECs). In udders, live E. coli elicits inflammatory and immune defenses through numerous cytokines and chemokines. Importantly, E. coli infection causes downregulation of genes encoding lipid biosynthesis enzymes that are involved in milk production. Additionally, host metabolism is generally suppressed. Finally, defensins and bacteria-recognition genes are upregulated, while the expression of the extracellular matrix protein transcripts is silenced. In PMECs, heat-inactivated E. coli elicits expression of ribosomal, cytoskeletal and angiogenic signaling genes, and causes suppression of the cell cycle and energy production genes. We hypothesize that heat-inactivated E. coli may have prophylactic effects against mastitis. Heat-inactivated S. aureus promotes stronger inflammatory and immune defenses than E. coli. Lipopolysaccharide by itself induces MHC antigen presentation components, an effect not seen in response to E. coli bacteria. These results provide the basis for strategies to prevent and treat mastitis and may lead to the reduction in the use of antibiotics. PMID:26933871

  4. Comparison of antimicrobial resistant Escherichia coli in wild and captive Japanese serows.

    PubMed

    Kinjo, T; Minamoto, N; Sugiyama, M; Sugiyama, Y

    1992-10-01

    The fecal Escherichia coli isolated from wild Japanese serows living in mountainous areas away from humans and those from captive serows kept in human areas were examined for antimicrobial resistance and the possession of transferable R plasmids. Of 874 E. coli strains isolated from 283 wild serows in 1980-1981, only 11 (1.3%) were resistant to at least one of 6 antimicrobial drugs; ampicillin, streptomycin, tetracycline, chloramphenicol, kanamycin and sulfadimethoxin. Seven (2.5%) individuals were found to carry resistant E. coli. To heighten the isolation frequency of drug-resistant strains, fecal samples of 244 wild serows in 1983-1984 were cultured directly onto drug-supplemented media. Only 12 (4.9%) serows were shown to have drug-resistant E. coli. No transferable R plasmid was detected among a total of 87 resistant strains from wild serows. In contrast, all 33 captive serows except one which was kept only one day after capture, showed resistant E. coli and 20 (60.6%) serows were excreting R plasmid-carrying E. coli. Of 161 drug-resistant strains from captive serows, 50 (31.1%) were found to carry R plasmids. Wild serows seemed to readily change to harbor resistant E. coli almost as soon they were reared in human areas without direct exposure to drugs. These results lead to the conclusion that drug-resistant E. coli can probably be used as microbial indicator for natural environmental pollution. PMID:1420561

  5. Thiophene metabolism by E. coli

    SciTech Connect

    Clark, D.P.

    1990-01-01

    The objective of this project is to investigate the mechanism of degradation of sulfur containing heterocyclic molecules by mutants of Escherichia coli K-12. We previously isolated multiple mutants of E. coli which were selected for improved oxidation of furan and thiophene derivatives. We have focused on the thdA mutation in our subsequent research as it appears to be of central importance in thiophene oxidation. We hope that analysis of the thd gene of E. coli will lead to improvement of our thiophene metabolizing bacterial strains.

  6. Thiophene metabolism by E. coli

    SciTech Connect

    Clark, D.P.

    1990-01-01

    The objective of this project is to investigate the mechanism of degradation of sulfur containing heterocyclic molecules such as those found in coal, by mutants of Escherichia coli K-12. We previously isolated multiple mutants of E. coli which were selected for improved oxidation of furan and thiophene derivatives. We have focused on the thdA mutation in our subsequent research as it appears to be of central importance in thiophene oxidation. We hope that analysis of the thd genes of E. coli will lead to improvement of our thiophene metabolizing bacterial strains. 1 tab.

  7. Pneumatosis coli in a dog.

    PubMed

    Russell, Nicholas J; Tyrrell, Dayle; Irwin, Peter J; Beck, Catherine

    2008-01-01

    A 17-year-old, castrated male Maltese was presented with chronic polyphagia and a 2-week history of tenesmus, diarrhea, hematochezia, weight loss, and ribbon-like feces. Pneumatosis coli was diagnosed by abdominal radiography. Concurrent hyperadrenocorticism was suspected. The clinical signs of colorectal disease resolved within 2 days of initiating a lowresidue diet and oral metronidazole. Pneumatosis coli should be considered as a differential diagnosis for colorectal disease in dogs. PMID:18175797

  8. Enterohemorrhagic Escherichia coli Adhesins.

    PubMed

    McWilliams, Brian D; Torres, Alfredo G

    2014-06-01

    Adhesins are a group of proteins in enterohemorrhagic Escherichia coli (EHEC) that are involved in the attachment or colonization of this pathogen to abiotic (plastic or steel) and biological surfaces, such as those found in bovine and human intestines. This review provides the most up-to-date information on these essential adhesion factors, summarizing important historical discoveries and analyzing the current and future state of this research. In doing so, the proteins intimin and Tir are discussed in depth, especially regarding their role in the development of attaching and effacing lesions and in EHEC virulence. Further, a series of fimbrial proteins (Lpf1, Lpf2, curli, ECP, F9, ELF, Sfp, HCP, and type 1 fimbria) are also described, emphasizing their various contributions to adherence and colonization of different surfaces and their potential use as genetic markers in detection and classification of different EHEC serotypes. This review also discusses the role of several autotransporter proteins (EhaA-D, EspP, Saa and Sab, and Cah), as well as other proteins associated with adherence, such as flagella, EibG, Iha, and OmpA. While these proteins have all been studied to varying degrees, all of the adhesins summarized in this article have been linked to different stages of the EHEC life cycle, making them good targets for the development of more effective diagnostics and therapeutics. PMID:26103974

  9. Magnetically-Actuated Escherichia coli System for Micro Lithography

    NASA Astrophysics Data System (ADS)

    Lauback, S.; Brown, E.; Pérez-Guzman, L.; Peace, C.; Pierce, C.; Lower, B. H.; Lower, S. K.; Sooryakumar, R.

    2015-03-01

    Technologies that control matter at the nano- and micro-scale are crucial for developing new engineered materials and devices. While the more traditional approaches for such manipulations often depend on lithographic fabrication, they can be expanded upon by taking advantage of the biological systems within a living cell which also operate on the nano- and micro- scale. In this study, a system is being developed to functionalize a targeted location on the surface of a chip with the protein AmCyan from transformed Escherichia coli cells. Using established methods in molecular biology where a plasmid with the amcyan gene sequence is inserted into the cell, E. coli are engineered to express the AmCyan protein on their outer surface. In order to transport the cells to the targeted location, the transformed E. coli are labeled with superparamagnetic micro-beads which exert directed forces on the cells in an external field. Preliminary results of the protein expression on E. coli, the transport of the cell through weak magnetic fields to targeted locations and the potential to transfer protein from the cell to the chip surface will be presented.

  10. A Survey for Escherichia coli Virulence Factors in Asymptomatic Free-Ranging Parrots

    PubMed Central

    Becker Saidenberg, André; Robaldo Guedes, Neiva Maria; Fernandes Seixas, Gláucia Helena; da Costa Allgayer, Mariangela; Pacífico de Assis, Erica; Fabio Silveira, Luis; Anne Melville, Priscilla; Benites, Nilson Roberti

    2012-01-01

    Parrots in captivity are frequently affected by Escherichia coli (E. coli) infections. The objective of this study was to collect information on the carrier state for E. coli pathotypes in asymptomatic free-ranging parrots. Cloacal swabs were collected from nestlings of Hyacinth, Lear's macaws and Blue-fronted Amazon parrots and tested by polymerase chain reaction (PCR) for virulence factors commonly found in enteropathogenic, avian pathogenic, and uropathogenic E. coli strains. In total, 44 samples were cultured and E. coli isolates were yielded, from which DNA was extracted and processed by PCR. Genes commonly found in APEC isolates from Blue-fronted Amazon parrots and Hyacinth macaws were expressed in 14 of these 44 samples. One atypical EPEC isolate was obtained from a sample from Lear's macaw. The most commonly found gene was the increased serum survival (iss) gene. This is the first report, that describes such pathotypes in asymptomatic free-living parrots. The findings of this study suggest the presence of a stable host/parasite relationship at the time of the sampling brings a new understanding to the role that E. coli plays in captive and wild parrots. Such information can be used to improve husbandry protocols as well as help conservation efforts of free-living populations. PMID:23738135

  11. A Survey for Escherichia coli Virulence Factors in Asymptomatic Free-Ranging Parrots.

    PubMed

    Becker Saidenberg, André; Robaldo Guedes, Neiva Maria; Fernandes Seixas, Gláucia Helena; da Costa Allgayer, Mariangela; Pacífico de Assis, Erica; Fabio Silveira, Luis; Anne Melville, Priscilla; Benites, Nilson Roberti

    2012-01-01

    Parrots in captivity are frequently affected by Escherichia coli (E. coli) infections. The objective of this study was to collect information on the carrier state for E. coli pathotypes in asymptomatic free-ranging parrots. Cloacal swabs were collected from nestlings of Hyacinth, Lear's macaws and Blue-fronted Amazon parrots and tested by polymerase chain reaction (PCR) for virulence factors commonly found in enteropathogenic, avian pathogenic, and uropathogenic E. coli strains. In total, 44 samples were cultured and E. coli isolates were yielded, from which DNA was extracted and processed by PCR. Genes commonly found in APEC isolates from Blue-fronted Amazon parrots and Hyacinth macaws were expressed in 14 of these 44 samples. One atypical EPEC isolate was obtained from a sample from Lear's macaw. The most commonly found gene was the increased serum survival (iss) gene. This is the first report, that describes such pathotypes in asymptomatic free-living parrots. The findings of this study suggest the presence of a stable host/parasite relationship at the time of the sampling brings a new understanding to the role that E. coli plays in captive and wild parrots. Such information can be used to improve husbandry protocols as well as help conservation efforts of free-living populations. PMID:23738135

  12. Treatment of LD100 Escherichia coli septic shock with netilmicin and methylprednisolone in baboons.

    PubMed

    Flournoy, D J; Archer, L T; Beller, B K; Passey, R; Hinshaw, L B

    1986-01-01

    Treatment efficacy with netilmicin sulphate/methylprednisolone sodium succinate in a severe septic shock baboon model, using an LD100 of live Escherichia coli, was evaluated. All the animals treated with both netilmicin and methylprednisolone were permanent (greater than or equal to 7 days) survivors, whereas none of the untreated baboons lived more than 24 hours. These results indicate that, in a baboon model, netilmicin is an effective alternative to gentamicin (with methylprednisolone) in the treatment of severe septic shock. PMID:3526104

  13. Living with Sarcoidosis

    MedlinePlus

    ... page from the NHLBI on Twitter. Living With Sarcoidosis Sarcoidosis has no cure, but you can take ... Content: NEXT >> Featured Video Living With and Managing Sarcoidosis 05/18/2011 This video—presented by the ...

  14. Living with hearing loss

    MedlinePlus

    ... medlineplus.gov/ency/patientinstructions/000360.htm Living with hearing loss To use the sharing features on this page, please enable JavaScript. If you are living with hearing loss, you know that it takes extra effort to ...

  15. Living with Atrial Fibrillation

    MedlinePlus

    ... Topics » Atrial Fibrillation » Living With Atrial Fibrillation Explore Atrial Fibrillation What Is... Types Other Names Causes Who Is at Risk Signs & Symptoms Diagnosis Treatments Prevention Living With Clinical Trials Links Related Topics Arrhythmia ...

  16. Living with Spina Bifida

    MedlinePlus

    ... Us Information For... Media Policy Makers Living With Spina Bifida Language: English Español (Spanish) Recommend on Facebook Tweet ... of the website provides information about living with spina bifida at different ages. Spina bifida affects the entire ...

  17. Binding of ciprofloxacin labelled with technetium Tc 99m versus 99mTc-pertechnetate to a live and killed equine isolate of Escherichia coil.

    PubMed

    Alexander, Kate; Drost, W Tod; Mattoon, John S; Kowalski, Joseph J; Funk, Julie A; Crabtree, Amanda C

    2005-10-01

    This paper describes a simple methodology for evaluating the bacterial binding of ciprofloxacin labelled with technetium Tc 99m. Using this methodology, the binding of 99mTc-ciprofloxacin by live Escherichia coli was compared with the binding of 99mTc-ciprofloxacin by killed E. coli and the binding of 99mTc-pertechnetate (99mTcO4-) by live E. coli. The antimicrobial effect of 99mTc-ciprofloxacin on E. coli was evaluated. Four groups were defined: live E. coli with 99mTc-ciprofloxacin, live E. coli with 99mTcO4 , killed E. coli with 99mTc-ciprofloxacin, and killed E. coli with 99mTcO4-. After 0, 2, and 4 h of incubation of 1 x 10(8) colony-forming units of E. coli suspended in 5 mL of sterile distilled water with 1.85 MBq of 99mTc-ciprofloxacin or 99mTcO4, 1 mL from each sample was centrifuged. The radioactivity of the bacterial pellet and that of the supernatant were measured separately, and the percentage of sample radioactivity attributable to bacterial binding was calculated. Of the 99mTc-ciprofloxacin, 3.6% to 5.9% was bound to live or killed E. coli; only 0.1% to 0.2% of the 99mTcO4- was bound to live E. coli (P < 0.0001). No significant difference in 99mTc-ciprofloxacin binding was found between live and killed E. coli (P = 0.887). An antimicrobial effect on E. coli was seen with 99mTc-ciprofloxacin: colony counts were reduced after 4 h. The small amount of 99mTc-ciprofloxacin binding and the lack of difference in binding between live and killed E. coli may limit the utility of this methodology in evaluating the presence of E. coli infection. PMID:16479725

  18. A systemic vaccine based on Escherichia coli O157:H7 bacterial ghosts (BGs) reduces the excretion of E. coli O157:H7 in calves.

    PubMed

    Vilte, D A; Larzábal, M; Mayr, U B; Garbaccio, S; Gammella, M; Rabinovitz, B C; Delgado, F; Meikle, V; Cantet, R J C; Lubitz, P; Lubitz, W; Cataldi, A; Mercado, E C

    2012-04-15

    Cattle are the main reservoir of enterohemorrhagic Escherichia coli O157:H7, a bacterium that, in humans, causes hemorrhagic colitis and hemolytic uremic syndrome (HUS), a life-threatening disease, especially in children and older people. Therefore, the development of vaccines preventing colonization of cattle by E. coli O157:H7 could be a main tool for an HUS control program. In the present study, we evaluated bacterial ghosts (BGs) of E. coli O157:H7 as an experimental vaccine against this pathogen. BGs are empty envelopes of Gram-negative bacteria, which retain the morphological surface make-up of their living counterparts and are produced by controlled expression of the cloned protein E, which causes loss of all the cytoplasm content. In this work, E. coli O157:H7 BGs were used for subcutaneous immunization of calves. The vaccinated animals elicited significant levels of BG-specific IgG but not IgA antibodies in serum. Low levels of IgA and IgG antibodies against BGs were detected in saliva from vaccinated animals. Following oral challenge with E. coli O157:H7, a significant reduction in both the duration and total bacterial shedding was observed in vaccinated calves compared to the nonimmunized group. We demonstrated that systemic vaccination with E. coli O157 BGs provides protection in a bovine experimental model. Further research is needed to reach a higher mucosal immune response leading to an optimal vaccine. PMID:22460171

  19. Shiga Toxin Producing Escherichia coli.

    PubMed

    Bryan, Allen; Youngster, Ilan; McAdam, Alexander J

    2015-06-01

    Shiga toxin-producing Escherichia coli (STEC) is among the common causes of foodborne gastroenteritis. STEC is defined by the production of specific toxins, but within this pathotype there is a diverse group of organisms. This diversity has important consequences for understanding the pathogenesis of the organism, as well as for selecting the optimum strategy for diagnostic testing in the clinical laboratory. This review includes discussions of the mechanisms of pathogenesis, the range of manifestations of infection, and the several different methods of laboratory detection of Shiga toxin-producing E coli. PMID:26004641

  20. Experimental evolution of E. coli

    NASA Astrophysics Data System (ADS)

    Zhang, Mengshi

    The evolution from unicellular to multicellular behavior is an essential step in the history of life. Our aim is to investigate the emergence of collective behavior in the model organism Escherichia coli (E. coli) and its selection advantages, such as better utilization of public goods. Our preliminary results suggest that the evolution of collective behavior may be a natural response to stressed conditions. Mailing address: Room 306 Science Centre North Block, The Chinese University of Hong Kong, Shatin, N.T. Hong Kong SAR. Phone: +852-3943-6354. Fax: +852-2603-5204. E-mail: mengshi0928@gmail.com.

  1. Serogroups of Escherichia coli from drinking water.

    PubMed

    Ramteke, P W; Tewari, Suman

    2007-07-01

    Fifty seven isolates of thermotolerant E. coli were recovered from 188 drinking water sources, 45 (78.9%) were typable of which 15 (26.3%) were pathogenic serotypes. Pathogenic serogroup obtained were 04 (Uropathogenic E. coli, UPEC), 025 (Enterotoxigenic E. coli, ETEC), 086 (Enteropathogenic E. coli, EPEC), 0103 (Shiga-toxin producing E. coli, STEC), 0157 (Shiga-toxin producing E. coli, STEC), 08 (Enterotoxigenic E. coli, ETEC) and 0113 (Shiga-toxin producing E. coli, STEC). All the pathogenic serotypes showed resistance to bacitracin and multiple heavy metal ions. Resistance to streptomycin and cotrimazole was detected in two strains whereas resistance to cephaloridine, polymixin-B and ampicillin was detected in one strain each. Transfer of resistances to drugs and metallic ions was observed in 9 out of 12 strains studied. Resistances to bacitracin were transferred in all nine strains. Among heavy metals resistance to As(3+) followed by Cr(6+) were transferred more frequently. PMID:17057960

  2. Induction of Haemophilus influenzae type b capsular antibody in neonatal rabbits by gastrointestinal colonization with cross-reacting Escherichia coli.

    PubMed

    Myerowitz, R L; Handzel, Z T; Scheerson, R; Robbins, J B

    1973-02-01

    In two separate experiments, newborn rabbits were fed a live suspension of either of two Escherichia coli strains which possess a "K" antigen cross-reactive with the capsular polysaccharide of Haemophilus influenzae type b. Both feedings were harmless and resulted in fecal excretion of the fed E. coli in most animals as well as active immunization of fed animals toward H. influenzae type b. Feeding non-enteropathogenic, cross-reacting E coli to newborns may be a method for inducing active immunity toward H. influenzae type b diseases by accelerating the acquisition of "natural" immunity. PMID:4572607

  3. Molecular Ecology of Waterborne E. coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Escherichia coli is a common inhabitant of surface and ground waters in the developed and developing worlds. The majority of the E coli present in water are not particularly pathogenic to humans; however, there are E coli present in small proportion, that possess virulence genes that allow them to c...

  4. Biosynthesis of a Fully Functional Cyclotide inside Living Bacterial Cells

    SciTech Connect

    Camarero, J A; Kimura, R H; Woo, Y; Cantor, J; Shekhtman, A

    2007-04-05

    The cyclotide MCoTI-II is a powerful trypsin inhibitor recently isolated from the seeds of Momordica cochinchinensis, a plant member of cucurbitaceae family. We report for the first time the in vivo biosynthesis of natively-folded MCoTI-II inside live E. coli cells. Our biomimetic approach involves the intracellular backbone cyclization of a linear cyclotide-intein fusion precursor mediated by a modified protein splicing domain. The cyclized peptide then spontaneously folds into its native conformation. The use of genetically engineered E. coli cells containing mutations in the glutathione and thioredoxin reductase genes considerably improves the production of folded MCoTI-II in vivo. Biochemical and structural characterization of the recombinant MCoTI-II confirmed its identity. Biosynthetic access to correctly-folded cyclotides allows the possibility of generating cell-based combinatorial libraries that can be screened inside living cells for their ability to modulate or inhibit cellular processes.

  5. EXTRAINTESTINAL PATHOGENIC ESCHERICHIA COLI (EXPEC)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extraintestinal pathogenic Escherichia coli (ExPEC) possess virulence traits that allow them to invade, colonize, and induce disease in bodily sites outside of the gastrointestinal tract. Human diseases caused by ExPEC include urinary tract infections, neonatal meningitis, sepsis, pneumonia, surgic...

  6. The endophytic lifestyle of Escherichia coli O157:H7: quantification and internal localization in roots.

    PubMed

    Wright, Kathryn M; Chapman, Sean; McGeachy, Kara; Humphris, Sonia; Campbell, Emma; Toth, Ian K; Holden, Nicola J

    2013-04-01

    The foodborne pathogen Escherichia coli O157:H7 is increasingly associated with fresh produce (fruit and vegetables). Bacterial colonization of fresh produce plants can occur to high levels on the external tissue but bacteria have also been detected within plant tissue. However, questions remain about the extent of internalization, its molecular basis, and internal location of the bacteria. We have determined the extent of internalization of E. coli O157:H7 in live spinach and lettuce plants and used high-resolution microscopy to examine colony formation in roots and pathways to internalization. E. coli O157:H7 was found within internal tissue of both produce species. Colonization occurred within the apoplast between plant cells. Furthermore, colonies were detected inside the cell wall of epidermal and cortical cells of spinach and Nicotiana benthamiana roots. Internal colonization of epidermal cells resembled that of the phytopathogen Pectobacterium atrosepticum on potato. In contrast, only sporadic cells of the laboratory strain of E. coli K-12 were found on spinach, with no internal bacteria evident. The data extend previous findings that internal colonization of plants appears to be limited to a specific group of plant-interacting bacteria, including E. coli O157:H7, and demonstrates its ability to invade the cells of living plants. PMID:23506361

  7. Integrating artificial with natural cells to translate chemical messages that direct E. coli behaviour.

    PubMed

    Lentini, Roberta; Santero, Silvia Perez; Chizzolini, Fabio; Cecchi, Dario; Fontana, Jason; Marchioretto, Marta; Del Bianco, Cristina; Terrell, Jessica L; Spencer, Amy C; Martini, Laura; Forlin, Michele; Assfalg, Michael; Dalla Serra, Mauro; Bentley, William E; Mansy, Sheref S

    2014-01-01

    Previous efforts to control cellular behaviour have largely relied upon various forms of genetic engineering. Once the genetic content of a living cell is modified, the behaviour of that cell typically changes as well. However, other methods of cellular control are possible. All cells sense and respond to their environment. Therefore, artificial, non-living cellular mimics could be engineered to activate or repress already existing natural sensory pathways of living cells through chemical communication. Here we describe the construction of such a system. The artificial cells expand the senses of Escherichia coli by translating a chemical message that E. coli cannot sense on its own to a molecule that activates a natural cellular response. This methodology could open new opportunities in engineering cellular behaviour without exploiting genetically modified organisms. PMID:24874202

  8. Discounting human lives

    SciTech Connect

    Cropper, M.L. ); Portney, P.R.

    1992-09-01

    The future costs of regulatory programs to protect human health are routinely discounted, but the lives they save in the future are not. To shed light on the public's attitude toward the discounting of human lives, researchers at Resources for the Future asked 2,600 individuals to choose between one hypothetical program that would save lives immediately and another that would save lives in 5, 10, 25, 50, or 100 years. From the responses, they inferred the number of lives that must be saved in the future to make people as content as saving one life today, compared this implicit discount rate to the respondents' discount rate for money, and identified several factors that affect discount rates for human lives.

  9. Characterization of a Novel Microcin That Kills Enterohemorrhagic Escherichia coli O157:H7 and O26

    PubMed Central

    Eberhart, Lauren J.; Deringer, James R.; Brayton, Kelly A.; Sawant, Ashish A.; Besser, Thomas E.

    2012-01-01

    A novel phenotype was recently identified in which specific strains of Escherichia coli inhibit competing E. coli strains via a mechanism that was designated “proximity-dependent inhibition” (PDI). PDI-expressing (PDI+) E. coli is known to inhibit susceptible (PDI−) E. coli strains, including several enterohemorrhagic (EHEC) and enterotoxigenic (ETEC) E. coli strains. In this study, every strain from a genetically diverse panel of E. coli O157:H7 (n = 25) and additional strains of E. coli serovar O26 were susceptible to the PDI phenotype. LIVE/DEAD staining was consistent with inhibition by killing of susceptible cells. Comparative genome analysis identified the genetic component of PDI, which is composed of a plasmid-borne (Incl1) operon encoding a putative microcin and associated genes for transport, immunity, and microcin activation. Transfer of the plasmid to a PDI− strain resulted in transfer of the phenotype, and deletion of the genes within the operon resulted in loss of the inhibition phenotype. Deletion of chromosomally encoded tolC also resulted in loss of the inhibitory phenotype, and this confirmed that the putative microcin is most likely secreted via a type I secretion pathway. Deletion of an unrelated plasmid gene did not affect the PDI phenotype. Quantitative reverse transcription (RT)-PCR demonstrated that microcin expression is correlated with logarithmic-phase growth. The ability to inhibit a diversity of E. coli strains indicates that this microcin may influence gut community composition and could be useful for control of important enteric pathogens. PMID:22773653

  10. Survival of Escherichia coli O157:H7 on Cattle Hides▿

    PubMed Central

    Arthur, Terrance M.; Nou, Xiangwu; Kalchayanand, Norasak; Bosilevac, Joseph M.; Wheeler, Tommy; Koohmaraie, Mohammad

    2011-01-01

    The objective of this study was to determine the time period that Escherichia coli O157:H7 survives on the hides of cattle. Extensive research has been conducted and is ongoing to identify and develop novel preharvest intervention strategies to reduce the presence of E. coli O157:H7 on live cattle and subsequent transfer to processed carcasses. If a reduction of E. coli O157:H7 levels in feces can be achieved through preharvest intervention, it is not known how long it would take for such reductions to be seen on the hide. In the study presented herein, three trials were conducted to follow E. coli O157:H7 hide prevalence over time. For each trial, 36 animals were housed in individual stanchions to minimize or prevent hide contamination events. Through prevalence determination and isolate genotyping with pulsed-field gel electrophoresis, survival of E. coli O157:H7 on the hides of live cattle was determined to be short lived, with an approximate duration of 9 days or less. The results of this study suggest that any preharvest interventions that are to be administered at the end of the finishing period will achieve maximum effect in reducing E. coli O157:H7 levels on cattle hides if given 9 days before the cattle are presented for processing. However, it should be noted that interventions reducing pathogen shedding would also contribute to decreasing hide contamination through lowering the contamination load of the processing plant lairage environment, regardless of the time of application. PMID:21398483

  11. Clinical implications of enteroadherent Escherichia coli.

    PubMed

    Arenas-Hernández, Margarita M P; Martínez-Laguna, Ygnacio; Torres, Alfredo G

    2012-10-01

    Pathogenic Escherichia coli that colonize the small intestine primarily cause gastrointestinal illness in infants and travelers. The main categories of pathogenic E. coli that colonize the epithelial lining of the small intestine are enterotoxigenic E. coli, enteropathogenic E. coli, and enteroaggregative E. coli. These organisms accomplish their pathogenic process by a complex, coordinated multistage strategy, including nonintimate adherence mediated by various adhesins. These so called "enteroadherent E. coli" categories subsequently produce toxins or effector proteins that are either secreted to the milieu or injected to the host cell. Finally, destruction of the intestinal microvilli results from the intimate adherence or the toxic effect exerted over the epithelia, resulting in water secretion and diarrhea. In this review, we summarize the current state of knowledge regarding these enteroadherent E. coli strains and the present clinical understanding of how these organisms colonize the human intestine and cause disease. PMID:22798032

  12. Clinical Implications of Enteroadherent Escherichia coli

    PubMed Central

    Arenas-Hernández, Margarita M.P.; Martínez-Laguna, Ygnacio; Torres, Alfredo G.

    2012-01-01

    Pathogenic Escherichia coli that colonize the small intestine primarily cause gastrointestinal illness in infants and travelers. The main categories of pathogenic E. coli that colonize the epithelial lining of the small intestine are enterotoxigenic E. coli enteropathogenic E. coli and enteroaggregative E. coli. These organisms accomplish their pathogenic process by a complex, coordinated multistage strategy, including non-intimate adherence mediated by various adhesins. These so called “enteroadherent E. coli ” categories subsequently produced toxins or effector proteins that are either secreted to the milieu or injected to the host cell. Finally, destruction of the intestinal microvilli results from the intimate adherence or the toxic effect exerted over the epithelia, resulting in water secretion and diarrhea. In this review, we summarize the current state of knowledge regarding these enteroadherent E. coli strains and the present clinical understanding of how these organisms colonize the human intestine and cause disease. PMID:22798032

  13. Infection strategies of enteric pathogenic Escherichia coli

    PubMed Central

    Clements, Abigail; Young, Joanna C.; Constantinou, Nicholas; Frankel, Gad

    2012-01-01

    Enteric Escherichia coli (E. coli) are both natural flora of humans and important pathogens causing significant morbidity and mortality worldwide. Traditionally enteric E. coli have been divided into 6 pathotypes, with further pathotypes often proposed. In this review we suggest expansion of the enteric E. coli into 8 pathotypes to include the emerging pathotypes of adherent invasive E. coli (AIEC) and Shiga-toxin producing enteroaggregative E. coli (STEAEC). The molecular mechanisms that allow enteric E. coli to colonize and cause disease in the human host are examined and for two of the pathotypes that express a type 3 secretion system (T3SS) we discuss the complex interplay between translocated effectors and manipulation of host cell signaling pathways that occurs during infection. PMID:22555463

  14. Living with Bowel Control Problems

    MedlinePlus

    ... Home Living with Bowel Control Problems Resources Bowel Control Awareness Campaign Home Resources for Health Care Providers ... Living with Bowel Control Problems Living with Bowel Control Problems Living with a bowel control problem can ...

  15. Occurrence of Escherichia coli in the Cuyahoga River in the Cuyahoga Valley National Park, Ohio

    USGS Publications Warehouse

    Brady, Amie M.G.; Plona, Meg B.

    2010-01-01

    There are several measures of the 'cleanliness' of a natural body of water, including concentrations of indicator bacteria, anthropogenic chemicals (chemicals derived from human activities), and nutrients, such as nitrogen and phosphorous. Escherichia coli (E. coli) is a bacterium that lives in the intestinal tract of warm-blooded animals, such as humans, deer, cows, and dogs. Most strains of E. coli are not harmful and are in fact beneficial to humans by aiding in the digestive process. A few strains, such as the O157 strain, produce toxins that can cause gastrointestinal illness, but occurrence of toxic strains in the environment is not common. E. coli is considered a good indicator bacterium because its occurrence in the environment indicates the presence of fecal contamination and therefore the possible presence of pathogenic organisms associated with feces. The U.S. Environmental Protection Agency (USEPA) recommends using measurements of E. coli to monitor freshwaters and set criteria for the concentration of bacteria that can be present in the water with minimal adverse human-health effects. Typically, a State's waters are assigned a recreational-use designation, such as bathing, primary-contact, or secondary contact waters, which is used to set the State's water-quality standards based on the USEPA criteria. The Cuyahoga River in the Cuyahoga Valley National Park is designated for primary-contact recreation; therefore, when concentrations of E. coli exceed 298 CFU/100mL, the river would be considered potentially unsafe for recreation.

  16. Multichromatic control of gene expression in Escherichia coli

    PubMed Central

    Tabor, Jeffrey J.; Levskaya, Anselm; Voigt, Christopher A.

    2010-01-01

    Light is a powerful tool for manipulating living cells because it can be applied with high resolution across space and over time. We previously constructed a red-light sensitive E. coli transcription system based on a chimera between the red/far red switchable cyanobacterial phytochrome Cph1 and the E. coli EnvZ/OmpR two-component signaling pathways. Here we report the development of a green light inducible transcription system in E. coli based on a recently discovered green/red photoswitchable two-component system from cyanobacteria. We demonstrate that transcriptional output is proportional to the intensity of green light applied and that the green sensor is orthogonal to the red sensor at intensities of 532nm light less than 0.01W/m2. Expression of both sensors in a single cell allows two-color optical control of transcription in both batch culture and in patterns across a lawn of engineered cells. Because each sensor functions as a photoreversible switch, this system should allow the spatial and temporal control of the expression of multiple genes though different combinations of light wavelengths. This feature should aid precision single cell and population-level studies in systems and synthetic biology. PMID:21035461

  17. Families and Assisted Living

    ERIC Educational Resources Information Center

    Gaugler, Joseph E.; Kane, Robert L.

    2007-01-01

    Purpose: Despite growing research on assisted living (AL) as a residential care option for older adults, the social ramifications of residents' transitions to AL are relatively unexplored. This article examines family involvement in AL, including family structures of residents, types of involvement from family members living outside the AL…

  18. Is It Living?

    ERIC Educational Resources Information Center

    Keeley, Page

    2011-01-01

    The word "living" is commonly used throughout elementary science lessons that focus on the biological world. It is a word teachers often take for granted when teaching life science concepts. How similar the constructed meaning of a common word like "living" is to the meaning intended by the teacher or instructional materials depends on how a…

  19. Living Willow Huts

    ERIC Educational Resources Information Center

    Keeler, Rusty

    2007-01-01

    Living Willow Huts are inexpensive to make, fun to plant, easy to grow, and make beautiful spaces for children. They involve planting dormant willow shoots in the ground and weaving them into shapes that will sprout and grow over time. People have been creating similar living architecture throughout the world for centuries in the forms of living…

  20. Thiophene metabolism by E. coli

    SciTech Connect

    Clark, D.P.

    1991-01-01

    The objective of this project is to investigate the mechanism of degradation of sulfur-containing heterocyclic molecules by mutant strains of Escherichia coli K-12. We have previously isolated multiple mutants of E. coli which had gained the capacity to oxidize thiophene compounds and their furan analogs. We have focused on the thdA mutation in our subsequent research, as this appears to be in a regulatory gene central to the thiophene/furan oxidation system. The thdF gene appears to be more directly involved in the oxidation reactions, whereas thdC and thdD are apparently required for increased protection against the toxic effects of thiophene and furan compounds. 4 tabs.

  1. A vaccine candidate for post-weaning diarrhea in swine constructed with a live attenuated Salmonella delivering Escherichia coli K88ab, K88ac, FedA, and FedF fimbrial antigens and its immune responses in a murine model

    PubMed Central

    Hur, Jin; Stein, Barry D.; Lee, John Hwa

    2012-01-01

    In order to construct a novel vaccine candidate for preventing post-weaning diarrhea in swine, the individual genes for Escherichia coli K88ab, K88ac, FedA, and FedF fimbriae were inserted into a secretion plasmid pBP244 containing asd, lepB, secA, and secB. These were transformed into Salmonella Typhimurium Δlon ΔcpxR Δasd. Secretion of the individual recombinant fimbrial antigens was confirmed by immunoblot analysis. Groups 1 and 2 mice received a single oral dose of the vaccine mixture and S. Typhimurium carrying pBP244 only as a control, respectively. In groups 3 and 4, mice were primed and boosted with the vaccine mixture and S. Typhimurium carrying pBP244 only as a control, respectively. In general, all immunized mice had significantly increased serum immunoglobulin (Ig)G (P < 0.05) and intestinal secretory IgA against the individual fimbrial antigens compared with those mice in the control group. In the IgG2a and IgG1 titer assay, only IgG2a titer was increased in group 1, while both IgG2a and IgG1 titers were increased in group 3. Furthermore, the vaccine strains were not detected in the excreted feces of any immunized mice. Thus, the vaccine candidate can be highly immunogenic and be safe to the environment. PMID:23277697

  2. Engineering an Escherichia coli platform to synthesize designer biodiesels.

    PubMed

    Wierzbicki, Michael; Niraula, Narayan; Yarrabothula, Akshitha; Layton, Donovan S; Trinh, Cong T

    2016-04-20

    Biodiesels, fatty acid esters (FAEs), can be synthesized by condensation of fatty acid acyl CoAs and alcohols via a wax ester synthase in living cells. Biodiesels have advantageous characteristics over petrodiesels such as biodegradability, a higher flash point, and less emission. Controlling fatty acid and alcohol moieties are critical to produce designer biodiesels with desirable physiochemical properties (e.g., high cetane number, low kinematic viscosity, high oxidative stability, and low cloud point). Here, we developed a flexible framework to engineer Escherichia coli cell factories to synthesize designer biodiesels directly from fermentable sugars. In this framework, we designed each FAE pathway as a biodiesel exchangeable production module consisting of acyl CoA, alcohol, and wax ester synthase submodules. By inserting the FAE modules in an engineered E. coli modular chassis cell, we generated E. coli cell factories to produce targeted biodiesels (e.g., fatty acid ethyl (FAEE) and isobutyl (FAIbE) esters) with tunable and controllable short-chain alcohol moieties. The engineered E. coli chassis carrying the FAIbE production module produced 54mg/L FAIbEs with high specificity, accounting for>90% of the total synthesized FAEs and ∼4.7 fold increase in FAIbE production compared to the wildtype. Fed-batch cultures further improved FAIbE production up to 165mg/L. By mixing ethanol and isobutanol submodules, we demonstrated controllable production of mixed FAEEs and FAIbEs. We envision the developed framework offers a flexible, alternative route to engineer designer biodiesels with tunable and controllable properties using biomass-derived fermentable sugars. PMID:26953744

  3. In Search of the E. coli Compounds that Change the Antibiotic Production Pattern of Streptomyces coelicolor During Inter-species Interaction.

    PubMed

    Mavituna, Ferda; Luti, Khalid Jaber Kadhum; Gu, Lixing

    2016-08-01

    The aim of this work was to investigate the interaction between E.coli and Streptomyces coelicolor A3 (2) for the increased production of undecylprodigiosin and identify the E. coli actives mediating this inter-species interaction. The antibiotics of interest were the red-pigmented undecylprodigiosin and blue-pigmented actinorhodin. Pure cultures of S. coelicolor in a defined medium produced higher concentrations of actinorhodin compared to those of undecylprodigiosin. The latter however, is more important due to its immunosuppressive and antitumor properties. As a strategy to increase undecylprodigiosin production, we added separately, live cells and heat-killed cells of E. coli C600, and the cell-free supernatant of E. coli culture to S. coelicolor cultures in shake flasks. The interaction with live cells of E. coli altered the antibiotic production pattern and undecylprodigiosin production was enhanced by 3.5-fold compared to the pure cultures of S. coelicolor and actinorhodin decreased by 15-fold. The heat-killed cells of E. coli however, had no effect on antibiotic production. In all cases, growth and glucose consumption of S. coelicolor remained almost the same as those observed in the pure culture indicating that the changes in antibiotic production were not due to nutritional stress. Results with cell-free supernatant of E. coli culture indicated that the interaction between S. coelicolor and E. coli was mediated via diffusible molecule(s). Using a set of extraction procedures and agar-well diffusion bioassays, we isolated and preliminarily identified a class of compounds. For the preliminary verification, we added the compound which was the common chemical structural moiety in this class of compounds to the pure S. coelicolor cultures. We observed similar effects on antibiotic production as with the live E. coli cells and their supernatant indicating that this class of compounds secreted by E. coli indeed could act as actives during interspecies

  4. Living Phenomena and Living Information : Centered on Living Structure and Design

    NASA Astrophysics Data System (ADS)

    Shizuno, Tomofumi

    The term ‘living’ has manifold meanings. The author interprets it in three reasonable ways : 1) sustaining one's life, 2) surviving under economic surroundings, 3) existing socially. Centered on ‘living structure’ which grasps static aspects of living and ‘living design’ which does dynamic aspects of living he investigates living phenomena and discusses their relationship to living information. The author also catches living phenomena from viewpoints as follows : 1) people, 2) corporation, 3) researcher, 4) administration, and investigates living information from the four viewpoints as above. The examples of classification for living itself as well as for living information are shown.

  5. Living with Alopecia Areata

    MedlinePlus

    ... you wear a wig Sadness and depression Hopelessness Anger Embarrassment Guilt or self-blame that you somehow ... For siblings and other family members, shame and anger because the disease has also affected their lives ...

  6. Living with Anemia

    MedlinePlus

    ... page from the NHLBI on Twitter. Living With Anemia Often, you can treat and control anemia. If ... by an inherited or chronic disease or trauma. Anemia and Children/Teens Infants and young children have ...

  7. Living with Pulmonary Hypertension

    MedlinePlus

    ... and Support Living with PH may cause fear, anxiety, depression, and stress. You may worry about your ... and friends also can help relieve stress and anxiety. Let your loved ones know how you feel ...

  8. Assisted Living Community Profile

    MedlinePlus

    ... News & Media News Releases Media Resources AHCA/NCAL Gazette Publications Social Media Resources & Publications Currently selected Assisted ... News & Media News Releases Media Resources AHCA/NCAL Gazette Publications Social Media Resources & Publications Assisted Living Studies ...

  9. [Promoting Living Kidney Transplantation].

    PubMed

    Lin, Chiu-Chu

    2016-04-01

    Kidney transplantation is the best approach for treating patients with end stage renal disease, offering patients the best chance of returning to normal health. While the techniques used in kidney transplantation surgery are mature and highly successful, there is a severe shortage of donor organs. Statistics show a serious imbalance between organ donations and patients on the waiting list for organ transplantation. Moreover, evidence from empirical studies has shown a better transplantation outcome for patients who receive living donor transplantation than for those who receive organs from cadavers. Although using relatives as donors offers an effective way to reduce the problem of organ shortage, this strategy faces many challenges and many other factors affect the promotion of living donor transplantation. This article elaborates how cultural and psychological factors, kidney transplantation awareness, and ethics and laws impact upon living kidney donations and then proposes coping strategies for promoting living kidney transplantation. PMID:27026555

  10. The Living Cosmos

    NASA Astrophysics Data System (ADS)

    Impey, Chris

    2011-06-01

    Preface; 1. The unfinished revolution; 2. Life's origins; 3. Extreme life; 4. Shaping evolution; 5. Living in the Solar System; 6. Distant worlds; 7. Are we alone?; Notes; Glossary; Reading list; Media resources; Illustration credits; Index.

  11. Living with VHL

    MedlinePlus

    ... Videos Contact Us Shop Community vhl alliance vhl alliance Patients What is VHL? Seeking Care Living with VHL Caregiver Center Stories Professionals Surveillance & Diagnosis Treatment Professional Meetings Research Genetic Research and VHL Progress Towards a ...

  12. Living with Paralysis

    MedlinePlus

    ... are available to answer your questions. Call toll-free 1-800-539-7309 Mon-Fri, 9am-5pm ... are people living with or impacted by paralysis. Free services and downloads > Paralysis Resource Guide Our free ...

  13. Fluorescence Live Cell Imaging

    PubMed Central

    Ettinger, Andreas

    2014-01-01

    Fluorescence microscopy of live cells has become an integral part of modern cell biology. Fluorescent protein tags, live cell dyes, and other methods to fluorescently label proteins of interest provide a range of tools to investigate virtually any cellular process under the microscope. The two main experimental challenges in collecting meaningful live cell microscopy data are to minimize photodamage while retaining a useful signal-to-noise ratio, and to provide a suitable environment for cells or tissues to replicate physiological cell dynamics. This chapter aims to give a general overview on microscope design choices critical for fluorescence live cell imaging that apply to most fluorescence microscopy modalities, and on environmental control with a focus on mammalian tissue culture cells. In addition, we provide guidance on how to design and evaluate fluorescent protein constructs by spinning disk confocal microscopy. PMID:24974023

  14. Living with Hearing Loss

    MedlinePlus

    ... Issues Special Section: Focus on Communication Living with Hearing Loss Past Issues / Fall 2008 Table of Contents For ... Fast Facts There are two main types of hearing loss. Permanent hearing loss (called sensorineural) usually involves damage ...

  15. Living with Oxygen Therapy

    MedlinePlus

    ... page from the NHLBI on Twitter. Living With Oxygen Therapy Oxygen therapy helps many people function better and be ... chronic obstructive pulmonary disease) Although you may need oxygen therapy continuously or for long periods, it doesn' ...

  16. Living with Hearing Loss

    MedlinePlus

    ... Current Issue Past Issues Special Section: Focus on Communication Living with Hearing Loss Past Issues / Fall 2008 ... the United States suffer some form of disordered communication. The National Institute on Deafness and Other Communication ...

  17. Living with Marfan Syndrome

    MedlinePlus

    ... live longer and enjoy a good quality of life. Many people who have Marfan syndrome and are ... tears and leaks blood. Aortic dissection is a life-threatening condition. The main symptom of aortic dissection ...

  18. Live Your Life Well

    MedlinePlus

    ... about reasonable steps that if used consistently can increase your comfort and boost your ability to build a rewarding life. About the Live Your Life Well Campaign Mental Health America is the country's leading non-profit ...

  19. Transcription of foreign DNA in Escherichia coli

    PubMed Central

    Warren, René L.; Freeman, John D.; Levesque, Roger C.; Smailus, Duane E.; Flibotte, Stephane; Holt, Robert A.

    2008-01-01

    Propagation of heterologous DNA in E. coli host cells is central to molecular biology. DNA constructs are often engineered for expression of recombinant protein in E. coli, but the extent of incidental transcription arising from natural regulatory sequences in cloned DNA remains underexplored. Here, we have used programmable microarrays and RT-PCR to measure, comprehensively, the transcription of H. influenzae, P. aeruginosa, and human DNA propagating in E. coli as bacterial artificial chromosomes. We find evidence that at least half of all H. influenzae genes are transcribed in E. coli. Highly transcribed genes are principally involved in energy metabolism, and their proximal promoter regions are significantly enriched with E. coli σ70 (also known as RpoD) binding sites. H. influenzae genes acquired from an ancient bacteriophage Mu insertion are also highly transcribed. Compared with H. influenzae, a smaller proportion of P. aeruginosa genes are transcribed in E. coli, and in E. coli there is punctuated transcription of human DNA. The presence of foreign DNA in E. coli disturbs the host transcriptional profile, with expression of the E. coli phage shock protein operon and the flagellar gene cluster being particularly strongly up-regulated. While cross-species transcriptional activation is expected to be enabling for horizontal gene transfer in bacteria, incidental expression of toxic genes can be problematic for DNA cloning. Ongoing characterization of cross-expression will help inform the design of biosynthetic gene clusters and synthetic microbial genomes. PMID:18701636

  20. Live biometric authenticity check

    NASA Astrophysics Data System (ADS)

    Szu, Harold H.; Hsu, Charles C.; Szu, Clifford; Wang, Shoujue

    2003-04-01

    This research defined the underpinning concepts of a system that was highly secure, yet was efficient and non-invasive enough for everyday use. The live biometric authenticity check augmented invariant fingerprints with variable live features offered superior security by combining physical characteristics of the user"s with a passcode (numerical PIN) or passphrase (a string of words), and might also easily be augmented with other biometric video imaging devices for the utmost security.

  1. Laparoscopic live donor nephrectomy.

    PubMed

    Hasan, Waleed A; Al-Akraa, Mahmoud M

    2005-07-01

    With the number of patients presently awaiting renal transplantation exceeding the number of cadaveric organs available, there is an increasing reliance on live renal donation. Of the 11,869 renal transplants performed in 2002 in the US, 52.6% were living donors from the United Network for Organ Sharing Registry. Renal allografts from living donors provide: superior immediate long-term function; require less waiting time and are more cost-effective than those from cadaveric donors. However, anticipation of postoperative pain and temporary occupational disability may dissuade many potential donors. Additionally, some recipients hesitate to accept a living donor kidney due to suffering that would be endured by the donor. It is a unique medical situation when a young, completely healthy donor undergoes a major surgical procedure to provide an organ for transplantation. It is mandatory to offer a surgical technique, which is safe and with minimal complications. It is also obvious for any organ transplantation, that the integrity of the organ remain intact, thus, enabling its successful transplantation into the recipient. An acceptably short ischemia time and adequate lengths of ureter and renal vasculature are favored. Many centers are performing laparoscopic live donor nephrectomy in an effort to ease convalescence of renal donors. This may encourage the consideration of live donation by recipients and potential donors. PMID:16047050

  2. Growth of Mycobacterium avium subsp. paratuberculosis, Escherichia coli, and Salmonella Enteritidis during Preparation and Storage of Yogurt

    PubMed Central

    Cirone, K.; Huberman, Y.; Morsella, C.; Méndez, L.; Jorge, M.; Paolicchi, F.

    2013-01-01

    The purpose of this study was to determine the viability of Mycobacterium avium subsp. paratuberculosis (MAP), Escherichia coli (E. coli), and Salmonella Enteritidis (S. Enteritidis) during preparation and refrigerated storage of yogurt. Three yogurts were prepared using pasteurized commercial milk. Each yogurt was artificially contaminated with (1) MAP, (2) E. coli + S. Enteritidis, and (3) MAP + E. coli + S. Enteritidis. Samples were taken during and after the fermentation process until day 20 after inoculation. MAP was not detected during their preparation and short-term storage but was recuperated after starting at 180 min after inoculation storage. Live bacterial counts of E. coli, and S. Enteritidis increased during the first 24 hours, followed by a slight decrease towards the end of the study. In this study it was shown how MAP, E. coli, and S. Enteritidis resisted the acidic conditions generated during the preparation of yogurt and low storage temperatures. This work contributes to current knowledge regarding survival of MAP, E. coli, and S. Enteritidis during preparation and refrigerated storage of yogurt and emphasizes the need to improve hygiene measures to ensure the absence of these pathogenic microorganisms in dairy products. PMID:24455399

  3. REAL-TIME PCR QUANTIFICATION OF PERSISTENCE OF ESCHERICHIA COLI O157:H7 IN SOIL IMPACTED BY FUMIGATIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Survival of Escherichia coli O157:H7 in the environment is a major concern to many municipalities where human and livestock live in close proximity to each other due to rapid urbanization. The major objectives of this study were to determine the effects of soil type and fumigant treatment on the sur...

  4. Bacteriophage Isolated from Feedlot Cattle Can Reduce Escherichia coli O157:H7 Populations in Ruminant Gastrointestinal Tracts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foodborne pathogenic bacteria, such as Escherichia coli O157:H7, can live undetected in the gut of food animals and be spread to humans via consumption of contaminated meat, direct animal contact, or water runoff into drinking and crop irrigation water supplies. Bacteriophages are viruses that prey...

  5. Biocompatible click chemistry enabled compartment-specific pH measurement inside E. coli.

    PubMed

    Yang, Maiyun; Jalloh, Abubakar S; Wei, Wei; Zhao, Jing; Wu, Peng; Chen, Peng R

    2014-01-01

    Bioorthogonal reactions, especially the Cu(I)-catalysed azide-alkyne cycloaddition, have revolutionized our ability to label and manipulate biomolecules under living conditions. The cytotoxicity of Cu(I) ions, however, has hindered the application of this reaction in the internal space of living cells. By systematically surveying a panel of Cu(I)-stabilizing ligands in promoting protein labelling within the cytoplasm of Escherichia coli, we identify a highly efficient and biocompatible catalyst for intracellular modification of proteins by azide-alkyne cycloaddition. This reaction permits us to conjugate an environment-sensitive fluorophore site specifically onto HdeA, an acid-stress chaperone that adopts pH-dependent conformational changes, in both the periplasm and cytoplasm of E. coli. The resulting protein-fluorophore hybrid pH indicators enable compartment-specific pH measurement to determine the pH gradient across the E. coli cytoplasmic membrane. This construct also allows the measurement of E. coli transmembrane potential, and the determination of the proton motive force across its inner membrane under normal and acid-stress conditions. PMID:25236616

  6. Localization of Protein Aggregation in Escherichia coli Is Governed by Diffusion and Nucleoid Macromolecular Crowding Effect

    PubMed Central

    Coquel, Anne-Sophie; Jacob, Jean-Pascal; Primet, Mael; Demarez, Alice; Dimiccoli, Mariella; Julou, Thomas; Moisan, Lionel

    2013-01-01

    Aggregates of misfolded proteins are a hallmark of many age-related diseases. Recently, they have been linked to aging of Escherichia coli (E. coli) where protein aggregates accumulate at the old pole region of the aging bacterium. Because of the potential of E. coli as a model organism, elucidating aging and protein aggregation in this bacterium may pave the way to significant advances in our global understanding of aging. A first obstacle along this path is to decipher the mechanisms by which protein aggregates are targeted to specific intercellular locations. Here, using an integrated approach based on individual-based modeling, time-lapse fluorescence microscopy and automated image analysis, we show that the movement of aging-related protein aggregates in E. coli is purely diffusive (Brownian). Using single-particle tracking of protein aggregates in live E. coli cells, we estimated the average size and diffusion constant of the aggregates. Our results provide evidence that the aggregates passively diffuse within the cell, with diffusion constants that depend on their size in agreement with the Stokes-Einstein law. However, the aggregate displacements along the cell long axis are confined to a region that roughly corresponds to the nucleoid-free space in the cell pole, thus confirming the importance of increased macromolecular crowding in the nucleoids. We thus used 3D individual-based modeling to show that these three ingredients (diffusion, aggregation and diffusion hindrance in the nucleoids) are sufficient and necessary to reproduce the available experimental data on aggregate localization in the cells. Taken together, our results strongly support the hypothesis that the localization of aging-related protein aggregates in the poles of E. coli results from the coupling of passive diffusion-aggregation with spatially non-homogeneous macromolecular crowding. They further support the importance of “soft” intracellular structuring (based on macromolecular

  7. Preparation of Sticky Escherichia coli through Surface Display of an Adhesive Catecholamine Moiety

    PubMed Central

    Park, Joseph P.; Choi, Min-Jung; Kim, Se Hun

    2014-01-01

    Mussels attach to virtually all types of inorganic and organic surfaces in aqueous environments, and catecholamines composed of 3,4-dihydroxy-l-phenylalanine (DOPA), lysine, and histidine in mussel adhesive proteins play a key role in the robust adhesion. DOPA is an unusual catecholic amino acid, and its side chain is called catechol. In this study, we displayed the adhesive moiety of DOPA-histidine on Escherichia coli surfaces using outer membrane protein W as an anchoring motif for the first time. Localization of catecholamines on the cell surface was confirmed by Western blot and immunofluorescence microscopy. Furthermore, cell-to-cell cohesion (i.e., cellular aggregation) induced by the displayed catecholamine and synthesis of gold nanoparticles on the cell surface support functional display of adhesive catecholamines. The engineered E. coli exhibited significant adhesion onto various material surfaces, including silica and glass microparticles, gold, titanium, silicon, poly(ethylene terephthalate), poly(urethane), and poly(dimethylsiloxane). The uniqueness of this approach utilizing the engineered sticky E. coli is that no chemistry for cell attachment are necessary, and the ability of spontaneous E. coli attachment allows one to immobilize the cells on challenging material surfaces such as synthetic polymers. Therefore, we envision that mussel-inspired catecholamine yielded sticky E. coli that can be used as a new type of engineered microbe for various emerging fields, such as whole living cell attachment on versatile material surfaces, cell-to-cell communication systems, and many others. PMID:24123747

  8. Preparation of sticky Escherichia coli through surface display of an adhesive catecholamine moiety.

    PubMed

    Park, Joseph P; Choi, Min-Jung; Kim, Se Hun; Lee, Seung Hwan; Lee, Haeshin

    2014-01-01

    Mussels attach to virtually all types of inorganic and organic surfaces in aqueous environments, and catecholamines composed of 3,4-dihydroxy-l-phenylalanine (DOPA), lysine, and histidine in mussel adhesive proteins play a key role in the robust adhesion. DOPA is an unusual catecholic amino acid, and its side chain is called catechol. In this study, we displayed the adhesive moiety of DOPA-histidine on Escherichia coli surfaces using outer membrane protein W as an anchoring motif for the first time. Localization of catecholamines on the cell surface was confirmed by Western blot and immunofluorescence microscopy. Furthermore, cell-to-cell cohesion (i.e., cellular aggregation) induced by the displayed catecholamine and synthesis of gold nanoparticles on the cell surface support functional display of adhesive catecholamines. The engineered E. coli exhibited significant adhesion onto various material surfaces, including silica and glass microparticles, gold, titanium, silicon, poly(ethylene terephthalate), poly(urethane), and poly(dimethylsiloxane). The uniqueness of this approach utilizing the engineered sticky E. coli is that no chemistry for cell attachment are necessary, and the ability of spontaneous E. coli attachment allows one to immobilize the cells on challenging material surfaces such as synthetic polymers. Therefore, we envision that mussel-inspired catecholamine yielded sticky E. coli that can be used as a new type of engineered microbe for various emerging fields, such as whole living cell attachment on versatile material surfaces, cell-to-cell communication systems, and many others. PMID:24123747

  9. Tellurite-exposed Escherichia coli exhibits increased intracellular {alpha}-ketoglutarate

    SciTech Connect

    Reinoso, Claudia A.; Auger, Christopher; Appanna, Vasu D.; Vasquez, Claudio C.

    2012-05-18

    Highlights: Black-Right-Pointing-Pointer Tellurite-exposed E. coli exhibits decreased {alpha}-KG dehydrogenase activity. Black-Right-Pointing-Pointer Cells lacking {alpha}-KGDH genes are more sensitive to ROS than isogenic, wt E. coli. Black-Right-Pointing-Pointer KG accumulation may serve to face tellurite-mediated oxidative damage in E. coli. -- Abstract: The tellurium oxyanion tellurite is toxic to most organisms because of its ability to generate oxidative stress. However, the detailed mechanism(s) how this toxicant interferes with cellular processes have yet to be fully understood. As part of our effort to decipher the molecular interactions of tellurite with living systems, we have evaluated the global metabolism of {alpha}-ketoglutarate a known antioxidant in Escherichia coli. Tellurite-exposed cells displayed reduced activity of the KG dehydrogenase complex (KGDHc), resulting in increased intracellular KG content. This complex's reduced activity seems to be due to decreased transcription in the stressed cells of sucA, a gene that encodes the E1 component of KGDHc. Furthermore, it was demonstrated that the increase in total reactive oxygen species and superoxide observed upon tellurite exposure was more evident in wild type cells than in E. coli with impaired KGDHc activity. These results indicate that KG may be playing a pivotal role in combating tellurite-mediated oxidative damage.

  10. Peptidoglycan Hydrolases of Escherichia coli

    PubMed Central

    van Heijenoort, Jean

    2011-01-01

    Summary: The review summarizes the abundant information on the 35 identified peptidoglycan (PG) hydrolases of Escherichia coli classified into 12 distinct families, including mainly glycosidases, peptidases, and amidases. An attempt is also made to critically assess their functions in PG maturation, turnover, elongation, septation, and recycling as well as in cell autolysis. There is at least one hydrolytic activity for each bond linking PG components, and most hydrolase genes were identified. Few hydrolases appear to be individually essential. The crystal structures and reaction mechanisms of certain hydrolases having defined functions were investigated. However, our knowledge of the biochemical properties of most hydrolases still remains fragmentary, and that of their cellular functions remains elusive. Owing to redundancy, PG hydrolases far outnumber the enzymes of PG biosynthesis. The presence of the two sets of enzymes acting on the PG bonds raises the question of their functional correlations. It is difficult to understand why E. coli keeps such a large set of PG hydrolases. The subtle differences in substrate specificities between the isoenzymes of each family certainly reflect a variety of as-yet-unidentified physiological functions. Their study will be a far more difficult challenge than that of the steps of the PG biosynthesis pathway. PMID:22126997

  11. Escherichia coli survival in waters: Temperature dependence

    EPA Science Inventory

    Knowing the survival rates of water-borne Escherichia coli is important in evaluating microbial contamination and making appropriate management decisions. E. coli survival rates are dependent on temperature, a dependency that is routinely expressed using an analogue of the Q10 mo...

  12. Strategies for Protein Overproduction in Escherichia coli.

    ERIC Educational Resources Information Center

    Mott, John E.

    1984-01-01

    Examines heterologous expression in Escherichia coli and the role of regulatory sequences which control gene expression at transcription resulting in abundant production of messenger RNA and regulatory sequences in mRNA which promote efficient translation. Also examines the role of E. coli cells in stabilizing mRNA and protein that is…

  13. Diagnosisand Investigation of Diarrheagenic Escherichia coli.

    PubMed

    Nataro, J P; Martinez, J

    1998-01-01

    Although most Escherichia coli are harmless commensals of the human intestine, certain specific, highly-adapted E. coli strains are capable of causing urinary tract, systemic or enteric/diarrheagenic infection. Diarrheagenic E coli are divided into six distinct categories, or pathotypes, each with a distinct pathogenic scheme (Table 1). Combined, diarrheagenic E coli have emerged as perhaps the most important enteric pathogens of man. In the developing world, the E coli categories account for more cases of gastroenteiltis among infants than any other cause (1) In addition, E coli are also the most common cause of traveller's diarrhea, which afflicts more than one million travellers to the developing world annually (1). Enterohemorrhagic E coli (EHEC) are the cause of hemolytic uremic syndrome (HUS), which has become a major foodborne threat in many parts of the developed world (2). Table 1 Categories of Diarrheagenic E. coli Category Toxins Invasion Virulence plasmid Adhesin Clinical syndrome ETEC LT, ST - Many CFA/I, CFA/II, CFA/IV, others Watery diarrhea EPEC - + 60 MDa Bundle-forming pilus Watery diarrhea of infants EHEC SLT-1, SLT-2 - 60 MDa( a ) Intimin, Fimbriae( a ) Hemorrhagic colitis, HUS EAEC EAST1( a ) ? 65 MDa( a ) AAF/I, AAF/I Watery, persistent diarrhea EIEC EIET( a ) +++ 140 MDa Ipa's(?) Watery diarrhea, dysentery DAEC ? ? ? F1845( a ) Watery diarrhea ( a )Role in pathogenesis unproven. PMID:21390758

  14. Third International E. coli genome meeting

    SciTech Connect

    1994-12-31

    Proceedings of the Third E. Coli Genome Meeting are provided. Presentations were divided into sessions entitled (1) Large Scale Sequencing, Sequence Analysis; (2) Databases; (3) Sequence Analysis; (4) Sequence Divergence in E. coli Strains; (5) Repeated Sequences and Regulatory Motifs; (6) Mutations, Rearrangements and Stress Responses; and (7) Origins of New Genes. The document provides a collection of abstracts of oral and poster presentations.

  15. E. coli survival in waters: temperature dependence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowing the survival rates of water-borne Escherichia coli is important for evaluating microbial contamination and in making appropriate management decisions. E. coli survival rates are dependent on temperature; this dependency is routinely expressed using an analog of the Q10 model. This suggestion...

  16. Living-Cell Microarrays

    PubMed Central

    Yarmush, Martin L.; King, Kevin R.

    2011-01-01

    Living cells are remarkably complex. To unravel this complexity, living-cell assays have been developed that allow delivery of experimental stimuli and measurement of the resulting cellular responses. High-throughput adaptations of these assays, known as living-cell microarrays, which are based on microtiter plates, high-density spotting, microfabrication, and microfluidics technologies, are being developed for two general applications: (a) to screen large-scale chemical and genomic libraries and (b) to systematically investigate the local cellular microenvironment. These emerging experimental platforms offer exciting opportunities to rapidly identify genetic determinants of disease, to discover modulators of cellular function, and to probe the complex and dynamic relationships between cells and their local environment. PMID:19413510

  17. Living in the question.

    PubMed

    Flower, J

    1999-01-01

    We live in a fast moving-world. Business has accelerated to breathtaking speeds in the 1990s--and in the last few years the afterburner has really kicked in. The speed of change is overwhelming. Especially in health care, who has time to "live in the question?" We need to decide things quickly, get the decision out of the way, and move on, right? Maybe. Biology shows us that you can't plan ahead very far. New things come along that you don't even have a category for, and therefore you don't even see them. Things are going to happen that you literally have no notion are even possible. The key to succeeding in this environment? Don't plan ahead. Stay curious. Make small bets. Build organizational hothouses. Feed the seedlings that grow. The challenge is to remain curious, to live in the question, both personally and organizationally. PMID:10557490

  18. Escherichia coli and Sudden Infant Death Syndrome

    PubMed Central

    Bettelheim, Karl A.; Goldwater, Paul N.

    2015-01-01

    This review examines the association of strains of Escherichia coli with sudden infant death syndrome (SIDS) and the possible role these bacteria play in this enigmatic condition. The review addresses evidence for E. coli in SIDS infants, potential sources of E. coli in the environment, colonization by commensal and pathogenic strains, the variety of currently accepted pathotypes, and how these pathotypes could compromise intestinal integrity and induce inflammation. Both intestinal and extraintestinal pathotypes are compared in relation to the apparent liability in which virulence traits can be gained or lost by strains of E. coli. The way in which E. coli infections fit with current views on infant sleeping position and other SIDS risk factors is highlighted. PMID:26191064

  19. Living My Family's Story

    PubMed Central

    Underhill, Meghan L.; Lally, Robin M.; Kiviniemi, Marc T.; Murekeyisoni, Christine; Dickerson, Suzanne S.

    2013-01-01

    Background Based on known or suggested genetic risk factors, a growing number of women now live with knowledge of a potential cancer diagnosis that may never occur. Given this, it is important to understand the meaning of living with high risk for hereditary breast cancer. Objective The objective of the study was to explore how women at high risk for hereditary breast cancer (1) form self-identity, (2) apply self-care strategies toward risk, and (3) describe the meaning of care through a high-risk breast program. Methods Interpretive hermeneutic phenomenology guided the qualitative research method. Women at high risk for hereditary breast cancer were recruited from a high-risk breast program. Open-ended interview questions focused on experiences living as women managing high risk for breast cancer. Consistent with hermeneutic methodology, the principal investigator led a team to analyze the interview transcripts. Results Twenty women participated in in-depth interviews. Analysis revealed that women describe their own identity based on their family story and grieve over actual and potential familial loss. This experience influences self-care strategies, including seeking care from hereditary breast cancer risk experts for early detection and prevention, as well as maintaining a connection for early treatment “when” diagnosis occurs. Conclusions Healthy women living with high risk for hereditary breast cancer are living within the context of their family cancer story, which influences how they define themselves and engage in self-care. Implications for Practice Findings present important practical, research, and policy information regarding health promotion, psychosocial assessment, and support for women living with this risk. PMID:22544165

  20. Intestinal transplantation: living related.

    PubMed

    Pollard, S G

    1997-01-01

    The use of live donors in intestinal transplantation could potentially both reduce the severity of rejection responses against this highly immunogenic organ by better tissue matching and also reduce cold ischaemia times. These two advantages over cadaveric grafts could preserve mucosal integrity and reduce the risk of systemic sepsis from bacterial translocation. The disadvantages of live donation are the inherent risk to the donor and the compromise of using a shorter graft. Although only a handful of such cases have been performed, the success rate has been high and this is a therapeutic modality which should be explored further. PMID:9536535

  1. Cryopreservation of Living Organs

    NASA Astrophysics Data System (ADS)

    Tanasawa, Ichiro; Nagata, Shinichi; Kimura, Naohiro

    Cryopreservation is considered to be the most promising way of preserving living organs or tissues for a long period of time without casuing any damage to their biological functions. However, cryopreservation has been succeeded only for simple and small-size tissues such as spermatozoon, ovum, erythrocyte, bone marrow and cornea. Cryopreservation of more complex and large-scale organs are not yet succssful. The authors have attempted to establish a technique for cryopreservation of larger living organs. An experiment was carried out using daphnia (water flea). The optimum rates of freezing and thawing were determined together with the optimum selection of cryoprotectant. High recovery rate was achieved under these conditions.

  2. New Lives of Teachers

    ERIC Educational Resources Information Center

    Day, Christopher

    2012-01-01

    The work and lives of teachers have always been subject to external influence as those who are nearing the end of their careers will attest, but it is arguable that what is new over the last two decades is the pace, complexity, and intensity of change as governments have responded to the shrinking world of economic competitiveness and social…

  3. Living with Cystic Fibrosis

    MedlinePlus

    ... from the NHLBI on Twitter. Living With Cystic Fibrosis If you or your child has cystic fibrosis (CF), you should learn as much as you ... about CF Care Centers, go to the Cystic Fibrosis Foundation's Care Center Network Web page. It's standard ...

  4. You Live, You Learn

    ERIC Educational Resources Information Center

    Biesta, Gert

    2008-01-01

    The Learning Lives project, a four-year study into the learning biographies and trajectories of adults, was conducted by a team of researchers from the universities of Stirling, Exeter, Brighton and Leeds as part of the Teaching and Learning Research Programme (TLRP) of the Economic and Social Research Council, and has just been completed. Whereas…

  5. Living with Pulmonary Embolism

    MedlinePlus

    ... Living With Clinical Trials Links Related Topics Arrhythmia Deep Vein Thrombosis Lung Ventilation/Perfusion Scan Overweight and Obesity Send ... Once you've had PE (with or without deep vein thrombosis (DVT)), you're at higher risk of having ...

  6. Learning and Living

    ERIC Educational Resources Information Center

    Adults Learning, 2004

    2004-01-01

    "Lifelong learning" is the latest educational mantra. Yet little is understood about the ways in which learning and living are interconnected. To find out more about the complexities of learning in the life course, Professor Gert Biesta, of the University of Exeter, is leading a team of researchers from four universities in the first large-scale…

  7. Loneliness and Living Arrangements

    ERIC Educational Resources Information Center

    Stancliffe, Roger J.; Lakin, K. Charlie; Doljanac, Robert; Byun, Soo-Yong; Taub, Sarah; Chiri, Giuseppina

    2007-01-01

    Adults with ID/DD live in increasingly small community settings, where the risk of loneliness may be greater. We examined self-reported loneliness among 1,002 individuals with ID/DD from 5 states in relation to community residence size, personal characteristics, social contact, and social climate. One third reported being lonely sometimes and one…

  8. Teachers Transform Lives.

    ERIC Educational Resources Information Center

    Bradshaw, Delia

    2001-01-01

    Teachers transform lives, and the ripple effect goes on for years. Three pertinent questions are asked in this paper: Where does this power come from? What is its source? and What makes teachers so special? Two aspects of these questions are the multiplicity of identities that coexist within each teacher and the passion inside teachers that…

  9. Live-cell imaging

    PubMed Central

    Cole, Richard

    2014-01-01

    It would be hard to argue that live-cell imaging has not changed our view of biology. The past 10 years have seen an explosion of interest in imaging cellular processes, down to the molecular level. There are now many advanced techniques being applied to live cell imaging. However, cellular health is often under appreciated. For many researchers, if the cell at the end of the experiment has not gone into apoptosis or is blebbed beyond recognition, than all is well. This is simply incorrect. There are many factors that need to be considered when performing live-cell imaging in order to maintain cellular health such as: imaging modality, media, temperature, humidity, PH, osmolality, and photon dose. The wavelength of illuminating light, and the total photon dose that the cells are exposed to, comprise two of the most important and controllable parameters of live-cell imaging. The lowest photon dose that achieves a measureable metric for the experimental question should be used, not the dose that produces cover photo quality images. This is paramount to ensure that the cellular processes being investigated are in their in vitro state and not shifted to an alternate pathway due to environmental stress. The timing of the mitosis is an ideal canary in the gold mine, in that any stress induced from the imaging will result in the increased length of mitosis, thus providing a control model for the current imagining conditions. PMID:25482523

  10. Design for Living

    ERIC Educational Resources Information Center

    Rosenblum, Todd

    2011-01-01

    Bringing a newborn home from the hospital can come with stress for any parent. Coming home with twins can be double the stress. This article shares the story of a couple faced with this situation 12 years ago with the birth of twins, one was born with complications. They lived in a Colonial until the twins were almost five years old, at which time…

  11. Microholography of Living Organisms.

    ERIC Educational Resources Information Center

    Solem, Johndale C.; Baldwin, George C.

    1982-01-01

    By using intense pulsed coherent x-ray sources it will be possible to obtain magnified three-dimensional images of living elementary biological structures at precisely defined instants. Discussed are sources/geometrics for x-ray holography, x-radiation interactions, factors affecting resolution, recording the hologram, high-intensity holography,…

  12. Living with Stepparents

    MedlinePlus

    ... doesn't live with you and knows how families work can help figure out how you can all ... also understand how much you still love your mother, even if she died. Families are about love and understanding, not about competing ...

  13. Moab's Living Room

    ERIC Educational Resources Information Center

    Berry, John N., III

    2007-01-01

    This article describes the Grand County Public Library (GCPL) which was awarded the 2007 Best Small Library in America, an award sponsored by "Library Journal" and the Bill & Melinda Gates Foundation. Some 4800 of Grand County, Utah's 8,826 people live in Moab and the rest in the adjacent Spanish Valley and environs. The locals are a sizable group…

  14. Living with Parkinson's

    MedlinePlus

    ... Tips from the Health Care Team Finding Resources Parkinson's HelpLine Learn More Educational Materials Do you want ... resources & more. Order Free Materials Today Living with Parkinson’s “Parkinson’s is a part of my life, but ...

  15. The Living Periodic Table

    ERIC Educational Resources Information Center

    Nahlik, Mary Schrodt

    2005-01-01

    To help make the abstract world of chemistry more concrete eighth-grade students, the author has them create a living periodic table that can be displayed in the classroom or hallway. This display includes information about the elements arranged in the traditional periodic table format, but also includes visual real-world representations of the…

  16. Learning from Live Theater

    ERIC Educational Resources Information Center

    Greene, Jay P.; Hitt, Collin; Kraybill, Anne; Bogulski, Cari A.

    2015-01-01

    Culturally enriching field trips matter. They produce significant benefits for students on a variety of educational outcomes that schools and communities care about. This experiment on the effects of field trips to see live theater demonstrates that seeing plays is an effective way to teach academic content; increases student tolerance by…

  17. Living or Nonliving?

    ERIC Educational Resources Information Center

    Legaspi, Britt; Straits, William

    2011-01-01

    Categorizing organisms as living or nonliving things may seem to be intuitive by nature. Yet, it is regulated by scientific criteria. Students come to school with rules already in place. Their categorizing criteria have already been influenced by their personal experiences, also known as observations and inferences. They believe that all things…

  18. Dementia and Assisted Living

    ERIC Educational Resources Information Center

    Hyde, Joan; Perez, Rosa; Forester, Brent

    2007-01-01

    Purpose: This article presents an overview of what is known about dementia services in assisted living settings and suggests areas for future research. Design and Methods: We undertook a search of Medline, the "Journals of Gerontology," and "The Gerontologist." We then organized publications dealing with the target subject into 10 topic areas and…

  19. Family Living Supplement.

    ERIC Educational Resources Information Center

    Truitt, Debbie

    This family living supplement contains 125 supplemental ideas and strategies designed to help vocational home economics teachers increase student motivation and enrich the teaching process. Ideas and strategies are organized into seven sections. These are career planning, securing a job, and career success; managing financial resources, buying…

  20. Living Systems Energy Module

    SciTech Connect

    1995-09-26

    The Living Systems Energy Module, renamed Voyage from the Sun, is a twenty-lesson curriculum designed to introduce students to the major ways in which energy is important in living systems. Voyage from the Sun tells the story of energy, describing its solar origins, how it is incorporated into living terrestrial systems through photosynthesis, how it flows from plants to herbivorous animals, and from herbivores to carnivores. A significant part of the unit is devoted to examining how humans use energy, and how human impact on natural habitats affects ecosystems. As students proceed through the unit, they read chapters of Voyage from the Sun, a comic book that describes the flow of energy in story form (Appendix A). During the course of the unit, an ``Energy Pyramid`` is erected in the classroom. This three-dimensional structure serves as a classroom exhibit, reminding students daily of the importance of energy and of the fragile nature of our living planet. Interactive activities teach students about adaptations that allow plants and animals to acquire, to use and to conserve energy. A complete list of curricular materials and copies of all activity sheets appear in Appendix B.

  1. Happy orang-utans live longer lives

    PubMed Central

    Weiss, Alexander; Adams, Mark J.; King, James E.

    2011-01-01

    Nonhuman primate ageing resembles its human counterpart. Moreover, ratings of subjective well-being traits in chimpanzees, orang-utans and rhesus macaques are similar to those of humans: they are intercorrelated, heritable, and phenotypically and genetically related to personality. We examined whether, as in humans, orang-utan subjective well-being was related to longer life. The sample included 184 zoo-housed orang-utans followed up for approximately 7 years. Age, sex, species and number of transfers were available for all subjects and 172 subjects were rated on at least one item of a subjective well-being scale. Of the 31 orang-utans that died, 25 died a mean of 3.4 years after being rated. Even in a model that included, and therefore, statistically adjusted for, sex, age, species and transfers, orang-utans rated as being “happier” lived longer. The risk differential between orang-utans that were one standard deviation above and one standard deviation below baseline in subjective well-being was comparable with approximately 11 years in age. This finding suggests that impressions of the subjective well-being of captive great apes are valid indicators of their welfare and longevity. PMID:21715398

  2. Happy orang-utans live longer lives.

    PubMed

    Weiss, Alexander; Adams, Mark J; King, James E

    2011-12-23

    Nonhuman primate ageing resembles its human counterpart. Moreover, ratings of subjective well-being traits in chimpanzees, orang-utans and rhesus macaques are similar to those of humans: they are intercorrelated, heritable, and phenotypically and genetically related to personality. We examined whether, as in humans, orang-utan subjective well-being was related to longer life. The sample included 184 zoo-housed orang-utans followed up for approximately 7 years. Age, sex, species and number of transfers were available for all subjects and 172 subjects were rated on at least one item of a subjective well-being scale. Of the 31 orang-utans that died, 25 died a mean of 3.4 years after being rated. Even in a model that included, and therefore, statistically adjusted for, sex, age, species and transfers, orang-utans rated as being "happier" lived longer. The risk differential between orang-utans that were one standard deviation above and one standard deviation below baseline in subjective well-being was comparable with approximately 11 years in age. This finding suggests that impressions of the subjective well-being of captive great apes are valid indicators of their welfare and longevity. PMID:21715398

  3. Mutual Enhancement of Virulence by Enterotoxigenic and Enteropathogenic Escherichia coli

    PubMed Central

    Crane, John K.; Choudhari, Shilpa S.; Naeher, Tonniele M.; Duffey, Michael E.

    2006-01-01

    Enterotoxigenic Escherichia coli (ETEC) and enteropathogenic E. coli (EPEC) are common causes of diarrhea in children in developing countries. Dual infections with both pathogens have been noted fairly frequently in studies of diarrhea around the world. In previous laboratory work, we noted that cholera toxin and forskolin markedly potentiated EPEC-induced ATP release from the host cell, and this potentiated release was found to be mediated by the cystic fibrosis transmembrane conductance regulator. In this study, we examined whether the ETEC heat-labile toxin (LT) or the heat-stable toxin (STa, also known as ST) potentiated EPEC-induced ATP release. We found that crude ETEC culture filtrates, as well as purified ETEC toxins, did potentiate EPEC-induced ATP release in cultured T84 cells. Coinfection of T84 cells with live ETEC plus EPEC bacteria also resulted in enhanced ATP release compared to EPEC alone. In Ussing chamber studies of chloride secretion, adenine nucleotides released from the host by EPEC also significantly enhanced the chloride secretory responses that were triggered by crude ETEC filtrates, purified STa, and the peptide hormone guanylin. In addition, adenosine and LT had additive or synergistic effects in inducing vacuole formation in T84 cells. Therefore, ETEC toxins and EPEC-induced damage to the host cell both enhance the virulence of the other type of E. coli. Our in vitro data demonstrate a molecular basis for a microbial interaction, which could result in increased severity of disease in vivo in individuals who are coinfected with ETEC and EPEC. PMID:16495521

  4. Nonperturbative Imaging of Nucleoid Morphology in Live Bacterial Cells during an Antimicrobial Peptide Attack

    PubMed Central

    Bakshi, Somenath; Choi, Heejun; Rangarajan, Nambirajan; Barns, Kenneth J.; Bratton, Benjamin P.

    2014-01-01

    Studies of time-dependent drug and environmental effects on single, live bacterial cells would benefit significantly from a permeable, nonperturbative, long-lived fluorescent stain specific to the nucleoids (chromosomal DNA). The ideal stain would not affect cell growth rate or nucleoid morphology and dynamics, even during laser illumination for hundreds of camera frames. In this study, time-dependent, single-cell fluorescence imaging with laser excitation and a sensitive electron-multiplying charge-coupled-device (EMCCD) camera critically tested the utility of “dead-cell stains” (SYTOX orange and SYTOX green) and “live-cell stains” (DRAQ5 and SYTO 61) and also 4′,6-diamidino-2-phenylindole (DAPI). Surprisingly, the dead-cell stains were nearly ideal for imaging live Escherichia coli, while the live-cell stains and DAPI caused nucleoid expansion and, in some cases, cell permeabilization and the halting of growth. SYTOX orange performed well for both the Gram-negative E. coli and the Gram-positive Bacillus subtilis. In an initial application, we used two-color fluorescence imaging to show that the antimicrobial peptide cecropin A destroyed nucleoid-ribosome segregation over 20 min after permeabilization of the E. coli cytoplasmic membrane, reminiscent of the long-term effects of the drug rifampin. In contrast, the human cathelicidin LL-37, while similar to cecropin A in structure, length, charge, and the ability to permeabilize bacterial membranes, had no observable effect on nucleoid-ribosome segregation. Possible underlying causes are suggested. PMID:24907320

  5. Nonchemotactic Mutants of Escherichia coli

    PubMed Central

    Armstrong, John B.; Adler, Julius; Dahl, Margaret M.

    1967-01-01

    We have isolated 40 mutants of Escherichia coli which are nonchemotactic as judged by their failure to swarm on semisolid tryptone plates or to make bands in capillary tubes containing tryptone broth. All the mutants have normal flagella, a fact shown by their shape and reaction with antiflagella serum. All are fully motile under the microscope and all are sensitive to the phage chi. Unlike its parent, one of the mutants, studied in greater detail, failed to show chemotaxis toward oxygen, glucose, serine, threonine, or aspartic acid. The failure to exhibit chemotaxis does not result from a failure to use the chemicals. The swimming of this mutant was shown to be random. The growth rate was normal under several conditions, and the growth requirements were unchanged. Images PMID:5335897

  6. Gas signatures from Escherichia coli and Escherichia coli-inoculated human whole blood

    PubMed Central

    2013-01-01

    Background The gaseous headspace above naïve Escherichia Coli (E. coli) cultures and whole human blood inoculated with E. coli were collected and analyzed for the presence of trace gases that may have the potential to be used as novel, non-invasive markers of infectious disease. Methods The naïve E. coli culture, LB broth, and human whole blood or E. coli inoculated whole blood were incubated in hermetically sealable glass bioreactors at 37°C for 24 hrs. LB broth and whole human blood were used as controls for background volatile organic compounds (VOCs). The headspace gases were collected after incubation and analyzed using a gas chromatographic system with multiple column/detector combinations. Results Six VOCs were observed to be produced by E. coli-infected whole blood while there existed nearly zero to relatively negligible amounts of these gases in the whole blood alone, LB broth, or E. coli-inoculated LB broth. These VOCs included dimethyl sulfide (DMS), carbon disulfide (CS2), ethanol, acetaldehyde, methyl butanoate, and an unidentified gas S. In contrast, there were several VOCs significantly elevated in the headspace above the E. coli in LB broth, but not present in the E. coli/blood mixture. These VOCs included dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), methyl propanoate, 1-propanol, methylcyclohexane, and unidentified gases R2 and Q. Conclusions This study demonstrates 1) that cultivated E. coli in LB broth produce distinct gas profiles, 2) for the first time, the ability to modify E. coli-specific gas profiles by the addition of whole human blood, and 3) that E. coli-human whole blood interactions present different gas emission profiles that have the potential to be used as non-invasive volatile biomarkers of E. coli infection. PMID:23842518

  7. Structure of Escherichia coli tryptophanase.

    PubMed

    Ku, Shao Yang; Yip, Patrick; Howell, P Lynne

    2006-07-01

    Pyridoxal 5'-phosphate (PLP) dependent tryptophanase has been isolated from Escherichia coli and its crystal structure has been determined. The structure shares the same fold with and has similar quaternary structure to Proteus vulgaris tryptophanase and tyrosine-phenol lyase, but is found in a closed conformation when compared with these two enzymes. The tryptophanase structure, solved in its apo form, does not have covalent PLP bound in the active site, but two sulfate ions. The sulfate ions occupy the phosphoryl-binding site of PLP and the binding site of the alpha-carboxyl of the natural substrate tryptophan. One of the sulfate ions makes extensive interactions with both the transferase and PLP-binding domains of the protein and appears to be responsible for holding the enzyme in its closed conformation. Based on the sulfate density and the structure of the P. vulgaris enzyme, PLP and the substrate tryptophan were modeled into the active site. The resulting model is consistent with the roles of Arg419 in orienting the substrate to PLP and acidifying the alpha-proton of the substrate for beta-elimination, Lys269 in the formation and decomposition of the PLP quinonoid intermediate, Arg230 in orienting the substrate-PLP intermediates in the optimal conformation for catalysis, and His463 and Tyr74 in determining substrate specificity and suggests that the closed conformation observed in the structure could be induced by substrate binding and that significant conformational changes occur during catalysis. A catalytic mechanism for tryptophanase is proposed. Since E. coli tryptophanase has resisted forming diffraction-quality crystals for many years, the molecular surface of tryptophanase has been analyzed in various crystal forms and it was rationalized that strong crystal contacts occur on the flat surface of the protein and that the size of crystal contact surface seems to correlate with the diffraction quality of the crystal. PMID:16790938

  8. Structure of Escherichia Coli Tryptophanase

    SciTech Connect

    Ku,S.; Yip, P.; Howell, P.

    2006-01-01

    Pyridoxal 5'-phosphate (PLP) dependent tryptophanase has been isolated from Escherichia coli and its crystal structure has been determined. The structure shares the same fold with and has similar quaternary structure to Proteus vulgaris tryptophanase and tyrosine-phenol lyase, but is found in a closed conformation when compared with these two enzymes. The tryptophanase structure, solved in its apo form, does not have covalent PLP bound in the active site, but two sulfate ions. The sulfate ions occupy the phosphoryl-binding site of PLP and the binding site of the {alpha}-carboxyl of the natural substrate tryptophan. One of the sulfate ions makes extensive interactions with both the transferase and PLP-binding domains of the protein and appears to be responsible for holding the enzyme in its closed conformation. Based on the sulfate density and the structure of the P. vulgaris enzyme, PLP and the substrate tryptophan were modeled into the active site. The resulting model is consistent with the roles of Arg419 in orienting the substrate to PLP and acidifying the {alpha}-proton of the substrate for {beta}-elimination, Lys269 in the formation and decomposition of the PLP quinonoid intermediate, Arg230 in orienting the substrate-PLP intermediates in the optimal conformation for catalysis, and His463 and Tyr74 in determining substrate specificity and suggests that the closed conformation observed in the structure could be induced by substrate binding and that significant conformational changes occur during catalysis. A catalytic mechanism for tryptophanase is proposed. Since E. coli tryptophanase has resisted forming diffraction-quality crystals for many years, the molecular surface of tryptophanase has been analyzed in various crystal forms and it was rationalized that strong crystal contacts occur on the flat surface of the protein and that the size of crystal contact surface seems to correlate with the diffraction quality of the crystal.

  9. Anaplasma marginale major surface protein 1a directs cell surface display of tick BM95 immunogenic peptides on Escherichia coli.

    PubMed

    Canales, Mario; Almazán, Consuelo; Pérez de la Lastra, José M; de la Fuente, José

    2008-07-31

    The surface display of heterologous proteins on live Escherichia coli using anchoring motifs from outer membranes proteins has impacted on many areas of biochemistry, molecular biology and biotechnology. The Anaplasma marginale major surface protein 1a (MSP1a) contains N-terminal surface-exposed repeated peptides (28-289 amino acids) that are involved in pathogen interaction with host cell receptors and is surface-displayed when the recombinant protein is expressed in E. coli. Therefore, it was predicted that MSP1a would surface display on E. coli peptides inserted in the N-terminal repeats region of the protein. The Rhipicephalus (Boophilus) microplus BM86 and BM95 glycoproteins are homologous proteins that protect cattle against tick infestations. In this study, we demonstrated that a recombinant protein comprising tick BM95 immunogenic peptides fused to the A. marginale MSP1a N-terminal region is displayed on the E. coli surface and is recognized by anti-BM86 and anti-MSP1a antibodies. This system provides a novel approach to the surface display of heterologous antigenic proteins on live E. coli and suggests the possibility to use the recombinant bacteria for immunization studies against cattle tick infestations. PMID:18582976

  10. Evolution and Biophysics of the Escherichia coli lac Operon

    NASA Astrophysics Data System (ADS)

    Ray, J. Christian; Igoshin, Oleg; Quan, Selwyn; Monds, Russell; Cooper, Tim; Balázsi, Gábor

    2011-03-01

    To understand, predict, and control the evolution of living organisms, we consider biophysical effects and molecular network architectures. The lactose utilization system of E. coli is among the most well-studied molecular networks in biology, making it an ideal candidate for such studies. Simulations show how the genetic architecture of the wild-type operon attenuates large metabolic intermediate fluctuations that are predicted to occur in an equivalent system with the component genes on separate operons. Quantification of gene expression in the lac operon evolved in growth conditions containing constant lactose, alternating with glucose, or constant glucose, shows characteristic gene expression patterns depending on conditions. We are simulating these conditions to show context-dependent biophysical sources and costs of different lac operon architectures.

  11. Advances in genoserotyping and subtyping of Escherichia coli

    Technology Transfer Automated Retrieval System (TEKTRAN)

    E. coli plays an important role as a member of the gut microbiota; however, pathogenic strains also exist, including various diarrheagenic E. coli pathotypes and extraintestinal pathogenic E. coli that cause illness outside of the GI-tract. E. coli have traditionally been serotyped using antisera a...

  12. Survival of pathogenic Escherichia coli on basil, lettuce, and spinach

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The contamination of lettuce, spinach and basil with pathogenic E. coli has caused numerous illnesses over the past decade. E. coli O157:H7, E. coli O104:H4 and avian pathogenic E. coli (APECstx- and APECstx+) were inoculated on basil plants and in promix soiless substrate using drip and overhead ir...

  13. Development of a multivalent live vaccine active against a wide range of Enterobacteriaceae.

    PubMed

    Levi, B; Witz, I; Malkinson, M; Singer, N; Wiseman, Y; Ron, E Z

    1980-01-01

    We have constructed a deletion mutant of E. coli which lacks O-antigen - "deep rough". Living bacteria of this strain were injected repeatedly in high numbers into mice and chicks and in all cases were found to be completely harmless. In C3HeB mice, protection was obtained against a wide variety of enteric bacteria and was accompanied by an appreciable increase in titer of antibodies which cross react with LPS extracted from these bacteria. Preliminary experiments indicate that the vaccine provides protection against avian coli pathogens. PMID:7010371

  14. Living history biography

    SciTech Connect

    Puck, T.T.

    1994-11-15

    A living history biography is presented of Theodore T. Puck. This history is intimately involved with the progress towards mapping of the human genome through research at the forefront of molecular cytogenetics. A review of historical research aims such as human genetics studies based on somatic cells, isolation of mutants as genetic markers, complementation analysis, gene mapping and the measurement of mutation is presented. 37 refs., 4 figs.

  15. Live-donor nephrectomy.

    PubMed

    Rocca, Juan P; Davis, Eric; Edye, Michael

    2012-01-01

    Six decades after its first implementation, kidney transplantation remains the optimal therapy for end-stage renal disease requiring dialysis. Despite the incontrovertible mortality reduction and cost-effectiveness of kidney transplantation, the greatest remaining barrier to treatment of end-stage renal disease is organ availability. Although the waiting list of patients who stand to benefit from kidney transplantation grows at a rate proportional to the overall population and proliferation of diabetes and hypertension, the pool of deceased-donor organs available for transplantation experiences minimal to no growth. Because the kidney is uniquely suited as a paired organ, the transplant community's answer to this shortage is living donation of a healthy volunteer's kidney to a recipient with end-stage renal disease. This review details the history and evolution of living-donor kidney transplantation in the United States as well as advances the next decade promises. Laparoscopic donor nephrectomy has overcome many of the obstacles to living donation in terms of donor morbidity and volunteerism. Known donor risks in terms of surgical and medical morbidity are reviewed, as well as the ongoing efforts to delineate and mitigate donor risk in the context of accumulating recipient morbidity while on the waiting list. PMID:22678857

  16. Biofuels from E. Coli: Engineering E. coli as an Electrofuels Chassis for Isooctane Production

    SciTech Connect

    2010-07-16

    Electrofuels Project: Ginkgo Bioworks is bypassing photosynthesis and engineering E. coli to directly use carbon dioxide (CO2) to produce biofuels. E. coli doesn’t naturally metabolize CO2, but Ginkgo Bioworks is manipulating and incorporating the genes responsible for CO2 metabolism into the microorganism. By genetically modifying E. coli, Ginkgo Bioworks will enhance its rate of CO2 consumption and liquid fuel production. Ginkgo Bioworks is delivering CO2 to E. coli as formic acid, a simple industrial chemical that provides energy and CO2 to the bacterial system.

  17. Escherichia coli in retail processed food.

    PubMed Central

    Pinegar, J. A.; Cooke, E. M.

    1985-01-01

    Four thousand two hundred and forty six samples of retail processed food were examined for the presence of Escherichia coli. Overall 12% of samples contained this organism, cakes and confectionery being more frequently contaminated (28%) than meat and meat based products (9%). Contamination was more frequent in the summer months than in the colder weather and 27% of the contaminated foods contained greater than 10(3) E. coli/g. E. coli from meat and meat based products were more commonly resistant to one or more antibiotics (14%) than were confectionery strains (1%). The significance of these findings in relation to the E. coli population of the human bowel is discussed. PMID:3894508

  18. Escherichia coli in retail processed food.

    PubMed

    Pinegar, J A; Cooke, E M

    1985-08-01

    Four thousand two hundred and forty six samples of retail processed food were examined for the presence of Escherichia coli. Overall 12% of samples contained this organism, cakes and confectionery being more frequently contaminated (28%) than meat and meat based products (9%). Contamination was more frequent in the summer months than in the colder weather and 27% of the contaminated foods contained greater than 10(3) E. coli/g. E. coli from meat and meat based products were more commonly resistant to one or more antibiotics (14%) than were confectionery strains (1%). The significance of these findings in relation to the E. coli population of the human bowel is discussed. PMID:3894508

  19. Vaginal Lactobacillus isolates inhibit uropathogenic Escherichia coli.

    PubMed

    Atassi, Fabrice; Brassart, Dominique; Grob, Philipp; Graf, Federico; Servin, Alain L

    2006-04-01

    The purpose of this study was to investigate the antibacterial activities of Lactobacillus jensenii KS119.1 and KS121.1, and Lactobacillus gasserii KS120.1 and KS124.3 strains isolated from the vaginal microflora of healthy women, against uropathogenic, diffusely adhering Afa/Dr Escherichia coli (Afa/Dr DAEC) strains IH11128 and 7372 involved in recurrent cystitis. We observed that some of the Lactobacillus isolates inhibited the growth and decreased the viability of E. coli IH11128 and 7372. In addition, we observed that adhering Lactobacillus strains inhibited adhesion of E. coli IH11128 onto HeLa cells, and inhibited internalization of E. coli IH11128 within HeLa cells. PMID:16553843

  20. First international E. coli genome meeting

    SciTech Connect

    Not Available

    1992-01-01

    This volume is a collection of abstracts of oral presentations and poster sessions of studies reported at the First International E. Coli Genome Meeting, held September 10-14, 1992 at the University of Wisconsin.

  1. First international E. coli genome meeting

    SciTech Connect

    Not Available

    1992-12-31

    This volume is a collection of abstracts of oral presentations and poster sessions of studies reported at the First International E. Coli Genome Meeting, held September 10-14, 1992 at the University of Wisconsin.

  2. Escherichia coli bacteriuria and contraceptive method.

    PubMed

    Hooton, T M; Hillier, S; Johnson, C; Roberts, P L; Stamm, W E

    1991-01-01

    We evaluated the effects of contraceptive method on the occurrence of bacteriuria and vaginal colonization with Escherichia coli in 104 women who were evaluated prior to having sexual intercourse, the morning after intercourse, and 24 hours later. After intercourse, the prevalence of E coli bacteriuria increased slightly in oral contraceptive users but dramatically in both foam and condom users and diaphragm-spermicide users. Twenty-four hours later, the prevalence of bacteriuria remained significantly elevated only in the latter two groups. Similarly, vaginal colonization with E coli was more dramatic and persistent in users of diaphragm-spermicide and foam and condoms. Vaginal colonization with Candida species, enterococci, and staphylococci also increased significantly in diaphragm-spermicide users after intercourse. We conclude that use of the diaphragm with spermicidal jelly or use of a spermicidal foam with a condom markedly alters normal vaginal flora and strongly predisposes users to the development of vaginal colonization and bacteriuria with E coli. PMID:1859519

  3. Adhesion behaviors of Escherichia coli on hydroxyapatite.

    PubMed

    Kamitakahara, Masanobu; Takahashi, Shohei; Yokoi, Taishi; Inoue, Chihiro; Ioku, Koji

    2016-04-01

    Optimum design of support materials for microorganisms is required for the construction of bioreactors. However, the effects of support materials on microorganisms are still unclear. In this study, we investigated the adhesion behavior of Escherichia coli (E. coli) on hydroxyapatite (HA), polyurethane (PU), poly(vinyl chloride) (PVC), and carbon (Carbon) to obtain basic knowledge for the design of support materials. The total metabolic activity and number of E. coli adhering on the samples followed the order of HA ≈ Carbon>PVC>PU. On the other hand, the water contact angle of the pellet surfaces followed the order of HAcoli. The results implied that HA has a potential as a support material for microorganisms used in bioreactors. PMID:26838837

  4. FTIR nanobiosensors for Escherichia coli detection

    PubMed Central

    Greppi, Gianfranco; Marongiu, Maria Laura; Roggero, Pier Paolo; Ravindranath, Sandeep P; Mauer, Lisa J; Schibeci, Nicoletta; Perria, Francesco; Piccinini, Massimo; Innocenzi, Plinio; Irudayaraj, Joseph

    2012-01-01

    Summary Infections due to enterohaemorrhagic E. coli (Escherichia coli) have a low incidence but can have severe and sometimes fatal health consequences, and thus represent some of the most serious diseases due to the contamination of water and food. New, fast and simple devices that monitor these pathogens are necessary to improve the safety of our food supply chain. In this work we report on mesoporous titania thin-film substrates as sensors to detect E. coli O157:H7. Titania films treated with APTES ((3-aminopropyl)triethoxysilane) and GA (glutaraldehyde) were functionalized with specific antibodies and the absorption properties monitored. The film-based biosensors showed a detection limit for E. coli of 1 × 102 CFU/mL, constituting a simple and selective method for the effective screening of water samples. PMID:23019542

  5. Fosfomycin Resistance in Escherichia coli, Pennsylvania, USA

    PubMed Central

    Alrowais, Hind; McElheny, Christi L.; Spychala, Caressa N.; Sastry, Sangeeta; Guo, Qinglan; Butt, Adeel A.

    2015-01-01

    Fosfomycin resistance in Escherichia coli is rare in the United States. An extended-spectrum β-lactamase–producing E. coli clinical strain identified in Pennsylvania, USA, showed high-level fosfomycin resistance caused by the fosA3 gene. The IncFII plasmid carrying this gene had a structure similar to those found in China, where fosfomycin resistance is commonly described. PMID:26488485

  6. Natural plasmid transformation in Escherichia coli.

    PubMed

    Tsen, Suh-Der; Fang, Suh-Sen; Chen, Mei-Jye; Chien, Jun-Yi; Lee, Chih-Chun; Tsen, Darwin Han-Lin

    2002-01-01

    Although Escherichia coli does not have a natural transformation process, strains of E. coli can incorporate extracellular plasmids into cytoplasm 'naturally' at low frequencies. A standard method was developed in which stationary phase cells were concentrated, mixed with plasmids, and then plated on agar plates with nutrients which allowed cells to grow. Transformed cells could then be selected by harvesting cells and plating again on selective agar plates. Competence developed in the lag phase, but disappeared during exponential growth. As more plasmids were added to the cell suspension, the number of transformants increased, eventually reaching a plateau. Supercoiled monomeric or linear concatemeric DNA could transform cells, while linear monomeric DNA could not. Plasmid transformation was not related to conjugation and was recA-independent. Most of the E. coli strains surveyed had this process. All tested plasmids, except pACYC184, could transform E. coli. Insertion of a DNA fragment containing the ampicillin resistance gene into pACYC184 made the plasmid transformable. By inserting random 20-base-pair oligonucleotides into pACYC184 and selecting for transformable plasmids, a most frequent sequence was identified. This sequence resembled the bacterial interspersed medium repetitive sequence of E. coli, suggesting the existence of a recognition sequence. We conclude that plasmid natural transformation exists in E. coli. PMID:12065899

  7. Systems Metabolic Engineering of Escherichia coli.

    PubMed

    Choi, Kyeong Rok; Shin, Jae Ho; Cho, Jae Sung; Yang, Dongsoo; Lee, Sang Yup

    2016-05-01

    Systems metabolic engineering, which recently emerged as metabolic engineering integrated with systems biology, synthetic biology, and evolutionary engineering, allows engineering of microorganisms on a systemic level for the production of valuable chemicals far beyond its native capabilities. Here, we review the strategies for systems metabolic engineering and particularly its applications in Escherichia coli. First, we cover the various tools developed for genetic manipulation in E. coli to increase the production titers of desired chemicals. Next, we detail the strategies for systems metabolic engineering in E. coli, covering the engineering of the native metabolism, the expansion of metabolism with synthetic pathways, and the process engineering aspects undertaken to achieve higher production titers of desired chemicals. Finally, we examine a couple of notable products as case studies produced in E. coli strains developed by systems metabolic engineering. The large portfolio of chemical products successfully produced by engineered E. coli listed here demonstrates the sheer capacity of what can be envisioned and achieved with respect to microbial production of chemicals. Systems metabolic engineering is no longer in its infancy; it is now widely employed and is also positioned to further embrace next-generation interdisciplinary principles and innovation for its upgrade. Systems metabolic engineering will play increasingly important roles in developing industrial strains including E. coli that are capable of efficiently producing natural and nonnatural chemicals and materials from renewable nonfood biomass. PMID:27223822

  8. Mechanism of Sperm Immobilization by Escherichia coli

    PubMed Central

    Prabha, Vijay; Sandhu, Ravneet; Kaur, Siftjit; Kaur, Kiranjeet; Sarwal, Abha; Mavuduru, Ravimohan S.; Singh, Shravan Kumar

    2010-01-01

    Aim. To explore the influence of Escherichia coli on the motility of human spermatozoa and its possible mechanism. Methods. Highly motile preparations of spermatozoa from normozoospermic patients were coincubated with Escherichia coli for 4 hours. At 1, 2 and 4 hours of incubation, sperm motility was determined. The factor responsible for sperm immobilization without agglutination was isolated and purified from filtrates. Results. This report confirms the immobilization of spermatozoa by E. coli and demonstrates sperm immobilization factor (SIF) excreted by E. coli. Further this factor was purified by ammonium sulfate precipitation, gel permeation chromatography, and ion-exchange chromatography. Purified SIF (56 kDa) caused instant immobilization without agglutination of human spermatozoa at 800 μg/mL and death at 2.1 mg/mL. Spermatozoa incubated with SIF revealed multiple and profound alterations involving all superficial structures of spermatozoa as observed by scanning electron microscopy. Conclusion. In conclusion, these results have shown immobilization of spermatozoa by E. coli and demonstrate a factor (SIF) produced and secreted by E. coli which causes variable structural damage as probable morphological correlates of immobilization. PMID:20379358

  9. Succinate production in Escherichia coli

    PubMed Central

    Thakker, Chandresh; Martínez, Irene; San, Ka-Yiu; Bennett, George N.

    2012-01-01

    Succinate has been recognized as an important platform chemical that can be produced from biomass. While a number of organisms are capable of succinate production naturally, this review focuses on the engineering of Escherichia coli for production of the four-carbon dicarboxylic acid. Important features of a succinate production system are to achieve optimal balance of reducing equivalents generated by consumption of the feedstock, while maximizing the amount of carbon that is channeled to the product. Aerobic and anaerobic production strains have been developed and applied to production from glucose as well as other abundant carbon sources. Metabolic engineering methods and strain evolution have been used and supplemented by the recent application of systems biology and in silico modeling tools to construct optimal production strains. The metabolic capacity of the production strain, as well as the requirement for efficient recovery of succinate and the reliability of the performance under scale-up are important in the overall process. The costs of the overall biorefinery compatible process will determine the economical commercialization of succinate and its impact in larger chemical markets. PMID:21932253

  10. Enterohemorrhagic E. coli (EHEC) pathogenesis

    PubMed Central

    Nguyen, Y; Sperandio, Vanessa

    2012-01-01

    Enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 is a human pathogen responsible for outbreaks of bloody diarrhea and hemolytic uremic syndrome (HUS) worldwide. Conventional antimicrobials trigger an SOS response in EHEC that promotes the release of the potent Shiga toxin that is responsible for much of the morbidity and mortality associated with EHEC infection. Cattle are a natural reservoir of EHEC, and approximately 75% of EHEC outbreaks are linked to the consumption of contaminated bovine-derived products. This review will discuss how EHEC causes disease in humans but is asymptomatic in adult ruminants. It will also analyze factors utilized by EHEC as it travels through the bovine gastrointestinal (GI) tract that allow for its survival through the acidic environment of the distal stomachs, and for its ultimate colonization in the recto-anal junction (RAJ). Understanding the factors crucial for EHEC survival and colonization in cattle will aid in the development of alternative strategies to prevent EHEC shedding into the environment and consequent human infection. PMID:22919681

  11. Dihydropteridine reductase from Escherichia coli.

    PubMed Central

    Vasudevan, S G; Shaw, D C; Armarego, W L

    1988-01-01

    A dihydropteridine reductase from Escherichia coli was purified to apparent homogeneity. It is a dimeric enzyme with identical subunits (Mr 27000) and a free N-terminal group. It can use NADH (Vmax./Km 3.36 s-1) and NADPH (Vmax./Km 1.07 s-1) when 6-methyldihydro-(6H)-pterin is the second substrate, as well as quinonoid dihydro-(6H)-biopterin (Vmax./Km 0.69 s-1), dihydro-(6H)-neopterin (Vmax./Km 0.58 s-1), dihydro-(6H)-monapterin 0.66 s-1), 6-methyldihydro-(6H)-pterin and cis-6,7-dimethyldihydro-(6H)-pterin (Vmax./Km 0.66 s-1) when NADH is the second substrate. The pure reductase has a yellow colour and contains bound FAD. The enzyme also has pterin-independent NADH and NADPH oxidoreductase activities when potassium ferricyanide is the electron acceptor. Images Fig. 2. PMID:3060113

  12. Live from the Arctic

    NASA Astrophysics Data System (ADS)

    Warnick, W. K.; Haines-Stiles, G.; Warburton, J.; Sunwood, K.

    2003-12-01

    For reasons of geography and geophysics, the poles of our planet, the Arctic and Antarctica, are places where climate change appears first: they are global canaries in the mine shaft. But while Antarctica (its penguins and ozone hole, for example) has been relatively well-documented in recent books, TV programs and journalism, the far North has received somewhat less attention. This project builds on and advances what has been done to date to share the people, places, and stories of the North with all Americans through multiple media, over several years. In a collaborative project between the Arctic Research Consortium of the United States (ARCUS) and PASSPORT TO KNOWLEDGE, Live from the Arctic will bring the Arctic environment to the public through a series of primetime broadcasts, live and taped programming, interactive virtual field trips, and webcasts. The five-year project will culminate during the 2007-2008 International Polar Year (IPY). Live from the Arctic will: A. Promote global understanding about the value and world -wide significance of the Arctic, B. Bring cutting-edge research to both non-formal and formal education communities, C. Provide opportunities for collaboration between arctic scientists, arctic communities, and the general public. Content will focus on the following four themes. 1. Pan-Arctic Changes and Impacts on Land (i.e. snow cover; permafrost; glaciers; hydrology; species composition, distribution, and abundance; subsistence harvesting) 2. Pan-Arctic Changes and Impacts in the Sea (i.e. salinity, temperature, currents, nutrients, sea ice, marine ecosystems (including people, marine mammals and fisheries) 3. Pan-Arctic Changes and Impacts in the Atmosphere (i.e. precipitation and evaporation; effects on humans and their communities) 4. Global Perspectives (i.e. effects on humans and communities, impacts to rest of the world) In The Earth is Faster Now, a recent collection of comments by members of indigenous arctic peoples, arctic

  13. Consumer Coalition on Assisted Living

    MedlinePlus

    Skip to content Home Dementia Action Alliance Consumers Caregiving Info Consumer Empowerment Informed Consumer Contact Us Person-Centered Living Person-Centered Living Overview PCL Resources Home- and Community-Based Services Overview ...

  14. Living with a Brain Tumor

    MedlinePlus

    ... Mentor The ABTA's Online Support Community Understanding The Affordable Care Act Living with a Brain Tumor Understanding Emotions Talking ... Mentor The ABTA's Online Support Community Understanding The Affordable Care Act Living with a Brain Tumor Understanding Emotions Talking ...

  15. Living with Tuberous Sclerosis Complex

    MedlinePlus

    ... living and employment while others may deal with dating issues and reproductive concerns. Throughout their lives, those ... Overview Outreach Toolkit Government Action Team TS Alliance Online Support Community Facebook Twitter YouTube How to Make ...

  16. "Living versus Dead":

    PubMed Central

    Chakrabarti, Pratik

    2010-01-01

    Summary The Semple antirabies vaccine was developed by David Semple in India in 1911. Semple introduced a peculiarly British approach within the Pasteurian tradition by using carbolized dead virus. This article studies this unique phase of vaccine research between 1910 and 1935 to show that in the debates and laboratory experiments around the potency and safety of vaccines, categories like "living" and "dead" were often used as ideological and moral denominations. These abstract and ideological debates were crucial in defining the final configuration of the Semple vaccine, the most popular antirabies vaccine used globally, and also in shaping international vaccination policies. PMID:21037397

  17. Microencapsulation Of Living Cells

    NASA Technical Reports Server (NTRS)

    Chang, Manchium; Kendall, James M.; Wang, Taylor G.

    1989-01-01

    In experimental technique, living cells and other biological materials encapsulated within submillimeter-diameter liquid-filled spheres. Sphere material biocompatible, tough, and compliant. Semipermeable, permitting relatively small molecules to move into and out of sphere core but preventing passage of large molecules. New technique promises to make such spherical capsules at high rates and in uniform, controllable sizes. Capsules injected into patient through ordinary hypodermic needle. Promising application for technique in treatment of diabetes. Also used to encapsulate pituitary cells and thyroid hormone adrenocortical cells for treatment of other hormonal disorders, to encapsulate other secreting cells for transplantation, and to package variety of pharmaceutical products and agricultural chemicals for controlled release.

  18. Living in Space

    NASA Technical Reports Server (NTRS)

    Brown, Ray (Editor)

    1993-01-01

    In this educational video from the 'Liftoff to Learning' series, astronauts from the STS-56 Mission (Ken Cockrell, Mike Foale, Ellen Ochoa, Steve Oswald, and Ken Cameron) explain and show through demonstrations how microgravity affects the way astronauts live onboard the Space Shuttle, and how these same daily habits or processes differ on Earth. A tour of the Space Shuttle is given, including the sleeping compartments, the kitchen area, the storage compartments, and the Waste Collection System (or WCS, as they call it). Daily habits (brushing teeth, shampooing hair and bathing, eating,...) are explained and actively illustrated, along with reasons of how these applications differ from their employment on Earth.

  19. Living with lightning

    SciTech Connect

    Lamarre, L.

    1994-01-01

    As many as 100 lightning flashes occur around the world each second. Electric utilities know well the impact of lightning in terms of dollars, lost productivity, and lives. EPRI research, which began with a study of lightning`s natural characteristics, has resulted in tools utilities can use to better track and prepare for thunderstorms. Recently the institute completed a series of tests using small rockets to trigger and direct lightning strikes. Now EPRI-sponsored researchers are developing a laser-based technology they believe will be able to guide thunderbolts safely to the ground and ultimately even to discharge thunderclouds.

  20. Living olefin polymerization processes

    DOEpatents

    Schrock, Richard R.; Bauman, Robert

    2006-11-14

    Processes for the living polymerization of olefin monomers with terminal carbon-carbon double bonds are disclosed. The processes employ initiators that include a metal atom and a ligand having two group 15 atoms and a group 16 atom or three group 15 atoms. The ligand is bonded to the metal atom through two anionic or covalent bonds and a dative bond. The initiators are particularly stable under reaction conditions in the absence of olefin monomer. The processes provide polymers having low polydispersities, especially block copolymers having low polydispersities. It is an additional advantage of these processes that, during block copolymer synthesis, a relatively small amount of homopolymer is formed.

  1. Living olefin polymerization processes

    DOEpatents

    Schrock, Richard R.; Baumann, Robert

    2003-08-26

    Processes for the living polymerization of olefin monomers with terminal carbon-carbon double bonds are disclosed. The processes employ initiators that include a metal atom and a ligand having two group 15 atoms and a group 16 atom or three group 15 atoms. The ligand is bonded to the metal atom through two anionic or covalent bonds and a dative bond. The initiators are particularly stable under reaction conditions in the absence of olefin monomer. The processes provide polymers having low polydispersities, especially block copolymers having low polydispersities. It is an additional advantage of these processes that, during block copolymer synthesis, a relatively small amount of homopolymer is formed.

  2. Living olefin polymerization processes

    DOEpatents

    Schrock, R.R.; Baumann, R.

    1999-03-30

    Processes for the living polymerization of olefin monomers with terminal carbon-carbon double bonds are disclosed. The processes employ initiators that include a metal atom and a ligand having two group 15 atoms and a group 16 atom or three group 15 atoms. The ligand is bonded to the metal atom through two anionic or covalent bonds and a dative bond. The initiators are particularly stable under reaction conditions in the absence of olefin monomer. The processes provide polymers having low polydispersities, especially block copolymers having low polydispersities. It is an additional advantage of these processes that, during block copolymer synthesis, a relatively small amount of homopolymer is formed.

  3. Living olefin polymerization processes

    DOEpatents

    Schrock, Richard R.; Baumann, Robert

    1999-01-01

    Processes for the living polymerization of olefin monomers with terminal carbon-carbon double bonds are disclosed. The processes employ initiators that include a metal atom and a ligand having two group 15 atoms and a group 16 atom or three group 15 atoms. The ligand is bonded to the metal atom through two anionic or covalent bonds and a dative bond. The initiators are particularly stable under reaction conditions in the absence of olefin monomer. The processes provide polymers having low polydispersities, especially block copolymers having low polydispersities. It is an additional advantage of these processes that, during block copolymer synthesis, a relatively small amount of homopolymer is formed.

  4. Pathogenic Escherichia coli strain discrimination using laser-induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Diedrich, Jonathan; Rehse, Steven J.; Palchaudhuri, Sunil

    2007-07-01

    A pathogenic strain of bacteria, Escherichia coli O157:H7 (enterohemorrhagic E. coli or EHEC), has been analyzed by laser-induced breakdown spectroscopy (LIBS) with nanosecond pulses and compared to three nonpathogenic E. coli strains: a laboratory strain of K-12 (AB), a derivative of the same strain termed HF4714, and an environmental strain, E. coli C (Nino C). A discriminant function analysis (DFA) was performed on the LIBS spectra obtained from live colonies of all four strains. Utilizing the emission intensity of 19 atomic and ionic transitions from trace inorganic elements, the DFA revealed significant differences between EHEC and the Nino C strain, suggesting the possibility of identifying and discriminating the pathogenic strain from commonly occurring environmental strains. EHEC strongly resembled the two K-12 strains, in particular, HF4714, making discrimination between these strains difficult. DFA was also used to analyze spectra from two of the nonpathogenic strains cultured in different media: on a trypticase soy (TS) agar plate and in a liquid TS broth. Strains cultured in different media were identified and effectively discriminated, being more similar than different strains cultured in identical media. All bacteria spectra were completely distinct from spectra obtained from the nutrient medium or ablation substrate alone. The ability to differentiate strains prepared and tested in different environments indicates that matrix effects and background contaminations do not necessarily preclude the use of LIBS to identify bacteria found in a variety of environments or grown under different conditions.

  5. Membrane-based electrochemical nanobiosensor for Escherichia coli detection and analysis of cells viability.

    PubMed

    Cheng, Ming Soon; Lau, Suk Hiang; Chow, Vincent T; Toh, Chee-Seng

    2011-08-01

    A sensitive and selective membrane-based electrochemical nanobiosensor is developed for specific quantitative label-free detection of Escherichia coli (E. coli) cells and analysis of viable but nonculturable (VBNC) E. coli cells which remain mostly undetected using current methods. The sensing mechanism relies on the blocking of nanochannels of a nanoporous alumina-membrane modified electrode, upon the formation of immune complexes at the nanoporous membrane. The resulting obstacle to diffusive mass transfer of a redox probe in the analysis solution to the underlying platinum electrode reduces the Faradaic signal response of the biosensor, measured using cyclic voltammetry. Antibody loading under conditions of varying antibody concentrations and pHs are optimized. The biosensor gives a low detection limit of 22 cfu mL(-1) (R(2) = 0.999) over a wide linear working range of 10 to 10(6) cfu mL(-1). It is specific toward E. coli with minimal cross-reactivity to two other pathogenic bacteria (commonly found in waters). Relative standard deviation (RSD) for triplicate measurements of 2.5% indicates reasonably useful level of reproducibility. Differentiation of live, VBNC, and dead cells are carried out after the cell capture and quantitation step, by simple monitoring of the cells' enzyme activity using the same redox probe in the analysis solution, in the presence of glucose. PMID:21688778

  6. Campylobacter jejuni Increases Flagellar Expression and Adhesion of Noninvasive Escherichia coli: Effects on Enterocytic Toll-Like Receptor 4 and CXCL-8 Expression

    PubMed Central

    Reti, Kristen L.; Tymensen, Lisa D.; Davis, Shevaun P.; Amrein, Matthias W.

    2015-01-01

    Campylobacter jejuni is the most common cause of bacterium-induced gastroenteritis, and while typically self-limiting, C. jejuni infections are associated with postinfectious intestinal disorders, including flares in patients with inflammatory bowel disease and postinfectious irritable bowel syndrome (PI-IBS), via mechanisms that remain obscure. Based on the hypothesis that acute campylobacteriosis may cause pathogenic microbiota dysbiosis, we investigated whether C. jejuni may activate dormant virulence genes in noninvasive Escherichia coli and examined the epithelial pathophysiological consequences of these alterations. Microarray and quantitative real-time PCR analyses revealed that E. coli adhesin, flagellum, and hemolysin gene expression were increased when E. coli was exposed to C. jejuni-conditioned medium. Increased development of bacterial flagella upon exposure to live C. jejuni or C. jejuni-conditioned medium was observed under transmission electron microscopy. Atomic force microscopy demonstrated that the forces of bacterial adhesion to colonic T84 enterocytes, and the work required to rupture this adhesion, were significantly increased in E. coli exposed to C. jejuni-conditioned media. Finally, C. jejuni-modified E. coli disrupted TLR4 gene expression and induced proinflammatory CXCL-8 gene expression in colonic enterocytes. Together, these data suggest that exposure to live C. jejuni, and/or to its secretory-excretory products, may activate latent virulence genes in noninvasive E. coli and that these alterations may directly trigger proinflammatory signaling in intestinal epithelia. These observations shed new light on mechanisms that may contribute, at least in part, to postcampylobacteriosis inflammatory disorders. PMID:26371123

  7. Campylobacter jejuni increases flagellar expression and adhesion of noninvasive Escherichia coli: effects on enterocytic Toll-like receptor 4 and CXCL-8 expression.

    PubMed

    Reti, Kristen L; Tymensen, Lisa D; Davis, Shevaun P; Amrein, Matthias W; Buret, Andre G

    2015-12-01

    Campylobacter jejuni is the most common cause of bacterium-induced gastroenteritis, and while typically self-limiting, C. jejuni infections are associated with postinfectious intestinal disorders, including flares in patients with inflammatory bowel disease and postinfectious irritable bowel syndrome (PI-IBS), via mechanisms that remain obscure. Based on the hypothesis that acute campylobacteriosis may cause pathogenic microbiota dysbiosis, we investigated whether C. jejuni may activate dormant virulence genes in noninvasive Escherichia coli and examined the epithelial pathophysiological consequences of these alterations. Microarray and quantitative real-time PCR analyses revealed that E. coli adhesin, flagellum, and hemolysin gene expression were increased when E. coli was exposed to C. jejuni-conditioned medium. Increased development of bacterial flagella upon exposure to live C. jejuni or C. jejuni-conditioned medium was observed under transmission electron microscopy. Atomic force microscopy demonstrated that the forces of bacterial adhesion to colonic T84 enterocytes, and the work required to rupture this adhesion, were significantly increased in E. coli exposed to C. jejuni-conditioned media. Finally, C. jejuni-modified E. coli disrupted TLR4 gene expression and induced proinflammatory CXCL-8 gene expression in colonic enterocytes. Together, these data suggest that exposure to live C. jejuni, and/or to its secretory-excretory products, may activate latent virulence genes in noninvasive E. coli and that these alterations may directly trigger proinflammatory signaling in intestinal epithelia. These observations shed new light on mechanisms that may contribute, at least in part, to postcampylobacteriosis inflammatory disorders. PMID:26371123

  8. Toxicity of dysprosium nano particles with glucose and sodium chloride on E. Coli

    NASA Astrophysics Data System (ADS)

    Anaya, N. M.; Solomon, F.; Oyanedel-Craver, V.

    2013-12-01

    Application of rare earth elements (REEs) such as, dysprosium nanoparticles (nDy), to the biomedical field are increasing due to their paramagnetic properties. Current applications of nDy in the biomedical field are in MRI screening and anti-cancer therapy. Environmental impacts of nDy released into the environment are unknown or poorly understood and are a concern due to the lack of appropriate recycling systems. The objective of this toxicological study is to assess the impacts of nDy at relevant environmental concentrations on Escherichia coli. A range of glucose concentrations were used to evaluate the impact under different aerobic metabolic stages when the bacteria are exposed to the nanoparticles. Two traditional techniques used to evaluate the physiological response of E. coli at different environmental conditions were dual staining with fluorescent dyes (Live/Dead BacLight viability kit) and respirometric assays. A high-through put array-based methodology was implemented to provide additional toxicity testing. Preliminary toxicology results for both traditional techniques showed a positive trend between nDy and carbon source concentrations. High concentrations of nDy (>5mg/L) in environments with high glucose concentration (>210mg/L) are more toxic to E. coli than environments with low glucose concentrations. On the other hand, Live/Dead experiments showed higher toxicity effect in comparison to the respirometric tests using the same exposure conditions, suggesting that even at high membrane disruption the bacteria can still performed some metabolic activity.

  9. Living liquid crystals

    PubMed Central

    Zhou, Shuang; Sokolov, Andrey; Lavrentovich, Oleg D.; Aranson, Igor S.

    2014-01-01

    Collective motion of self-propelled organisms or synthetic particles, often termed “active fluid,” has attracted enormous attention in the broad scientific community because of its fundamentally nonequilibrium nature. Energy input and interactions among the moving units and the medium lead to complex dynamics. Here, we introduce a class of active matter––living liquid crystals (LLCs)––that combines living swimming bacteria with a lyotropic liquid crystal. The physical properties of LLCs can be controlled by the amount of oxygen available to bacteria, by concentration of ingredients, or by temperature. Our studies reveal a wealth of intriguing dynamic phenomena, caused by the coupling between the activity-triggered flow and long-range orientational order of the medium. Among these are (i) nonlinear trajectories of bacterial motion guided by nonuniform director, (ii) local melting of the liquid crystal caused by the bacteria-produced shear flows, (iii) activity-triggered transition from a nonflowing uniform state into a flowing one-dimensional periodic pattern and its evolution into a turbulent array of topological defects, and (iv) birefringence-enabled visualization of microflow generated by the nanometers-thick bacterial flagella. Unlike their isotropic counterpart, the LLCs show collective dynamic effects at very low volume fraction of bacteria, on the order of 0.2%. Our work suggests an unorthodox design concept to control and manipulate the dynamic behavior of soft active matter and opens the door for potential biosensing and biomedical applications. PMID:24474746

  10. Living liquid crystals.

    PubMed

    Zhou, Shuang; Sokolov, Andrey; Lavrentovich, Oleg D; Aranson, Igor S

    2014-01-28

    Collective motion of self-propelled organisms or synthetic particles, often termed "active fluid," has attracted enormous attention in the broad scientific community because of its fundamentally nonequilibrium nature. Energy input and interactions among the moving units and the medium lead to complex dynamics. Here, we introduce a class of active matter--living liquid crystals (LLCs)--that combines living swimming bacteria with a lyotropic liquid crystal. The physical properties of LLCs can be controlled by the amount of oxygen available to bacteria, by concentration of ingredients, or by temperature. Our studies reveal a wealth of intriguing dynamic phenomena, caused by the coupling between the activity-triggered flow and long-range orientational order of the medium. Among these are (i) nonlinear trajectories of bacterial motion guided by nonuniform director, (ii) local melting of the liquid crystal caused by the bacteria-produced shear flows, (iii) activity-triggered transition from a nonflowing uniform state into a flowing one-dimensional periodic pattern and its evolution into a turbulent array of topological defects, and (iv) birefringence-enabled visualization of microflow generated by the nanometers-thick bacterial flagella. Unlike their isotropic counterpart, the LLCs show collective dynamic effects at very low volume fraction of bacteria, on the order of 0.2%. Our work suggests an unorthodox design concept to control and manipulate the dynamic behavior of soft active matter and opens the door for potential biosensing and biomedical applications. PMID:24474746