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Sample records for coli pnpase central

  1. Next generation sequencing analysis reveals that the ribonucleases RNase II, RNase R and PNPase affect bacterial motility and biofilm formation in E. coli.

    Science.gov (United States)

    Pobre, Vânia; Arraiano, Cecília M

    2015-02-14

    The RNA steady-state levels in the cell are a balance between synthesis and degradation rates. Although transcription is important, RNA processing and turnover are also key factors in the regulation of gene expression. In Escherichia coli there are three main exoribonucleases (RNase II, RNase R and PNPase) involved in RNA degradation. Although there are many studies about these exoribonucleases not much is known about their global effect in the transcriptome. In order to study the effects of the exoribonucleases on the transcriptome, we sequenced the total RNA (RNA-Seq) from wild-type cells and from mutants for each of the exoribonucleases (∆rnb, ∆rnr and ∆pnp). We compared each of the mutant transcriptome with the wild-type to determine the global effects of the deletion of each exoribonucleases in exponential phase. We determined that the deletion of RNase II significantly affected 187 transcripts, while deletion of RNase R affects 202 transcripts and deletion of PNPase affected 226 transcripts. Surprisingly, many of the transcripts are actually down-regulated in the exoribonuclease mutants when compared to the wild-type control. The results obtained from the transcriptomic analysis pointed to the fact that these enzymes were changing the expression of genes related with flagellum assembly, motility and biofilm formation. The three exoribonucleases affected some stable RNAs, but PNPase was the main exoribonuclease affecting this class of RNAs. We confirmed by qPCR some fold-change values obtained from the RNA-Seq data, we also observed that all the exoribonuclease mutants were significantly less motile than the wild-type cells. Additionally, RNase II and RNase R mutants were shown to produce more biofilm than the wild-type control while the PNPase mutant did not form biofilms. In this work we demonstrate how deep sequencing can be used to discover new and relevant functions of the exoribonucleases. We were able to obtain valuable information about the

  2. A PNPase Dependent CRISPR System in Listeria

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    Sesto, Nina; Touchon, Marie; Andrade, José Marques; Kondo, Jiro; Rocha, Eduardo P. C.; Arraiano, Cecilia Maria; Archambaud, Cristel; Westhof, Éric; Romby, Pascale; Cossart, Pascale

    2014-01-01

    The human bacterial pathogen Listeria monocytogenes is emerging as a model organism to study RNA-mediated regulation in pathogenic bacteria. A class of non-coding RNAs called CRISPRs (clustered regularly interspaced short palindromic repeats) has been described to confer bacterial resistance against invading bacteriophages and conjugative plasmids. CRISPR function relies on the activity of CRISPR associated (cas) genes that encode a large family of proteins with nuclease or helicase activities and DNA and RNA binding domains. Here, we characterized a CRISPR element (RliB) that is expressed and processed in the L. monocytogenes strain EGD-e, which is completely devoid of cas genes. Structural probing revealed that RliB has an unexpected secondary structure comprising basepair interactions between the repeats and the adjacent spacers in place of canonical hairpins formed by the palindromic repeats. Moreover, in contrast to other CRISPR-Cas systems identified in Listeria, RliB-CRISPR is ubiquitously present among Listeria genomes at the same genomic locus and is never associated with the cas genes. We showed that RliB-CRISPR is a substrate for the endogenously encoded polynucleotide phosphorylase (PNPase) enzyme. The spacers of the different Listeria RliB-CRISPRs share many sequences with temperate and virulent phages. Furthermore, we show that a cas-less RliB-CRISPR lowers the acquisition frequency of a plasmid carrying the matching protospacer, provided that trans encoded cas genes of a second CRISPR-Cas system are present in the genome. Importantly, we show that PNPase is required for RliB-CRISPR mediated DNA interference. Altogether, our data reveal a yet undescribed CRISPR system whose both processing and activity depend on PNPase, highlighting a new and unexpected function for PNPase in “CRISPRology”. PMID:24415952

  3. Identification of genes potentially regulated by human polynucleotide phosphorylase (hPNPase old-35 using melanoma as a model.

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    Upneet K Sokhi

    Full Text Available Human Polynucleotide Phosphorylase (hPNPase(old-35 or PNPT1 is an evolutionarily conserved 3'→ 5' exoribonuclease implicated in the regulation of numerous physiological processes including maintenance of mitochondrial homeostasis, mtRNA import and aging-associated inflammation. From an RNase perspective, little is known about the RNA or miRNA species it targets for degradation or whose expression it regulates; except for c-myc and miR-221. To further elucidate the functional implications of hPNPase(old-35 in cellular physiology, we knocked-down and overexpressed hPNPase(old-35 in human melanoma cells and performed gene expression analyses to identify differentially expressed transcripts. Ingenuity Pathway Analysis indicated that knockdown of hPNPase(old-35 resulted in significant gene expression changes associated with mitochondrial dysfunction and cholesterol biosynthesis; whereas overexpression of hPNPase(old-35 caused global changes in cell-cycle related functions. Additionally, comparative gene expression analyses between our hPNPase(old-35 knockdown and overexpression datasets allowed us to identify 77 potential "direct" and 61 potential "indirect" targets of hPNPase(old-35 which formed correlated networks enriched for cell-cycle and wound healing functional association, respectively. These results provide a comprehensive database of genes responsive to hPNPase(old-35 expression levels; along with the identification new potential candidate genes offering fresh insight into cellular pathways regulated by PNPT1 and which may be used in the future for possible therapeutic intervention in mitochondrial- or inflammation-associated disease phenotypes.

  4. Ciprofloxacin-resistant Escherichia coli in Central Greece: mechanisms of resistance and molecular identification

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    Mavroidi Angeliki

    2012-12-01

    Full Text Available Abstract Background Fluoroquinolone resistant E. coli isolates, that are also resistant to other classes of antibiotics, is a significant challenge to antibiotic treatment and infection control policies. In Central Greece a significant increase of ciprofloxacin-resistant Escherichia coli has occurred during 2011, indicating the need for further analysis. Methods A total of 106 ciprofloxacin-resistant out of 505 E. coli isolates consecutively collected during an eight months period in a tertiary Greek hospital of Central Greece were studied. Antimicrobial susceptibility patterns and mechanisms of resistance to quinolones were assessed, whereas selected isolates were further characterized by multilocus sequence typing and β-lactamase content. Results Sequence analysis of the quinolone-resistance determining region of the gyrA and parC genes has revealed that 63% of the ciprofloxacin-resistant E. coli harbored a distinct amino acid substitution pattern (GyrA:S83L + D87N; ParC:S80I + E84V, while 34% and 3% carried the patterns GyrA:S83L + D87N; ParC:S80I and GyrA:S83L + D87N; ParC:S80I + E84G respectively. The aac (6’-1b-cr plasmid-mediated quinolone resistance determinant was also detected; none of the isolates was found to carry the qnrA, qnrB and qnrS. Genotyping of a subset of 35 selected ciprofloxacin-resistant E. coli by multilocus sequence typing has revealed the presence of nine sequence types; ST131 and ST410 were the most prevalent and were exclusively correlated with hospital and health care associated infections, while strains belonging to STs 393, 361 and 162 were associated with community acquired infections. The GyrA:S83L + D87N; ParC:S80I + E84V substitution pattern was found exclusively among ST131 ciprofloxacin-resistant E. coli. Extended-spectrum β-lactamase-positive ST131 ciprofloxacin-resistant isolates produced CTX-M-type enzymes; eight the CTX-M-15 and one the CTX-M-3 variant. CTX-M-1 like and KPC-2 enzymes were detected

  5. Genetic response to metabolic fluctuations: correlation between central carbon metabolism and DNA replication in Escherichia coli

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    Szalewska-Pałasz Agnieszka

    2011-03-01

    Full Text Available Abstract Background Until now, the direct link between central carbon metabolism and DNA replication has been demonstrated only in Bacillus. subtilis. Therefore, we asked if this is a specific phenomenon, characteristic for this bacterium and perhaps for its close relatives, or a more general biological rule. Results We found that temperature-sensitivity of mutants in particular genes coding for replication proteins could be suppressed by deletions of certain genes coding for enzymes of the central carbon metabolism. Namely, the effects of dnaA46(ts mutation could be suppressed by dysfunction of pta or ackA, effects of dnaB(ts by dysfunction of pgi or pta, effects of dnaE486(ts by dysfunction of tktB, effects of dnaG(ts by dysfunction of gpmA, pta or ackA, and effects of dnaN159(ts by dysfunction of pta or ackA. The observed suppression effects were not caused by a decrease in bacterial growth rate. Conclusions The genetic correlation exists between central carbon metabolism and DNA replication in the model Gram-negative bacterium, E. coli. This link exists at the steps of initiation and elongation of DNA replication, indicating the important global correlation between metabolic status of the cell and the events leading to cell reproduction.

  6. Antibiotic sensitivity of escherichia coli isolated from urinary tract infection referred to Kermanshah central laboratory

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    Parviz Mohajeri

    2011-03-01

    Full Text Available Background: Escherichia coli (Ecoli has been considered as the most common agent of urinary tract infection in all regions. Recently, increased drug resistance has been lead to some problems in treatment related diseases. So, evaluation of resistance patterns of bacteria in each region could be a valuable guide for empirical treatment.Methods: All referred urine sample to Kermanshah Central Laboratory during 1998 that was reported positive to Ecoli were assessed. Susceptibility pattern to 19 antimicrobial agents was evaluated using Kirby Bauer method according to CLSI standards.Results: A total of 834 Ecoli isolated from 19,208 positive urine cultures. 84% of subjects were females and 16% males. Sensitivity rate for nitrofurantoin (84%, ceftizoxime (72%, norfloxacin (70%, cefotaxime (69%, Amikacin (66%, ciprofloxacin (65%, ceftriaxone (64%, ceftazidim (55% was higher than 50%. Sensitivity to nalidixic acid, cefexime, gentamicin, co-trimoxazole, ticarcillin, caphalexin, cephalotin, tetracycline, amoxicillin, amoxicillin clavulanate and ampicillin were determined less than 50%.Conclusion: Nitrofurantoin and ceftizoxime are currently effective against Ecoli, although an indiscriminate use of antibiotics should be avoided because of drug resistance probable. It seems that ampicillin could be excluded from routine sensitivity testing.

  7. Presence and characterization of Escherichia coli virulence genes isolated from diseased pigs in the central region of Argentina

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    Fernando A. Bessone

    2017-08-01

    Full Text Available Background: The main pathogen of neonatal and post weaning diarrhea and edema disease (ED is Escherichia coli and pathotypes involved are enterotoxigenic, enteropathogenic, and shiga toxigenic (ETEC, EPEC, and STEC, respectively. Those diseases cause economic loss in pig production. Aim: The aim of this work was to evaluate the presence of strains expressing virulence markers genes and the antibiotic susceptibility profiles of E. coli from clinical cases of post weaning diarrhea and ED in farms in the central area of Argentina. Materials and Methods: Intensive pig farms from the central region of Argentina were sampled. Intestinal mucosa swabs from pigs with diarrhea were taken, seeded on MacConkey agar plates, biochemically typified and tested by polymerase chain reaction (PCR. Antibiograms were made by disk-diffusion method. Results: A total of 54 strains from clinical cases studied showed PCR findings: 88.88% (48/54 expressed at least one gene coding for a virulence factor. Colonization factors found were: 39.58% of strains had F18, 33.33% were F4 and 31.25% adhesin involved in diffuse adherence-I; 29.17%, 25%, and 2.1% expressed LT, STb, and STa, respectively. 25% were STx and 16.67% were eae positive. Only 2.1% were STx2. The most active antibiotics against most strains were gentamicin and ceftiofur, but resistance profiles against many antibiotics were found. Conclusion: High circulation of pathogens strains of E. coli among pigs with diarrhea with an extended antibiotic resistance profile.

  8. Molecular epidemiology over an 11-year period (2000 to 2010) of extended-spectrum β-lactamase-producing Escherichia coli causing bacteremia in a centralized Canadian region

    NARCIS (Netherlands)

    G. Peirano (G.); A.K. van der Bij (Akke); S. Gregson (Simon); J.D.D. Pitout (J. D D)

    2012-01-01

    textabstractA study was designed to assess the importance of sequence types among extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates causing bacteremia over an 11-year period (2000 to 2010) in a centralized Canadian region. A total of 197 patients with incident infections were

  9. Extraction of elementary rate constants from global network analysis of E. coli central metabolism

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    Broderick Gordon

    2008-05-01

    Full Text Available Abstract Background As computational performance steadily increases, so does interest in extending one-particle-per-molecule models to larger physiological problems. Such models however require elementary rate constants to calculate time-dependent rate coefficients under physiological conditions. Unfortunately, even when in vivo kinetic data is available, it is often in the form of aggregated rate laws (ARL that do not specify the required elementary rate constants corresponding to mass-action rate laws (MRL. There is therefore a need to develop a method which is capable of automatically transforming ARL kinetic information into more detailed MRL rate constants. Results By incorporating proteomic data related to enzyme abundance into an MRL modelling framework, here we present an efficient method operating at a global network level for extracting elementary rate constants from experiment-based aggregated rate law (ARL models. The method combines two techniques that can be used to overcome the difficult properties in parameterization. The first, a hybrid MRL/ARL modelling technique, is used to divide the parameter estimation problem into sub-problems, so that the parameters of the mass action rate laws for each enzyme are estimated in separate steps. This reduces the number of parameters that have to be optimized simultaneously. The second, a hybrid algebraic-numerical simulation and optimization approach, is used to render some rate constants identifiable, as well as to greatly narrow the bounds of the other rate constants that remain unidentifiable. This is done by incorporating equality constraints derived from the King-Altman and Cleland method into the simulated annealing algorithm. We apply these two techniques to estimate the rate constants of a model of E. coli glycolytic pathways. The simulation and statistical results show that our innovative method performs well in dealing with the issues of high computation cost, stiffness, local

  10. Extraction of elementary rate constants from global network analysis of E. coli central metabolism

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    Zhao, Jiao; Ridgway, Douglas; Broderick, Gordon; Kovalenko, Andriy; Ellison, Michael

    2008-01-01

    Background As computational performance steadily increases, so does interest in extending one-particle-per-molecule models to larger physiological problems. Such models however require elementary rate constants to calculate time-dependent rate coefficients under physiological conditions. Unfortunately, even when in vivo kinetic data is available, it is often in the form of aggregated rate laws (ARL) that do not specify the required elementary rate constants corresponding to mass-action rate laws (MRL). There is therefore a need to develop a method which is capable of automatically transforming ARL kinetic information into more detailed MRL rate constants. Results By incorporating proteomic data related to enzyme abundance into an MRL modelling framework, here we present an efficient method operating at a global network level for extracting elementary rate constants from experiment-based aggregated rate law (ARL) models. The method combines two techniques that can be used to overcome the difficult properties in parameterization. The first, a hybrid MRL/ARL modelling technique, is used to divide the parameter estimation problem into sub-problems, so that the parameters of the mass action rate laws for each enzyme are estimated in separate steps. This reduces the number of parameters that have to be optimized simultaneously. The second, a hybrid algebraic-numerical simulation and optimization approach, is used to render some rate constants identifiable, as well as to greatly narrow the bounds of the other rate constants that remain unidentifiable. This is done by incorporating equality constraints derived from the King-Altman and Cleland method into the simulated annealing algorithm. We apply these two techniques to estimate the rate constants of a model of E. coli glycolytic pathways. The simulation and statistical results show that our innovative method performs well in dealing with the issues of high computation cost, stiffness, local minima and uncertainty

  11. Antimicrobial-resistant faecal Escherichia coli in wild mammals in central Europe: multiresistant Escherichia coli producing extended-spectrum ß-lactamases in wild boars

    DEFF Research Database (Denmark)

    Literak, I.; Dolejska, Monika; Radimersky, T.

    2010-01-01

    Aims: To determine the presence of antibiotic-resistant faecal Escherichia coli in populations of wild mammals in the Czech Republic and Slovakia. Methods and Results: Rectal swabs or faeces collected during 2006-2008 from wild mammals were spread on MacConkey agar and MacConkey agar containing 2...... mg l-1 of cefotaxime. From plates with positive growth, one isolate was recovered and identified as E. coli. Susceptibility to 12 antibiotics was tested using the disk diffusion method. Resistance genes, class 1 and 2 integrons and gene cassettes were detected in resistant isolates by polymerase...... of resistant isolates was 6%. Class 1 and 2 integrons with various gene cassettes were recorded in resistant isolates. From wild boars, five (2%, n(rectal smears) = 293) multiresistant isolates producing ESBL were recovered: one isolate with bla(CTX-M-1) + bla(TEM-1), three with bla(CTX-M-1) and one with bla...

  12. Prevalencia y resistencia a antibióticos de Escherichia coli O157:H7 aislada de canales de bovinos sacrificados en rastros del altiplano central Mexicano

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    Nydia Edith Reyes-Rodríguez

    2013-01-01

    Full Text Available La carne es el principal vehículo de toxiinfecciones alimentarias como consecuencia de una higiene deficiente en el sacrificio de los animales o durante el manejo de las canales. En este estudio se analizaron tres rastros municipales del Altiplano Central Mexicano, de los cuales se obtuvieron 228 muestras pareadas de canal (n=114 y contenido de colon (n=114 de bovinos que fueron sacrificados en estos rastros; se obtuvieron 2 (0.8 % cepas de E. coli O157:NM a partir de contenido de colon y 6 (2.6 % cepas de E. coli O157:H7 (5 de canales y 1 de contenido de colon. El porcentaje de aislamiento de cada rastro fue variable, encontrando diferencias significativas ( P <0.05. En las cepas de E. coli O157:NM y O157:H7 se observa que la resistencia más alta fue para cefalotina con un 75 %, carbencilina con 62.5 %, amikacina con 50 % y gentamicina con 50 %, el 16.7 % de las cepas de E. coli O157:H7 presentaron los geneseae , stx1 y stx2 y el 66.7 % los gen eae y stx2 . En conclusión los resultados obtenidos muestra la presencia E. coli O157:H7 con factores de virulencia y resistencia a antibióticos, en canales de bovinos de rastros del altiplano central Mexicano, considerándose una fuente de contaminación importante y un riesgo para la salud pública.

  13. Sorption Kinetics of Escherichia coli and Salmonella sp on Two Soil Layers Associated with a Groundwater Table in Yaounde, Cameroon (Central Africa

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    Norbert Kemka

    2005-12-01

    Full Text Available A laboratory study has been carried out on two soil layers (HX and HY located above a groundwater table in Yaounde, Cameroon (Central Africa. The main purpose of this study was to assess the retention potential or sorption kinetics of Escherichia coli and Salmonella sp. on these soil layers. For both soil layers, bacterial sorption on soil particles occurred rapidly during the first 30 minutes of incubation of bacteria and soil particles in aqueous media, and increased gradually with incubation time up to 300 min. In some cases, adsorption rates fluctuated after 30 min of incubation, probably due to bacterial cell sorption to and de-sorption from soil particles. Using Freundlich isotherms, it was noted that adsorption coefficient related to adsorption capacity varied from 19 to 4026 E. coli.mg-1 of soil, and from 506 to 847 Salmonella sp.mg-1 of soil. For both bacterial species, the adsorption coefficient of layer HY (located in close proximity of the water table was greater than that of HX (located above layer HY and seemed to positively correlate with the pH values and N/P ratios, and to negatively correlate with the values of C/N and C/P ratios. The linearity coefficient related to adsorption intensity varied from 0.5841 to 1.0023 for E. coli, and from 0.7068 to 1.5236 for Salmonella sp. The physico-chemical characteristics of soil particles seemed to influence the sorption kinetics of bacteria on soil.

  14. Bactericidal peptidoglycan recognition protein induces oxidative stress in Escherichia coli through a block in respiratory chain and increase in central carbon catabolism.

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    Kashyap, Des R; Kuzma, Marcin; Kowalczyk, Dominik A; Gupta, Dipika; Dziarski, Roman

    2017-09-01

    Mammalian Peptidoglycan Recognition Proteins (PGRPs) kill both Gram-positive and Gram-negative bacteria through simultaneous induction of oxidative, thiol and metal stress responses in bacteria. However, metabolic pathways through which PGRPs induce these bactericidal stress responses are unknown. We screened Keio collection of Escherichia coli deletion mutants and revealed that deleting genes for respiratory chain flavoproteins or for tricarboxylic acid (TCA) cycle resulted in increased resistance of E. coli to PGRP killing. PGRP-induced killing depended on the production of hydrogen peroxide, which required increased supply of NADH for respiratory chain oxidoreductases from central carbon catabolism (glycolysis and TCA cycle), and was controlled by cAMP-Crp. Bactericidal PGRP induced a rapid decrease in respiration, which suggested that the main source of increased production of hydrogen peroxide was a block in respiratory chain and diversion of electrons from NADH oxidoreductases to oxygen. CpxRA two-component system was a negative regulator of PGRP-induced oxidative stress. By contrast, PGRP-induced thiol stress (depletion of thiols) and metal stress (increase in intracellular free Zn 2+ through influx of extracellular Zn 2+ ) were mostly independent of oxidative stress. Thus, manipulating pathways that induce oxidative, thiol and metal stress in bacteria could be a useful strategy to design new approaches to antibacterial therapy. © 2017 John Wiley & Sons Ltd.

  15. The carbon storage regulator (Csr) system exerts a nutrient-specific control over central metabolism in Escherichia coli strain Nissle 1917.

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    Revelles, Olga; Millard, Pierre; Nougayrède, Jean-Philippe; Dobrindt, Ulrich; Oswald, Eric; Létisse, Fabien; Portais, Jean-Charles

    2013-01-01

    The role of the post-transcriptional carbon storage regulator (Csr) system in nutrient utilization and in the control of the central metabolism in E. coli reference commensal strain Nissle 1917 was investigated. Analysis of the growth capabilities of mutants altered for various components of the Csr system (csrA51, csrB, csrC and csrD mutations) showed that only the protein CsrA - the key component of the system - exerts a marked role in carbon nutrition. Attenuation of CsrA activity in the csrA51 mutant affects the growth efficiency on a broad range of physiologically relevant carbon sources, including compounds utilized by the Entner-Doudoroff (ED) pathway. Detailed investigations of the metabolomes and fluxomes of mutants and wild-type cells grown on carbon sources representative of glycolysis and of the ED pathway (glucose and gluconate, respectively), revealed significant re-adjusting of central carbon metabolism for both compounds in the csrA51 mutant. However, the metabolic re-adjusting observed on gluconate was strikingly different from that observed on glucose, indicating a nutrient-specific control of metabolism by the Csr system.

  16. Prevalence of shiga toxin producing Escherichia coli, Salmonella enterica, and Listeria monocytogenes at public access watershed sites in a California Central Coast agricultural region.

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    Cooley, Michael B; Quiñones, Beatriz; Oryang, David; Mandrell, Robert E; Gorski, Lisa

    2014-01-01

    Produce contaminated with enteric pathogens is a major source of foodborne illness in the United States. Lakes, streams, rivers, and ponds were sampled with Moore swabs bi-monthly for over 2 years at 30 locations in the vicinity of a leafy green growing region on the Central California Coast and screened for Shiga toxin producing Escherichia coli (STEC), Salmonella enterica, and Listeria monocytogenes to evaluate the prevalence and persistence of pathogen subtypes. The prevalence of STEC from 1386 samples was 11%; 110 samples (8%) contained E. coli O157:H7 with the highest prevalence occurring close to cattle operations. Non-O157 STEC isolates represented major clinical O-types and 57% contained both shiga toxin types 1 and 2 and intimin. Multiple Locus Variable Number Tandem Repeat Analysis of STEC isolates indicated prevalent strains during the period of study. Notably, Salmonella was present at high levels throughout the sampling region with 65% prevalence in 1405 samples resulting in 996 isolates with slightly lower prevalence in late autumn. There were 2, 8, and 14 sites that were Salmonella-positive over 90, 80, and 70% of the time, respectively. The serotypes identified most often were 6,8:d:-, Typhimurium, and Give. Interestingly, analysis by Pulsed Field Gel Electrophoresis indicated persistence and transport of pulsotypes in the region over several years. In this original study of L. monocytogenes in the region prevalence was 43% of 1405 samples resulting in 635 individual isolates. Over 85% of the isolates belonged to serotype 4b with serotypes 1/2a, 1/2b, 3a, 4d with 4e representing the rest, and there were 12 and 2 sites that were positive over 50 and 80% of the time, respectively. Although surface water is not directly used for irrigation in this region, transport to the produce can occur by other means. This environmental survey assesses initial contamination levels toward an understanding of transport leading to produce recalls or outbreaks.

  17. Modelling and analysis of central metabolism operating regulatory interactions in salt stress conditions in a L-carnitine overproducing E. coli strain.

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    Guido Santos

    Full Text Available Based on experimental data from E. coli cultures, we have devised a mathematical model in the GMA-power law formalism that describes the central and L-carnitine metabolism in and between two steady states, non-osmotic and hyperosmotic (0.3 M NaCl. A key feature of this model is the introduction of type of kinetic order, the osmotic stress kinetic orders (g(OSn, derived from the power law general formalism, which represent the effect of osmotic stress in each metabolic process of the model.By considering the values of the g(OSn linked to each metabolic process we found that osmotic stress has a positive and determinant influence on the increase in flux in energetic metabolism (glycolysis; L-carnitine biosynthesis production; the transformation/excretion of Acetyl-CoA into acetate and ethanol; the input flux of peptone into the cell; the anabolic use of pyruvate and biomass decomposition. In contrast, we found that although the osmotic stress has an inhibitory effect on the transformation flux from the glycolytic end products (pyruvate to Acetyl-CoA, this inhibition is counteracted by other effects (the increase in pyruvate concentration to the extent that the whole flux increases. In the same vein, the down regulation exerted by osmotic stress on fumarate uptake and its oxidation and the production and export of lactate and pyruvate are reversed by other factors up to the point that the first increased and the second remained unchanged.The model analysis shows that in osmotic conditions the energy and fermentation pathways undergo substantial rearrangement. This is illustrated by the observation that the increase in the fermentation fluxes is not connected with fluxes towards the tricaboxylic acid intermediates and the synthesis of biomass. The osmotic stress associated with these fluxes reflects these changes. All these observations support that the responses to salt stress observed in E. coli might be conserved in halophiles.Flux evolution

  18. E. Coli

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    ... for the bacteria's medical name Escherichia coli . The strange thing about these bacteria — and lots of other ... In some cases, E. coli poisoning can cause life-threatening kidney problems. What Can Kids Do? Adults ...

  19. Suppression of the Escherichia coli dnaA46 mutation by changes in the activities of the pyruvate-acetate node links DNA replication regulation to central carbon metabolism.

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    Tymecka-Mulik, Joanna; Boss, Lidia; Maciąg-Dorszyńska, Monika; Matias Rodrigues, João F; Gaffke, Lidia; Wosinski, Anna; Cech, Grzegorz M; Szalewska-Pałasz, Agnieszka; Węgrzyn, Grzegorz; Glinkowska, Monika

    2017-01-01

    To ensure faithful transmission of genetic material to progeny cells, DNA replication is tightly regulated, mainly at the initiation step. Escherichia coli cells regulate the frequency of initiation according to growth conditions. Results of the classical, as well as the latest studies, suggest that the DNA replication in E. coli starts at a predefined, constant cell volume per chromosome but the mechanisms coordinating DNA replication with cell growth are still not fully understood. Results of recent investigations have revealed a role of metabolic pathway proteins in the control of cell division and a direct link between metabolism and DNA replication has also been suggested both in Bacillus subtilis and E. coli cells. In this work we show that defects in the acetate overflow pathway suppress the temperature-sensitivity of a defective replication initiator-DnaA under acetogenic growth conditions. Transcriptomic and metabolic analyses imply that this suppression is correlated with pyruvate accumulation, resulting from alterations in the pyruvate dehydrogenase (PDH) activity. Consequently, deletion of genes encoding the pyruvate dehydrogenase subunits likewise resulted in suppression of the thermal-sensitive growth of the dnaA46 strain. We propose that the suppressor effect may be directly related to the PDH complex activity, providing a link between an enzyme of the central carbon metabolism and DNA replication.

  20. Oxazolidinone resistance mutations in 23S rRNA of Escherichia coli reveal the central region of domain V as the primary site of drug action

    DEFF Research Database (Denmark)

    Xiong, L; Kloss, P; Douthwaite, S

    2000-01-01

    Oxazolidinone antibiotics inhibit bacterial protein synthesis by interacting with the large ribosomal subunit. The structure and exact location of the oxazolidinone binding site remain obscure, as does the manner in which these drugs inhibit translation. To investigate the drug-ribosome interaction......, we selected Escherichia coli oxazolidinone-resistant mutants, which contained a randomly mutagenized plasmid-borne rRNA operon. The same mutation, G2032 to A, was identified in the 23S rRNA genes of several independent resistant isolates. Engineering of this mutation by site-directed mutagenesis...

  1. Escherichia Coli

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    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…

  2. Characterization of 16S rRNA Processing with Pre-30S Subunit Assembly Intermediates from E. coli.

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    Smith, Brian A; Gupta, Neha; Denny, Kevin; Culver, Gloria M

    2018-06-08

    Ribosomal RNA (rRNA) is a major component of ribosomes and is fundamental to the process of translation. In bacteria, 16S rRNA is a component of the small ribosomal subunit and plays a critical role in mRNA decoding. rRNA maturation entails the removal of intervening spacer sequences contained within the pre-rRNA transcript by nucleolytic enzymes. Enzymatic activities involved in maturation of the 5'-end of 16S rRNA have been identified, but those involved in 3'-end maturation of 16S rRNA are more enigmatic. Here, we investigate molecular details of 16S rRNA maturation using purified in vivo-formed small subunit (SSU) assembly intermediates (pre-SSUs) from wild-type Escherichia coli that contain precursor 16S rRNA (17S rRNA). Upon incubation of pre-SSUs with E. coli S100 cell extracts or purified enzymes implicated in 16S rRNA processing, the 17S rRNA is processed into additional intermediates and mature 16S rRNA. These results illustrate that exonucleases RNase R, RNase II, PNPase, and RNase PH can process the 3'-end of pre-SSUs in vitro. However, the endonuclease YbeY did not exhibit nucleolytic activity with pre-SSUs under these conditions. Furthermore, these data demonstrate that multiple pathways facilitate 16S rRNA maturation with pre-SSUs in vitro, with the dominant pathways entailing complete processing of the 5'-end of 17S rRNA prior to 3'-end maturation or partial processing of the 5'-end with concomitant processing of the 3'-end. These results reveal the multifaceted nature of SSU biogenesis and suggest that E. coli may be able to escape inactivation of any one enzyme by using an existing complementary pathway. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Anti - microbial resistance stratified by risk factor among Escherichia coli strains isolated from the urinary tract at a rural clinic in Central India

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    Chatterjee B

    2009-01-01

    Full Text Available Background: The failure of empirical therapy is frequently observed, even in community-acquired urinary tract infections. We, therefore, conducted a prospective, clinic-based study in 2004-2005 to document anti-microbial resistance rates and correlate them with possible risk factors to assist empirical decision-making. Materials and Methods: Symptomatic patients with pyuria underwent urine culture. Isolates were identified using standard methods and anti-microbial resistance was determined by disk-diffusion. Ultrasonography was used to detect complicating factors. Patients were stratified by the presence of complicating factors and history of invasive procedures for comparison of resistance rates. Statistical Method Used: Chi-square or Fisher exact tests, as appropriate. Results: There were 156 E. coli isolates, of which 105 were community-acquired. Twenty-three community-acquired isolates were from patients with complicating factors while 82 were from patients without any. Fifty-one isolates were from patients who had recently undergone invasive procedures on the urinary tract. Thirty-two community-acquired isolates from reproductive-age women without apparent complicating factors had resistance rates of 50% or above against tetracyclines, Co-trimoxazole, aminopenicillins, Nalidixic acid, Ciprofloxacin and 1 st generation cephalosporins. Resistance rates were significantly higher among isolates from patients subjected to invasive procedures, except against Co-trimoxazole, tetracyclines and Amikacin. Conclusion: High rates of anti-microbial resistance in community-acquired uropathogens have made antimicrobial sensitivity testing necessary even in a rural, primary-care setting.

  4. E. Coli and Pregnancy

    Science.gov (United States)

    ... chat Live Help Fact Sheets Share Escherichia coli (E. coli) Friday, 01 September 2017 In every pregnancy, a ... risk. This sheet talks about whether exposure to E. coli may increase the risk for birth defects over ...

  5. E coli enteritis

    Science.gov (United States)

    ... coli; Food poisoning - E. coli; E. coli diarrhea; Hamburger disease ... coleslaw or potato salad) that have been out of the refrigerator too ... reheated Fish or oysters Raw fruits or vegetables that have ...

  6. Escherichia coli pathotypes

    Science.gov (United States)

    Escherichia coli strains are important commensals of the intestinal tract of humans and animals; however, pathogenic strains, including diarrhea-inducing E. coli and extraintestinal pathogenic E. coli. Intestinal E. coli pathotypes may cause a dehydrating watery diarrhea, or more severe diseases su...

  7. Prevalence of Shiga toxin Producing Escherichia coli, Salmonella enterica and Listeria monocytogenes at Public Access Watershed Sites in a California Central Coast Agricultural Region

    Directory of Open Access Journals (Sweden)

    Michael B Cooley

    2014-03-01

    Full Text Available Produce contaminated with enteric pathogens is a major source of foodborne illness in the United States. Lakes, streams, rivers, and ponds were sampled with Moore swabs bi-monthly for over two years at 30 locations in the vicinity of a leafy green growing region on the Central California Coast and screened for Shiga toxin producing Escherichia coli (STEC, Salmonella enterica, and Listeria monocytogenes to evaluate the prevalence and persistence of pathogen subtypes. The prevalence of STEC from 1,386 samples was 11%; 110 samples (8% contained E. coli O157:H7 with the highest prevalence occurring close to cattle operations. Non-O157 STEC isolates represented major clinical O-types and 57% contained both shiga toxin types 1 and 2 and intimin. Multiple Locus Variable Number Tandem Repeat Analysis of STEC isolates indicated prevalent strains during the period of study. Notably, Salmonella was present at high levels throughout the sampling region with 65% prevalence in 1,405 samples resulting in 996 isolates with slightly lower prevalence in late autumn. There were 2, 8 and 14 sites that were Salmonella-positive over 90%, 80% and 70% of the time, respectively. The serotypes identified most often were 6,8:d:-, Typhimurium, and Give. Interestingly, analysis by Pulsed Field Gel Electrophoresis indicated persistence and transport of pulsotypes in the region over several years. In this original study of L. monocytogenes in the region prevalence was 43% of 1,405 samples resulting in 635 individual isolates. Over 85% of the isolates belonged to serotype 4b with serotypes 1/2a, 1/2b, 3a, 4d with 4e representing the rest, and there were 12 and 2 sites that were positive over 50% and 80% of the time, respectively. Although surface water is not directly used for irrigation in this region, transport to the produce can occur by other means. This environmental survey assesses initial contamination levels towards an understanding of transport leading to produce

  8. E. Coli Infections

    Science.gov (United States)

    E. coli is the name of a type of bacteria that lives in your intestines. Most types of E. coli are harmless. However, some types can make you ... type causes travelers' diarrhea. The worst type of E. coli causes bloody diarrhea, and can sometimes cause kidney ...

  9. Control analysis of the dependence of Escherichia coli physiology on the H+ -ATPase

    DEFF Research Database (Denmark)

    Jensen, Peter Ruhdal; Michelsen, Ole; Westerhoff, Hans V.

    1993-01-01

    The H+-ATPase plays a central role in Escherichia coli free-energy transduction and hence in E. coli physiology. We here investigate the extent to which this enzyme also controls the growth rate, growth yield, and respiratory rate of E. coli. We modulate the expression of the atp operon and deter...

  10. ANALISIS CEMARAN BAKTERI Escherichia coli ANALISIS CEMARAN BAKTERI Escherichia coli ANALISIS CEMARAN BAKTERI Escherichia coli

    OpenAIRE

    ANGGREINI, RAHAYU

    2015-01-01

    2015 RAHAYU ANGGREINI coli Penelitian ini bertujuan untuk melakukan identifikasi cemaran bakteri E. coli O157:H7 pada daging sapi di kota Makassar. Sampel pada penelitian ini sebanyak 72 sampel Kata Kunci : Daging sapi, pasar tradisional, E. coli, E. coli O157:H7, kontaminasi bakteri, identifikasi E. coli O157:H7.

  11. Conjugation in Escherichia coli

    Science.gov (United States)

    Boyer, Herbert

    1966-01-01

    Boyer, Herbert (Yale University, New Haven, Conn.). Conjugation in Escherichia coli. J. Bacteriol. 91:1767–1772. 1966.—The sex factor of Escherichia coli K-12 was introduced into an E. coli B/r strain by circumventing the host-controlled modification and restriction incompatibilities known to exist between these closely related strains. The sexual properties of the constructed F+ B strain and its Hfr derivatives were examined. These studies showed that the E. coli strain B/r F+ and Hfr derivatives are similar to the E. coli strain K-12 F+ and Hfr derivatives. However, the site of sex factor integration was found to be dependent on the host genome. PMID:5327905

  12. Shiga toxin-producing Escherichia coli in Central Greece: prevalence and virulence genes of O157:H7 and non-O157 in animal feces, vegetables, and humans.

    Science.gov (United States)

    Pinaka, O; Pournaras, S; Mouchtouri, V; Plakokefalos, E; Katsiaflaka, A; Kolokythopoulou, F; Barboutsi, E; Bitsolas, N; Hadjichristodoulou, C

    2013-11-01

    In Greece, Shiga toxin-producing Escherichia coli (STEC) have only been sporadically reported. The objective of this study was to estimate the prevalence of STEC and Escherichia coli O157:H7 in farm animals, vegetables, and humans in Greece. A total number of 1,010 fecal samples were collected from farm animals (sheep, goats, cattle, chickens, pigs), 667 diarrheal samples from humans, and 60 from vegetables, which were cultured in specific media for STEC isolates. Enzyme-linked immunosorbent assay (ELISA) was used to detect toxin-producing colonies, which, subsequently, were subjected to a multiplex polymerase chain reaction (PCR) for stx1, stx2, eae, rfbE O157, and fliC h7 genes. Eighty isolates (7.9 %) from animal samples were found to produce Shiga toxin by ELISA, while by PCR, O157 STEC isolates were detected from 8 (0.8 %) samples and non-O157 STEC isolates from 43 (4.2 %) samples. STEC isolates were recovered mainly from sheep and goats, rarely from cattle, and not from pigs and chickens, suggesting that small ruminants constitute a potential risk for human infections. However, only three human specimens (0.4 %) were positive for the detection of Shiga toxins and all were PCR-negative. Similarly, all 60 vegetable samples were negative for toxin production and for toxin genes, but three samples (two roman rockets and one spinach) were positive by PCR for rfbE O157 and fliC h7 genes. These findings indicate that sheep, goats, cattle, and leafy vegetables can be a reservoir of STEC and Escherichia coli O157:H7 isolates in Greece, which are still rarely detected among humans.

  13. Enterohemorrhagic Escherichia coli (EHEC

    Directory of Open Access Journals (Sweden)

    Abdullah Kilic

    2011-08-01

    Full Text Available Escherichia coli is a bacterium that is commonly found in the gut of humans and warm-blooded animals. Most strains of E. coli are harmless for human. E. coli O157:H7 is the most common member of a group of pathogenic E. coli strains known variously as enterohaemorrhagic, verocytotoxin-producing, or Shiga-toxin-producing organisms. EHEC bacterium is the major cause of haemorrhagic colitis and haemolytic uraemic syndrome. The reservoir of this pathogen appears to be mainly cattle and other ruminants such as camels. It is transmitted to humans primarily through consumption of contaminated foods. [TAF Prev Med Bull 2011; 10(4.000: 387-388

  14. Can E. coli fly?

    DEFF Research Database (Denmark)

    Lindeberg, Yrja Lisa; Egedal, Karen; Hossain, Zenat Zebin

    2018-01-01

    , and the numbers of flies landing on the exposed rice were counted. Following exposure, the surface of the rice was microbiologically and molecularly analysed for the presence of E. coli and genes of diarrheagenic E. coli and Shigella strains. RESULTS: Rice was at greater risk (p ... with E. coli if flies landed on the rice than if no flies landed on the rice (odds ratio 5·4 (p ...-landings, the average CFU per fly-landing was > 0·6 x 103 CFU. Genes of diarrheagenic E. coli and Shigella species were detected in 39 of 60 (65%) of exposed rice samples. Two fly species were identified; the common housefly (Musca domestica) and the oriental latrine fly (Chrysomya megacephala). CONCLUSION: Flies may...

  15. Endogenous E. coli endophthalmitis.

    Science.gov (United States)

    Shammas, H F

    1977-01-01

    A case of Escherichia coli septicemia with associated metastatic en dophthalmitis and endocarditis is presented. The ocular signs and symptoms were the initial manifestations of sepsis. Irreversible damage to the eye occurred in less than 24 hours. The pattern of metastatic bacterial endophthalmitis has changed since the introduction of potent antimicrobial agents, with an increased incidence of Gram-negative bacillemia. E. coli endophthalmitis carries a poor prognosis. Early diagnosis and systemic treatment will prevent the life-threatening complications of sepsis.

  16. Thioredoxin from Escherichia coli

    International Nuclear Information System (INIS)

    Holmgren, A.; Ohlsson, I.; Grankvist, M.L.

    1978-01-01

    A competition radioimmunoassay for Escherichia coli thioredoxin using 125 I-labeled thioredoxin-S 2 and a double antibody technique was developed. The method permits determination of picomole amounts of thioredoxin in crude cell extracts and was used to study the localization of thioredoxin cell fractions. E. coli B was calculated to have approximately 10,000 copies of thioredoxin per cell mainly located in the soluble fraction after separation of the membrane and soluble fractions by gentle lysis and centrifugation. E. coli B tsnC mutants which are defective in the replication of phage T7 DNA in vivo and in vitro were examined for their content of thioredoxin. E. coli B tsnC 7004 contained no detectable level of thioredoxin in cell-free extracts examined under a variety of conditions. The results strongly suggest that tsnC 7004 is a nonsense or deletion mutant. Two other E. coli tsnC mutants, 7007 and 7008, contained detectable levels of thioredoxin in crude extracts as measured by thioredoxin reductase and gave similar immunoprecipitation reactions as the parent strain B/1. By radioimmunoassay incompletely cross-reacting material was present in both strains. These results show that tsnC 7007 and 7008 belong to a type of thioredoxin mutants with missence mutations in the thioredoxin gene affecting the function of thioredoxin as subunit in phage T7 DNA polymerase

  17. Engineering Escherichia coli for methanol conversion.

    Science.gov (United States)

    Müller, Jonas E N; Meyer, Fabian; Litsanov, Boris; Kiefer, Patrick; Potthoff, Eva; Heux, Stéphanie; Quax, Wim J; Wendisch, Volker F; Brautaset, Trygve; Portais, Jean-Charles; Vorholt, Julia A

    2015-03-01

    Methylotrophic bacteria utilize methanol and other reduced one-carbon compounds as their sole source of carbon and energy. For this purpose, these bacteria evolved a number of specialized enzymes and pathways. Here, we used a synthetic biology approach to select and introduce a set of "methylotrophy genes" into Escherichia coli based on in silico considerations and flux balance analysis to enable methanol dissimilation and assimilation. We determined that the most promising approach allowing the utilization of methanol was the implementation of NAD-dependent methanol dehydrogenase and the establishment of the ribulose monophosphate cycle by expressing the genes for hexulose-6-phosphate synthase (Hps) and 6-phospho-3-hexuloisomerase (Phi). To test for the best-performing enzymes in the heterologous host, a number of enzyme candidates from different donor organisms were selected and systematically analyzed for their in vitro and in vivo activities in E. coli. Among these, Mdh2, Hps and Phi originating from Bacillus methanolicus were found to be the most effective. Labeling experiments using (13)C methanol with E. coli producing these enzymes showed up to 40% incorporation of methanol into central metabolites. The presence of the endogenous glutathione-dependent formaldehyde oxidation pathway of E. coli did not adversely affect the methanol conversion rate. Taken together, the results of this study represent a major advancement towards establishing synthetic methylotrophs by gene transfer. Copyright © 2015 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  18. escherichia coli serotypes confirmed in experimental mammary ...

    African Journals Online (AJOL)

    DJFLEX

    VARIATIONS IN VIRULENCE OF THREE (3) ESCHERICHIA COLI. SEROTYPES CONFIRMED IN ... ows are susceptible to E. coli infection because. E. coli exist in the .... Coli infections in mice: A laboratory animal model for research in.

  19. Explaining and modeling the concentration and loading of Escherichia coli in a stream-A case study.

    Science.gov (United States)

    Wang, Chaozi; Schneider, Rebecca L; Parlange, Jean-Yves; Dahlke, Helen E; Walter, M Todd

    2018-09-01

    Escherichia coli (E. coli) level in streams is a public health indicator. Therefore, being able to explain why E. coli levels are sometimes high and sometimes low is important. Using citizen science data from Fall Creek in central NY we found that complementarily using principal component analysis (PCA) and partial least squares (PLS) regression provided insights into the drivers of E. coli and a mechanism for predicting E. coli levels, respectively. We found that stormwater, temperature/season and shallow subsurface flow are the three dominant processes driving the fate and transport of E. coli. PLS regression modeling provided very good predictions under stormwater conditions (R 2  = 0.85 for log (E. coli concentration) and R 2  = 0.90 for log (E. coli loading)); predictions under baseflow conditions were less robust. But, in our case, both E. coli concentration and E. coli loading were significantly higher under stormwater condition, so it is probably more important to predict high-flow E. coli hazards than low-flow conditions. Besides previously reported good indicators of in-stream E. coli level, nitrate-/nitrite-nitrogen and soluble reactive phosphorus were also found to be good indicators of in-stream E. coli levels. These findings suggest management practices to reduce E. coli concentrations and loads in-streams and, eventually, reduce the risk of waterborne disease outbreak. Copyright © 2018. Published by Elsevier B.V.

  20. Ontology-based literature mining of E. coli vaccine-associated gene interaction networks.

    Science.gov (United States)

    Hur, Junguk; Özgür, Arzucan; He, Yongqun

    2017-03-14

    Pathogenic Escherichia coli infections cause various diseases in humans and many animal species. However, with extensive E. coli vaccine research, we are still unable to fully protect ourselves against E. coli infections. To more rational development of effective and safe E. coli vaccine, it is important to better understand E. coli vaccine-associated gene interaction networks. In this study, we first extended the Vaccine Ontology (VO) to semantically represent various E. coli vaccines and genes used in the vaccine development. We also normalized E. coli gene names compiled from the annotations of various E. coli strains using a pan-genome-based annotation strategy. The Interaction Network Ontology (INO) includes a hierarchy of various interaction-related keywords useful for literature mining. Using VO, INO, and normalized E. coli gene names, we applied an ontology-based SciMiner literature mining strategy to mine all PubMed abstracts and retrieve E. coli vaccine-associated E. coli gene interactions. Four centrality metrics (i.e., degree, eigenvector, closeness, and betweenness) were calculated for identifying highly ranked genes and interaction types. Using vaccine-related PubMed abstracts, our study identified 11,350 sentences that contain 88 unique INO interactions types and 1,781 unique E. coli genes. Each sentence contained at least one interaction type and two unique E. coli genes. An E. coli gene interaction network of genes and INO interaction types was created. From this big network, a sub-network consisting of 5 E. coli vaccine genes, including carA, carB, fimH, fepA, and vat, and 62 other E. coli genes, and 25 INO interaction types was identified. While many interaction types represent direct interactions between two indicated genes, our study has also shown that many of these retrieved interaction types are indirect in that the two genes participated in the specified interaction process in a required but indirect process. Our centrality analysis of

  1. A genomically modified Escherichia coli strain carrying an orthogonal E. coli histidyl-tRNA synthetase•tRNAHis pair.

    Science.gov (United States)

    Englert, Markus; Vargas-Rodriguez, Oscar; Reynolds, Noah M; Wang, Yane-Shih; Söll, Dieter; Umehara, Takuya

    2017-11-01

    Development of new aminoacyl-tRNA synthetase (aaRS)•tRNA pairs is central for incorporation of novel non-canonical amino acids (ncAAs) into proteins via genetic code expansion (GCE). The Escherichia coli and Caulobacter crescentus histidyl-tRNA synthetases (HisRS) evolved divergent mechanisms of tRNA His recognition that prevent their cross-reactivity. Although the E. coli HisRS•tRNA His pair is a good candidate for GCE, its use in C. crescentus is limited by the lack of established genetic selection methods and by the low transformation efficiency of C. crescentus. E. coli was genetically engineered to use a C. crescentus HisRS•tRNA His pair. Super-folder green fluorescent protein (sfGFP) and chloramphenicol acetyltransferase (CAT) were used as reporters for read-through assays. A library of 313 ncAAs coupled with the sfGFP reporter system was employed to investigate the specificity of E. coli HisRS in vivo. A genomically modified E. coli strain (named MEOV1) was created. MEVO1 requires an active C. crescentus HisRS•tRNA His pair for growth, and displays a similar doubling time as the parental E. coli strain. sfGFP- and CAT-based assays showed that the E. coli HisRS•tRNA His pair is orthogonal in MEOV1 cells. A mutation in the anticodon loop of E. coli tRNA His CUA elevated its suppression efficiency by 2-fold. The C. crescentus HisRS•tRNA His pair functionally complements an E. coli ΔhisS strain. The E. coli HisRS•tRNA His is orthogonal in MEOV1 cells. E. coli tRNA His CUA is an efficient amber suppressor in MEOV1. We developed a platform that allows protein engineering of E. coli HisRS that should facilitate GCE in E. coli. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. PART I. ESCHERICHIA COLI

    Directory of Open Access Journals (Sweden)

    Sanaa Mahdi Oraibi

    2016-11-01

    Full Text Available The presence of Escherichia coli in the air of facilities involved in management and composting of post-slaughter poultry wastes in selected plants of West Western Pomerania region was studied. Measurements were made on four dates in a variety of weather conditions during the year. The study was conducted at 5 objects that differ in the type of waste and the degree of preparation for composting. These were: chemical treatment and preliminary processing plant, liquid wastes reservoir, platform for preparation of materials for composting, storage of biological sediments, and composting facility. Measurement of bacteria count was carried out in accordance with the applicable procedures on selective chromogenic TBX medium. The assays revealed the presence of E. coli at all test objects, but not always on all measurement dates. It has been shown that the presence of E. coli was from 20 to 3047 CFU∙m-3 of air, although the largest quantities were most frequently detected in the air of the building for post-slaughter waste pre-treatment in chemical treatment plant.

  3. ANIMAL ENTEROTOXIGENIC ESCHERICHIA COLI

    Science.gov (United States)

    Dubreuil, J. Daniel; Isaacson, Richard E.; Schifferli, Dieter M.

    2016-01-01

    Enterotoxigenic Escherichia coli (ETEC) is the most common cause of E. coli diarrhea in farm animals. ETEC are characterized by the ability to produce two types of virulence factors; adhesins that promote binding to specific enterocyte receptors for intestinal colonization and enterotoxins responsible for fluid secretion. The best-characterized adhesins are expressed in the context of fimbriae, such as the F4 (also designated K88), F5 (K99), F6 (987P), F17 and F18 fimbriae. Once established in the animal small intestine, ETEC produces enterotoxin(s) that lead to diarrhea. The enterotoxins belong to two major classes; heat-labile toxin that consist of one active and five binding subunits (LT), and heat-stable toxins that are small polypeptides (STa, STb, and EAST1). This chapter describes the disease and pathogenesis of animal ETEC, the corresponding virulence genes and protein products of these bacteria, their regulation and targets in animal hosts, as well as mechanisms of action. Furthermore, vaccines, inhibitors, probiotics and the identification of potential new targets identified by genomics are presented in the context of animal ETEC. PMID:27735786

  4. ROS mediated selection for increased NADPH availability in Escherichia coli.

    Science.gov (United States)

    Reynolds, Thomas S; Courtney, Colleen M; Erickson, Keesha E; Wolfe, Lisa M; Chatterjee, Anushree; Nagpal, Prashant; Gill, Ryan T

    2017-11-01

    The economical production of chemicals and fuels by microbial processes remains an intense area of interest in biotechnology. A key limitation in such efforts concerns the availability of key co-factors, in this case NADPH, required for target pathways. Many of the strategies pursued for increasing NADPH availability in Escherichia coli involve manipulations to the central metabolism, which can create redox imbalances and overall growth defects. In this study we used a reactive oxygen species based selection to search for novel methods of increasing NADPH availability. We report a loss of function mutation in the gene hdfR appears to increase NADPH availability in E. coli. Additionally, we show this excess NADPH can be used to improve the production of 3HP in E. coli. © 2017 Wiley Periodicals, Inc.

  5. Asymptomatic bacteriuria Escherichia coli strains

    DEFF Research Database (Denmark)

    Hancock, Viktoria; Nielsen, E.M.; Klemm, Per

    2006-01-01

    Urinary tract infections (UTIs) affect millions of people each year. Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU) in humans. Persons affected by ABU may carry a particular E. coli strain for extended periods of time without any symptoms. In contrast...... to uropathogenic E. coli (UPEC) that cause symptomatic UTI, very little is known about the mechanisms by which these strains colonize the urinary tract. Here, we have investigated the growth characteristics in human urine as well as adhesin repertoire of nine ABU strains; the ability of ABU strains to compete...

  6. The role of Cra in regulating acetate excretion and osmotic tolerance in E. coli K-12 and E. coli B at high density growth.

    Science.gov (United States)

    Son, Young-Jin; Phue, Je-Nie; Trinh, Loc B; Lee, Sang Jun; Shiloach, Joseph

    2011-06-30

    E. coli B (BL21), unlike E.coli K-12 (JM109) is insensitive to glucose concentration and, therefore, grows faster and produces less acetate than E. coli K-12, especially when growing to high cell densities at high glucose concentration. By performing genomic analysis, it was demonstrated that the cause of this difference in sensitivity to the glucose concentration is the result of the differences in the central carbon metabolism activity. We hypothesized that the global transcription regulator Cra (FruR) is constitutively expressed in E. coli B and may be responsible for the different behaviour of the two strains. To investigate this possibility and better understand the function of Cra in the two strains, cra - negative E. coli B (BL21) and E. coli K-12 (JM109) were prepared and their growth behaviour and gene expression at high glucose were evaluated using microarray and real-time PCR. The deletion of the cra gene in E. coli B (BL21) minimally affected the growth and maximal acetate accumulation, while the deletion of the same gene in E.coli K-12 (JM109) caused the cells to stop growing as soon as acetate concentration reached 6.6 g/L and the media conductivity reached 21 mS/cm. ppsA (gluconeogenesis gene), aceBA (the glyoxylate shunt genes) and poxB (the acetate producing gene) were down-regulated in both strains, while acs (acetate uptake gene) was down-regulated only in E.coli B (BL21). These transcriptional differences had little effect on acetate and pyruvate production. Additionally, it was found that the lower growth of E. coli K-12 (JM109) strain was the result of transcription inhibition of the osmoprotectant producing bet operon (betABT). The transcriptional changes caused by the deletion of cra gene did not affect the activity of the central carbon metabolism, suggesting that Cra does not act alone; rather it interacts with other pleiotropic regulators to create a network of metabolic effects. An unexpected outcome of this work is the finding that cra

  7. Chromosomal features of Escherichia coli serotype O2:K2, an avian pathogenic E. coli

    DEFF Research Database (Denmark)

    Jørgensen, Steffen L; Kudirkiene, Egle; Li, Lili

    2017-01-01

    Escherichia coli causing infection outside the gastrointestinal system are referred to as extra-intestinal pathogenic E. coli. Avian pathogenic E. coli is a subgroup of extra-intestinal pathogenic E. coli and infections due to avian pathogenic E. coli have major impact on poultry production econo...

  8. Temporal variations of Escherichia coli concentrations in a large Midwestern river

    Science.gov (United States)

    Schilling, K.E.; Zhang, Y.-K.; Hill, D.R.; Jones, C.S.; Wolter, C.F.

    2009-01-01

    The Raccoon River used by the Des Moines Water Works to serve more than 400,000 people in central Iowa is threatened by contamination from Escherichia coli bacteria from point and nonpoint sources. The 9389 km2 watershed is highly agricultural, with 73% of the land in row crop production and widespread animal production. Results from 2155 grab samples from 1997 to 2005 for E. coli analysis were examined for temporal variations. E. coli concentrations were found to vary across years, seasons, and flow conditions, with a 9-year mean value of 1156 most probable number (MPN)/100 ml. Monthly concentrations exhibited clear seasonality with highest values in May through July. Although E. coli concentrations were higher during periods of greater discharge, the relation of log E. coli to log discharge was not particularly strong (r2 = 0.35). The variogram of E. coli concentrations showed temporal correlation within a span of 4 days suggesting that concentrations measured on 1 day may be related in time to concentrations measured up to 3 days later and beyond 4 days the concentrations vary randomly. The spectral analysis of the time series of E. coli was also carried out and was fitted well with the spectrum of an exponential covariance function. Deciphering temporal patterns and correlation of E. coli bacteria in streams may be useful for developing future monitoring strategies to track concentration patterns and loads. ?? 2008 Elsevier B.V. All rights reserved.

  9. Diarrheagenic Escherichia coli Markers and Phenotypes among Fecal E. coli Isolates Collected from Nicaraguan Infants ▿

    OpenAIRE

    Reyes, Daniel; Vilchez, Samuel; Paniagua, Margarita; Colque-Navarro, Patricia; Weintraub, Andrej; Möllby, Roland; Kühn, Inger

    2010-01-01

    We analyzed the prevalence of diarrheagenic Escherichia coli (DEC) markers and common phenotypes in 2,164 E. coli isolates from 282 DEC-positive samples. Enteropathogenic E. coli (EPEC) and enteroaggregative E. coli (EAEC) were very diverse and were not correlated with diarrhea. Enterotoxigenic E. coli (ETEC) estA and enterohemorrhagic E. coli (EHEC) belonged to a few phenotypes and were significantly correlated with diarrhea.

  10. Photoreactivating enzyme from Escherichia coli

    International Nuclear Information System (INIS)

    Snapka, R.M.; Fuselier, C.O.

    1977-01-01

    Escherichia coli photoreactivating enzyme (PRE) has been purified in large amounts from an E.coli strain lysogenic for a defective lambda bacteriophage carrying the phr gene. The resulting enzyme had a pH optimum of 7.2 and an ionic strength optimum of 0.18. It consisted of an apoprotein and cofactor, both of which were necessary for catalytic activity. The apoprotein had a monomer molecular weight of 35,200 and showed stable aggregates under denaturing conditions. The amino acid analysis of the E.coli enzyme was very similar to that of the photoreactivating enzyme from orchid seedlings (Cattelya aurantiaca). Both had arginine at the amino terminus. The cofactor, like the holoenzyme, showed absorption, magnetic circular dichroism, and emission properties indicative of an adenine moiety. Although the isolated enzyme had an action spectrum which peaked at about 360 nm, neither the cofactor, apoenzyme nor holoenzyme showed any detectable absorption between 300 and 400 nm. (author)

  11. Photoreactivating enzyme from Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Snapka, R M; Fuselier, C O [California Univ., Irvine (USA)

    1977-05-01

    Escherichia coli photoreactivating enzyme (PRE) has been purified in large amounts from an E.coli strain lysogenic for a defective lambda bacteriophage carrying the phr gene. The resulting enzyme had a pH optimum of 7.2 and an ionic strength optimum of 0.18. It consisted of an apoprotein and cofactor, both of which were necessary for catalytic activity. The apoprotein had a monomer molecular weight of 35,200 and showed stable aggregates under denaturing conditions. The amino acid analysis of the E.coli enzyme was very similar to that of the photoreactivating enzyme from orchid seedlings (Cattelya aurantiaca). Both had arginine at the amino terminus. The cofactor, like the holoenzyme, showed absorption, magnetic circular dichroism, and emission properties indicative of an adenine moiety. Although the isolated enzyme had an action spectrum which peaked at about 360 nm, neither the cofactor, apoenzyme nor holoenzyme showed any detectable absorption between 300 and 400 nm.

  12. Expression in E. coli systems

    DEFF Research Database (Denmark)

    Krogsdam, Anne-M; Kristiansen, Karsten; Nøhr, Jane

    2003-01-01

    intracellularly in soluble form. In E. coli, proteins containing disulfide bonds are best produced by secretion because the disulfide forming foldases reside in the periplasm. Likewise, a correct N-terminus is more likely to be obtained upon secretion. Moreover, potentially toxic proteins are more likely......Owing to cost advantage, speed of production, and often high product yield (up to 50% of total cell protein), expression in Escherichia coli is generally the first choice when attempting to express a recombinant protein. Expression systems exist to produce recombinant protein intracellularly...

  13. Experimental evolution of E. coli

    Science.gov (United States)

    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.

  14. The oxygen effect in E. coli cells

    International Nuclear Information System (INIS)

    Myasnik, M.N.; Skvortsov, V.G.; Sokolov, V.A.

    1982-01-01

    In experiments on E. coli strains deficient in some stages of DNA repair from radiation damages, it was demonstrated that the value of the oxygen effect, under optimal conditions for manifestation thereof, decreases in the following order: E. coli WP2 (the wild type) → E. coli WP2 exr - and E. coli B → E. coli WP2 uvr A6 → E. coli WP2 rec Al and E. coli WP2 hcr - exr - . It was detected that 0.14 M NaCl solution sensitizes the anoxic cells of some E. coli strains to the effect of γ-radiation. It was established that mutation of the uvr A-gene increases sharply the sensitivity of cells to iradiation under the anoxic conditions in the presence of NaCl, the reverse'' oxygen effect being observed

  15. Glucose uptake regulation in E. coli by the small RNA SgrS: comparative analysis of E. coli K-12 (JM109 and MG1655 and E. coli B (BL21

    Directory of Open Access Journals (Sweden)

    Ng Weng-Ian

    2010-09-01

    Full Text Available Abstract Background The effect of high glucose concentration on the transcription levels of the small RNA SgrS and the messenger RNA ptsG, (encoding the glucose transporter IICBGlc, was studied in both E. coli K-12 (MG1655 and JM109 and E. coli B (BL21. It is known that the transcription level of sgrS increases when E. coli K-12 (MG1655 and JM109 is exposed to the non-metabolized glucose alpha methyl glucoside (αMG or when the bacteria with a defective glycolysis pathway is grown in presence of glucose. The increased level of sRNA SgrS reduces the level of the ptsG mRNA and consequently lowers the level of the glucose transporter IICBGlc. The suggested trigger for this action is the accumulation of the corresponding phospho-sugars. Results In the course of the described work, it was found that E. coli B (BL21 and E. coli K-12 (JM109 and MG1655 responded similarly to αMG: both strains increased SgrS transcription and reduced ptsG transcription. However, the two strains reacted differently to high glucose concentration (40 g/L. E. coli B (BL21 reacted by increasing sgrS transcription and reducing ptsG transcription while E. coli K-12 (JM109 and MG1655 did not respond to the high glucose concentration, and, therefore, transcription of sgrS was not detected and ptsG mRNA level was not affected. Conclusions The results suggest that E. coli B (BL21 tolerates high glucose concentration not only by its more efficient central carbon metabolism, but also by controlling the glucose transport into the cells regulated by the sRNA SgrS, which may suggest a way to control glucose consumption and increase its efficient utilization.

  16. Actions and advice in coli

    DEFF Research Database (Denmark)

    Knoche, Hendrik; Jamadagni, HS; Rao, PR Sheshagiri

    2015-01-01

    To improve their agricultural output, farmers require timely and contextualized information and advice. Relevant information and advice provided by trusted peers represents a promising approach. We present the considerations for the design of coli, an agricultural information network on touch scr...

  17. Infektionen mit darmpathogenen Escherichia coli.

    NARCIS (Netherlands)

    Friedrich, Alexander; Stein, Jürgen; Dignass, Axel

    2001-01-01

    E. coli ist ein wesentlicher Bestandteil der physiologischen Darmflora des Menschen. Die üblicherweise im Darm vorkommenden Kolibakterien sind apathogen und für den Menschen eher nützlich (Sonnenborn u. Greinwald 1990). Allerdings kennen wir bei dieser Bakterienspezies auch ein breites Spektrum von

  18. 76 FR 20542 - Escherichia coli

    Science.gov (United States)

    2011-04-13

    ... beef, Escherichia coli and coliphages were found in chicken, fresh pork, fresh oyster, fresh mushrooms, lettuce, chicken pot pie, biscuit dough, deli loaf, deli roasted turkey, and package roasted chicken... surfaces, and in foods such as ground beef, pork sausage, chicken, oysters, cheese, fresh mushrooms, and...

  19. ESCHERICHIA COLI AND STAPHYLOCOCCUS AUREUS

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. The bio-effects of the ethanol extracts from the leaf and stem of Momordica charantia were studied with the view to ascertain the medical usefulness ascribed to the plant by the locals. The plant parts, stem and leaf, revealed remarkable activity against Escherichia coli and Staphlococcus aureus. The leaves ...

  20. Conjugal Pairing in Escherichia Coli

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 8. Conjugal Pairing in Escherichia Coli. Joshua Lederberg. Classics Volume 13 Issue 8 August 2008 pp 793-794. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/013/08/0793-0794 ...

  1. Escherichia coli as a probiotic?

    NARCIS (Netherlands)

    Jansen, GJ; Wildeboer-Veloo, ACM; van der Waaij, D; Degener, JE

    1998-01-01

    The influence of oral treatment with a suspension of non-pathogenic Escherichia coli cells (commercially available as: Symbioflor II(R)) on the morphological composition of the gut microflora and on the systemic humoral immune response (the IgG-, IgA- and IgM-isotype) against the bacterial cells in

  2. Expression in E. coli systems

    DEFF Research Database (Denmark)

    Krogsdam, Anne-M; Kristiansen, Karsten; Nøhr, Jane

    2003-01-01

    intracellularly in soluble form. In E. coli, proteins containing disulfide bonds are best produced by secretion because the disulfide forming foldases reside in the periplasm. Likewise, a correct N-terminus is more likely to be obtained upon secretion. Moreover, potentially toxic proteins are more likely...

  3. 99mTechnetium labelled Escherichia coli

    International Nuclear Information System (INIS)

    Diniz, S.O.F.; Cardoso, V.N.; Resende, B.M.; Nunan, E.A.; Simal, C.J.R.

    1999-01-01

    Samples of a culture of unlabeled Escherichia coli were incubated with different concentrations of stannous chloride for various time periods. 99m Tc (26.0 MBq) was added to each preparation and the results showed a labelling yield of 98% for E. coli. Since the bacterial viability of 99m Tc-E. coli and E. coli did not show any statistical differences, these results demonstrate that labelling of E. coli with 99m Tc does not modify the bacterial viability, and the radiolabelled bacteria may be a good model to study bacterial translocation

  4. Human Meningitis-Associated Escherichia coli

    Science.gov (United States)

    KIM, KWANG SIK

    2016-01-01

    E. coli is the most common Gram-negative bacillary organism causing meningitis and E. coli meningitis continues to be an important cause of mortality and morbidity throughout the world. Our incomplete knowledge of its pathogenesis contributes to such mortality and morbidity. Recent reports of E. coli strains producing CTX-M-type or TEM-type extended-spectrum β-lactamases create a challenge. Studies using in vitro and in vivo models of the blood-brain barrier have shown that E. coli meningitis follows a high-degree of bacteremia and invasion of the blood-brain barrier. E. coli invasion of the blood-brain barrier, the essentials step in the development of E. coli meningitis, requires specific microbial and host factors as well as microbe- and host-specific signaling molecules. Blockade of such microbial and host factors contributing to E. coli invasion of the blood-brain barrier is shown to be efficient in preventing E. coli penetration into the brain. The basis for requiring a high-degree of bacteremia for E. coli penetration of the blood-brain barrier, however, remains unclear. Continued investigation on the microbial and host factors contributing to a high-degree of bacteremia and E. coli invasion of the blood-brain barrier is likely to identify new targets for prevention and therapy of E. coli meningitis. PMID:27223820

  5. Molecular photonic imaging of cancer using light-emitting e. coli

    International Nuclear Information System (INIS)

    Park, Jae Hyo; Min, Jung Joon; Moon, Sung Min; Kim, Hyun Ju; Hong, Yeong Jin; Choy, Hyon E.; Bom, Hee Seung; Jeong, Jae Ho; Cho, Kyoung Oh

    2005-01-01

    Cancer research has long sought a magic bullet that would selectively target and destroy malignant cells. In this study, we exploited that E. coli injected into tumor-bearing mice selectively target and proliferate in solid tumors by employing optical imaging technique. Lux operon or GFP has been cloned into pUC19 plasmid to engineer pUC19Lux or pUC19gfp which was transformed into varying kinds of wild type (MG1655) or mutant E.coli strains. For stable expression, lux operon was cloned with asd (aspartate β-semialdehyde dehydrogenase) gene and transformed into asd defective E. coli (MG1655asd-/asd+lux). These bacteria were i.v. injected into tumor mice or directly into central necrosis of tumor. The imaging signal from wild type E.coli was detected initially at liver (20min), then migrated to and shine in the tumor mass until 2 weeks of injection which was consistently observed in immuno-defective (nude) and -competent (Balb/c) mice. Imaging signal of stbaly transformed strain (MG1655asd-/asd+lux) was stronger and longer-lasting than that of transiently transformed strain (MG1655lux). Flagella defective E. coli strain failed to reach tumor loci. Only a few amounts of stress regulatory defective E. coli strain arrived at but couldn't survive at the tumor loci. E. coli colonies expressing GFP was mostly observed at the border of central necrosis and peripheral proliferative areas in immunofluorescence studies. Directly injected MG1655ad-/asd+lux was transiently observed at central necrosis followed by spreading to the peripheral tumor mass which was consistent with the finding by tail vein injection. We successfully engineered E. coli strain stably expressing lux reporter gene. E. coli strongly targeted solid tumor regardless of host immune status. Our results support that the targeting of tumor by E.coli is an active process and would be applied as a delivery vehicle of varying imaging markers or therapeutic molecules

  6. Construction of a minimum-size functional flagellin of Escherichia coli.

    OpenAIRE

    Kuwajima, G

    1988-01-01

    Various deletions were introduced into the central region of Escherichia coli flagellin (497 residues) without destroying its ability to form flagellar filaments. The smallest flagellin retained only the N-terminal 193 residues and the C-terminal 117 residues, which are suggested to be the domains essential for filament formation.

  7. Functional studies of elongation factor Tu from Escherichia coli : Site-directed mutagenesis and antibiotic action

    NARCIS (Netherlands)

    Krab, Ivo Maarten

    2001-01-01

    This PhD thesis describes several studies into the structure and function of Escherichia coli Elongation Factor Tu (EF-Tu). EF-Tu plays a central role in the bacterial protein synthesis machinery as the carrier of "coded building blocks" for protein synthesis, aminoacylated tRNA (aa-tRNA). Without

  8. Pneumatosis Coli Mimicking Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Teresa Jacob

    2014-01-01

    Full Text Available Pneumatosis coli (PC is a rare condition of the gastrointestinal tract involving extraluminal gas confined within the bowel wall. We report the case of a 40-year-old gentleman presenting clinically and endoscopically with suspected colorectal cancer. In light of the patient’s red flag symptoms, and carpet of polyps seen endoscopically, surgical management by an anterior resection was performed with the patient making a successful recovery. Histological analysis of the resected specimen confirmed pneumatosis coli with no evidence of colonic neoplasia. Although PC can be an incidental finding in asymptomatic patients and considered a benign condition, it can also present as a life-threatening emergency with bowel necrosis and obstruction requiring emergency surgical intervention. Also, when PC mimics malignancy, surgical management is the most appropriate step to ensure that the diagnosis of cancer is not missed.

  9. Multiplex PCR Assay for Identification of Human Diarrheagenic Escherichia coli

    OpenAIRE

    Toma, Claudia; Lu, Yan; Higa, Naomi; Nakasone, Noboru; Chinen, Isabel; Baschkier, Ariela; Rivas, Marta; Iwanaga, Masaaki

    2003-01-01

    A multiplex PCR assay for the identification of human diarrheagenic Escherichia coli was developed. The targets selected for each category were eae for enteropathogenic E. coli, stx for Shiga toxin-producing E. coli, elt and est for enterotoxigenic E. coli, ipaH for enteroinvasive E. coli, and aggR for enteroaggregative E. coli. This assay allowed the categorization of a diarrheagenic E. coli strain in a single reaction tube.

  10. The adenomatous polyposis coli protein.

    OpenAIRE

    Näthke, I S

    1999-01-01

    Mutations in the adenomatous polyposis coli (APC) gene are associated with most colorectal cancers. The APC protein has been implicated in many aspects of tumour development. This article will discuss recent data suggesting that APC may have multiple functions in the cell. First, APC is a component of the Wnt signalling pathway; second, APC may have a role in cell migration; finally, APC may regulate proliferation and apoptosis.

  11. Central Chile

    Science.gov (United States)

    2002-01-01

    The beginning of spring in central Chile looked like this to SeaWiFS. The snow-covered Andes mark the country's eastern border, and phytoplankton blooms and river sediment plumes fill the waters off its west coast. A large eddy due west of Concepcion is highlighted by the phytoplankton it contains.

  12. Afrique Centrale

    African Journals Online (AJOL)

    PR BOKO

    (Afrique Centrale) : peuplement de protozoaires ciliés et macro invertébrés ... Le lac d'Obili est un écosystème aquatique situé en plein cœur de Yaoundé en ...... électrique des eaux est assez stable, autour de 200 ; ce qui suppose que la ...

  13. ESBL Escherichia coli Ventriculitis after Aneurysm Clipping: A Rare and Difficult Therapeutic Challenge

    Directory of Open Access Journals (Sweden)

    F. A. Zeiler

    2015-01-01

    Full Text Available Background. Extended spectrum beta-lactamase (ESBL produced Escherichia coli (E. coli ventriculitis is a rare infection of the central nervous system, with increasing rarity in the adult population. The therapeutic strategy to achieve cure may need to involve a combination of intraventricular and intravenous (IV therapy. Objective. To describe a case of ESBL E. coli meningitis/ventriculitis in an adult and outline the antimicrobial therapy that leads to cure. Methods. We retrospectively reviewed the records of a patient admitted to the neurosurgical department for aneurysmal subarachnoid hemorrhage, who developed ESBL E. coli ventriculitis. Results. A 55-year-old female, admitted for a Fisher grade 3, World Federation of Neurological Surgeons grade 1, subarachnoid hemorrhage, developed ESBL E. coli ventriculitis requiring a combination of intraventricular gentamicin and high dose intravenous meropenem for clearance. Cerebrospinal fluid clearance occurred at 7 days after initiation of combined therapy. The patient remained shunt dependent. Conclusions. Meningitis and ventriculitis caused by ESBL E. coli species are rare and pose significant challenges to the treating physician. Early consideration for combined intraventricular and IV therapy should be made.

  14. Annual Surveillance Summary: Escherichia coli (E. coli) Infections in the Military Health System (MHS), 2015

    Science.gov (United States)

    2017-03-01

    Annual Surveillance Summary: Escherichia coli ( E . coli ) Infections in the Military Health System (MHS...or position of the Department of the Navy, Department of Defense, nor the U.S. Government. i i E . coli in the MHS: Annual Summary 2015 Prepared...March 2017 EpiData Center Department NMCPHC-EDC-TR-187-2017 ii ii E . coli in the MHS: Annual Summary 2015 Prepared March 2017 EpiData

  15. Chromosomal features of Escherichia coli serotype O2:K2, an avian pathogenic E. coli.

    Science.gov (United States)

    Jørgensen, Steffen L; Kudirkiene, Egle; Li, Lili; Christensen, Jens P; Olsen, John E; Nolan, Lisa; Olsen, Rikke H

    2017-01-01

    Escherichia coli causing infection outside the gastrointestinal system are referred to as extra-intestinal pathogenic E. coli. Avian pathogenic E. coli is a subgroup of extra-intestinal pathogenic E. coli and infections due to avian pathogenic E. coli have major impact on poultry production economy and welfare worldwide. An almost defining characteristic of avian pathogenic E. coli is the carriage of plasmids, which may encode virulence factors and antibiotic resistance determinates. For the same reason, plasmids of avian pathogenic E. coli have been intensively studied. However, genes encoded by the chromosome may also be important for disease manifestation and antimicrobial resistance. For the E. coli strain APEC_O2 the plasmids have been sequenced and analyzed in several studies, and E. coli APEC_O2 may therefore serve as a reference strain in future studies. Here we describe the chromosomal features of E. coli APEC_O2. E. coli APEC_O2 is a sequence type ST135, has a chromosome of 4,908,820 bp (plasmid removed), comprising 4672 protein-coding genes, 110 RNA genes, and 156 pseudogenes, with an average G + C content of 50.69%. We identified 82 insertion sequences as well as 4672 protein coding sequences, 12 predicated genomic islands, three prophage-related sequences, and two clustered regularly interspaced short palindromic repeats regions on the chromosome, suggesting the possible occurrence of horizontal gene transfer in this strain. The wildtype strain of E. coli APEC_O2 is resistant towards multiple antimicrobials, however, no (complete) antibiotic resistance genes were present on the chromosome, but a number of genes associated with extra-intestinal disease were identified. Together, the information provided here on E. coli APEC_O2 will assist in future studies of avian pathogenic E. coli strains, in particular regarding strain of E. coli APEC_O2, and aid in the general understanding of the pathogenesis of avian pathogenic E. coli .

  16. Hemolytic porcine intestinal Escherichia coli without virulence-associated genes typical of intestinal pathogenic E. coli.

    Science.gov (United States)

    Schierack, Peter; Weinreich, Joerg; Ewers, Christa; Tachu, Babila; Nicholson, Bryon; Barth, Stefanie

    2011-12-01

    Testing 1,666 fecal or intestinal samples from healthy and diarrheic pigs, we obtained hemolytic Escherichia coli isolates from 593 samples. Focusing on hemolytic E. coli isolates without virulence-associated genes (VAGs) typical for enteropathogens, we found that such isolates carried a broad variety of VAGs typical for extraintestinal pathogenic E. coli.

  17. Direct observation of processive exoribonuclease motion using optical tweezers.

    Science.gov (United States)

    Fazal, Furqan M; Koslover, Daniel J; Luisi, Ben F; Block, Steven M

    2015-12-08

    Bacterial RNases catalyze the turnover of RNA and are essential for gene expression and quality surveillance of transcripts. In Escherichia coli, the exoribonucleases RNase R and polynucleotide phosphorylase (PNPase) play critical roles in degrading RNA. Here, we developed an optical-trapping assay to monitor the translocation of individual enzymes along RNA-based substrates. Single-molecule records of motion reveal RNase R to be highly processive: one molecule can unwind over 500 bp of a structured substrate. However, enzyme progress is interrupted by pausing and stalling events that can slow degradation in a sequence-dependent fashion. We found that the distance traveled by PNPase through structured RNA is dependent on the A+U content of the substrate and that removal of its KH and S1 RNA-binding domains can reduce enzyme processivity without affecting the velocity. By a periodogram analysis of single-molecule records, we establish that PNPase takes discrete steps of six or seven nucleotides. These findings, in combination with previous structural and biochemical data, support an asymmetric inchworm mechanism for PNPase motion. The assay developed here for RNase R and PNPase is well suited to studies of other exonucleases and helicases.

  18. Europa central

    Directory of Open Access Journals (Sweden)

    Karel BARTOSEK

    2010-02-01

    Full Text Available La investigación francesa continúa interesándose por Europa Central. Desde luego, hay límites a este interés en el ambiente general de mi nueva patria: en la ignorancia, producto del largo desinterés de Francia por este espacio después de la Segunda Guerra Mundial, y en el comportamiento y la reflexión de la clase política y de los medios de comunicación (una anécdota para ilustrar este ambiente: durante la preparación de nuestro coloquio «Refugiados e inmigrantes de Europa Central en el movimiento antifascista y la Resistencia en Francia, 1933-1945», celebrado en París en octubre de 1986, el problema de la definición fue planteado concreta y «prácticamente». ¡Y hubo entonces un historiador eminente, para quién Alemania no formaría parte de Europa Central!.

  19. Enteroaggregative Escherichia coli in Daycare

    DEFF Research Database (Denmark)

    Hebbelstrup Jensen, Betina; Stensvold, Christen R.; Struve, Carsten

    2016-01-01

    Enteroaggregative Escherichia coli (EAEC) has been associated with persistent diarrhea, reduced growth acceleration, and failure to thrive in children living in developing countries and with childhood diarrhea in general in industrialized countries. The clinical implications of an EAEC carrier...... and answered a questionnaire regarding gastrointestinal symptoms and exposures. Exposures included foreign travel, consumption of antibiotics, and contact with a diseased animal. In the capital area of Denmark, a total of 179 children aged 0-6 years were followed in a cohort study, in the period between 2009...

  20. Peptidoglycan Hydrolases of Escherichia coli

    Science.gov (United States)

    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

  1. Third International E. coli genome meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    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.

  2. Escherichia Coli Removal from Water Using Electrophotocatalytic ...

    African Journals Online (AJOL)

    Michael Horsfall

    inactivation of bacterial microorganisms in areas with low ... disinfection of water contaminated with fecal indicators such as E. coli ... media, brain heart infusion, sodium chloride, sodium hydroxide ... furnace at temperature 105 and 320°C f0r 60 min. For 2- and .... charge of E. coli logarithmic growth phase might affect the ...

  3. Antimicrobial resistance among commensal Escherichia coli from ...

    African Journals Online (AJOL)

    Commensal bacteria contribute to the distribution and persistence of antimicrobial resistance in the environment. This study monitored antimicrobial resistance in commensal Escherichia coli from the faeces of on-farm and slaughter cattle and beef. A total of 342 (89.5%) E. coli isolates were obtained from 382 samples.

  4. Characterization of Escherichia coli Phylogenetic Groups ...

    African Journals Online (AJOL)

    Background: Escherichia coli strains mainly fall into four phylogenetic groups (A, B1, B2, and D) and that virulent extra‑intestinal strains mainly belong to groups B2 and D. Aim: The aim was to determine the association between phylogenetic groups of E. coli causing extraintestinal infections (ExPEC) regarding the site of ...

  5. Biochemical and serological characterization of Escherichia coli ...

    African Journals Online (AJOL)

    This study was designed to determine the isolation rate, serotypes and biochemical profiles of E. coli from colibacillosis and dead-in-shell embryos in Zaria, Northern-Nigeria. The isolation rate of E. coli from hatcheries studied were 4.67% and 7.50% from farms of Simtu Agricultural Company and National Animal Production ...

  6. PATHOGENIC POTENTIALS OF ESCHERICHIA COLI ISOLATED ...

    African Journals Online (AJOL)

    Electrolyte and haematological parameters in rabbits infected with pathogenic isolates of Escherichia coli from rural water supplies in Rivers State, Nigeria, where monitored. Rabbits were orally infected with suspension containing 3x107 cfu /ml of Escherichia coli to induce diarrhoea, and the electrolyte (sodium, potassium ...

  7. Fosfomycin Resistance in Escherichia coli, Pennsylvania, USA.

    Science.gov (United States)

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

    2015-11-01

    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.

  8. Strategies for Protein Overproduction in Escherichia coli.

    Science.gov (United States)

    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…

  9. Escherichia coli survival in waters: Temperature dependence

    Science.gov (United States)

    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...

  10. Comparison of 61 Sequenced Escherichia coli Genomes

    DEFF Research Database (Denmark)

    Lukjancenko, Oksana; Wassenaar, T. M.; Ussery, David

    2010-01-01

    Escherichia coli is an important component of the biosphere and is an ideal model for studies of processes involved in bacterial genome evolution. Sixty-one publically available E. coli and Shigella spp. sequenced genomes are compared, using basic methods to produce phylogenetic and proteomics...

  11. Antimicrobial resistance among commensal Escherichia coli from ...

    African Journals Online (AJOL)

    user1

    2012-07-19

    Jul 19, 2012 ... Commensal bacteria contribute to the distribution and persistence of antimicrobial resistance in the environment. This study monitored antimicrobial resistance in commensal Escherichia coli from the faeces of on-farm and slaughter cattle and beef. A total of 342 (89.5%) E. coli isolates were obtained.

  12. Fimbrial adhesins from extraintestinal Escherichia coli

    DEFF Research Database (Denmark)

    Klemm, Per; Hancock, Viktoria; Schembri, Mark A.

    2010-01-01

    Extraintestinal pathogenic Escherichia coli (ExPEC) represent an important subclass of E. coli that cause a wide spectrum of diseases in human and animal hosts. Fimbriae are key virulence factors of ExPEC strains. These long surface located rod-shaped organelles mediate receptor-specific attachment...

  13. lactamase in clinical isolates of Escherichia coli

    African Journals Online (AJOL)

    Jane

    2011-08-22

    Aug 22, 2011 ... The beta lactamase enzyme producing E. coli, resistant to β-lactam antibiotics, created many problems ... Key words: Escherichia coli, β-lactamase enzymes, TEM-type extended spectrum ... difficulties in treatment using antibiotics that are currently ... and chloramphenicol (30 µg) (Mast Diagnostics Ltd., UK).

  14. central t

    Directory of Open Access Journals (Sweden)

    Manuel R. Piña Monarrez

    2007-01-01

    Full Text Available Dado que la Regresión Ridge (RR, es una estimación sesgada que parte de la solución de la regresión de Mínimos Cuadrados (MC, es vital establecer las condiciones para las que la distribución central t de Student que se utiliza en la prueba de hipótesis en MC, sea también aplicable a la regresión RR. La prueba de este importante resultado se presenta en este artículo.

  15. Central sleep apnea

    Science.gov (United States)

    Sleep apnea - central; Obesity - central sleep apnea; Cheyne-Stokes - central sleep apnea; Heart failure - central sleep apnea ... Central sleep apnea results when the brain temporarily stops sending signals to the muscles that control breathing. The condition ...

  16. Metabolic engineering of Escherichia coli for the production of riboflavin

    Science.gov (United States)

    2014-01-01

    Background Riboflavin (vitamin B2), the precursor of the flavin cofactors flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), is used commercially as an animal feed supplement and food colorant. E. coli is a robust host for various genetic manipulations and has been employed for efficient production of biofuels, polymers, amino acids, and bulk chemicals. Thus, the aim of this study was to understand the metabolic capacity of E. coli for the riboflavin production by modification of central metabolism, riboflavin biosynthesis pathway and optimization of the fermentation conditions. Results The basic producer RF01S, in which the riboflavin biosynthesis genes ribABDEC from E. coli were overexpressed under the control of the inducible trc promoter, could accumulate 229.1 mg/L of riboflavin. Further engineering was performed by examining the impact of expression of zwf (encodes glucose 6-phosphate dehydrogenase) and gnd (encodes 6-phosphogluconate dehydrogenase) from Corynebacterium glutamicum and pgl (encodes 6-phosphogluconolactonase) from E. coli on riboflavin production. Deleting pgi (encodes glucose-6-phosphate isomerase) and genes of Entner-Doudoroff (ED) pathway successfully redirected the carbon flux into the oxidative pentose phosphate pathway, and overexpressing the acs (encodes acetyl-CoA synthetase) reduced the acetate accumulation. These modifications increased riboflavin production to 585.2 mg/L. By further modulating the expression of ribF (encodes riboflavin kinase) for reducing the conversion of riboflavin to FMN in RF05S, the final engineering strain RF05S-M40 could produce 1036.1 mg/L riboflavin in LB medium at 37°C. After optimizing the fermentation conditions, strain RF05S-M40 produced 2702.8 mg/L riboflavin in the optimized semi-defined medium, which was a value nearly 12-fold higher than that of RF01S, with a yield of 137.5 mg riboflavin/g glucose. Conclusions The engineered strain RF05S-M40 has the highest yield among all

  17. Metabolic engineering of Escherichia coli for the production of riboflavin.

    Science.gov (United States)

    Lin, Zhenquan; Xu, Zhibo; Li, Yifan; Wang, Zhiwen; Chen, Tao; Zhao, Xueming

    2014-07-16

    Riboflavin (vitamin B2), the precursor of the flavin cofactors flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), is used commercially as an animal feed supplement and food colorant. E. coli is a robust host for various genetic manipulations and has been employed for efficient production of biofuels, polymers, amino acids, and bulk chemicals. Thus, the aim of this study was to understand the metabolic capacity of E. coli for the riboflavin production by modification of central metabolism, riboflavin biosynthesis pathway and optimization of the fermentation conditions. The basic producer RF01S, in which the riboflavin biosynthesis genes ribABDEC from E. coli were overexpressed under the control of the inducible trc promoter, could accumulate 229.1 mg/L of riboflavin. Further engineering was performed by examining the impact of expression of zwf (encodes glucose 6-phosphate dehydrogenase) and gnd (encodes 6-phosphogluconate dehydrogenase) from Corynebacterium glutamicum and pgl (encodes 6-phosphogluconolactonase) from E. coli on riboflavin production. Deleting pgi (encodes glucose-6-phosphate isomerase) and genes of Entner-Doudoroff (ED) pathway successfully redirected the carbon flux into the oxidative pentose phosphate pathway, and overexpressing the acs (encodes acetyl-CoA synthetase) reduced the acetate accumulation. These modifications increased riboflavin production to 585.2 mg/L. By further modulating the expression of ribF (encodes riboflavin kinase) for reducing the conversion of riboflavin to FMN in RF05S, the final engineering strain RF05S-M40 could produce 1036.1 mg/L riboflavin in LB medium at 37°C. After optimizing the fermentation conditions, strain RF05S-M40 produced 2702.8 mg/L riboflavin in the optimized semi-defined medium, which was a value nearly 12-fold higher than that of RF01S, with a yield of 137.5 mg riboflavin/g glucose. The engineered strain RF05S-M40 has the highest yield among all reported riboflavin production

  18. Central hypothyroidism

    Directory of Open Access Journals (Sweden)

    Vishal Gupta

    2011-01-01

    Full Text Available Central hypothyroidism is defined as hypothyroidism due to insufficient stimulation by thyroid stimulating hormone (TSH of an otherwise normal thyroid gland. It has an estimated prevalence of approximately 1 in 80,000 to 1 in 120,000. It can be secondary hypothyroidism (pituitary or tertiary hypothyroidism (hypothalamus in origin. In children, it is usually caused by craniopharyngiomas or previous cranial irradiation for brain tumors or hematological malignancies. In adults, it is usually due to pituitary macroadenomas, pituitary surgeries or post-irradiation. Fatigue and peripheral edema are the most specific clinical features. Diagnosis is established by the presence of normal to low-normal TSH on the background of low-normal thyroid hormones, confirmed by the thyrotropin releasing hormone stimulation test. Therapy includes use of levothyroxine titrated to improvement in symptomology and keeping free T4 in the upper limit of normal reference range.

  19. Bacteraemia Caused by Escherichia Coli in Cancer Patients at a Specialist Center in Pakistan

    International Nuclear Information System (INIS)

    Parveen, A.; Sultan, F.; Saleem, S.; Nazeer, S. H.; Raza, A.; Zafar, W.; Nizamuddin, S.; Mahboob, A.

    2015-01-01

    Objective: To analyse the antimicrobial susceptibility patterns of Escherichia coli bacteraemia among cancer patients, and to assess the risk factors and outcomes of multidrug-resistant Escherichia coli bacteraemia. Methods: The retrospective study was conducted at Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, and comprised medical records of patients with Escherichia coli bacteraemia presenting between December 2012 and November 2013. Multivariable logistic regression analyses were used to determine the factors associated with the development and 30-day mortality of multidrug-resistant Escherichia coli bacteraemia. Results: Out of 1603 episodes of bacteraemia, 227(35.6 percent) were caused by E.coli, of which 98(43.2 percent) were multidrug-resistant. In multivariable analysis, age less than 18 years (adjusted odds ratio 3.92; 95 percent confidence interval 1.43-10.68), presence of central venous catheter (adjusted odds ratio 2.12; 95 percent confidence interval 1.04-4.33) and exposure to piperacillin/tazobactam within 90 days prior to infection (adjusted odds ratio 2.37; 95 percent confidence interval 1.15-4.86) were identified as independent risk factors for acquisition of multidrug-resistant Escherichia coli bacteraemia. The overall 30 day mortality rate was 35.2 percent (80/227). Risk factors for mortality were intensive care unit admission (adjusted odds ratio 3.95; 95 percent confidence interval 1.79-8.71) and profound neutropenia (adjusted odds ratio 4.03; 95 percent confidence interval 1.55-10.49). Conclusion: Bloodstream infections with multidrug-resistant Escherichia coli were common in cancer patients. However it was not a predictor of mortality. (author)

  20. Mechanisms of antibiotic resistance to enrofloxacin in uropathogenic Escherichia coli in dog.

    Science.gov (United States)

    Piras, Cristian; Soggiu, Alessio; Greco, Viviana; Martino, Piera Anna; Del Chierico, Federica; Putignani, Lorenza; Urbani, Andrea; Nally, Jarlath E; Bonizzi, Luigi; Roncada, Paola

    2015-09-08

    Escherichia coli (E. coli) urinary tract infections (UTIs) are becoming a serious problem both for pets and humans (zoonosis) due to the close contact and to the increasing resistance to antibiotics. This study has been performed in order to unravel the mechanism of induced enrofloxacin resistance in canine E. coli isolates that represent a good tool to study this pathology. The isolated E. coli has been induced with enrofloxacin and studied through 2D DIGE and shotgun MS. Discovered differentially expressed proteins are principally involved in antibiotic resistance and linked to oxidative stress response, to DNA protection and to membrane permeability. Moreover, since enrofloxacin is an inhibitor of DNA gyrase, the overexpression of DNA starvation/stationary phase protection protein (Dsp) could be a central point to discover the mechanism of this clone to counteract the effects of enrofloxacin. In parallel, the dramatic decrease of the synthesis of the outer membrane protein W, which represents one of the main gates for enrofloxacin entrance, could explain additional mechanism of E. coli defense against this antibiotic. All 2D DIGE and MS data have been deposited into the ProteomeXchange Consortium with identifier PXD002000 and DOI http://dx.doi.org/10.6019/PXD002000. This article is part of a Special Issue entitled: HUPO 2014. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Metabolic flux balance analysis and the in silico analysis of Escherichia coli K-12 gene deletions

    Directory of Open Access Journals (Sweden)

    Edwards Jeremy S

    2000-07-01

    Full Text Available Abstract Background Genome sequencing and bioinformatics are producing detailed lists of the molecular components contained in many prokaryotic organisms. From this 'parts catalogue' of a microbial cell, in silico representations of integrated metabolic functions can be constructed and analyzed using flux balance analysis (FBA. FBA is particularly well-suited to study metabolic networks based on genomic, biochemical, and strain specific information. Results Herein, we have utilized FBA to interpret and analyze the metabolic capabilities of Escherichia coli. We have computationally mapped the metabolic capabilities of E. coli using FBA and examined the optimal utilization of the E. coli metabolic pathways as a function of environmental variables. We have used an in silico analysis to identify seven gene products of central metabolism (glycolysis, pentose phosphate pathway, TCA cycle, electron transport system essential for aerobic growth of E. coli on glucose minimal media, and 15 gene products essential for anaerobic growth on glucose minimal media. The in silico tpi-, zwf, and pta- mutant strains were examined in more detail by mapping the capabilities of these in silico isogenic strains. Conclusions We found that computational models of E. coli metabolism based on physicochemical constraints can be used to interpret mutant behavior. These in silica results lead to a further understanding of the complex genotype-phenotype relation. Supplementary information: http://gcrg.ucsd.edu/supplementary_data/DeletionAnalysis/main.htm

  2. Effect of bile on growth, peritoneal absorption, and blood clearance of Escherichia coli in E coli peritonitis

    International Nuclear Information System (INIS)

    Andersson, R.; Schalen, C.; Tranberg, K.G.

    1991-01-01

    The effect of intraperitoneal bile on growth, peritoneal absorption, and clearance of Escherichia coli was determined in E coli peritonitis in the rat. In E coli peritonitis, intraperitoneal bacterial counts gradually decreased, whereas they increased (after 2 hours) with subsequent development of bacteremia in E coli plus bile peritonitis. After an intraperitoneal injection of labeled bacteria, blood radioactivity was only initially lower in E coli plus bile peritonitis compared with E coli peritonitis. Clearance from blood was lower in E coli plus bile peritonitis than in E coli peritonitis. Organ localization was similar in E coli peritonitis and E coli plus bile peritonitis with decreased splenic, increased pulmonary, and unchanged hepatic uptakes compared with controls. Impaired peritoneal absorption of bacteria, together with impaired local host defense, is likely to enhance the noxious effect of bile in E coli peritonitis

  3. Infectious endocarditis caused by Escherichia coli

    DEFF Research Database (Denmark)

    Lauridsen, Trine Kiilerich; Arpi, Magnus; Fritz-Hansen, Thomas

    2011-01-01

    Although Escherichia coli is among the most common causes of Gram-negative bacteraemia, infectious endocarditis (IE) due to this pathogen is rare. A 67-y-old male without a previous medical history presented with a new mitral regurgitation murmur and persisting E. coli bacteraemia in spite of broad......-spectrum intravenous antibiotics. Transthoracic and transoesophageal echocardiography revealed a severe mitral endocarditis. E. coli DNA was identified from the mitral valve and the vegetation, and no other pathogen was found. The case was further complicated by spondylodiscitis and bilateral endophthalmitis. Extra...

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

    Science.gov (United States)

    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...

  5. 21 CFR 866.3255 - Escherichia coli serological reagents.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Escherichia coli serological reagents. 866.3255... coli serological reagents. (a) Identification. Escherichia coli serological reagents are devices that consist of antigens and antisera used in serological tests to identify Escherichia coli from cultured...

  6. A scoping study on the prevalence of Escherichia coli and ...

    African Journals Online (AJOL)

    In the Eastern Cape Province E. coli and enterococci were detected in 7 and 4 of the 15 RHRW tanks, respectively. Enterococci were detected only from one river whereas E. coli was detected in all three rivers; in spring water neither enterococci nor E. coli were detected. Samples from GRWH tanks were positive for E. coli ...

  7. Protective effects of indigenous Escherichia coli against a pathogenic E. coli challenge strain in pigs.

    Science.gov (United States)

    Vahjen, W; Cuisiniere, T; Zentek, J

    2017-10-13

    To investigate the inhibitory effect of indigenous enterobacteria on pathogenic Escherichia coli, a challenge trial with postweaning pigs was conducted. A pathogenic E. coli strain was administered to all animals and their health was closely monitored thereafter. Faecal samples were taken from three healthy and three diarrhoeic animals. Samples were cultivated on MacConkey agar and isolates were subcultured. A soft agar overlay assay was used to determine the inhibitory activity of the isolates. A total of 1,173 enterobacterial isolates were screened for their ability to inhibit the E. coli challenge strain. Colony forming units of enterobacteria on MacConkey agar were not different between healthy and diarrhoeic animals in the original samples. Furthermore, numbers of isolates per animal were also not significantly different between healthy (482 isolates) and diarrhoeic animals (691 isolates). A total of 43 isolates (3.7%) with inhibitory activity against the pathogenic E. coli challenge strain were detected. All inhibitory isolates were identified as E. coli via MALDI-TOF. The isolates belonged to the phylotypes A, C and E. Many isolates (67.4%) were commensal E. coli without relevant porcine pathogenic factors, but toxin- and fimbrial genes (stx2e, fae, estIb, elt1a, fas, fan) were detected in 14 inhibitory isolates. Healthy animals showed significantly (P=0.003) more inhibitory isolates (36 of 482 isolates; 7.5%) than diseased animals (7 of 691 isolates; 1.0%). There were no significant correlations regarding phylotype or pathogenic factors between healthy and diseased animals. This study has shown that a small proportion of indigenous E. coli is able to inhibit in vitro growth of a pathogenic E. coli strain in pigs. Furthermore, healthy animals possess significantly more inhibitory E. coli strains than diarrhoeic animals. The inhibition of pathogenic E. coli by specific indigenous E. coli strains may be an underlying principle for the containment of pathogenic

  8. (ESBL) producing Escherichia coli and Klebsiella pneumoniae

    African Journals Online (AJOL)

    use

    2011-11-21

    Nov 21, 2011 ... the most common serious bacterial infections in infants ... UTI is a common cause of morbidity .... of ESBL and non-ESBL producing Escherichia coli and Klebsiella pneumonia. ... in hospital and community acquired infections.

  9. FTIR nanobiosensors for Escherichia coli detection

    Directory of Open Access Journals (Sweden)

    Stefania Mura

    2012-07-01

    Full Text Available 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-aminopropyltriethoxysilane 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.

  10. Escherichia coli pyomyositis in an immunocompromised host.

    Science.gov (United States)

    Sharma, Umesh; Schwan, William R; Agger, William A

    2011-08-01

    Pyomyositis due to Escherichia coli (E. coil) is rarely reported in immunocompromised patients with hematological malignancy. We present a case report of a 34-year-old man who developed E. coli pyomyositis as a complication of acute myelogenous leukemia (AML). Magnetic resonance imaging (MRI) of the right hip suggested myofascial infection of the gluteal muscles, and a needle muscle aspiration grew E. coli phylogenetic group B2. The patient responded to intravenous piperacillin/tazobactam followed by prolonged oral levofloxacin. Pyomyositis should be suspected in all immunocompromised patients complaining of muscle pain and may exhibit signs of localized muscle infection. Appropriate antibiotic therapy targeting fluoroquinolone-resistant E. coli should be considered for initial empiric therapy of pyomyositis in immunocompromised patients.

  11. Characterization of Escherichia coli Phylogenetic Groups ...

    African Journals Online (AJOL)

    tract infection (UTI), bacteremia, pneumonia, soft-tissue infection, and ... Keywords: Drug resistance, Escherichia coli, Extraintestinal infections, Polymerase chain reaction, .... gynecology, 12 from orthopedics and 5 from pediatrics units.

  12. Infectious endocarditis caused by Escherichia coli

    DEFF Research Database (Denmark)

    Lauridsen, Trine Kiilerich; Arpi, Magnus; Fritz-Hansen, Thomas

    2011-01-01

    Although Escherichia coli is among the most common causes of Gram-negative bacteraemia, infectious endocarditis (IE) due to this pathogen is rare. A 67-y-old male without a previous medical history presented with a new mitral regurgitation murmur and persisting E. coli bacteraemia in spite of broad......-spectrum intravenous antibiotics. Transthoracic and transoesophageal echocardiography revealed a severe mitral endocarditis. E. coli DNA was identified from the mitral valve and the vegetation, and no other pathogen was found. The case was further complicated by spondylodiscitis and bilateral endophthalmitis. Extra......-intestinal pathogenic E. coli (ExPEC) are able to colonize tissue outside the gastrointestinal tract and contain a variety of virulence factors that may enable the pathogens to invade and induce infections in the cardiac endothelia. In these cases echocardiography as the imaging technology is of paramount importance...

  13. Synergistic effects in mixed Escherichia coli biofilms

    DEFF Research Database (Denmark)

    Reisner, A.; Holler, B.M.; Molin, Søren

    2006-01-01

    Bacterial biofilms, often composed of multiple species and genetically distinct strains, develop under complex influences of cell-cell interactions. Although detailed knowledge about the mechanisms underlying formation of single-species laboratory biofilms has emerged, little is known about...... the pathways governing development of more complex heterogeneous communities. In this study, we established a laboratory model where biofilm-stimulating effects due to interactions between genetically diverse strains of Escherichia coli were monitored. Synergistic induction of biofilm formation resulting from...... the cocultivation of 403 undomesticated E. coli strains with a characterized E. coli K-12 strain was detected at a significant frequency. The survey suggests that different mechanisms underlie the observed stimulation, yet synergistic development of biofilm within the subset of E. coli isolates (n = 56) exhibiting...

  14. Experimental induced avian E. coli salpingitis

    DEFF Research Database (Denmark)

    Olsen, Rikke Heidemann; Thøfner, Ida; Pors, Susanne Elisabeth

    2016-01-01

    Several types of Escherichia coli have been associated with extra-intestinal infections in poultry, however, they may vary significantly in their virulence potential. The aim of the present study was to investigate the virulence of five strains of E. coli obtained from different disease......) had a distinct ability to cause disease. Results of the study shows major differences in virulence of different strains of E. coli in ascending infections; however, there was no indication of tissue-specific adaptation, since strains obtained from lesions unrelated to the reproductive system were...... fully capable of causing experimental infection. In conclusion, the study provides evidence for the clinical outcome of infection with E. coli in poultry is largely influenced by the specific strain as well as individual host factors....

  15. ECMDB: The E. coli Metabolome Database

    OpenAIRE

    Guo, An Chi; Jewison, Timothy; Wilson, Michael; Liu, Yifeng; Knox, Craig; Djoumbou, Yannick; Lo, Patrick; Mandal, Rupasri; Krishnamurthy, Ram; Wishart, David S.

    2012-01-01

    The Escherichia coli Metabolome Database (ECMDB, http://www.ecmdb.ca) is a comprehensively annotated metabolomic database containing detailed information about the metabolome of E. coli (K-12). Modelled closely on the Human and Yeast Metabolome Databases, the ECMDB contains >2600 metabolites with links to ?1500 different genes and proteins, including enzymes and transporters. The information in the ECMDB has been collected from dozens of textbooks, journal articles and electronic databases. E...

  16. Quantitative analysis of relationships between fluxome and metabolome in Escherichia coli

    OpenAIRE

    Taymaz Nikerel, H.

    2010-01-01

    Kinetic models, which predict the behaviour of metabolic reaction networks under different conditions, are indispensible to fully and quantitatively understand the relation between a product pathway and connected central metabolism. In this thesis the focus was to develop tools for future in vivo kinetic modeling in Escherichia coli. The relations between fluxome and metabolome at steady-state or transient state but where enzyme levels can be assumed constant are investigated. In addition, we...

  17. Application of DNA hybridization techniques in the assessment of diarrheal disease among refugess in Thailand. [Shigella; Escherichia coli; Campylobacter; Cryptosporidium

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, D.N.; Echeverria, P.; Pitarangsi, C.; Seriwatana, J.; Sethabutr, O.; Bodhidatta, L.; Brown, C.; Herrmann, J.E.; Blacklow, N.R.

    1988-01-01

    The epidemiology and etiology of acute diarrheal disease were determined in a Hmong refugee camp on the Thai-Laotian border from April 11 to May 14, 1985. DNA hybridization techniques were used to detect Shigella species, enteroinvasive Escherichia coli, and enterotoxigenic E. coli. A monoclonal enzyme-linked immunosorbent assay was used to detect rotavirus, and standard microbiology was used to detect other enteropathogens. The age-specific diarrheal disease rates were 47 episodes per month per 1000 children less than five years old and 113 episodes per month per 1000 children less than one year old. Rotavirus, enterotoxigenic E. coli, Campylobacter, and Cryptosporidium were the predominant pathogens in children less than two years old. The DNA probe hybridized with 94% of 31 specimens identified as enterotoxigenic E. coli by the standard assays and with none of the specimens in which the standard assays were negative. The probe for Shigella and enteroinvasive E. coli hybridized in eight of 10 stools that contained Shigella and four of 314 stools from which Shigella and enteroinvasive E. coli were not isolated. The use of DNA probes allows specimens to be collected in remote areas with a minimum amount of equipment and technical expertise so that they can be easily transported to a central laboratory for further processing.

  18. Identification and Prevalence of Escherichia coli and Escherichia coli O157: H7 in Foods

    Directory of Open Access Journals (Sweden)

    Ancuta Mihaela Rotar

    2013-11-01

    Full Text Available The objective of this study is to investigate the incidence of Escherichia coli in animal and non-animal foods, and mainly the incidence of the serotype O157: H7 producing verotoxin. The presence of common Escherichia coli and Escherichia coli O157: H7 in various foods (of animal and non animal origin was performed in Transylvania area. We analyzed a total of one hundred forty-one samples of minced meat, one hundred twenty-six samples of meat , twenty six samples of meat products, five samples of alcoholic beverages, three samples of seafood, one hundred samples of cheese from pasteurized milk, seventeen samples of butter, four samples of vegetables and one sample of milk powder, using the standard cultural method and Vidas Eco method for E. coli O157: H7 strains. E. coli was identified in 50 samples of minced meat, 55 samples of meat prepared, 4 samples of meat products, 2 samples of alcoholic beverages, 25 samples of cheese from pasteurized milk, 6 samples of butter and 1 sample of vegetables. In this study were not been identified any foods contaminated with the E. coli O157: H7 serotype. The results of this reasearch have demostrated that E. coli wich represents a hygienic indicator of recent food contamination, can be destroyed with heat treatment and hygienic handling of foods. Our country over the years has been among the few countries where the incidence of the E. coli O157: H7 serotype has been minimal.

  19. The asymptomatic bacteriuria Escherichia coli strain 83972 outcompetes uropathogenic E. coli strains in human urine

    DEFF Research Database (Denmark)

    Hancock, Viktoria; Ulett, G.C.; Schembri, M.A.

    2006-01-01

    Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU). In contrast to uropathogenic E. coli (UPEC), which causes symptomatic urinary tract infections (UTI), very little is known about the mechanisms by which these strains colonize the human urinary tract....... The prototype ABU E. coli strain 83972 was originally isolated from a girl who had carried it asymptomatically for 3 years. Deliberate colonization of UTI-susceptible individuals with E. coli 83972 has been used successfully as an alternative approach for the treatment of patients who are refractory...... to conventional therapy. Colonization with strain 83972 appears to prevent infection with UPEC strains in such patients despite the fact that this strain is unable to express the primary adhesins involved in UTI, viz. P and type 1 fimbriae. Here we investigated the growth characteristics of E. coli 83972 in human...

  20. Photoinactivation of mcr-1 positive Escherichia coli

    Science.gov (United States)

    Caires, C. S. A.; Leal, C. R. B.; Rodrigues, A. C. S.; Lima, A. R.; Silva, C. M.; Ramos, C. A. N.; Chang, M. R.; Arruda, E. J.; Oliveira, S. L.; Nascimento, V. A.; Caires, A. R. L.

    2018-01-01

    The emergence of plasmid-mediated colistin resistance in Enterobacteriaceae, mostly in Escherichia coli due to the mcr-1 gene, has revealed the need to develop alternative approaches in treating mcr-1 positive bacterial infections. This is because colistin is a broad-spectrum antibiotic and one of the ‘last-resort’ antibiotics for multidrug resistant bacteria. The present study evaluated for the first time, to the best of our knowledge, the efficacy of photoinactivation processes to kill a known mcr-1 positive E. coli strain. Eosin methylene-blue (EMB) was investigated as a photoantimicrobial agent for inhibiting the growth of a mcr-1 positive E. coli strain obtained from a patient with a diabetic foot infection. The photoantimicrobial activity of EMB was also tested in a non-multidrug resistant E. coli strain. The photoinactivation process was tested using light doses in the 30-45 J cm-2 range provided by a LED device emitting at 625 nm. Our findings demonstrate that a mcr-1 positive E. coli strain is susceptible to photoinactivation. The results show that the EMB was successfully photoactivated, regardless of the bacterial multidrug resistance; inactivating the bacterial growth by oxidizing the cells in accordance with the generation of the oxygen reactive species. Our results suggest that bacterial photoinactivation is an alternative and effective approach to kill mcr-1 positive bacteria.

  1. Profiling of Escherichia coli Chromosome database.

    Science.gov (United States)

    Yamazaki, Yukiko; Niki, Hironori; Kato, Jun-ichi

    2008-01-01

    The Profiling of Escherichia coli Chromosome (PEC) database (http://www.shigen.nig.ac.jp/ecoli/pec/) is designed to allow E. coli researchers to efficiently access information from functional genomics studies. The database contains two principal types of data: gene essentiality and a large collection of E. coli genetic research resources. The essentiality data are based on data compilation from published single-gene essentiality studies and on cell growth studies of large-deletion mutants. Using the circular and linear viewers for both whole genomes and the minimal genome, users can not only gain an overview of the genome structure but also retrieve information on contigs, gene products, mutants, deletions, and so forth. In particular, genome-wide exhaustive mutants are an essential resource for studying E. coli gene functions. Although the genomic database was constructed independently from the genetic resources database, users may seamlessly access both types of data. In addition to these data, the PEC database also provides a summary of homologous genes of other bacterial genomes and of protein structure information, with a comprehensive interface. The PEC is thus a convenient and useful platform for contemporary E. coli researchers.

  2. Lethality Prediction for Escherichia Coli O157:H7 and Uropathogenic E. coli in Ground Chicken Treated with High Pressure Processing and Trans-Cinnamaldehyde.

    Science.gov (United States)

    Sheen, Shiowshuh; Huang, Chi-Yun; Ramos, Rommel; Chien, Shih-Yung; Scullen, O Joseph; Sommers, Christopher

    2018-03-01

    Pathogenic Escherichia coli, intestinal (O157:H7) as well as extraintestinal types (for example, Uropathogenic E. coli [UPEC]) are commonly found in many foods including raw chicken meat. The resistance of E. coli O157:H7 to UPEC in chicken meat under the stresses of high hydrostatic Pressure (HHP, also known as HPP-high pressure processing) and trans-cinnamaldehyde (an essential oil) was investigated and compared. UPEC was found slightly less resistant than O157:H7 in our test parameter ranges. With the addition of trans-cinnamaldehyde as an antimicrobial to meat, HPP lethality enhanced both O157:H7 and UPEC inactivation. To facilitate the predictive model development, a central composite design (CCD) was used to assess the 3-parameter effects, that is, pressure (300 to 400 MPa), trans-cinnamaldehyde dose (0.2 to 0.5%, w/w), and pressure-holding time (15 to 25 min), on the inactivation of E. coli O157:H7 and UPEC in ground chicken. Linear models were developed to estimate the lethality of E. coli O157:H7 (R 2 = 0.86) and UPEC (R 2 = 0.85), as well as dimensionless nonlinear models. All models were validated with data obtained from separated CCD combinations. Because linear models of O157:H7 and UPEC had similar R 2 and the significant lethality difference of CCD points was only 9 in 20; all data were combined to generate models to include both O157:H7 and UPEC. The results provide useful information/tool to predict how pathogenic E. coli may survive HPP in the presence of trans-cinnamaldehyde and to achieve a great than 5 log CFU/g reduction in chicken meat. The models may be used for process optimization, product development and to assist the microbial risk assessment. The study provided an effective means to reduce the high hydrostatic pressure level with incorporation of antimicrobial compound to achieve a 5-log reduction of pathogenic E. coli without damaging the raw meat quality. The developed models may be used to predict the high pressure processing

  3. Optimal cofactor swapping can increase the theoretical yield for chemical production in Escherichia coli and Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    King, Zachary A.; Feist, Adam

    2014-01-01

    Maintaining cofactor balance is a critical function in microorganisms, but often the native cofactor balance does not match the needs of an engineered metabolic flux state. Here, an optimization procedure is utilized to identify optimal cofactor-specificity "swaps" for oxidoreductase enzymes...... specificity of central metabolic enzymes (especially GAPD and ALCD2x) is shown to increase NADPH production and increase theoretical yields for native products in E. coli and yeast-including l-aspartate, l-lysine, l-isoleucine, l-proline, l-serine, and putrescine-and non-native products in E. coli-including 1...

  4. Current pathogenic Escherichia coli foodborne outbreak cases and therapy development.

    Science.gov (United States)

    Yang, Shih-Chun; Lin, Chih-Hung; Aljuffali, Ibrahim A; Fang, Jia-You

    2017-08-01

    Food contamination by pathogenic microorganisms has been a serious public health problem and a cause of huge economic losses worldwide. Foodborne pathogenic Escherichia coli (E. coli) contamination, such as that with E. coli O157 and O104, is very common, even in developed countries. Bacterial contamination may occur during any of the steps in the farm-to-table continuum from environmental, animal, or human sources and cause foodborne illness. To understand the causes of the foodborne outbreaks by E. coli and food-contamination prevention measures, we collected and investigated the past 10 years' worldwide reports of foodborne E. coli contamination cases. In the first half of this review article, we introduce the infection and symptoms of five major foodborne diarrheagenic E. coli pathotypes: enteropathogenic E. coli (EPEC), Shiga toxin-producing E. coli/enterohemorrhagic E. coli (STEC/EHEC), Shigella/enteroinvasive E. coli (EIEC), enteroaggregative E. coli (EAEC), and enterotoxigenic E. coli (ETEC). In the second half of this review article, we introduce the foodborne outbreak cases caused by E. coli in natural foods and food products. Finally, we discuss current developments that can be applied to control and prevent bacterial food contamination.

  5. Action of sodium deoxycholate on Escherichia coli

    International Nuclear Information System (INIS)

    D'Mello, A.; Yotis, W.W.

    1987-01-01

    Sodium deoxycholate is used in a number of bacteriological media for the isolation and classification of gram-negative bacteria from food and the environment. Initial experiments to study the effect of deoxycholate on the growth parameters of Escherichia coli showed an increase in the lag time constant and generation time and a decrease in the growth rate constant total cell yield of this microorganisms. Cell fractionation studies indicated that sodium deoxycholate at levels used in bacteriological media interferes with the incorporation of [U- 14 C]glucose into the cold-trichloroacetic acid-soluble, ethanol-soluble, and trypsin-soluble cellular fractions of E. coli. Finally, sodium deoxycholate interfered with the flagellation and motility of Proteus mirabilis and E. coli. It would appear then that further improvement of the deoxycholate medium may be in order

  6. Prodigiosin - A Multifaceted Escherichia coli Antimicrobial Agent.

    Directory of Open Access Journals (Sweden)

    Tjaša Danevčič

    Full Text Available Despite a considerable interest in prodigiosin, the mechanism of its antibacterial activity is still poorly understood. In this work, Escherichia coli cells were treated with prodigiosin to determine its antimicrobial effect on bacterial physiology. The effect of prodigiosin was concentration dependent. In prodigiosin treated cells above MIC value no significant DNA damage or cytoplasmic membrane disintegration was observed. The outer membrane, however, becomes leaky. Cells had severely decreased respiration activity. In prodigiosin treated cells protein and RNA synthesis were inhibited, cells were elongated but could not divide. Pre-treatment with prodigiosin improved E. coli survival rate in media containing ampicillin, kanamycin and erythromycin but not phleomycin. The results suggest that prodigiosin acts as a bacteriostatic agent in E. coli cells. If prodigiosin was diluted, cells resumed growth. The results indicate that prodigiosin has distinct mode of antibacterial action in different bacteria.

  7. Deuterium incorporation into Escherichia-coli proteins

    DEFF Research Database (Denmark)

    Lederer, H.; May, R. P.; Kjems, Jørgen

    1986-01-01

    Neutron small-angle scattering studies of single protein subunits in a protein-DNA complex require the adjustment of the neutron scattering-length densities of protein and DNA, which is attainable by specific deuteration of the protein. The neutron scattering densities of unlabelled DNA and DNA......-dependent RNA polymerase of Escherichia coli match when RNA polymerase is isolated from cells grown in a medium containing 46% D2O and unlabelled glucose as carbon source. Their contrasts vanish simultaneously in a dialysis buffer containing 65% D2O. An expression was evaluated which allows the calculation...... of the degree of deuteration and match point of any E. coli protein from the D2O content of the growth medium, taking the 2H incorporation into RNA polymerase amino acids to be representative for all amino acids in E. coli proteins. The small-angle scattering results, on which the calculation of the degree...

  8. Action of sodium deoxycholate on Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    D' Mello, A.; Yotis, W.W.

    1987-08-01

    Sodium deoxycholate is used in a number of bacteriological media for the isolation and classification of gram-negative bacteria from food and the environment. Initial experiments to study the effect of deoxycholate on the growth parameters of Escherichia coli showed an increase in the lag time constant and generation time and a decrease in the growth rate constant total cell yield of this microorganisms. Cell fractionation studies indicated that sodium deoxycholate at levels used in bacteriological media interferes with the incorporation of (U-/sup 14/C)glucose into the cold-trichloroacetic acid-soluble, ethanol-soluble, and trypsin-soluble cellular fractions of E. coli. Finally, sodium deoxycholate interfered with the flagellation and motility of Proteus mirabilis and E. coli. It would appear then that further improvement of the deoxycholate medium may be in order.

  9. Central Nervous System Vasculitis

    Science.gov (United States)

    ... of Vasculitis / Central Nervous System (CNS) Vasculitis Central Nervous System (CNS) Vasculitis Swap out your current Facebook Profile ... Facebook personal page. Replace with this image. Central nervous system (CNS) vasculitis is inflammation of blood vessel walls ...

  10. Melanosis coli in patients with colon cancer

    Directory of Open Access Journals (Sweden)

    Dorota Biernacka-Wawrzonek

    2016-12-01

    Full Text Available Intoduction: Melanosis coli is a benign lesion affecting the mucosa of the large intestine. There is a relationship between the presence of melanosis and anthraquinone laxative use. Melanosis coli is also observed in patients with colon cancer, but there is doubt whether these two conditions are related. Aim : To analyze the correlation between melanosis and colon cancer. Material and methods: We analyzed retrospectively 436 patients undergoing colon cancer surgery. There were 246 women and 190 men. Patients were divided into three age groups: under 50 years, between 51 and 65 years, and over 66 years. We analyzed sections of the cancer and intestinal mucosa from the tumor’s proximal (2–5 cm and distal (8–10 cm zone. Results : Melanosis coli was present in 52 patients, which represents 11.9% of patients with colon cancer. More often it was present in women. The most common location of melanosis and colon cancer was the terminal part of the large intestine. In patients below 50 years of age in both sexes melanosis coli did not occur. In men, melanosis was more common in the age group over 66 years. Intensity of pigmentation was higher in the tumor’s distal zone. Conclusions : The incidence of melanosis coli increases with age, similar to that of colon cancer. Melanosis was not present inside tumors, in almost half of the cases it was not present in the proximal zone, and the degree of pigmentation increased in distal zone. The cause-effect relationship between melanosis coli and colon cancer remains uncertain.

  11. Hydrogen production by recombinant Escherichia coli strains

    Science.gov (United States)

    Maeda, Toshinari; Sanchez‐Torres, Viviana; Wood, Thomas K.

    2012-01-01

    Summary The production of hydrogen via microbial biotechnology is an active field of research. Given its ease of manipulation, the best‐studied bacterium Escherichia coli has become a workhorse for enhanced hydrogen production through metabolic engineering, heterologous gene expression, adaptive evolution, and protein engineering. Herein, the utility of E. coli strains to produce hydrogen, via native hydrogenases or heterologous ones, is reviewed. In addition, potential strategies for increasing hydrogen production are outlined and whole‐cell systems and cell‐free systems are compared. PMID:21895995

  12. Vaginal Lactobacillus isolates inhibit uropathogenic Escherichia coli.

    OpenAIRE

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

    2006-01-01

    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....

  13. Synthesis of avenanthramides using engineered Escherichia coli.

    Science.gov (United States)

    Lee, Su Jin; Sim, Geun Young; Kang, Hyunook; Yeo, Won Seok; Kim, Bong-Gyu; Ahn, Joong-Hoon

    2018-03-22

    Hydroxycinnamoyl anthranilates, also known as avenanthramides (avns), are a group of phenolic alkaloids with anti-inflammatory, antioxidant, anti-itch, anti-irritant, and antiatherogenic activities. Some avenanthramides (avn A-H and avn K) are conjugates of hydroxycinnamic acids (HC), including p-coumaric acid, caffeic acid, and ferulic acid, and anthranilate derivatives, including anthranilate, 4-hydroxyanthranilate, and 5-hydroxyanthranilate. Avns are primarily found in oat grain, in which they were originally designated as phytoalexins. Knowledge of the avns biosynthesis pathway has now made it possible to synthesize avns through a genetic engineering strategy, which would help to further elucidate their properties and exploit their beneficial biological activities. The aim of the present study was to synthesize natural avns in Escherichia coli to serve as a valuable resource. We synthesized nine avns in E. coli. We first synthesized avn D from glucose in E. coli harboring tyrosine ammonia lyase (TAL), 4-coumarate:coenzyme A ligase (4CL), anthranilate N-hydroxycinnamoyl/benzoyltransferase (HCBT), and anthranilate synthase (trpEG). A trpD deletion mutant was used to increase the amount of anthranilate in E. coli. After optimizing the incubation temperature and cell density, approximately 317.2 mg/L of avn D was synthesized. Avn E and avn F were then synthesized from avn D, using either E. coli harboring HpaBC and SOMT9 or E. coli harboring HapBC alone, respectively. Avn A and avn G were synthesized by feeding 5-hydroxyanthranilate or 4-hydroxyanthranilate to E. coli harboring TAL, 4CL, and HCBT. Avn B, avn C, avn H, and avn K were synthesized from avn A or avn G, using the same approach employed for the synthesis of avn E and avn F from avn D. Using different HCs, nine avns were synthesized, three of which (avn D, avn E, and avn F) were synthesized from glucose in E. coli. These diverse avns provide a strategy to synthesize both natural and unnatural avns

  14. Epidemiology and clinical manifestations of enteroaggregative Escherichia coli

    DEFF Research Database (Denmark)

    Hebbelstrup Jensen, Betina; Olsen, Katharina E P; Struve, Carsten

    2014-01-01

    Enteroaggregative Escherichia coli (EAEC) represents a heterogeneous group of E. coli strains. The pathogenicity and clinical relevance of these bacteria are still controversial. In this review, we describe the clinical significance of EAEC regarding patterns of infection in humans, transmission...

  15. lactamases genes among0 Escherichia coli from patients with ...

    African Journals Online (AJOL)

    -lactamases (ESBLs) that mediate resistance to b-lactam drugs among Escherichia coli and other uropathogens have been reported worldwide. However, there is little information on the detection of ESBLs genes in E. coli from patients with ...

  16. Plasmid-Mediated Quinolone Resistance Genes in Escherichia coli ...

    African Journals Online (AJOL)

    Erah

    PMQR) genes and the prevalence of extended spectrum β-lactamase (ESBL) types in Escherichia coli clinical isolates. Methods: Sixty-one ESBL-producing urinary E. coli isolates were studied. An antibiotic susceptibility test was performed ...

  17. Preferential use of central metabolism in vivo reveals a nutritional basis for polymicrobial infection.

    Directory of Open Access Journals (Sweden)

    Christopher J Alteri

    2015-01-01

    Full Text Available The human genitourinary tract is a common anatomical niche for polymicrobial infection and a leading site for the development of bacteremia and sepsis. Most uncomplicated, community-acquired urinary tract infections (UTI are caused by Escherichia coli, while another bacterium, Proteus mirabilis, is more often associated with complicated UTI. Here, we report that uropathogenic E. coli and P. mirabilis have divergent requirements for specific central pathways in vivo despite colonizing and occupying the same host environment. Using mutants of specific central metabolism enzymes, we determined glycolysis mutants lacking pgi, tpiA, pfkA, or pykA all have fitness defects in vivo for P. mirabilis but do not affect colonization of E. coli during UTI. Similarly, the oxidative pentose phosphate pathway is required only for P. mirabilis in vivo. In contrast, gluconeogenesis is required only for E. coli fitness in vivo. The remarkable difference in central pathway utilization between E. coli and P. mirabilis during experimental UTI was also observed for TCA cycle mutants in sdhB, fumC, and frdA. The distinct in vivo requirements between these pathogens suggest E. coli and P. mirabilis are not direct competitors within host urinary tract nutritional niche. In support of this, we found that co-infection with E. coli and P. mirabilis wild-type strains enhanced bacterial colonization and persistence of both pathogens during UTI. Our results reveal that complementary utilization of central carbon metabolism facilitates polymicrobial disease and suggests microbial activity in vivo alters the host urinary tract nutritional niche.

  18. Preferential Use of Central Metabolism In Vivo Reveals a Nutritional Basis for Polymicrobial Infection

    Science.gov (United States)

    Alteri, Christopher J.; Himpsl, Stephanie D.; Mobley, Harry L. T.

    2015-01-01

    The human genitourinary tract is a common anatomical niche for polymicrobial infection and a leading site for the development of bacteremia and sepsis. Most uncomplicated, community-acquired urinary tract infections (UTI) are caused by Escherichia coli, while another bacterium, Proteus mirabilis, is more often associated with complicated UTI. Here, we report that uropathogenic E. coli and P. mirabilis have divergent requirements for specific central pathways in vivo despite colonizing and occupying the same host environment. Using mutants of specific central metabolism enzymes, we determined glycolysis mutants lacking pgi, tpiA, pfkA, or pykA all have fitness defects in vivo for P. mirabilis but do not affect colonization of E. coli during UTI. Similarly, the oxidative pentose phosphate pathway is required only for P. mirabilis in vivo. In contrast, gluconeogenesis is required only for E. coli fitness in vivo. The remarkable difference in central pathway utilization between E. coli and P. mirabilis during experimental UTI was also observed for TCA cycle mutants in sdhB, fumC, and frdA. The distinct in vivo requirements between these pathogens suggest E. coli and P. mirabilis are not direct competitors within host urinary tract nutritional niche. In support of this, we found that co-infection with E. coli and P. mirabilis wild-type strains enhanced bacterial colonization and persistence of both pathogens during UTI. Our results reveal that complementary utilization of central carbon metabolism facilitates polymicrobial disease and suggests microbial activity in vivo alters the host urinary tract nutritional niche. PMID:25568946

  19. FREQUENCY AND DISTRIBUTION OF DIARRHOEAGENIC ESCHERICHIA COLI STRAINS ISOLATED FROM PEDIATRIC PATIENTS WITH DIARRHOEA IN BOSNIA AND HERZEGOVINA

    OpenAIRE

    Dedeić-Ljubović, AmeLa; Hukić, Mirsada; Bekić, DaRia; Zvizdić, AmrA

    2009-01-01

    Diarrhoeal disease is a major cause of illness and death among infants and young children worldwide. Among the Escherichia coli (E. coli) causing intestinal diseases, there are six well-described categories: enteroaggregative E. coli (EAEC), diffusely adherent E. coli (DAEC), enteroinvasive E. coli (EIEC), entero-pathogenic E. coli (EPEC), enterohaemorrhagic E. coli (EHEC) and enterotoxigenic E. coli (ETEC).

  20. Distribution of Diverse Escherichia coli between Cattle and Pasture

    OpenAIRE

    NandaKafle, Gitanjali; Seale, Tarren; Flint, Toby; Nepal, Madhav; Venter, Stephanus N.; Brözel, Volker S.

    2017-01-01

    Escherichia coli is widely considered to not survive for extended periods outside the intestines of warm-blooded animals; however, recent studies demonstrated that E. coli strains maintain populations in soil and water without any known fecal contamination. The objective of this study was to investigate whether the niche partitioning of E. coli occurs between cattle and their pasture. We attempted to clarify whether E. coli from bovine feces differs phenotypically and genotypically from isola...

  1. Lipocalin 2 is protective against E. coli pneumonia

    DEFF Research Database (Denmark)

    Wu, Hong; Santoni-Rugiu, Eric; Ralfkiaer, Elisabeth

    2010-01-01

    Lipocalin 2 is a bacteriostatic protein that binds the siderophore enterobactin, an iron-chelating molecule produced by Escherichia coli (E. coli) that is required for bacterial growth. Infection of the lungs by E. coli is rare despite a frequent exposure to this commensal bacterium. Lipocalin 2...... is an effector molecule of the innate immune system and could therefore play a role in hindering growth of E. coli in the lungs....

  2. Prevalence of antimicrobial resistant Escherichia coli from patients with suspected urinary tract infection in primary care, Denmark

    DEFF Research Database (Denmark)

    Cordoba, Gloria; Holm, Anne; Hansen, Frank

    2017-01-01

    Background: Escherichia coli is the most common pathogen causing Urinary Tract Infections (UTI). Data from the current National Surveillance program in Denmark (DANMAP) may not accurately represent the prevalence of resistant E. coli in primary care, because only urine samples from complicated......: Observational study carried out from December 2014 to December 2015. Thirty-nine general practices from The Capital Region of Denmark included adult patients with urinary tract symptoms and suspected UTI. All urine samples were sent to the central laboratory Statens Serum Institut (SSI). Significant bacteriuria...... 485 (96%) patients. According to the European Urinalysis Standards, 261 (54%) patients had positive bacteriuria. The most common uropathogen in patients with uncomplicated (uUTI) and complicated (cUTI) urinary tract infection was E. coli 105 (69%) and 76 (70%), respectively. Eighty-two (45%) of 181 E...

  3. Is central dogma a global property of cellular information flow?

    OpenAIRE

    Piras, Vincent; Tomita, Masaru; Selvarajoo, Kumar

    2012-01-01

    The central dogma of molecular biology has come under scrutiny in recent years. Here, we reviewed high-throughput mRNA and protein expression data of Escherichia coli, Saccharomyces cerevisiae, and several mammalian cells. At both single cell and population scales, the statistical comparisons between the entire transcriptomes and proteomes show clear correlation structures. In contrast, the pair-wise correlations of single transcripts to proteins show nullity. These data suggest that the orga...

  4. WGS accurately predicts antimicrobial resistance in Escherichia coli

    Science.gov (United States)

    Objectives: To determine the effectiveness of whole-genome sequencing (WGS) in identifying resistance genotypes of multidrug-resistant Escherichia coli (E. coli) and whether these correlate with observed phenotypes. Methods: Seventy-six E. coli strains were isolated from farm cattle and measured f...

  5. Increased multi-drug resistant Escherichia coli from hospitals in ...

    African Journals Online (AJOL)

    Background: Multidrug-resistant Escherichia coli (MDR E. coli) has become a major public health concern in Sudan and many countries, causing failure in treatment with consequent huge health burden. Objectives: To determine the prevalence and susceptibility of MDR E. coli isolated from patients in hospitals at Khartoum ...

  6. Antimicrobial susceptibility patterns of E. coli from clinical sources in ...

    African Journals Online (AJOL)

    Background: Escherichia coli is the leading cause of urinary tract, ear, wound and other infections in humans. Increasing rates of antimicrobial resistance among E. coli is a growing concern worldwide. Objectives: The aim of this study was to determine the prevalence and antimicrobial susceptibility of E. coli from clinical ...

  7. 77 FR 9888 - Shiga Toxin-Producing Escherichia coli

    Science.gov (United States)

    2012-02-21

    ... Toxin-Producing Escherichia coli in Certain Raw Beef Products AGENCY: Food Safety and Inspection Service... toxin-producing Escherichia coli (STEC) serogroups (O26, O45, O103, O111, O121, and O145). This new date..., that are contaminated with Shiga toxin-producing Escherichia coli (STEC) O26, O45, O103, O111, O121...

  8. Gene encoding virulence markers among Escherichia coli isolates ...

    African Journals Online (AJOL)

    River water sources and diarrhoeic stools of residents in the Venda Region, Limpopo Province of South Africa were analysed for the prevalence of Escherichia coli (E. coli) and the presence of virulence genes among the isolates. A control group of 100 nondiarrhoeic stool samples was included. Escherichia coli was ...

  9. Isolation and genomic characterization of Escherichia coli O157:NM ...

    African Journals Online (AJOL)

    Human diseases caused by Escherichia coli O157:NM and E. coli O157:H7 strains have been reported throughout the world. In developed countries, serotype O157:H7 represents the major cause of human diseases; however, there have been increasing reports of non-O157 Shiga toxin (Stx)-producing E. coli strains ...

  10. Neonatal infections caused by Escherichia coli at the National ...

    African Journals Online (AJOL)

    Background: Escherichia coli (E.coli) has been implicated as a common cause of both early and late onset neonatal infections. The emergence of different strains of E.coli that are multiply resistant to commonly used antibiotics has made continuous antibiotics surveillance relevant. Knowledge about common infections ...

  11. neonatal infections caused by escherichia coli at the national

    African Journals Online (AJOL)

    boaz

    Background: Escherichia coli (E.coli) has been implicated as a common cause of both early and late onset neonatal infections. The emergence of different strains of E.coli that are multiply resistant to commonly used antibiotics has made continuous antibiotics surveillance relevant. Knowledge about common infections ...

  12. Ethanol production using engineered mutant E. coli

    Science.gov (United States)

    Ingram, Lonnie O.; Clark, David P.

    1991-01-01

    The subject invention concerns novel means and materials for producing ethanol as a fermentation product. Mutant E. coli are transformed with a gene coding for pyruvate decarboxylase activity. The resulting system is capable of producing relatively large amounts of ethanol from a variety of biomass sources.

  13. E. Coli: Preventing Outbreaks at Camp.

    Science.gov (United States)

    McKinney, Mary D.

    1996-01-01

    One strain of E. coli is not usually found in foods, but has been related to consumption of undercooked ground beef. Symptoms are stomach cramps and diarrhea, and 2-7% of infections lead to hemolytic uremic syndrome, which is life threatening. Camps can prevent outbreaks by avoiding uncooked meat on overnight campouts and requiring appropriate…

  14. Identifying New Small Proteins in Escherichia coli.

    Science.gov (United States)

    VanOrsdel, Caitlin E; Kelly, John P; Burke, Brittany N; Lein, Christina D; Oufiero, Christopher E; Sanchez, Joseph F; Wimmers, Larry E; Hearn, David J; Abuikhdair, Fatimeh J; Barnhart, Kathryn R; Duley, Michelle L; Ernst, Sarah E G; Kenerson, Briana A; Serafin, Aubrey J; Hemm, Matthew R

    2018-04-12

    The number of small proteins (SPs) encoded in the Escherichia coli genome is unknown, as current bioinformatics and biochemical techniques make short gene and small protein identification challenging. One method of small protein identification involves adding an epitope tag to the 3' end of a short open reading frame (sORF) on the chromosome, with synthesis confirmed by immunoblot assays. In this study, this strategy was used to identify new E. coli small proteins, tagging 80 sORFs in the E. coli genome, and assayed for protein synthesis. The selected sORFs represent diverse sequence characteristics, including degrees of sORF conservation, predicted transmembrane domains, sORF direction with respect to flanking genes, ribosome binding site (RBS) prediction, and ribosome profiling results. Of 80 sORFs, 36 resulted in encoded synthesized proteins-a 45% success rate. Modeling of detected versus non-detected small proteins analysis showed predictions based on RBS prediction, transcription data, and ribosome profiling had statistically-significant correlation with protein synthesis; however, there was no correlation between current sORF annotation and protein synthesis. These results suggest substantial numbers of small proteins remain undiscovered in E. coli, and existing bioinformatics techniques must continue to improve to facilitate identification. © 2018 The Authors. Proteomics Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, Towson University.

  15. Optimization of plasmid electrotransformation into Escherichia coli ...

    African Journals Online (AJOL)

    In order to improve electroporation, optical density of bacteria, recovery time and electrical parameter (field strength and capacitance) were optimized using the Taguchi statistical method. ANOVA of obtained data indicated that the optimal conditions of electrotransformation of pET-28a (+) plasmid into Escherichia coli ...

  16. Transport proteins promoting Escherichia coli pathogenesis

    Science.gov (United States)

    Tang, Fengyi; Saier, Milton H.

    2014-01-01

    Escherichia coli is a genetically diverse species infecting hundreds of millions of people worldwide annually. We examined seven well-characterized E. coli pathogens causing urinary tract infections, gastroenteritis, pyelonephritis and haemorrhagic colitis. Their transport proteins were identified and compared with each other and a non-pathogenic E. coli K12 strain to identify transport proteins related to pathogenesis. Each pathogen possesses a unique set of protein secretion systems for export to the cell surface or for injecting effector proteins into host cells. Pathogens have increased numbers of iron siderophore receptors and ABC iron uptake transporters, but the numbers and types of low-affinity secondary iron carriers were uniform in all strains. The presence of outer membrane iron complex receptors and high-affinity ABC iron uptake systems correlated, suggesting co-evolution. Each pathovar encodes a different set of pore-forming toxins and virulence-related outer membrane proteins lacking in K12. Intracellular pathogens proved to have a characteristically distinctive set of nutrient uptake porters, different from those of extracellular pathogens. The results presented in this report provide information about transport systems relevant to various types of E. coli pathogenesis that can be exploited in future basic and applied studies. PMID:24747185

  17. Transport proteins promoting Escherichia coli pathogenesis.

    Science.gov (United States)

    Tang, Fengyi; Saier, Milton H

    2014-01-01

    Escherichia coli is a genetically diverse species infecting hundreds of millions of people worldwide annually. We examined seven well-characterized E. coli pathogens causing urinary tract infections, gastroenteritis, pyelonephritis and haemorrhagic colitis. Their transport proteins were identified and compared with each other and a non-pathogenic E. coli K12 strain to identify transport proteins related to pathogenesis. Each pathogen possesses a unique set of protein secretion systems for export to the cell surface or for injecting effector proteins into host cells. Pathogens have increased numbers of iron siderophore receptors and ABC iron uptake transporters, but the numbers and types of low-affinity secondary iron carriers were uniform in all strains. The presence of outer membrane iron complex receptors and high-affinity ABC iron uptake systems correlated, suggesting co-evolution. Each pathovar encodes a different set of pore-forming toxins and virulence-related outer membrane proteins lacking in K12. Intracellular pathogens proved to have a characteristically distinctive set of nutrient uptake porters, different from those of extracellular pathogens. The results presented in this report provide information about transport systems relevant to various types of E. coli pathogenesis that can be exploited in future basic and applied studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Isolation and molecular characterization of Campylobacter coli

    African Journals Online (AJOL)

    Campylobacter coli is prevalent among trade pigs in Kafanchan, Nigeria and is distributed across four of the five states from which trade pigs were sourced. Adequate hand hygiene is recommended for farmers, traders and Veterinary professionals handling pigs to prevent the transmission of this zoonosis to humans.

  19. Inhibition of Escherichia Coli, Salmonella and Staphylococcus ...

    African Journals Online (AJOL)

    Escherichia coli O157:H7, Salmonella typhimurium and Staphylococcus. aureus are of great concern to the food industry, especially in foods stored under refrigerated conditions where, unlike most food-borne pathogens are able to multiply. This investigation was conducted to study the inhibitory effect of some spice ...

  20. (ESBL) producing Escherichia coli and Klebsiella pneumoniae

    African Journals Online (AJOL)

    Emerging antibiotic resistance due to extended spectrum β-lactamase (ESBL) production limited the use of β-lactam antibiotics against Escherichia coli and Klebsiella pneumoniae. This observational study was conducted at the Microbiology department of the Children's Hospital, Lahore Pakistan, from June, 2009 to ...

  1. Mutagenic DNA repair in Escherichia coli

    International Nuclear Information System (INIS)

    Bridges, B.A.; Sharif, Firdaus

    1986-01-01

    The authors report a study of the misincorporation step in excision proficient umuC Escherichia coli as revealed by delayed photoreversal and show that it parallels the loss of photoreversibility of mutations induced in isogenic umu + bacteria; in both cases the end-point was mutation to streptomycin resistance. (author)

  2. Emergence of Quinolone Resistance amongst Escherichia coli ...

    African Journals Online (AJOL)

    Rate of resistance was 22.3% showing an increase in quinolone resistance when ... FQR E. coli was more common in patients with urinary tract infection (22.9%). ... in the faeces of healthy adults was 22.9%, 6.7% in children and 22.2% in avian. ... thereby aiding the spread of antibiotic resistant strains from avians to human ...

  3. Antibiotic resistance properties of uropathogenic Escherichia coli ...

    African Journals Online (AJOL)

    Purpose: To investigate the antibiotic resistance pattern of uropathogenic Escherichia coli (UPEC) strains isolated from pregnant women with history of recurrent urinary tract infections (RUTIs) and healthy pregnant women. Methods: A total of 485 high vaginal swab specimens were collected from pregnant women with ...

  4. Prevalence of Arcobacter, Escherichia coli, Staphylococcus aureus ...

    African Journals Online (AJOL)

    In this study, varying level of resistance of Escherichia coli 66(84.6%), Salmonella 6(100%) and Arcobacter 57(100%) to amoxicillin was observed. The susceptibility pattern indicates that the bacterial isolates exhibited a varying level of resistance to two or more antimicrobial agents with maximum resistance to amoxicillin.

  5. E.coli O157:H7

    Directory of Open Access Journals (Sweden)

    Treor Francis Fernandez

    2008-06-01

    Full Text Available The serious nature of the symptoms of haemorrhagic colitis and HUS and the apparent low infectious dose (<100 cells of E.coli O157:H7 places this food borne pathogen a most serious of known food borne pathogens. Persuasive evidence suggests that healthy cattle are a reservoir of O157 and they can enter the food chain to provide a source of exposure for humans. A possible route of transmission of O157 VTEC may involve infections initially in calves that shed their organism into faecal slurry that may be used on grazing grass. This provides potential for infection of other animals from which the organism may contaminate milk or carcasses at slaughter. Possible sources of VTEC in healthy animals other E.coli O157:H7 than cattle and a wider range of foodstuffs require further investigation. Many features of E.coli O157:H7 strains remain poorly understood. It includes: (i Role of virulent genes in the animal, (ii Mechanism of evolution of the organism, (iii The progress of individual cases of E.coli O157:H7 infection, and (iv The difference in incidence of infection in different geographical areas. [Veterinary World 2008; 1(3.000: 83-87

  6. Leaner and meaner genomes in Escherichia coli

    DEFF Research Database (Denmark)

    Ussery, David

    2006-01-01

    A 'better' Escherichia coli K-12 genome has recently been engineered in which about 15% of the genome has been removed by planned deletions. Comparison with related bacterial genomes that have undergone a natural reduction in size suggests that there is plenty of scope for yet more deletions....

  7. ANTIMICIROBIAL SUSCEPTIBILITY PATTERNS OF Escherichia coli ...

    African Journals Online (AJOL)

    DR. AMINU

    A total of 56 and 24 strains of E. coli and Shigella sp. isolated from children less than five years with diarrhoea attending 3 ... parasitic infections, as well as food intolerance, reaction to ..... Escherichia coil 0157:H7 as a model of entry of a new.

  8. Cellular chain formation in Escherichia coli biofilms

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk; Klemm, Per

    2009-01-01

    ; type I fimbriae expression significantly reduced cellular chain formation, presumably by steric hindrance. Cellular chain formation did not appear to be specific to E coli K-12. Although many urinary tract infection (UTI) isolates were found to form rather homogeneous, flat biofilms, three isolates...

  9. Escherichia coli in broiler chickens with airsacculitis

    Directory of Open Access Journals (Sweden)

    Leandro S. Machado

    2014-09-01

    Full Text Available ABSTRACT. Machado L.S., do Nascimento E.R., Pereira V.L.A., Abreu D.L.C., Gouvea R. & Santos L.M.M. 2014. [Escherichia coli in broiler chickens with airsacculitis.] Escherichia coli em frangos de corte com aerossaculite. Revista Brasileira de Medicina Veterinária, 36(3:261-265, 2014. Departamento de Medicina Veterinária Preventiva e Saúde Pública, Faculdade de Veterinária, Universidade Federal Fluminense, Rua Dr. Vital Brazil Filho 64, Vital Brazil, Niterói, RJ 24230-340, Brazil. E-mail: leandromachadovet@yahoo.com.br The Brazilian poultry industry grows each year and becomes increasingly representative in the production and export of products. The health care with poultry have accompanied and favored this evolution, however, respiratory agents that affect the weight and carcass quality, continue to cause great damage to the poultry industry. Airsacculitis is considered the main cause of total and partial condemnation of carcasses of broilers, and has been attributed to Mycoplasmosis mostly caused by Mycoplasma gallisepticum (MG and Mycoplasma synoviae (MS and Escherichia coli. The aim of this study was to relate the positivity of MG / MS and E. coli detected by PCR as a risk factor for airsacculitis in condemnation of broilers in Health Inspection Service. We studied 30 broiler poultry slaughtered in a slaughterhouse under Federal Sanitary Inspection, located in the State of Rio de Janeiro. 30 chickens were randomly collected from different lots and tracheas obtained in each PCR. DNA was extracted by phenol-chloroform method and amplified using pairs of “primer”specific for MG, MS and E. coli. Of the 30 chickens analyzed by PCR, 30% (9/30 had lesions in air sacs. None of the birds showed infection with MG and/or MS PCR, however 33.3% (3/9 birds were positive for airsacculitis iss gene from E.coli. E.coli found in broiler chickens that were negative for mycoplasma airsacculitis, implying the presence of such bacteria may be sufficient

  10. Genetic Transfer of Salmonella typhimurium and Escherichia coli Lipopolysaccharide Antigens to Escherichia coli K-12

    Science.gov (United States)

    Jones, Randall T.; Koeltzow, Donald E.; Stocker, B. A. D.

    1972-01-01

    Escherichia coli K-12 ϰ971 was crossed with a smooth Salmonella typhimurium donor, HfrK6, which transfers early the ilv-linked rfa region determining lipopolysaccharide (LPS) core structure. Two ilv+ hybrids differing in their response to the LPS-specific phages FO and C21 were then crossed with S. typhimurium HfrK9, which transfers early the rfb gene cluster determining O repeat unit structure. Most recombinants selected for his+ (near rfb) were agglutinated by Salmonella factor 4 antiserum. Transfer of an F′ factor (FS400) carrying the rfb–his region of S. typhimurium to the same two ilv+ hybrids gave similar results. LPS extracted from two ilv+,his+, factor 4-positive hybrids contained abequose, the immunodominant sugar for factor 4 specificity. By contrast, his+ hybrids obtained from ϰ971 itself by similar HfrK9 and F′FS400 crosses were not agglutinated by factor 4 antiserum, indicating that the parental E. coli ϰ971 does not have the capacity to attach Salmonella O repeat units to its LPS core. It is concluded that the Salmonella rfb genes are expressed only in E. coli ϰ971 hybrids which have also acquired ilv-linked genes (presumably rfa genes affecting core structure or O-translocase ability, or both) from a S. typhimurium donor. When E. coli ϰ971 was crossed with a smooth E. coli donor, Hfr59, of serotype O8, which transfers his early, most his+ recombinants were agglutinated by E. coli O8 antiserum and lysed by the O8-specific phage, Ω8. This suggests that, although the parental E. coli K-12 strain ϰ971 cannot attach Salmonella-specific repeat units to its LPS core, it does have the capacity to attach E. coli O8-specific repeat units. PMID:4559827

  11. FimH adhesin of Escherichia coli K1 type 1 fimbriae activates BV-2 microglia

    International Nuclear Information System (INIS)

    Lee, Jongseok; Shin, Sooan; Teng, C.-H.; Hong, Suk Jin; Kim, Kwang Sik

    2005-01-01

    The generation of intense inflammation in the subarachnoid space in response to meningitis-causing bacteria contributes to brain dysfunction and neuronal injury in bacterial meningitis. Microglia, the major immune effector cells in the central nervous system (CNS), become activated by bacterial components to produce proinflammatory immune mediators. In this study, we showed that FimH adhesin, a tip component of type 1 fimbriae of meningitis-causing Escherichia coli K1, activated the murine microglial cell line, BV-2, which resulted in the production of nitric oxide and the release of tumor necrosis factor-α. Mitogen-activated protein kinases, ERK and p-38, and nuclear factor-κB were involved in FimH adhesin-mediated microglial activation. These findings suggest that FimH adhesin contributes to the CNS inflammatory response by virtue of activating microglia in E. coli meningitis

  12. Hemolytic Porcine Intestinal Escherichia coli without Virulence-Associated Genes Typical of Intestinal Pathogenic E. coli ▿ †

    Science.gov (United States)

    Schierack, Peter; Weinreich, Joerg; Ewers, Christa; Tachu, Babila; Nicholson, Bryon; Barth, Stefanie

    2011-01-01

    Testing 1,666 fecal or intestinal samples from healthy and diarrheic pigs, we obtained hemolytic Escherichia coli isolates from 593 samples. Focusing on hemolytic E. coli isolates without virulence-associated genes (VAGs) typical for enteropathogens, we found that such isolates carried a broad variety of VAGs typical for extraintestinal pathogenic E. coli. PMID:21965399

  13. Transport of Escherichia coli and F-RNA bacteriophages in a 5 m column of saturated pea gravel

    Science.gov (United States)

    Sinton, Lester W.; Mackenzie, Margaret L.; Karki, Naveena; Braithwaite, Robin R.; Hall, Carollyn H.; Flintoft, Mark J.

    2010-09-01

    The relative transport and attenuation of bacteria, bacteriophages, and bromide was determined in a 5 m long × 0.3 m diameter column of saturated pea gravel. The velocity ( V), longitudinal dispersivity ( αx) and total removal rate ( λ) were calculated from the breakthrough curves at 1 m, 3 m, and 5 m, at a flow rate of 32 L h - 1 . Inactivation ( μ) rates were determined in survival chambers. Two pure culture experiments with Escherichia coli J6-2 and F-RNA phage MS2 produced an overall V ranking of E. coli J6-2 > MS2 > bromide, consistent with velocity enhancement, whereby larger particles progressively move into faster, central streamlines of saturated pores. Removal rates were near zero for MS2, but were higher for E. coli J6-2. In two sewage experiments, E. coli and F-RNA phage Vs were similar (but > bromide). This was attributed to phage adsorption to colloids similar in size to E. coli cells. Sewage phage removal rates were higher than for the pure MS2 cultures. The application of filtration theory suggested that, whereas free phage were unaffected by settling, this was the primary removal mechanism for the colloid-associated phage. However, cultured and sewage E. coli removal rates were similar, suggesting the dominance of free E. coli cells in the sewage. When MS2 was attached to kaolin particles, it was transported faster than free MS2, but at similar rates to sewage phage. The μ values indicated little contribution of inactivation to removal of either cultured or sewage microorganisms. The results showed the importance of association with colloids in determining the relative transport of bacteria and viruses in gravels.

  14. PCR approach for rapid detection of Escherichia coli in tempe using a specific primer

    Directory of Open Access Journals (Sweden)

    Siti Harnina Bintari

    2014-12-01

    Full Text Available Tempe known as a traditional fermented food originated from Indonesia. It has a unique flavour and texture. It also contains high protein and usually serves to substitute meat, fish, or egg as a complement to rice. The manufacture process of Tempe is quite complex and mostly, the traditional process has not employed the hygienic standard. In the process of Tempe making, there are two critical stages of the whole process; i.e. soaking of soybeans and solid state fermentation by Rhizopus sp. During the process, foodborne pathogen bacteria such as Escherichia coli could contaminate the product of Tempe. The bacterial contamination could be revealed through culture dependent methods which is costly, laborious, and time consuming. Therefore, the culture-independent method such as polymerase chain reaction using a specific primer could be applied to detect target microorganism to save time and labour. In this study, thirty-one Tempe samples collected from different manufacturers in Semarang, Central Java, Indonesia were analysed by PCR. In order to obtain the bacterial genomic DNA, a modified Chelex 100-Microwave method was employed. The results of DNA extraction showed that the method was an applicable method. It gave high quantity and quality of DNA; therefore, it could be applied in the PCR reaction. The DNA samples were employed in PCR for detection of Escherichia coli using Ecoli706F/R. It was found that 27 out of 31 samples were detected having Escherichia coli contamination showed by the presence of the amplified product size 706 bp. The application of this method could significantly reduce costs and time of analysis in the laboratory. Further response after E. coli were detected could be employed, including investigation of the critical factors in Tempe manufacturing process which allowed E. coli contamination.

  15. Copper Homeostasis in Escherichia coli and Other Enterobacteriaceae.

    Science.gov (United States)

    Rensing, Christopher; Franke, Sylvia

    2007-04-01

    An interesting model for studying environmental influences shaping microbial evolution is provided by a multitude of copper resistance and copper homeostasis determinants in enteric bacteria. This review describes these determinants and tries to relate their presence to the habitat of the respective organism, as a current hypothesis predicts that the environment should determine an organism's genetic makeup. In Escherichia coli there are four regulons that are induced in the presence of copper. Two, the CueR and the CusR regulons, are described in detail. A central component regulating intracellular copper levels, present in all free-living enteric bacteria whose genomes have so far been sequenced, is a Cu(I)translocating P-type ATPase. The P-type ATPase superfamily is a ubiquitous group of proteins involved in the transport of charged substrates across biological membranes. Whereas some components involved in copper homeostasis can be found in both anaerobes and aerobes, multi-copper oxidases (MCOs) implicated in copper tolerance in E. coli, such as CueO and the plasmid-based PcoA, can be found only in aerobic organisms. Several features indicate that CueO, PcoA, and other related MCOs are specifically adapted to combat copper-mediated oxidative damage. In addition to these well-characterized resistance operons, there are numerous other genes that appear to be involved in copper binding and trafficking that have not been studied in great detail. SilE and its homologue PcoE, for example, are thought to effect the periplasmic binding and sequestration of silver and copper, respectively.

  16. Comparative proteomic analysis of proteins expression changes in the mammary tissue of cows infected with Escherichia coli mastitis.

    Science.gov (United States)

    Zhao, Xiao-wei; Yang, Yong-xin; Huang, Dong-wei; Cheng, Guang-long; Zhao, Hui-ling

    2015-01-01

    Cows infected with Escherichia (E.) coli usually experience severe clinical symptoms, including damage to mammary tissues, reduced milk yield, and altered milk composition. In order to investigate the host response to E. coli infection and discover novel markers for mastitis treatment, mammary tissue samples were collected from healthy cows and bovines with naturally occurring severe E. coli mastitis. Changes of mammary tissue proteins were examined using two-dimensional gel electrophoresis and label-free proteomic approaches. A total of 95 differentially expressed proteins were identified. Of these, 56 proteins were categorized according to molecular function, cellular component, and biological processes. The most frequent biological processes influenced by the proteins were response to stress, transport, and establishment of localization. Furthermore, a network analysis of the proteins with altered expression in mammary tissues demonstrated that these factors are predominantly involved with binding and structural molecule activities. Vimentin and a-enolase were central "functional hubs" in the network. Based on results from the present study, disease-induced alterations of protein expression in mammary glands and potential markers for the effective treatment of E. coli mastitis were identified. These data have also helped elucidate defense mechanisms that protect the mammary glands and promote the pathogenesis of E. coli mastitis.

  17. Antimicrobial Resistance Characteristics and Phylogenetic Groups of Escherichia coli Isolated From Diarrheic Calves in Southeast of Iran

    Directory of Open Access Journals (Sweden)

    Zahedeh Naderi

    2016-11-01

    Full Text Available Background: Antimicrobial resistance is one of the main challenges in diarrheal diseases in human and animals. Regardless to the main reason of the disease, approximately all antimicrobial actions including treatment, control and prevention are mostly centralized against Escherichia coli (E. coli strains. Objectives: This work purposed to antimicrobial resistance (AR and determinate virulence genes and phylogenetic groups in E. coli isolates (n=170 obtained from calves with diarrhea. Materials and methods: Isolates were molecular characterized for 17 AR genes and 3 phylogenetic sequences. AR phenotyping were performed on all strains for 12 antimicrobial agents by using disc diffusion method. Results: All AR genes but qnrS were identified with different prevalence in E. coli isolates that the most common genes were aadA (20%, blaTEM (11.7% and sulII (11.2 % belonging to aminoglycoside, β-lactamase and sulphonamide families, respectively. Resistance to the penicillin and sulphamethoxazole drugs was found in 100% of isolates and followed by tetracycline (73.5%, streptomycin (60%, trimethoprim sulphamethoxazole (56.5% and kanamycin (53.5%. The phylogenetic groups A and B1 considerably surrounded the majority of isolates with the frequency of 65.8% and 30.6%, respectively. Conclusions: In Iran, diarrheic calves have an important role as reservoir of resistant E. coli strains against the some drugs which are registered for treatment of calf diarrhea.

  18. Is central dogma a global property of cellular information flow?

    Science.gov (United States)

    Piras, Vincent; Tomita, Masaru; Selvarajoo, Kumar

    2012-01-01

    The central dogma of molecular biology has come under scrutiny in recent years. Here, we reviewed high-throughput mRNA and protein expression data of Escherichia coli, Saccharomyces cerevisiae, and several mammalian cells. At both single cell and population scales, the statistical comparisons between the entire transcriptomes and proteomes show clear correlation structures. In contrast, the pair-wise correlations of single transcripts to proteins show nullity. These data suggest that the organizing structure guiding cellular processes is observed at omics-wide scale, and not at single molecule level. The central dogma, thus, globally emerges as an average integrated flow of cellular information.

  19. Is central dogma a global property of cellular information flow?

    Directory of Open Access Journals (Sweden)

    Vincent ePiras

    2012-11-01

    Full Text Available The central dogma of molecular biology has come under scrutiny in recent years. Here, we reviewed high-throughput mRNA and protein expression data of Escherichia coli, Saccharomyces cerevisiae, and several mammalian cells. At both single cell and population scales, the statistical comparisons between the entire transcriptomes and proteomes show clear correlation structures. In contrast, the pair-wise correlations of single transcript to protein show nullity. These data suggest that the organizing structure guiding cellular processes is observed at omics-wide scale and not at single molecule level. The central dogma, thus, globally emerges as an average integrated flow of cellular information.

  20. Flux balance analysis of ammonia assimilation network in E. coli predicts preferred regulation point.

    Science.gov (United States)

    Wang, Lu; Lai, Luhua; Ouyang, Qi; Tang, Chao

    2011-01-25

    Nitrogen assimilation is a critical biological process for the synthesis of biomolecules in Escherichia coli. The central ammonium assimilation network in E. coli converts carbon skeleton α-ketoglutarate and ammonium into glutamate and glutamine, which further serve as nitrogen donors for nitrogen metabolism in the cell. This reaction network involves three enzymes: glutamate dehydrogenase (GDH), glutamine synthetase (GS) and glutamate synthase (GOGAT). In minimal media, E. coli tries to maintain an optimal growth rate by regulating the activity of the enzymes to match the availability of the external ammonia. The molecular mechanism and the strategy of the regulation in this network have been the research topics for many investigators. In this paper, we develop a flux balance model for the nitrogen metabolism, taking into account of the cellular composition and biosynthetic requirements for nitrogen. The model agrees well with known experimental results. Specifically, it reproduces all the (15)N isotope labeling experiments in the wild type and the two mutant (ΔGDH and ΔGOGAT) strains of E. coli. Furthermore, the predicted catalytic activities of GDH, GS and GOGAT in different ammonium concentrations and growth rates for the wild type, ΔGDH and ΔGOGAT strains agree well with the enzyme concentrations obtained from western blots. Based on this flux balance model, we show that GS is the preferred regulation point among the three enzymes in the nitrogen assimilation network. Our analysis reveals the pattern of regulation in this central and highly regulated network, thus providing insights into the regulation strategy adopted by the bacteria. Our model and methods may also be useful in future investigations in this and other networks.

  1. Flux balance analysis of ammonia assimilation network in E. coli predicts preferred regulation point.

    Directory of Open Access Journals (Sweden)

    Lu Wang

    Full Text Available Nitrogen assimilation is a critical biological process for the synthesis of biomolecules in Escherichia coli. The central ammonium assimilation network in E. coli converts carbon skeleton α-ketoglutarate and ammonium into glutamate and glutamine, which further serve as nitrogen donors for nitrogen metabolism in the cell. This reaction network involves three enzymes: glutamate dehydrogenase (GDH, glutamine synthetase (GS and glutamate synthase (GOGAT. In minimal media, E. coli tries to maintain an optimal growth rate by regulating the activity of the enzymes to match the availability of the external ammonia. The molecular mechanism and the strategy of the regulation in this network have been the research topics for many investigators. In this paper, we develop a flux balance model for the nitrogen metabolism, taking into account of the cellular composition and biosynthetic requirements for nitrogen. The model agrees well with known experimental results. Specifically, it reproduces all the (15N isotope labeling experiments in the wild type and the two mutant (ΔGDH and ΔGOGAT strains of E. coli. Furthermore, the predicted catalytic activities of GDH, GS and GOGAT in different ammonium concentrations and growth rates for the wild type, ΔGDH and ΔGOGAT strains agree well with the enzyme concentrations obtained from western blots. Based on this flux balance model, we show that GS is the preferred regulation point among the three enzymes in the nitrogen assimilation network. Our analysis reveals the pattern of regulation in this central and highly regulated network, thus providing insights into the regulation strategy adopted by the bacteria. Our model and methods may also be useful in future investigations in this and other networks.

  2. Statistical Optimization of the Induction of Phytase Production by Arabinose in a recombinant E. coli using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Abd-El Aziem Farouk

    2017-11-01

    Full Text Available The production of phytase in a recombinant E.coli using the pBAD expression  system was optimized using response surface methodology with full-factorial faced centered central composite design. The ampicilin and arabinose concentration in the cultivation media and the incubation temperature were optimized in order to maximize phytase production using 2 3  central composite experimental design. With this design the number of actual experiment performed could be reduced while allowing eludidation of possible interactions among these factors. The most significant parameter was shown to be the linear and quadratic effect of the incubation temperature.  Optimal conditions for phytase production were determined to be 100 µg/ml ampicilin, 0.2 % arabinose and an incubation temperature of 37ºC. The production of phytase in the recombinant E. coli was scaled up to 100 ml and 1000 ml.

  3. Expression of maize prolamins in Escherichia Coli

    International Nuclear Information System (INIS)

    Wang, Szu-zhen; Esen, Asim

    1985-01-01

    We have constructed a cDNA expression library of developing corn (Zea manys L.) endosperm using plasmid pUC8 as vector and Escherichia coli strain DH1 as host. The expression library was screened with non-radioactive immunological probes to detect the expression of gamma-zein and alpha-zein. When anti-gamma-zein antibody was used as the probe, 23 colonies gave positive reactions. The lengths of cDNA inserts of the 23 colonies were found to be 250-900 base pairs. When anti-alpha zein antibody was used, however, fewer colonies gave positive reactions. The library was also screened by colony-hybridization with 32 P-labeled DNA probes. Based on immunological and hybridization screening of the library and other evidence, we conclude that alpha-zein was either toxic to E. coli cells or rapidly degraded whereas gamma-zein and its fragments were readily expressed. (author)

  4. Genes under positive selection in Escherichia coli

    DEFF Research Database (Denmark)

    Petersen, Lise; Bollback, Jonathan P; Dimmic, Matt

    2007-01-01

    We used a comparative genomics approach to identify genes that are under positive selection in six strains of Escherichia coli and Shigella flexneri, including five strains that are human pathogens. We find that positive selection targets a wide range of different functions in the E. coli genome......, including cell surface proteins such as beta barrel porins, presumably because of the involvement of these genes in evolutionary arms races with other bacteria, phages, and/or the host immune system. Structural mapping of positively selected sites on trans-membrane beta barrel porins reveals...... that the residues under positive selection occur almost exclusively in the extracellular region of the proteins that are enriched with sites known to be targets of phages, colicins, or the host immune system. More surprisingly, we also find a number of other categories of genes that show very strong evidence...

  5. Vascular Endothelial Growth Factor Receptor 1 Contributes to Escherichia coli K1 Invasion of Human Brain Microvascular Endothelial Cells through the Phosphatidylinositol 3-Kinase/Akt Signaling Pathway▿ †

    OpenAIRE

    Zhao, Wei-Dong; Liu, Wei; Fang, Wen-Gang; Kim, Kwang Sik; Chen, Yu-Hua

    2010-01-01

    Escherichia coli is the most common Gram-negative organism causing neonatal meningitis. Previous studies demonstrated that E. coli K1 invasion of brain microvascular endothelial cells (BMEC) is required for penetration into the central nervous system, but the microbe-host interactions that are involved in this process remain incompletely understood. Here we report the involvement of vascular endothelial growth factor receptor 1 (VEGFR1) expressed on human brain microvascular endothelial cells...

  6. Energetics of sodium efflux from Escherichia coli

    International Nuclear Information System (INIS)

    Borbolla, M.G.; Rosen, B.P.

    1984-01-01

    When energy-starved cells of Escherichia coli were passively loaded with 22 Na+, efflux of sodium could be initiated by addition of a source of metabolic energy. Conditions were established where the source of energy was phosphate bond energy, an electrochemical proton gradient, or both. Only an electrochemical proton gradient was required for efflux from intact cells. These results are consistent with secondary exchange of Na+ for H+ catalyzed by a sodium/proton antiporter

  7. Silver nanoparticle-E. coli colloidal interaction in water and effect on E. coli survival.

    Science.gov (United States)

    Dror-Ehre, A; Mamane, H; Belenkova, T; Markovich, G; Adin, A

    2009-11-15

    Silver nanoparticles exhibit antibacterial properties via bacterial inactivation and growth inhibition. The mechanism is not yet completely understood. This work was aimed at elucidating the effect of silver nanoparticles on inactivation of Escherichia coli, by studying particle-particle interactions in aqueous suspensions. Stable, molecularly capped, positively or negatively charged silver nanoparticles were mixed at 1 to 60microgmL(-1) with suspended E. coli cells to examine their effect on inactivation of the bacteria. Gold nanoparticles with the same surfactant were used as a control, being of similar size but made up of a presumably inert metal. Log reduction of 5log(10) and complete inactivation were obtained with the silver nanoparticles while the gold nanoparticles did not show any inactivation ability. The effect of molecularly capped nanoparticles on E. coli survival was dependent on particle number. Log reduction of E. coli was associated with the ratio between the number of nanoparticles and the initial bacterial cell count. Electrostatic attraction or repulsion mechanisms in silver nanoparticle-E. coli cell interactions did not contribute to the inactivation process.

  8. Observations of central stars

    International Nuclear Information System (INIS)

    Lutz, J.H.

    1978-01-01

    Difficulties occurring in the observation of central stars of planetary nebulae are reviewed with emphasis on spectral classifications and population types, and temperature determination. Binary and peculiar central stars are discussed. (U.M.G.)

  9. Gangs in Central America

    National Research Council Canada - National Science Library

    Ribando, Clare

    2005-01-01

    ... activities of Central American gangs. Citizens in several Central American countries have identified crime and gang violence among the top issues of popular concern, and Honduras and El Salvador have recently enacted tough anti-gang legislation...

  10. NIDDK Central Repository

    Data.gov (United States)

    U.S. Department of Health & Human Services — The NIDDK Central Repository stores biosamples, genetic and other data collected in designated NIDDK-funded clinical studies. The purpose of the NIDDK Central...

  11. Secretion of clostridium cellulase by E. coli

    Science.gov (United States)

    Yu, Ida Kuo

    1998-01-01

    A gene, encoding an endocellulase from a newly isolated mesophilic Clostridium strain IY-2 which can digest bamboo fibers, cellulose, rice straw, and sawdust, was isolated by shotgun cloning in an E. coli expression plasmid pLC2833. E. coli positive clones were selected based on their ability to hydrolyze milled bamboo fibers and cellulose present in agar plates. One clone contained a 2.8 kb DNA fragment that was responsible for cellulase activity. Western blot analyses indicated that the positive clone produced a secreted cellulase with a mass of about 58,000 daltons that was identical in size to the subunit of one of the three major Clostridium cellulases. The products of cellulose digestion by this cloned cellulase were cellotetraose and soluble higher polymers. The cloned DNA contained signal sequences capable of directing the secretion of heterologous proteins from an E. coli host. The invention describes a bioprocess for the treatment of cellulosic plant materials to produce cellular growth substrates and fermentation end products suitable for production of liquid fuels, solvents, and acids.

  12. Multiple loci affecting photoreactivation in Escherichia coli

    International Nuclear Information System (INIS)

    Sutherland, B.M.; Hausrath, S.G.

    1979-01-01

    Sutherland et al. mapped a phr gene in Escherichia coli at 17 min and found that induction of an E. coli stain lysogenic for a lambda phage carrying this gene increased photoreactivating enzyme levels 2,000-fold. Recently, Smith and Youngs and Sancar and Rupert located a phr gene at 15.9 min. We have therefore investigated the properties of photoreactivating enzyme and cellular photoreactivation in cells containing deletions of the gene at 17 min. Cells with this deletion photoreactivated ultraviolet-induced killing at a rate 20% of normal; they also contained approximately 20% of the normal photoreactivating enzyme level. The residual enzyme in these cells was characterized to determine whether the reduced cellular photoreactivation rate and photoreactivating enzyme levels resulted from reduced numbers of normal enzymes or from an altered enzyme. Photoreactivating enzymes from strains carrying a deletion of the region at 17 min has an apparent K/sub m/ about two- to threefold higher than normal enzyme and showed markedly increased heat lability. The gene at 17 min thus contains information determining the function of the E. coli photoreactivating enzyme rather than the quantity of the enzyme. It is proposed that the gene at 17 min be termed phrA and that located at 15.9 min be termed phrB

  13. Environmental Escherichia coli: Ecology and public health implications - A review

    Science.gov (United States)

    Jang, Jeonghwan; Hur, Hor-Gil; Sadowsky, Michael J.; Byappanahalli, Muruleedhara; Yan, Tao; Ishii, Satoshi

    2017-01-01

    Escherichia coli is classified as a rod-shaped, Gram-negative bacterium in the family Enterobacteriaceae. The bacterium mainly inhabits the lower intestinal tract of warm-blooded animals, including humans, and is often discharged into the environment through feces or wastewater effluent. The presence of E. coli in environmental waters has long been considered as an indicator of recent fecal pollution. However, numerous recent studies have reported that some specific strains of E. coli can survive for long periods of time, and potentially reproduce, in extra-intestinal environments. This indicates that E. coli can be integrated into indigenous microbial communities in the environment. This naturalization phenomenon calls into question the reliability of E. coli as a fecal indicator bacterium (FIB). Recently, many studies reported that E. coli populations in the environment are affected by ambient environmental conditions affecting their long-term survival. Large-scale studies of population genetics provide the diversity and complexity of E. coli strains in various environments, affected by multiple environmental factors. This review examines the current knowledge on the ecology of E. coli strains in various environments in regards to its role as a FIB and as a naturalized member of indigenous microbial communities. Special emphasis is given on the growth of pathogenic E. coli in the environment, and the population genetics of environmental members of the genus Escherichia. The impact of environmental E. coli on water quality and public health is also discussed.

  14. Is banking supervision central to central banking?

    OpenAIRE

    Joe Peek; Eric S. Rosengren; Geoffrey M. B. Tootell

    1997-01-01

    Whether central banks should play an active role in bank supervision and regulation is being debated both in the United States and abroad. While the Bank of England has recently been stripped of its supervisory responsibilities and several proposals in the United States have advocated removing bank supervision from the Federal Reserve System, other countries are considering enhancing central bank involvement in this area. Many of the arguments for and against these proposals hinge on the effe...

  15. Post-Transcriptional Regulation by the Csr Global Regulatory System in Escherichia coli

    OpenAIRE

    Suzuki, Kazushi; 鈴木, 一史

    2007-01-01

    In many species of bacteria, the Csr (carbon storage regulator) global regulatory system coordinates the expression of various genes. In Escherichia coli, the central component of this system, CsrA, is a RNA-binding protein. The CsrA is a homodimer and binds to leader segments of target mRNAs, affecting their translation and stability. CsrA activity is regulated by two small non-coding RNAs, CsrB and CsrC. These RNAs contain multiple CsrA-binding sequences and act by sequestering CsrA. In thi...

  16. A Mathematical Model of Metabolism and Regulation Provides a Systems-Level View of How Escherichia coli Responds to Oxygen

    Directory of Open Access Journals (Sweden)

    Michael eEderer

    2014-03-01

    Full Text Available The efficient redesign of bacteria for biotechnological purposes, such as biofuel production, waste disposal or specific biocatalytic functions, requires a quantitative systems-level understanding of energy supply, carbon and redox metabolism. The measurement of transcript levels, metabolite concentrations and metabolic fluxes per se gives an incomplete picture. An appreciation of the interdependencies between the different measurement values is essential for systems-level understanding. Mathematical modeling has the potential to provide a coherent and quantitative description of the interplay between gene expression, metabolite concentrations and metabolic fluxes. Escherichia coli undergoes major adaptations in central metabolism when the availability of oxygen changes. Thus, an integrated description of the oxygen response provides a benchmark of our understanding of carbon, energy and redox metabolism. We present the first comprehensive model of the central metabolism of E. coli that describes steady-state metabolism at different levels of oxygen availability. Variables of the model are metabolite concentrations, gene expression levels, transcription factor activities, metabolic fluxes and biomass concentration. We analyze the model with respect to the production capabilities of central metabolism of E. coli. In particular, we predict how precursor and biomass concentration are affected by product formation.

  17. Evaluation of Petrifilm™ Select E. coli Count Plate medium to discriminate antimicrobial resistant Escherichia coli

    Directory of Open Access Journals (Sweden)

    Jensen Lars

    2008-09-01

    Full Text Available Abstract Background Screening and enumeration of antimicrobial resistant Escherichia coli directly from samples is needed to identify emerging resistant clones and obtain quantitative data for risk assessment. Aim of this study was to evaluate the performance of 3M™ Petrifilm™ Select E. coli Count Plate (SEC plate supplemented with antimicrobials to discriminate antimicrobial-resistant and non-resistant E. coli. Method A range of E. coli isolates were tested by agar dilution method comparing the Minimal Inhibitory Concentration (MIC for eight antimicrobials obtained by Mueller-Hinton II agar, MacConkey agar and SEC plates. Kappa statistics was used to assess the levels of agreement when classifying strains as resistant, intermediate or susceptible. Results SEC plate showed that 74% of all strains agreed within ± 1 log2 dilution when comparing MICs with Mueller-Hinton II media. High agreement levels were found for gentamicin, ampicillin, chloramphenicol and cefotaxime, resulting in a kappa value of 0.9 and 100% agreement within ± 1 log2 dilution. Significant variances were observed for oxytetracycline and sulphamethoxazole. Further tests showed that the observed discrepancy in classification of susceptibility to oxytetracycline by the two media could be overcome when a plate-dependent breakpoint of 64 mg/L was used for SEC plates. For sulphamethoxazole, SEC plates provided unacceptably high MICs. Conclusion SEC plates showed good agreement with Mueller-Hinton II agar in MIC studies and can be used to screen and discriminate resistant E. coli for ampicillin, cephalothin, streptomycin, chloramphenicol, cefotaxime and gentamicin using CLSI standardized breakpoints, but not for sulphamethoxazole. SEC plates can also be used to discriminate oxytetracycline-resistant E. coli if a plate-dependent breakpoint value of 64 mg/L is used.

  18. Production of caffeoylmalic acid from glucose in engineered Escherichia coli.

    Science.gov (United States)

    Li, Tianzhen; Zhou, Wei; Bi, Huiping; Zhuang, Yibin; Zhang, Tongcun; Liu, Tao

    2018-07-01

    To achieve biosynthesis of caffeoylmalic acid from glucose in engineered Escherichia coli. We constructed the biosynthetic pathway of caffeoylmalic acid in E. coli by co-expression of heterologous genes RgTAL, HpaBC, At4CL2 and HCT2. To enhance the production of caffeoylmalic acid, we optimized the tyrosine metabolic pathway of E. coli to increase the supply of the substrate caffeic acid. Consequently, an E. coli-E. coli co-culture system was used for the efficient production of caffeoylmalic acid. The final titer of caffeoylmalic acid reached 570.1 mg/L. Microbial production of caffeoylmalic acid using glucose has application potential. In addition, microbial co-culture is an efficient tool for producing caffeic acid esters.

  19. Regional variations in fluoroquinolone non-susceptibility among Escherichia coli bloodstream infections within the Veterans Healthcare Administration

    Directory of Open Access Journals (Sweden)

    Daniel J. Livorsi

    2016-10-01

    Full Text Available Abstract Objectives We sought to define regional variations in fluoroquinolone non-susceptibility (FQ-NS among bloodstream isolates of Escherichia coli across the Veterans Health Administration (VHA in the United States. Methods We analyzed a retrospective cohort of patients managed at 136 VHA hospitals who had a blood culture positive for E.coli between 2003 and 2013. Hospitals were classified based on US Census Divisions, and regional variations in FQ-NS were analyzed. Results Twenty-four thousand five hundred twenty-three unique E.coli bloodstream infections (BSIs were identified between 2003 and 2013. 53.9 % of these were community-acquired, 30.7 % were healthcare-associated, and 15.4 % were hospital-onset BSIs. The proportion of E.coli BSIs with FQ-NS significantly varied across US Census Divisions (p < 0.001. During 2003–2013, the proportion of E.coli BSIs with FQ-NS was highest in the West South-Central Division (32.7 % and lowest in the Mountain Division (20.0 %. Multivariable analysis showed that there were universal secular trends towards higher FQ-NS rates (p < 0.001 with significant variability of slopes across US Census Divisions (p < 0.001. Conclusion There has been a universal increase in FQ-NS among E.coli BSIs within VHA, but the rate of increase has significantly varied across Census Divisions. The reasons for this variability are unclear. These findings reinforce the importance of using local data to develop and update local antibiograms and antibiotic-prescribing guidelines.

  20. Escherichia coli Shiga Toxin Mechanisms of Action in Renal Disease

    Directory of Open Access Journals (Sweden)

    Tom G. Obrig

    2010-12-01

    Full Text Available Shiga toxin-producing Escherichia coli is a contaminant of food and water that in humans causes a diarrheal prodrome followed by more severe disease of the kidneys and an array of symptoms of the central nervous system. The systemic disease is a complex referred to as diarrhea-associated hemolytic uremic syndrome (D+HUS. D+HUS is characterized by thrombocytopenia, microangiopathic hemolytic anemia, and acute renal failure. This review focuses on the renal aspects of D+HUS. Current knowledge of this renal disease is derived from a combination of human samples, animal models of D+HUS, and interaction of Shiga toxin with isolated renal cell types. Shiga toxin is a multi-subunit protein complex that binds to a glycosphingolipid receptor, Gb3, on select eukaryotic cell types. Location of Gb3 in the kidney is predictive of the sites of action of Shiga toxin. However, the toxin is cytotoxic to some, but not all cell types that express Gb3. It also can cause apoptosis or generate an inflammatory response in some cells. Together, this myriad of results is responsible for D+HUS disease.

  1. Replication and Transcription of Eukaryotic DNA in Esherichia coli

    Science.gov (United States)

    Morrow, John F.; Cohen, Stanley N.; Chang, Annie C. Y.; Boyer, Herbert W.; Goodman, Howard M.; Helling, Robert B.

    1974-01-01

    Fragments of amplified Xenopus laevis DNA, coding for 18S and 28S ribosomal RNA and generated by EcoRI restriction endonuclease, have been linked in vitro to the bacterial plasmid pSC101; and the recombinant molecular species have been introduced into E. coli by transformation. These recombinant plasmids, containing both eukaryotic and prokaryotic DNA, replicate stably in E. coli. RNA isolated from E. coli minicells harboring the plasmids hybridizes to amplified X. laevis rDNA. Images PMID:4600264

  2. Characterization of diarrhoeagenic Escherichia coli isolates in Jordanian children.

    Science.gov (United States)

    Shehabi, Asem A; Bulos, Najawa-Kuri; Hajjaj, Kamal G

    2003-01-01

    In a prospective study carried out among Jordanian children in Amman, a total of 73/250 (29.2%) stool specimens were positive for 1 or more diarrhoeagenic Escherichia coli strains using a multiplex polymerase chain reaction method. This study indicated that diarrhoeagenic E. coli isolates were found frequently more in stools of children with diarrhoea (34%) than without diarrhoea (23.1%), but without any significant difference (p > 0.05). The predominant diarrhoeagenic E. coli strains associated with diarrhoea were enteropathogenic E. coli (11.3%), followed by enterotoxigenic E. coli (9.8%) and enteroaggrative E. coli (9%), whereas in the control group these were 4.3%, 11.1% and 6%, respectively. Enteroinvasive E. coli strains (2.9%) were found only in stools of children with diarrhoea. This study revealed the absence of enterohaemorrhagic E. coli in both diarrhoeal and control stools, and found that diarrhoeagenic E. coli isolates were highly resistance to tetracycline (55%), co-trimoxazole (60%) and ampicillin (89%), which are commonly used antibiotics in Jordan.

  3. Complete Genome Sequence of Escherichia coli Strain WG5

    DEFF Research Database (Denmark)

    Imamovic, Lejla; Misiakou, Maria-Anna; van der Helm, Eric

    2018-01-01

    Escherichia coli strain WG5 is a widely used host for phage detection, including somatic coliphages employed as standard ISO method 10705-1 (2000). Here, we present the complete genome sequence of a commercial E. coli WG5 strain.......Escherichia coli strain WG5 is a widely used host for phage detection, including somatic coliphages employed as standard ISO method 10705-1 (2000). Here, we present the complete genome sequence of a commercial E. coli WG5 strain....

  4. Sphingosine 1-Phosphate Activation of EGFR As a Novel Target for Meningitic Escherichia coli Penetration of the Blood-Brain Barrier

    Science.gov (United States)

    Wang, Xiangru; Maruvada, Ravi; Morris, Andrew J.; Liu, Jun O.; Baek, Dong Jae; Kim, Kwang Sik

    2016-01-01

    Central nervous system (CNS) infection continues to be an important cause of mortality and morbidity, necessitating new approaches for investigating its pathogenesis, prevention and therapy. Escherichia coli is the most common Gram-negative bacillary organism causing meningitis, which develops following penetration of the blood–brain barrier (BBB). By chemical library screening, we identified epidermal growth factor receptor (EGFR) as a contributor to E. coli invasion of the BBB in vitro. Here, we obtained the direct evidence that CNS-infecting E. coli exploited sphingosine 1-phosphate (S1P) for EGFR activation in penetration of the BBB in vitro and in vivo. We found that S1P was upstream of EGFR and participated in EGFR activation through S1P receptor as well as through S1P-mediated up-regulation of EGFR-related ligand HB-EGF, and blockade of S1P function through targeting sphingosine kinase and S1P receptor inhibited EGFR activation, and also E. coli invasion of the BBB. We further found that both S1P and EGFR activations occurred in response to the same E. coli proteins (OmpA, FimH, NlpI), and that S1P and EGFR promoted E. coli invasion of the BBB by activating the downstream c-Src. These findings indicate that S1P and EGFR represent the novel host targets for meningitic E. coli penetration of the BBB, and counteracting such targets provide a novel approach for controlling E. coli meningitis in the era of increasing resistance to conventional antibiotics. PMID:27711202

  5. Impact of dry chilling on the genetic diversity of Escherichia coli on beef carcasses and on the survival of E. coli and E. coli O157.

    Science.gov (United States)

    Visvalingam, Jeyachchandran; Liu, Yang; Yang, Xianqin

    2017-03-06

    The objective of this study was to examine the effect of dry chilling on the genetic diversity of naturally occurring Escherichia coli on beef carcasses, and to examine whether two populations of E. coli recovered from carcasses during chilling and E. coli O157 differed in their response to desiccation. Isolates of E. coli were obtained from beef carcasses during a 67h dry chilling process and were genotyped using multiple-locus variable-number tandem-repeat analysis (MLVA). Ten E. coli genotypes found only at 0h (group A) and found more than once (group B), as well as five strains of E. coli O157 (group C) were inoculated on stainless steel coupons and their survival was examined after exposure to 75 and 100% relative humidity (RH) at 0 or 35°C for 67h. A total of 450 E. coli isolates were obtained, with 254, 49, 49, 51, 23, 20, and 4 from 0, 1, 2, 4, 6, 8 and 24h of chilling, respectively. No E. coli were recovered at 67h. MLVA of the isolates revealed 173 distinct genotypes. Genetic diversity of E. coli isolates, defined as ratio of the number of isolates to the number of genotypes, remained between 2.3 and 1.3 during the 24h of chilling. All strains inoculated on stainless steel coupons and exposed to 75% RH at 35°C were completely inactivated, irrespective of their groups. Inactivation of E. coli of the three groups was not significantly (P>0.05) different by exposure to 75% RH at 0°C. The findings indicate that the genetic diversity of E. coli on beef carcasses was not affected by dry chilling. In addition, inactivation of E. coli genotypes and E. coli O157 by desiccation on stainless steel simulating dry chilling conditions did not differ significantly (P>0.05). Thus, dry chilling may be used as an effective antimicrobial intervention for beef carcasses. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  6. The Csr System Regulates Escherichia coli Fitness by Controlling Glycogen Accumulation and Energy Levels.

    Science.gov (United States)

    Morin, Manon; Ropers, Delphine; Cinquemani, Eugenio; Portais, Jean-Charles; Enjalbert, Brice; Cocaign-Bousquet, Muriel

    2017-10-31

    In the bacterium Escherichia coli , the posttranscriptional regulatory system Csr was postulated to influence the transition from glycolysis to gluconeogenesis. Here, we explored the role of the Csr system in the glucose-acetate transition as a model of the glycolysis-to-gluconeogenesis switch. Mutations in the Csr system influence the reorganization of gene expression after glucose exhaustion and disturb the timing of acetate reconsumption after glucose exhaustion. Analysis of metabolite concentrations during the transition revealed that the Csr system has a major effect on the energy levels of the cells after glucose exhaustion. This influence was demonstrated to result directly from the effect of the Csr system on glycogen accumulation. Mutation in glycogen metabolism was also demonstrated to hinder metabolic adaptation after glucose exhaustion because of insufficient energy. This work explains how the Csr system influences E. coli fitness during the glycolysis-gluconeogenesis switch and demonstrates the role of glycogen in maintenance of the energy charge during metabolic adaptation. IMPORTANCE Glycogen is a polysaccharide and the main storage form of glucose from bacteria such as Escherichia coli to yeasts and mammals. Although its function as a sugar reserve in mammals is well documented, the role of glycogen in bacteria is not as clear. By studying the role of posttranscriptional regulation during metabolic adaptation, for the first time, we demonstrate the role of sugar reserve played by glycogen in E. coli Indeed, glycogen not only makes it possible to maintain sufficient energy during metabolic transitions but is also the key component in the capacity of cells to resume growth. Since the essential posttranscriptional regulatory system Csr is a major regulator of glycogen accumulation, this work also sheds light on the central role of posttranscriptional regulation in metabolic adaptation. Copyright © 2017 Morin et al.

  7. A combined quantitative mass spectrometry and electron microscopy analysis of ribosomal 30S subunit assembly in E. coli.

    Science.gov (United States)

    Sashital, Dipali G; Greeman, Candacia A; Lyumkis, Dmitry; Potter, Clinton S; Carragher, Bridget; Williamson, James R

    2014-10-14

    Ribosome assembly is a complex process involving the folding and processing of ribosomal RNAs (rRNAs), concomitant binding of ribosomal proteins (r-proteins), and participation of numerous accessory cofactors. Here, we use a quantitative mass spectrometry/electron microscopy hybrid approach to determine the r-protein composition and conformation of 30S ribosome assembly intermediates in Escherichia coli. The relative timing of assembly of the 3' domain and the formation of the central pseudoknot (PK) structure depends on the presence of the assembly factor RimP. The central PK is unstable in the absence of RimP, resulting in the accumulation of intermediates in which the 3'-domain is unanchored and the 5'-domain is depleted for r-proteins S5 and S12 that contact the central PK. Our results reveal the importance of the cofactor RimP in central PK formation, and introduce a broadly applicable method for characterizing macromolecular assembly in cells.

  8. Translational coupling in Escherichia coli of a heterologous Bacillus subtilis-Escherichia coli gene fusion.

    OpenAIRE

    Zaghloul, T I; Doi, R H

    1986-01-01

    The efficient expression in Escherichia coli of the Tn9-derived chloramphenicol acetyltransferase (EC 2.3.1.28) gene fused distal to the promoter and N terminus of the Bacillus subtilis aprA gene was dependent on the initiation of translation from the ribosome-binding site in the aprA gene.

  9. ELECTROPHORETIC MOBILITIES OF ESCHERICHIA COLI 0157:H7 AND WILD-TYPE ESCHERICHIA COLI STRAINS

    Science.gov (United States)

    The electrophoretic mobility (EPM) of a number of human-virulent and "wild-type" Escherichia coli strains in phosphate buffered water was measured. The impact of pH, ionic strength, cation type (valence) and concentration, and bacterial strain on the EPM was investigated. Resul...

  10. Enteropathogenic Escherichia coli: foe or innocent bystander?

    Science.gov (United States)

    Hu, Jia; Torres, Alfredo G.

    2015-01-01

    Enteropathogenic Escherichia coli (EPEC) remain one the most important pathogens infecting children and they are one of the main causes of persistent diarrhea worldwide. Historically, typical EPEC (tEPEC), defined as those isolates with the attaching and effacement (A/E) genotype (eae+), which possess bfpA+ and lack the stx- genes are found strongly associated with diarrheal cases. However, occurrence of atypical EPEC (aEPEC; eae+ bfpA- stx-) in diarrheal and asymptomatic hosts has made investigators question the role of these pathogens in human disease. Current epidemiological data is helping answering the question whether EPEC is mainly a foe or an innocent bystander during infection. PMID:25726041

  11. Dynamics of chromosome segregation in Escherichia coli

    DEFF Research Database (Denmark)

    Nielsen, Henrik Jørck

    2007-01-01

    Since the 1960’es the conformation and segregation of the chromosome in Escherichia coli has been a subject of interest for many scientists. However, after 40 years of research, we still know incredibly little about how the chromosome is organized inside the cell, how it manages to duplicate...... this incredibly big molecule and separate the two daughter chromosomes and how it makes sure that the daughter cells receives one copy each. The fully extended chromosome is two orders of magnitude larger than the cell in which it is contained. Hence the chromosome is heavily compacted in the cell...

  12. Escherichia coli photoreactivating enzyme: purification and properties

    International Nuclear Information System (INIS)

    Snapka, R.M.; Sutherland, B.M.

    1980-01-01

    Researchers have purified large quantities of Escherichia coli photoreactivating enzyme to apparent homogeneity and have studied its physical and chemical properties. The enzyme has a molecular weight of 36,800 and a S/sub 20,w/ 0 of 3.72 S. Amino acid analysis revealed an apparent absence of tryptophan, a low content of aromatic residues, and the presence of no unusual amino acids. The N terminus is arginine. The purified enzyme contained up to 13% carbohydrate by weight. The carbohydrate was composed of mannose, galactose, glucose, and N-acetylglucosamine. The enzyme is also associated with RNA containing uracil, adenine, guanine, and cytosine with no unusual bases detected

  13. Multiplex Genome Editing in Escherichia coli

    DEFF Research Database (Denmark)

    Ingemann Jensen, Sheila; Nielsen, Alex Toftgaard

    2018-01-01

    Lambda Red recombineering is an easy and efficient method for generating genetic modifications in Escherichia coli. For gene deletions, lambda Red recombineering is combined with the use of selectable markers, which are removed through the action of, e.g., flippase (Flp) recombinase. This PCR......-based engineering method has also been applied to a number of other bacteria. In this chapter, we describe a recently developed one plasmid-based method as well as the use of a strain with genomically integrated recombineering genes, which significantly speeds up the engineering of strains with multiple genomic...

  14. Identification of Genes Important for Growth of Asymptomatic Bacteriuria Escherichia coli in Urine

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk; de Evgrafov, Mari Cristina Rodriguez; Phan, Minh Duy

    2012-01-01

    Escherichia coli is the most important etiological agent of urinary tract infections (UTIs). Unlike uropathogenic E. coli, which causes symptomatic infections, asymptomatic bacteriuria (ABU) E. coli strains typically lack essential virulence factors and colonize the bladder in the absence...

  15. Central Laboratories Services

    Data.gov (United States)

    Federal Laboratory Consortium — The TVA Central Laboratories Services is a comprehensive technical support center, offering you a complete range of scientific, engineering, and technical services....

  16. Central Pain Syndrome

    Science.gov (United States)

    ... such as neurontin (gabapentin) can be useful. Lowering stress levels appears to reduce pain. View Full Treatment Information Definition Central pain syndrome is a neurological condition caused ...

  17. Central Diabetes Insipidus, Central Hypothyroidism, Renal Tubular ...

    African Journals Online (AJOL)

    readmitted to the hospital because of jaundice and failure to thrive, for which he was investigated and diagnosed to have central congenital hypothyroidism. Shortly thereafter, he was admitted to our institute with a history of vomiting, decreased oral intake, polyuria, and dehydration having lasted 5 days. He was investigated ...

  18. Deactivation of the E. coli pH stress sensor CadC by cadaverine.

    Science.gov (United States)

    Haneburger, Ina; Fritz, Georg; Jurkschat, Nicole; Tetsch, Larissa; Eichinger, Andreas; Skerra, Arne; Gerland, Ulrich; Jung, Kirsten

    2012-11-23

    At acidic pH and in the presence of lysine, the pH sensor CadC activates transcription of the cadBA operon encoding the lysine/cadaverine antiporter CadB and the lysine decarboxylase CadA. In effect, these proteins contribute to acid stress adaptation in Escherichia coli. cadBA expression is feedback inhibited by cadaverine, and a cadaverine binding site is predicted within the central cavity of the periplasmic domain of CadC on the basis of its crystallographic analysis. Our present study demonstrates that this site only partially accounts for the cadaverine response in vivo. Instead, evidence for a second, pivotal binding site was collected, which overlaps with the pH-responsive patch of amino acids located at the dimer interface of the periplasmic domain. The temporal response of the E. coli Cad module upon acid shock was measured and modeled for two CadC variants with mutated cadaverine binding sites. These studies supported a cascade-like binding and deactivation model for the CadC dimer: binding of cadaverine within the pair of central cavities triggers a conformational transition that exposes two further binding sites at the dimer interface, and the occupation of those stabilizes the inactive conformation. Altogether, these data represent a striking example for the deactivation of a pH sensor. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Escherichia coli clearance after splenic autotransplants

    International Nuclear Information System (INIS)

    Marques, R.G.; Petroianu, A.; Oliveira, M.B.N.; Bernardo-Filho, M.; Portela, M.C.

    2002-01-01

    Background: Splenic autotransplantation seems to be the only alternative for preservation of splenic tissue, after total splenectomy. The present study was carried out to analyze Escherichia coli depuration by mononuclear phagocyte system organs after total splenectomy and splenic autotransplantation. Methods: We utilized an experimental model including young and adult Wistar rats, of both sexes, submitted to total splenectomy and splenic autotransplantation. The evaluation method was intravenous inoculation of a suspension of Escherichia coli labeled with technetium-99m. We analyzed bacteria uptake by mononuclear phagocyte system organs and bacteria remnant in the bloodstream. Results: There was no difference between young and adult animals in bacteria uptake by mononuclear phagocyte system organs. In the comparison of groups, it was found out that the mean percent uptake by spleen and liver of animals in the control group was higher than that observed for animals with splenic implants. However, bacteria uptake in the lung was higher in the splenic implant group than in the control group. Although spleen bacteria uptake in the control group animals has been higher than that of animals in the splenic implant group, the remnant bacteria in the bloodstream was similar. Animals submitted to isolated total splenectomy showed higher bacteria remnant in the bloodstream than animals of the control group or the group submitted to total splenectomy combined with splenic autotransplantation. Conclusion: Our results indicate that autogenous splenic implant is efficacious in bacteria depuration in rats, by means of their macrophages phagocytosis. In addition, it does not modify bacteria removal function of liver and lung

  20. Plasmid Conjugation in E. coli and Drug Resistance | Igwe ...

    African Journals Online (AJOL)

    This study aimed at determining the antibiotics susceptibility pattern of E. coli isolates claimed to be multidrug resistance using disc diffusion method. It also determined the presence of transferable resistance plasmids through conjugation and evaluated the medical significance of plasmid encoding E. coli and drug ...

  1. Changes in Escherichia coli resistance to co-trimoxazole in ...

    African Journals Online (AJOL)

    In Thyolo district, Malawi, an operational research study is being conducted on the efficacy and feasibility of co-trimoxazole prophylaxis in preventing deaths in HIV-positive patients with tuberculosis (TB). A series of cross-sectional studies were carried out to determine i) whether faecal Escherichia coli (E.coli) resistance to ...

  2. Escherichia coli growth modeling using neural network | Shamsudin ...

    African Journals Online (AJOL)

    technique that has the ability to predict with efficient and good performance. Using NARX, a highly accurate model was developed to predict the growth of Escherichia coli (E. coli) based on pH water parameter. The multiparameter portable sensor and spectrophotometer data were used to build and train the neural network.

  3. Growth modeling of uropathogenic Escherichia coli in ground chicken meat

    Science.gov (United States)

    Extraintestinal Pathogenic Escherichia coli (ExPEC), including Uropathogenic E. coli (UPEC), are common contaminants in poultry meat, and are a major pathogen associated with inflammatory bowel disease, ulcerative colitis, sepsis, and urinary tract infections. The purpose of this study was to determ...

  4. Antimicrobial susceptibilities of avian Escherichia coli isolates in ...

    African Journals Online (AJOL)

    Colibacillosis is a poultry disease of economic importance in Iran and all around the world. The aim of this study is to test the antibiotic sensitivity of Escherichia coli strains which were isolated in Tabriz. A total of 100 E. coli strains isolated from avian colibacillosis of 50 farms from 2008 to 2009 in Tabriz, were investigated for ...

  5. Prevalence and antibiogram of Escherichia coli O157 isolated from ...

    African Journals Online (AJOL)

    E. coli O157 is an important serotype that caused many food borne outbreaks worldwide in the past decades. This study was carried out to estimate the prevalence and determine the antimicrobial susceptibility of E. coli O157 isolated from bovine carcasses and cecal contents at one abattoir in Jimma. A total of 300 samples ...

  6. Antibiotic resistant Salmonella and Escherichia coli isolated from ...

    African Journals Online (AJOL)

    Results: A hundred and four indigenous chicken rectal swabs were analysed, of which 67.3% were contaminated with Escherichia coli and 12.5% with Salmonella typhimurium. Seventy Escherichia coli isolates showed resistance phenotypes to one, two or more antibiotics. The most common antimicrobial resistance pattern ...

  7. Effect of high pressurized carbon dioxide on Escherichia coli ...

    African Journals Online (AJOL)

    Carbon dioxide at high pressure can retard microbial growth and sometimes kill microorganisms depending on values of applied pressure, temperature and exposure time. In this study the effect of high pressurised carbon dioxide (HPCD) on Escherichia coli was investigated. Culture of E. coli was subjected to high ...

  8. Prevalence of Aeromonas species and Escherichia coli in stool ...

    African Journals Online (AJOL)

    Background: Diarrhoea is one of the main causes of mortality and morbidity in childhood. Bacterial diarrhoea is a common disorder. Aeromonas species and Escherichia coli (E. coli) are some of the aetiological agents associated with diarrhoea in children. Objective: To determine the prevalence of Aeromonas species and ...

  9. Adsorption of Escherichia coli Using Bone Char | Rezaee | Journal ...

    African Journals Online (AJOL)

    The aim of study was providing a novel adsorbent for the removal of Escherichia coli (E.coli) as a microbial model from contaminated air especially in hospital units using bone char (BC). The BC was prepared from cattle animal bone by pyrolysis in a furnace at 450°C for 2 h. The characteristics of BC have been determined ...

  10. Anthranoid self-medication causing rapid development of melanosis coli

    NARCIS (Netherlands)

    M. Willems; H.R. van Buuren (Henk); R.R. de Krijger (Ronald)

    2003-01-01

    textabstractIt is widely known that long-term use of anthranoid-containing laxatives is the cause of melanosis coli. We describe a case of melanosis coli, which occurred in a 39-year-old liver transplant patient who took an over-the-counter product containing aloe, rheum and

  11. Draft Genome Sequence of Escherichia coli K-12 (ATCC 10798)

    OpenAIRE

    Dimitrova, Daniela; Engelbrecht, Kathleen C.; Putonti, Catherine; Koenig, David W.; Wolfe, Alan J.

    2017-01-01

    ABSTRACT Here, we present the draft genome sequence of Escherichia coli ATCC 10798. E.?coli ATCC 10798 is a K-12 strain, one of the most well-studied model microorganisms. The size of the genome was 4,685,496?bp, with a G+C content of 50.70%. This assembly consists of 62 contigs and the F plasmid.

  12. Chromatin architecture and gene expression in Escherichia coli

    DEFF Research Database (Denmark)

    Willenbrock, Hanni; Ussery, David

    2004-01-01

    Two recent genome-scale analyses underscore the importance of DNA topology and chromatin structure in regulating transcription in Escherichia coli.......Two recent genome-scale analyses underscore the importance of DNA topology and chromatin structure in regulating transcription in Escherichia coli....

  13. Genomic Comparative Study of Bovine Mastitis Escherichia coli.

    Science.gov (United States)

    Kempf, Florent; Slugocki, Cindy; Blum, Shlomo E; Leitner, Gabriel; Germon, Pierre

    2016-01-01

    Escherichia coli, one of the main causative agents of bovine mastitis, is responsible for significant losses on dairy farms. In order to better understand the pathogenicity of E. coli mastitis, an accurate characterization of E. coli strains isolated from mastitis cases is required. By using phylogenetic analyses and whole genome comparison of 5 currently available mastitis E. coli genome sequences, we searched for genotypic traits specific for mastitis isolates. Our data confirm that there is a bias in the distribution of mastitis isolates in the different phylogenetic groups of the E. coli species, with the majority of strains belonging to phylogenetic groups A and B1. An interesting feature is that clustering of strains based on their accessory genome is very similar to that obtained using the core genome. This finding illustrates the fact that phenotypic properties of strains from different phylogroups are likely to be different. As a consequence, it is possible that different strategies could be used by mastitis isolates of different phylogroups to trigger mastitis. Our results indicate that mastitis E. coli isolates analyzed in this study carry very few of the virulence genes described in other pathogenic E. coli strains. A more detailed analysis of the presence/absence of genes involved in LPS synthesis, iron acquisition and type 6 secretion systems did not uncover specific properties of mastitis isolates. Altogether, these results indicate that mastitis E. coli isolates are rather characterized by a lack of bona fide currently described virulence genes.

  14. Sigma factors in a thousand E. coli genomes

    DEFF Research Database (Denmark)

    Cook, Helen Victoria; Ussery, David

    2013-01-01

    , 2013), only less than half (983) are of sufficient quality to use in comparative genomic work. Unfortunately, even some of the ‘complete’ E. coli genomes are in pieces, and a few ‘draft’ genomes are good quality. Six of the seven known sigma factors in E. coli strain K‐12 are extremely well conserved...

  15. Antibiotic Resistance and Virulence Properties in Escherichia coli ...

    African Journals Online (AJOL)

    This study determined E. coli resistance to commonly used antibiotics together with their virulence properties in Ile-Ife, Nigeria. A total of 137 E. coli isolates from cases of urinary tract infection were tested for their sensitivity to commonly used antibiotics and possession of virulence factors using standard methods.

  16. Incidence of Escherichia coli  - Glucuronidase Positive on Goat Milk

    Directory of Open Access Journals (Sweden)

    Zorica Voşgan

    2016-11-01

    Full Text Available Papers on beta- glucuronidase sensitivity and specificity for identifying Escherichia coli in sources of environment, food, water, etc. have been published since 1976. In this study we conducted a review of the incidence of E. coli β- glucuronidase -positive in goat milk, obtained by hand milking throughout the lactation: spring, summer, autumn. The presence of E. coli in milk is considered both as a health indicator and a pathogenic factor capable of causing food poisoning. The determination of the E. coli β-glucuronidase-positive was carried using TBX medium by cultivating colonies typical blue at 440C. The absence of E. coli in milk yielded during the spring, when the animal milking is done three times a day, was found in the performed analyses; the same was observed during fall, when the milk production is lower and the milking is done once a day. The load of E. coli β-glucuronidase-positive was averaging 66.67 CFU/ml of goat milk, during the middle lactation period (July-August, in conditions of higher temperature. During this period, milking is done in the mountain zone, where the transhumance of animals takes place in summer. The presence of the species E. coli was also confirmed by microscopic examination. Attention should be paid to hygiene and milk should be immediately cooled, during hot weather, as E. coli can be a source of food poisoning.

  17. Interaction of Escherichia coli with growing salad spinach plants.

    Science.gov (United States)

    Warriner, Keith; Ibrahim, Faozia; Dickinson, Matthew; Wright, Charles; Waites, William M

    2003-10-01

    In this study, the interaction of a bioluminescence-labeled Escherichia coli strain with growing spinach plants was assessed. Through bioluminescence profiles, the direct visualization of E. coli growing around the roots of developing seedlings was accomplished. Subsequent in situ glucuronidase (GUS) staining of seedlings confirmed that E. coli had become internalized within root tissue and, to a limited extent, within hypocotyls. When inoculated seeds were sown in soil microcosms and cultivated for 42 days, E. coli was recovered from the external surfaces of spinach roots and leaves as well as from surface-sterilized roots. When 20-day-old spinach seedlings (from uninoculated seeds) were transferred to soil inoculated with E. coli, the bacterium became established on the plant surface, but internalization into the inner root tissue was restricted. However, for seedlings transferred to a hydroponic system containing 10(2) or 10(3) CFU of E. coli per ml of the circulating nutrient solution, the bacterium was recovered from surface-sterilized roots, indicating that it had been internalized. Differences between E. coli interactions in the soil and those in the hydroponic system may be attributed to greater accessibility of the roots in the latter model. Alternatively, the presence of a competitive microflora in soil may have restricted root colonization by E. coli. The implications of this study's findings with regard to the microbiological safety of minimally processed vegetables are discussed.

  18. Antibiotic Resistance of Escherichia coli Isolated from Healthy Food ...

    African Journals Online (AJOL)

    It was concluded from the study that healthy food animals form a reservoir of multiple resistant E. coli which may be transmitted to humans through the food chain. Thus, continued surveillance of E. coli obtained from food production continuum is merited to identify emerging antimicrobial-resistant phenotypes. The Kenya ...

  19. Expression of green fluorescent protein (GFPuv) in Escherichia coli ...

    African Journals Online (AJOL)

    Administrator

    The recombinant green fluorescent protein (GFPuv) was expressed by transformed cells of Escherichia coli DH5-α grown in LB/amp broth at 37oC, for 8 h and 24 h. To evaluate the effectiveness of different parameters to improve the expression of GFPuv by E. coli, four variable culturing conditions were set up for assays by ...

  20. Optimal Central Bank Transparency

    NARCIS (Netherlands)

    van der Cruijsen, C.A.B.; Eijffinger, S.C.W.; Hoogduin, L.H.

    2008-01-01

    Should central banks increase their degree of transparency any further? We show that there is likely to be an optimal intermediate degree of central bank transparency. Up to this optimum more transparency is desirable: it improves the quality of private sector inflation forecasts. But beyond the

  1. Optimal central bank transparency

    NARCIS (Netherlands)

    van der Cruijsen, C.A.B.; Eijffinger, S.C.W.; Hoogduin, L.

    2008-01-01

    Should central banks increase their degree of transparency any further? We show that there is likely to be an optimal intermediate degree of central bank transparency. Up to this optimum more transparency is desirable: it improves the quality of private sector inflation forecasts. But beyond the

  2. Optimal central bank transparency

    NARCIS (Netherlands)

    van der Cruijsen, C.A.B.; Eijffinger, S.C.W.; Hoogduin, L.H.

    2010-01-01

    Should central banks increase their degree of transparency any further? We show that there is likely to be an optimal intermediate degree of central bank transparency. Up to this optimum more transparency is desirable: it improves the quality of private sector inflation forecasts. But beyond the

  3. Idiopathic central diabetes Insipidus.

    Science.gov (United States)

    Grace, Mary; Balachandran, Venu; Menon, Sooraj

    2011-10-01

    Idiopathic central diabetes insipidus (CDI) is a rare disorder characterized clinically by polyuria and polydipsia, and an abnormal urinary concentration without any identified etiology. We report a case of central diabetes insipidus in a 60-year-old lady in the absence of secondary causes like trauma, infection, and infiltrative disorders of brain.

  4. ESBL-Producing Escherichia coli

    DEFF Research Database (Denmark)

    Hertz, Frederik Boetius

    Urinary tract infection (UTI) is one the most common bacterial infections and is regularly treated in primary health care. The most common cause of UTI is extraintestinal pathogenic Escherichia coli (ExPEC) already present in the intestinal microflora, often as the dominating strain. Resistance...... in E.coli is increasing and especially isolates producing Extended-Spectrum Beta-Lactamases (ESBL) have been reported worldwide. Treatment of UTI is usually initiated by the general practitioners and a significant proportion of clinical isolates are now resistant to first line antibiotics. The global...... to investigate (i) antibiotics involved in selection of ESBL-producing E.coli, in an experimental mouse model in vivo, (ii) risk factors for UTI with ESBL-producing E.coli and (iii) to describe the phylogenetic composition of E.coli populations with different resistance patterns. We found that different...

  5. No evidence for a bovine mastitis Escherichia coli pathotype.

    Science.gov (United States)

    Leimbach, Andreas; Poehlein, Anja; Vollmers, John; Görlich, Dennis; Daniel, Rolf; Dobrindt, Ulrich

    2017-05-08

    Escherichia coli bovine mastitis is a disease of significant economic importance in the dairy industry. Molecular characterization of mastitis-associated E. coli (MAEC) did not result in the identification of common traits. Nevertheless, a mammary pathogenic E. coli (MPEC) pathotype has been proposed suggesting virulence traits that differentiate MAEC from commensal E. coli. The present study was designed to investigate the MPEC pathotype hypothesis by comparing the genomes of MAEC and commensal bovine E. coli. We sequenced the genomes of eight E. coli isolated from bovine mastitis cases and six fecal commensal isolates from udder-healthy cows. We analyzed the phylogenetic history of bovine E. coli genomes by supplementing this strain panel with eleven bovine-associated E. coli from public databases. The majority of the isolates originate from phylogroups A and B1, but neither MAEC nor commensal strains could be unambiguously distinguished by phylogenetic lineage. The gene content of both MAEC and commensal strains is highly diverse and dominated by their phylogenetic background. Although individual strains carry some typical E. coli virulence-associated genes, no traits important for pathogenicity could be specifically attributed to MAEC. Instead, both commensal strains and MAEC have very few gene families enriched in either pathotype. Only the aerobactin siderophore gene cluster was enriched in commensal E. coli within our strain panel. This is the first characterization of a phylogenetically diverse strain panel including several MAEC and commensal isolates. With our comparative genomics approach we could not confirm previous studies that argue for a positive selection of specific traits enabling MAEC to elicit bovine mastitis. Instead, MAEC are facultative and opportunistic pathogens recruited from the highly diverse bovine gastrointestinal microbiota. Virulence-associated genes implicated in mastitis are a by-product of commensalism with the primary function

  6. Comparative genomics and transcriptomics of Escherichia coli isolates carrying virulence factors of both enteropathogenic and enterotoxigenic E. coli.

    Science.gov (United States)

    Hazen, Tracy H; Michalski, Jane; Luo, Qingwei; Shetty, Amol C; Daugherty, Sean C; Fleckenstein, James M; Rasko, David A

    2017-06-14

    Escherichia coli that are capable of causing human disease are often classified into pathogenic variants (pathovars) based on their virulence gene content. However, disease-associated hybrid E. coli, containing unique combinations of multiple canonical virulence factors have also been described. Such was the case of the E. coli O104:H4 outbreak in 2011, which caused significant morbidity and mortality. Among the pathovars of diarrheagenic E. coli that cause significant human disease are the enteropathogenic E. coli (EPEC) and enterotoxigenic E. coli (ETEC). In the current study we use comparative genomics, transcriptomics, and functional studies to characterize isolates that contain virulence factors of both EPEC and ETEC. Based on phylogenomic analysis, these hybrid isolates are more genomically-related to EPEC, but appear to have acquired ETEC virulence genes. Global transcriptional analysis using RNA sequencing, demonstrated that the EPEC and ETEC virulence genes of these hybrid isolates were differentially-expressed under virulence-inducing laboratory conditions, similar to reference isolates. Immunoblot assays further verified that the virulence gene products were produced and that the T3SS effector EspB of EPEC, and heat-labile toxin of ETEC were secreted. These findings document the existence and virulence potential of an E. coli pathovar hybrid that blurs the distinction between E. coli pathovars.

  7. Colonization of Enteroaggregative Escherichia coli and Shiga toxin-producing Escherichia coli in chickens and humans in southern Vietnam

    NARCIS (Netherlands)

    Trung, Nguyen Vinh; Nhung, Hoang Ngoc; Carrique-Mas, Juan J.; Mai, Ho Huynh; Tuyen, Ha Thanh; Campbell, James; Nhung, Nguyen Thi; van Minh, Pham; Wagenaar, Jaap A.; Mai, Nguyen Thi Nhu; Hieu, Thai Quoc; Schultsz, Constance; Hoa, Ngo Thi

    2016-01-01

    Enteroaggregative (EAEC) and Shiga-toxin producing Escherichia coli (STEC) are a major cause of diarrhea worldwide. E. coli carrying both virulence factors characteristic for EAEC and STEC and producing extended-spectrum beta-lactamase caused severe and protracted disease during an outbreak of E.

  8. Fitness of Escherichia coli during urinary tract infection requires gluconeogenesis and the TCA cycle.

    Directory of Open Access Journals (Sweden)

    Christopher J Alteri

    2009-05-01

    Full Text Available Microbial pathogenesis studies traditionally encompass dissection of virulence properties such as the bacterium's ability to elaborate toxins, adhere to and invade host cells, cause tissue damage, or otherwise disrupt normal host immune and cellular functions. In contrast, bacterial metabolism during infection has only been recently appreciated to contribute to persistence as much as their virulence properties. In this study, we used comparative proteomics to investigate the expression of uropathogenic Escherichia coli (UPEC cytoplasmic proteins during growth in the urinary tract environment and systematic disruption of central metabolic pathways to better understand bacterial metabolism during infection. Using two-dimensional fluorescence difference in gel electrophoresis (2D-DIGE and tandem mass spectrometry, it was found that UPEC differentially expresses 84 cytoplasmic proteins between growth in LB medium and growth in human urine (P<0.005. Proteins induced during growth in urine included those involved in the import of short peptides and enzymes required for the transport and catabolism of sialic acid, gluconate, and the pentose sugars xylose and arabinose. Proteins required for the biosynthesis of arginine and serine along with the enzyme agmatinase that is used to produce the polyamine putrescine were also up-regulated in urine. To complement these data, we constructed mutants in these genes and created mutants defective in each central metabolic pathway and tested the relative fitness of these UPEC mutants in vivo in an infection model. Import of peptides, gluconeogenesis, and the tricarboxylic acid cycle are required for E. coli fitness during urinary tract infection while glycolysis, both the non-oxidative and oxidative branches of the pentose phosphate pathway, and the Entner-Doudoroff pathway were dispensable in vivo. These findings suggest that peptides and amino acids are the primary carbon source for E. coli during infection of

  9. Central Diffraction in ALICE

    CERN Document Server

    Schicker, R

    2012-01-01

    The ALICE experiment at the Large Hadron Collider (LHC) at CERN consists of a central barrel, a muon spectrometer and of additional detectors for trigger and event classification purposes. The low transverse momentum threshold of the central barrel gives ALICE a unique opportunity to study the low mass sector of central production at the LHC. I will report on first analysis results of meson production in double gap events in minimum-bias proton-proton collisions at sqrt{s} = 7 TeV, and will describe a dedicated double gap trigger for future data taking.

  10. Initiation of Replication in Escherichia coli

    DEFF Research Database (Denmark)

    Frimodt-Møller, Jakob

    The circular chromosome of Escherichia coli is replicated by two replisomes assembled at the unique origin and moving in the opposite direction until they meet in the less well defined terminus. The key protein in initiation of replication, DnaA, facilitates the unwinding of double-stranded DNA...... to single-stranded DNA in oriC. Although DnaA is able to bind both ADP and ATP, DnaA is only active in initiation when bound to ATP. Although initiation of replication, and the regulation of this, is thoroughly investigated it is still not fully understood. The overall aim of the thesis was to investigate...... the regulation of initiation, the effect on the cell when regulation fails, and if regulation was interlinked to chromosomal organization. This thesis uncovers that there exists a subtle balance between chromosome replication and reactive oxygen species (ROS) inflicted DNA damage. Thus, failure in regulation...

  11. Control of Ribosome Synthesis in Escherichia coli

    DEFF Research Database (Denmark)

    Molin, Søren; Meyenburg, K. von; Måløe, O.

    1977-01-01

    The rate of ribosome synthesis and accumulation in Escherichia coli during the transition after an energy source shift-down was analyzed. The shift was imposed on cultures of stringent and relaxed strains growing in glucose minimal medium by the addition of the glucose analogue {alpha...... and to estimate the transcription time for the rRNA operon under different conditions. In steady states of growth with growth rates ranging from 0.75 to 2.3 doublings/h, as well as during the transition after a shift-down, the transcription time of the rRNA operon was constant. The rate of synthesis of r......RNA correlated during this transition – in contrast to the rate of accumulation (M. T. Hansen et al., J. Bacteriol. 122: 585-591, 1975) – with the ppGpp pool in the same way as has been observed during partial amino acid starvation....

  12. Repair replication in permeabilized Escherichia coli

    International Nuclear Information System (INIS)

    Masker, W.E.; Simon, T.J.; Hanawalt, P.C.

    1975-01-01

    We have examined the modes of DNA synthesis in Escherichia coli strains made permeable to nucleoside triphosphates by treatment with toluene. In this quasi in vitro system, polymerase-I-deficient mutants exhibit a nonconservative mode of synthesis with properties expected for the resynthesis step of excision-repair. This uv-stimulated DNA synthesis can be performed by either DNA polymerase II or III and it also requires the uvrA gene product. It requires the four deoxynucleoside triphosphates; but, in contrast to the semiconservative mode, the ATP requirement can be partially satisfied by other nucleoside triphosphates. The ATP-dependent recBC nuclease is not involved. The observed uv-stimulated mode of DNA synthesis may be part of an alternate excision-repair mechanism which supplements or complements DNA-polymerase-I-dependent repair in vivo

  13. Progressive segregation of the Escherichia coli chromosome

    DEFF Research Database (Denmark)

    Nielsen, Henrik Jørck; Youngren, Brenda; Hansen, Flemming G.

    2006-01-01

    We have followed the fate of 14 different loci around the Escherichia coli chromosome in living cells at slow growth rate using a highly efficient labelling system and automated measurements. Loci are segregated as they are replicated, but with a marked delay. Most markers segregate in a smooth...... temporal progression from origin to terminus. Thus, the overall pattern is one of continuous segregation during replication and is not consistent with recently published models invoking extensive sister chromosome cohesion followed by simultaneous segregation of the bulk of the chromosome. The terminus......, and a region immediately clockwise from the origin, are exceptions to the overall pattern and are subjected to a more extensive delay prior to segregation. The origin region and nearby loci are replicated and segregated from the cell centre, later markers from the various positions where they lie...

  14. Metabolic regulation analysis of an ethanologenic Escherichia coli strain based on RT-PCR and enzymatic activities

    Directory of Open Access Journals (Sweden)

    Martinez Alfredo

    2008-05-01

    Full Text Available Abstract Background A metabolic regulation study was performed, based upon measurements of enzymatic activities, fermentation performance, and RT-PCR analysis of pathways related to central carbon metabolism, in an ethanologenic Escherichia coli strain (CCE14 derived from lineage C. In comparison with previous engineered strains, this E coli derivative has a higher ethanol production rate in mineral medium, as a result of the elevated heterologous expression of the chromosomally integrated genes encoding PDCZm and ADHZm (pyruvate decarboxylase and alcohol dehydrogenase from Zymomonas mobilis. It is suggested that this behavior might be due to lineage differences between E. coli W and C. Results This study demonstrated that the glycolytic flux is controlled, in this case, by reactions outside glycolysis, i.e., the fermentative pathways. Changes in ethanol production rate in this ethanologenic strain result in low organic acid production rates, and high glycolytic and ethanologenic fluxes, that correlate with enhanced transcription and enzymatic activity levels of PDCZm and ADHZm. Furthermore, a higher ethanol yield (90% of the theoretical in glucose-mineral media was obtained with CCE14 in comparison with previous engineered E. coli strains, such as KO11, that produces a 70% yield under the same conditions. Conclusion Results suggest that a higher ethanol formation rate, caused by ahigher PDCZm and ADHZm activities induces a metabolic state that cells compensate through enhanced glucose transport, ATP synthesis, and NAD-NADH+H turnover rates. These results show that glycolytic enzymatic activities, present in E. coli W and C under fermentative conditions, are sufficient to contend with increases in glucose consumption and product formation rates.

  15. Nanotextile membranes for bacteria Escherichia coli capturing

    Directory of Open Access Journals (Sweden)

    Jaroslav Lev

    2010-01-01

    Full Text Available The article describes an experimental study dealing with the possibility of nanotextile materials usa­ge for microbiologically contaminated water filtration. The aim of the study is to verify filtration ability of different nanotextile materials and evaluate the possibilities of practical usage. Good detention ability of these materials in the air filtration is the presumption for nanotextile to be used for bacteria filtration from a liquid. High nanotextile porosity with the nanotextile pores dimensions smaller than a bacteria size predicates the possibility of a successful usage of these materials. For the experiment were used materials made from electrospinning nanofibres under the label PA612, PUR1, PUR2 s PUR3 on the supporting unwoven textiles (viscose and PP. As a model simulation of the microbial contamination, bacteria Escherichia coli was chosen. Contaminated water was filtered during the overpressure activity of 105Pa on the input side of the filter from the mentioned material. After three-day incubation on the nutrient medium, cultures found in the samples before and after filtration were compared. In the filtrated water, bacteria E. coli were indicated, which did not verify the theoretical presumptions about an absolut bacteria detention. However, used materials caught at least 94% of bacteria in case of material PUR1 and up to 99,996% in case of material PUR2. These results predict the possibility of producing effective nanotextile filters for microbiologically contaminated water filtration.Recommendation: For the production of materials with better filtrating qualities, experiments need to be done, enabling better understanding of the bacteria detention mechanisms on the nanotextile material, and parameters of the used materials that influence the filtrating abilities need to be verified.

  16. Genome analysis of E. coli isolated from Crohn's disease patients.

    Science.gov (United States)

    Rakitina, Daria V; Manolov, Alexander I; Kanygina, Alexandra V; Garushyants, Sofya K; Baikova, Julia P; Alexeev, Dmitry G; Ladygina, Valentina G; Kostryukova, Elena S; Larin, Andrei K; Semashko, Tatiana A; Karpova, Irina Y; Babenko, Vladislav V; Ismagilova, Ruzilya K; Malanin, Sergei Y; Gelfand, Mikhail S; Ilina, Elena N; Gorodnichev, Roman B; Lisitsyna, Eugenia S; Aleshkin, Gennady I; Scherbakov, Petr L; Khalif, Igor L; Shapina, Marina V; Maev, Igor V; Andreev, Dmitry N; Govorun, Vadim M

    2017-07-19

    Escherichia coli (E. coli) has been increasingly implicated in the pathogenesis of Crohn's disease (CD). The phylogeny of E. coli isolated from Crohn's disease patients (CDEC) was controversial, and while genotyping results suggested heterogeneity, the sequenced strains of E. coli from CD patients were closely related. We performed the shotgun genome sequencing of 28 E. coli isolates from ten CD patients and compared genomes from these isolates with already published genomes of CD strains and other pathogenic and non-pathogenic strains. CDEC was shown to belong to A, B1, B2 and D phylogenetic groups. The plasmid and several operons from the reference CD-associated E. coli strain LF82 were demonstrated to be more often present in CDEC genomes belonging to different phylogenetic groups than in genomes of commensal strains. The operons include carbon-source induced invasion GimA island, prophage I, iron uptake operons I and II, capsular assembly pathogenetic island IV and propanediol and galactitol utilization operons. Our findings suggest that CDEC are phylogenetically diverse. However, some strains isolated from independent sources possess highly similar chromosome or plasmids. Though no CD-specific genes or functional domains were present in all CD-associated strains, some genes and operons are more often found in the genomes of CDEC than in commensal E. coli. They are principally linked to gut colonization and utilization of propanediol and other sugar alcohols.

  17. Quantitative Brightness Analysis of Fluorescence Intensity Fluctuations in E. Coli.

    Directory of Open Access Journals (Sweden)

    Kwang-Ho Hur

    Full Text Available The brightness measured by fluorescence fluctuation spectroscopy specifies the average stoichiometry of a labeled protein in a sample. Here we extended brightness analysis, which has been mainly applied in eukaryotic cells, to prokaryotic cells with E. coli serving as a model system. The small size of the E. coli cell introduces unique challenges for applying brightness analysis that are addressed in this work. Photobleaching leads to a depletion of fluorophores and a reduction of the brightness of protein complexes. In addition, the E. coli cell and the point spread function of the instrument only partially overlap, which influences intensity fluctuations. To address these challenges we developed MSQ analysis, which is based on the mean Q-value of segmented photon count data, and combined it with the analysis of axial scans through the E. coli cell. The MSQ method recovers brightness, concentration, and diffusion time of soluble proteins in E. coli. We applied MSQ to measure the brightness of EGFP in E. coli and compared it to solution measurements. We further used MSQ analysis to determine the oligomeric state of nuclear transport factor 2 labeled with EGFP expressed in E. coli cells. The results obtained demonstrate the feasibility of quantifying the stoichiometry of proteins by brightness analysis in a prokaryotic cell.

  18. Molecular prophage typing of avian pathogenic Escherichia coli.

    Science.gov (United States)

    Kwon, Hyuk-Joon; Seong, Won-Jin; Kim, Jae-Hong

    2013-03-23

    Escherichia coli prophages confer virulence and resistance to physico-chemical, nutritional, and antibiotic stresses on their hosts, and they enhance the evolution of E. coli. Thus, studies on profiles of E. coli prophages are valuable to understand the population structure and evolution of E. coli pathogenicity. Large terminase genes participate in phage genome packaging and are one of the cornerstones for the identification of prophages. Thus, we designed primers to detect 16 types of large terminase genes and analyzed the genomes of 48 E. coli and Shigella reference strains for the prophage markers. We also investigated the distribution of the 16 prophage markers among 92 avian pathogenic E. coli (APEC) strains. APEC strains were classified into 61 prophage types (PPTs). Each strain was different from the reference strains as measured by the PPTs and from the frequency of each prophage marker. Investigation of the distribution of prophage-related serum resistance (bor), toxin (stx1 and cdtI), and T3SS effector (lom, espK, sopE, nleB, and ospG) genes revealed the presence of bor (44.1%), lom (95.5%) and cdtI (9.1%) in APEC strains with related prophages. Therefore, the molecular prophage typing method may be useful to understand population structure and evolution of E. coli pathogenicity, and further studies on the mobility of the prophages and the roles of virulence genes in APEC pathogenicity may be valuable. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Asymptomatic bacteriuria Escherichia coli are live biotherapeutics for UTI.

    Science.gov (United States)

    Rudick, Charles N; Taylor, Aisha K; Yaggie, Ryan E; Schaeffer, Anthony J; Klumpp, David J

    2014-01-01

    Urinary tract infections (UTI) account for approximately 8 million clinic visits annually with symptoms that include acute pelvic pain, dysuria, and irritative voiding. Empiric UTI management with antimicrobials is complicated by increasing antimicrobial resistance among uropathogens, but live biotherapeutics products (LBPs), such as asymptomatic bacteriuria (ASB) strains of E. coli, offer the potential to circumvent antimicrobial resistance. Here we evaluated ASB E. coli as LBPs, relative to ciprofloxacin, for efficacy against infection and visceral pain in a murine UTI model. Visceral pain was quantified as tactile allodynia of the pelvic region in response to mechanical stimulation with von Frey filaments. Whereas ciprofloxacin promoted clearance of uropathogenic E. coli (UPEC), it did not reduce pelvic tactile allodynia, a measure of visceral pain. In contrast, ASB E. coli administered intravesically or intravaginally provided comparable reduction of allodynia similar to intravesical lidocaine. Moreover, ASB E. coli were similarly effective against UTI allodynia induced by Proteus mirabilis, Enterococccus faecalis and Klebsiella pneumoniae. Therefore, ASB E. coli have anti-infective activity comparable to the current standard of care yet also provide superior analgesia. These studies suggest that ASB E. coli represent novel LBPs for UTI symptoms.

  20. "Central Station" Londonis

    Index Scriptorium Estoniae

    2000-01-01

    Londoni galeriis Milch seitsme läti, leedu ja eesti kunstniku projekt "Central Station". Kuraatorid Lisa Panting, Sally Tallant. Eestist osalevad Hanno Soans (Catarina Campinoga koostöös valminud video), Kiwa, Kai Kaljo

  1. The central noradrenergic system

    African Journals Online (AJOL)

    2006-07-27

    Jul 27, 2006 ... recognition of a direct influence of the central noradrenergic system on peripheral ... influences on cerebral function and behavior it is impossible to imagine ... stimuli and to speed-up information processing.4. The influence of ...

  2. Central Asian Republic Info

    Data.gov (United States)

    US Agency for International Development — CAR Info is designed and managed by the Central Asian Republic Mission to fill in the knowledge and reporting gaps in existing agency systems for that Mission. It...

  3. Outsourcing central banking

    DEFF Research Database (Denmark)

    Khoury, Sarkis Joseph; Wihlborg, Clas

    2005-01-01

    The literature on Currency Boards (CB) stops at the water edge in terms of dealing with the totality of the functions of a central bank. Monetary policy, and banking supervisioncan be "outsourced" in an open economy with substantial foreign direct investment (FDI)in the banking sector if political...... nationalism does not trump economic rationality. An orthodox CB renders the central banking function redundant in terms of interest rate and exchange rate determination. FDI in banking could perform the same role for the supervisory function of central banks. We use the case of Estonia to illustrate...... the feasibility of, and constraints on, outsourcing of central bank functions. A brief discussion of the Argentinian experience is used for contrast.Key words: Currency Board, Foreign Banks, Supervision, Regional Integration,outsourcing....

  4. Central nervous system resuscitation

    DEFF Research Database (Denmark)

    McIntosh, T K; Garde, E; Saatman, K E

    1997-01-01

    Traumatic injury to the central nervous system induces delayed neuronal death, which may be mediated by acute and chronic neurochemical changes. Experimental identification of these injury mechanisms and elucidation of the neurochemical cascade following trauma may provide enhanced opportunities...

  5. Central nervous system

    Science.gov (United States)

    The central nervous system is composed of the brain and spinal cord. Your brain and spinal cord serve as the main "processing center" for your entire nervous system. They control all the workings of your body.

  6. Central Pontine Myelinolysis

    Science.gov (United States)

    ... Clinical Trials Organizations Publications Definition Central pontine myelinolysis (CPM) is a neurological disorder that most frequently occurs ... Experts estimate that 10 percent of those with CPM will also have areas of EPM. The initial ...

  7. Central banks: Paradise lost

    OpenAIRE

    Issing, Otmar

    2012-01-01

    The focus of the paper is to analyze how the concept behind central bank policy developed over time and how the recent financial crisis and its consequences will have an influence. While the principles of the institutional arrangement for central banks (independence, clear mandate, prohibition of monetary financing) are relevant as ever, pre- crisis consensus strategies of monetary policy have been revealed as flawed. The close monitoring of money and credit developments, a key lesson to be d...

  8. Escherichia coli O26 IN RAW BUFFALO MILK: PRELIMINARY RESULTS

    Directory of Open Access Journals (Sweden)

    A. Rella

    2013-02-01

    Full Text Available Escherichia coli O26 is considered to be one of the most important food-borne pathogen. In this study, 120 buffalo milk samples collected in Lazio and in Apulia regions were tested for the presence of E. coli O26. One buffalo milk sample (0,8% tested positive for E. coli O26; the isolate was positive at the verocytotoxicity test and it showed resistance properties to different antimicrobial classes. These preliminary results highlight the need to monitor the foods of animal origin used for production and eaten by a wide range of persons, respect VTEC organism.

  9. Spontaneous Escherichia coli Meningitis Associated with Hemophagocytic Lymphohistiocytosis

    Directory of Open Access Journals (Sweden)

    Kuo-Hsuan Chang

    2006-01-01

    Full Text Available Spontaneous Escherichia coli meningitis has not been previously reported in association with hemophago-cytic lymphohistiocytosis (HLH. A previously healthy 72-year-old woman was admitted due to fever, nuchal rigidity, disturbed consciousness and splenomegaly. Anemia, thrombocytopenia and hyperfer-ritinemia developed on the 8th day of hospitalization. Cultures of cerebrospinal fluid and blood grew E. coli. Abundant macrophages overwhelmed erythrocytes in the bone marrow aspirate, confirming the presence of hemophagocytosis. E. coli meningitis was managed with a 40-day course of antibiotic treatment. However, the severity of anemia and thrombocytopenia progressed despite intensive transfusion therapy. The patient died of HLH on the 60th day of hospitalization.

  10. Findings of Escherichia coli and Enterococcus spp. in homemade cheese

    Directory of Open Access Journals (Sweden)

    Tambur Zoran

    2007-01-01

    Full Text Available During the period from February until March 2004, 108 samples of soft cheese originating from markets of Pancevo, Subotica and Belgrade were examined. Microbiological analyses of the cheese samples to the presence of Escherichia coli was performed using methods described in the Regulations on methods for performing microbiological analyses and super analyses of consumer articles, while the presence of bacteria Enteroccocus spp. was performed on the dexter agar. From 108 samples of soft cheese from the territories of Pancevo, Belgrade and Subotica were isolated: Enterococcus spp. from 96% and Escherichia coli from 69%, cheese samples. Verocytotoxic E.coli was not isolated from any of the taken cheese samples.

  11. Prevalence of antimicrobial resistant Escherichia coli from patients with suspected urinary tract infection in primary care, Denmark.

    Science.gov (United States)

    Córdoba, Gloria; Holm, Anne; Hansen, Frank; Hammerum, Anette M; Bjerrum, Lars

    2017-10-10

    Escherichia coli is the most common pathogen causing Urinary Tract Infections (UTI). Data from the current National Surveillance program in Denmark (DANMAP) may not accurately represent the prevalence of resistant E. coli in primary care, because only urine samples from complicated cases may be forwarded to the microbiological departments at hospitals for diagnostic examination. The aim of this study was to assess the prevalence of resistant E. coli to the most commonly used antimicrobial agents in primary care in a consecutive sample of patients from general practice. Observational study carried out from December 2014 to December 2015. Thirty-nine general practices from The Capital Region of Denmark included adult patients with urinary tract symptoms and suspected UTI. All urine samples were sent to the central laboratory Statens Serum Institut (SSI). Significant bacteriuria was interpreted according to the European Urinalysis Standards. Susceptibility testing was performed and interpreted according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) standards. From the 39 general practices 505 patients were recruited. Completed data were obtained from 485 (96%) patients. According to the European Urinalysis Standards, 261 (54%) patients had positive bacteriuria. The most common uropathogen in patients with uncomplicated (uUTI) and complicated (cUTI) urinary tract infection was E. coli 105 (69%) and 76 (70%), respectively. Eighty-two (45%) of 181 E. coli isolates were resistant to at least one of the tested antibiotics and 50 out of 82 isolates were resistant to two or more antimicrobial agents. The highest resistance-rate was found against ampicillin 34% (95% CI 24;42) in uUTI and 36% (24;46) in cUTI. There were no differences in the distribution of resistance between uncomplicated and complicated cases. The prevalence of resistance was similar to the one reported in DANMAP 2014. In E. coli from uUTI there is high resistance rates to

  12. Prevalence and behavior of multidrug-resistant shiga toxin-producing Escherichia coli, enteropathogenic E. coli and enterotoxigenic E. coli on coriander.

    Science.gov (United States)

    Gómez-Aldapa, Carlos A; Segovia-Cruz, Jesús A; Cerna-Cortes, Jorge F; Rangel-Vargas, Esmeralda; Salas-Rangel, Laura P; Gutiérrez-Alcántara, Eduardo J; Castro-Rosas, Javier

    2016-10-01

    The prevalence and behavior of multidrug-resistant diarrheagenic Escherichia coli pathotypes on coriander was determined. One hundred coriander samples were collected from markets. Generic E. coli were determined using the most probable number procedure. Diarrheagenic E. coli pathotypes (DEPs) were identified using two multiplex polymerase chain reaction procedures. Susceptibility to sixteen antibiotics was tested for the isolated DEPs strains by standard test. The behavior of multidrug-resistant DEPs isolated from coriander was determined on coriander leaves and chopped coriander at 25°± 2 °C and 3°± 2 °C. Generic E. coli and DEPs were identified, respectively, in 43 and 7% of samples. Nine DEPs strains were isolated from positive coriander samples. The identified DEPs included Shiga toxin-producing E. coli (STEC, 4%) enterotoxigenic E. coli (ETEC, 2%) and enteropathogenic E. coli (EPEC, 1%). All isolated DEPs strains exhibited multi-resistance to antibiotics. On inoculated coriander leaves stored at 25°± 2 °C or 3°± 2 °C, no growth was observed for multidrug-resistant DEPs strains. However, multidrug-resistant DEPs strains grew in chopped coriander: after 24 h at 25° ± 2 °C, DEPs strains had grown to approximately 3 log CFU/g. However, at 3°± 2 °C the bacterial growth was inhibited. To the best of our knowledge, this is the first report of the presence and behavior of multidrug-resistant STEC, ETEC and EPEC on coriander and chopped coriander. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. 75 FR 14607 - Small Entity Compliance Guide: Bottled Water: Total Coliform and E. coli

    Science.gov (United States)

    2010-03-26

    ...] Small Entity Compliance Guide: Bottled Water: Total Coliform and E. coli; Availability AGENCY: Food and... the availability of a guidance for industry entitled ``Bottled Water: Total Coliform and E. coli... determine whether any of the coliform organisms are Escherichia coli (E. coli), an indicator of fecal...

  14. The organisational structure of protein networks: revisiting the centrality-lethality hypothesis.

    Science.gov (United States)

    Raman, Karthik; Damaraju, Nandita; Joshi, Govind Krishna

    2014-03-01

    Protein networks, describing physical interactions as well as functional associations between proteins, have been unravelled for many organisms in the recent past. Databases such as the STRING provide excellent resources for the analysis of such networks. In this contribution, we revisit the organisation of protein networks, particularly the centrality-lethality hypothesis, which hypothesises that nodes with higher centrality in a network are more likely to produce lethal phenotypes on removal, compared to nodes with lower centrality. We consider the protein networks of a diverse set of 20 organisms, with essentiality information available in the Database of Essential Genes and assess the relationship between centrality measures and lethality. For each of these organisms, we obtained networks of high-confidence interactions from the STRING database, and computed network parameters such as degree, betweenness centrality, closeness centrality and pairwise disconnectivity indices. We observe that the networks considered here are predominantly disassortative. Further, we observe that essential nodes in a network have a significantly higher average degree and betweenness centrality, compared to the network average. Most previous studies have evaluated the centrality-lethality hypothesis for Saccharomyces cerevisiae and Escherichia coli; we here observe that the centrality-lethality hypothesis hold goods for a large number of organisms, with certain limitations. Betweenness centrality may also be a useful measure to identify essential nodes, but measures like closeness centrality and pairwise disconnectivity are not significantly higher for essential nodes.

  15. Membrane Topology and Biochemical Characterization of the Escherichia coli BacA Undecaprenyl-Pyrophosphate Phosphatase.

    Directory of Open Access Journals (Sweden)

    Guillaume Manat

    Full Text Available Several integral membrane proteins exhibiting undecaprenyl-pyrophosphate (C55-PP phosphatase activity were previously identified in Escherichia coli that belonged to two distinct protein families: the BacA protein, which accounts for 75% of the C55-PP phosphatase activity detected in E. coli cell membranes, and three members of the PAP2 phosphatidic acid phosphatase family, namely PgpB, YbjG and LpxT. This dephosphorylation step is required to provide the C55-P carrier lipid which plays a central role in the biosynthesis of various cell wall polymers. We here report detailed investigations of the biochemical properties and membrane topology of the BacA protein. Optimal activity conditions were determined and a narrow-range substrate specificity with a clear preference for C55-PP was observed for this enzyme. Alignments of BacA protein sequences revealed two particularly well-conserved regions and several invariant residues whose role in enzyme activity was questioned by using a site-directed mutagenesis approach and complementary in vitro and in vivo activity assays. Three essential residues Glu21, Ser27, and Arg174 were identified, allowing us to propose a catalytic mechanism for this enzyme. The membrane topology of the BacA protein determined here experimentally did not validate previous program-based predicted models. It comprises seven transmembrane segments and contains in particular two large periplasmic loops carrying the highly-conserved active site residues. Our data thus provide evidence that all the different E. coli C55-PP phosphatases identified to date (BacA and PAP2 catalyze the dephosphorylation of C55-PP molecules on the same (outer side of the plasma membrane.

  16. Virulence gene profiles of avian pathogenic Escherichia coli isolated from chickens with colibacillosis in Bulawayo, Zimbabwe

    Directory of Open Access Journals (Sweden)

    Joshua Mbanga

    2015-04-01

    Full Text Available Colibacillosis, a disease caused by avian pathogenic Escherichia coli (APEC, is one of the main causes of economic losses in the poultry industry worldwide. This study was carried out in order to determine the APEC-associated virulence genes contained by E. coli isolates causing colibacillosis in chickens. A total of 45 E. coli isolates were obtained from the diagnostics and research branch of the Central Veterinary Laboratories, Bulawayo, Zimbabwe. These isolates were obtained from chickens with confirmed cases of colibacillosis after postmortem examination. The presence of the iutA, hlyF, ompT, frz, sitD, fimH, kpsM, sitA, sopB, uvrY, pstB and vat genes were investigated by multiplex polymerase chain reaction (PCR assay. Of the 45 isolates, 93% were positive for the presence of at least one virulence gene. The three most prevalent virulence genes were iutA (80%, fimH (33.3% and hlyF (24.4%. The kpsM, pstB and ompT genes had the lowest prevalence, having been detected in only 2.2% of the isolates. All 12 virulence genes studied were detected in the 45 APEC isolates. Virulence gene profiles were constructed for each APEC isolate from the multiplex data. The APEC isolates were profiled as 62.2% fitting profile A, 31.1% profile B and 6.7% profile C. None of the isolates had more than seven virulence genes. Virulence profiles of Zimbabwean APEC isolates are different from those previously reported. Zimbabwean APEC isolates appear to be less pathogenic and may rely on environmental factors and stress in hosts to establish infection.

  17. Evolutionary patterns of Escherichia coli small RNAs and their regulatory interactions.

    Science.gov (United States)

    Peer, Asaf; Margalit, Hanah

    2014-07-01

    Most bacterial small RNAs (sRNAs) are post-transcriptional regulators of gene expression, exerting their regulatory function by base-pairing with their target mRNAs. While it has become evident that sRNAs play central regulatory roles in the cell, little is known about their evolution and the evolution of their regulatory interactions. Here we used the prokaryotic phylogenetic tree to reconstruct the evolutionary history of Escherichia coli sRNAs and their binding sites on target mRNAs. We discovered that sRNAs currently present in E. coli mainly accumulated inside the Enterobacteriales order, succeeding the appearance of other types of noncoding RNAs and concurrently with the evolution of a variant of the Hfq protein exhibiting a longer C-terminal region. Our analysis of the evolutionary ages of sRNA-mRNA interactions revealed that while all sRNAs were evolutionarily older than most of their known binding sites on mRNA targets, for quite a few sRNAs there was at least one binding site that coappeared with or preceded them. It is conceivable that the establishment of these first interactions forced selective pressure on the sRNAs, after which additional targets were acquired by fitting a binding site to the active region of the sRNA. This conjecture is supported by the appearance of many binding sites on target mRNAs only after the sRNA gain, despite the prior presence of the target gene in ancestral genomes. Our results suggest a selective mechanism that maintained the sRNAs across the phylogenetic tree, and shed light on the evolution of E. coli post-transcriptional regulatory network. © 2014 Peer and Margalit; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  18. CENTRAL PLATEAU REMEDIATION

    International Nuclear Information System (INIS)

    ROMINE, L.D.

    2006-01-01

    A systematic approach to closure planning is being implemented at the Hanford Site's Central Plateau to help achieve the goal of closure by the year 2035. The overall objective of Central Plateau remediation is to protect human health and the environment from the significant quantity of contaminated material that resulted from decades of plutonium production in support of the nation's defense. This goal will be achieved either by removing contaminants or placing the residual contaminated materials in a secure configuration that minimizes further migration to the groundwater and reduces the potential for inadvertent intrusion into contaminated sites. The approach to Central Plateau cleanup used three key concepts--closure zones, closure elements, and closure process steps--to create an organized picture of actions required to complete remediation. These actions were merged with logic ties, constraints, and required resources to produce an integrated time-phased schedule and cost profile for Central Plateau closure. Programmatic risks associated with implementation of Central Plateau closure were identified and analyzed. Actions to mitigate the most significant risks are underway while high priority remediation projects continue to make progress

  19. Alterations induced in Escherichia Coli cells by gamma radiation

    International Nuclear Information System (INIS)

    Kappke, J.; Schelin, H.R.; Paschuk, S.A.; Denyak, V.; Silva, E.R. da; Jesus, E.F.O. de; Lopes, R.T.; Carlin, N.; Toledo, E.S.

    2007-01-01

    Modifications occurred in Escherichia coli cells exposed to gamma radiation ( 60 Co source) were investigated. The irradiations were done at the LIN-COPPE laboratory of the UFRJ and the analysis at the Biology Department of the UTFPR. The E. coli cells were irradiated with 30, 60, 90, 120, 150, 180, 210, 240, 300, 480, 600 e 750 Gy doses. The samples were analyzed with Gram-stain, biochemical tests in EPM, MIO and Lysine Broth, Simmons Cytrate Medium and Rhamnose Broth, antibiogram and isolation of auxotrophic mutants. It was observed that for the received doses the E. coli did not show morphological alterations in the tests. Some E. Coli cells showed to be able to deaminade the L-tryptophan or they changed their sensibility for amoxillin and cephaloonine after the irradiation. The existence of aauxotrophic mutants after irradiation was also verified. (author)

  20. Distribution of Escherichia Coli as Soil Pollutant around Antang Landfills

    Science.gov (United States)

    Artiningsih, Andi; Zubair, Hazairin; Imran, A. M.; Widodo, Sri

    2018-03-01

    Tamangapa Antang Landfill locates around the residential area and faces an air and water pollution due to an open dumping system in its operation. The system arises a potential pollution in air, water and soil. Sampling was done surround the landfill in two parts, parallel and perpendicular to the ground water flow. This study shows the abundance of E. coli bacteria in soil around the Antang Landfills at depth of 10 to 20 cm (93x105 cfu/gr of soil) in the direction of groundwater flow. While in other locations the E. coli bacteria is not detected. The abundance of E. coli bacteria is a conjunction factor from landfill and human activities surround the area. The absence of E. coli bacteria in other location highly interpreted that the landfill is the major contributor of pollutant.

  1. The Escherichia coli transcriptome linked to growth fitness

    Directory of Open Access Journals (Sweden)

    Bei-Wen Ying

    2016-03-01

    Full Text Available A series of Escherichia coli strains with varied genomic sequences were subjected to high-density microarray analyses to elucidate the fitness-correlated transcriptomes. Fitness, which is commonly evaluated by the growth rate during the exponential phase, is not only determined by the genome but is also linked to growth conditions, e.g., temperature. We previously reported genetic and environmental contributions to E. coli transcriptomes and evolutionary transcriptome changes in thermal adaptation. Here, we describe experimental details on how to prepare microarray samples that truly represent the growth fitness of the E. coli cells. A step-by-step record of sample preparation procedures that correspond to growing cells and transcriptome data sets that are deposited at the GEO database (GSE33212, GSE52770, GSE61739 are also provided for reference. Keywords: Transcriptome, Growth fitness, Escherichia coli, Microarray

  2. Evolution in the Lab: Biocide Resistance in E.coli.

    Science.gov (United States)

    Welden, Charles W.; Hossler, Rex A.

    2003-01-01

    Describes a laboratory experiment on resistance to teach about evolution and issues of misuse of antimicrobial compounds. Investigates Escherichia coli's response to treatment of triclosan, a biocide used in consumer products. (Contains 12 references.) (YDS)

  3. A magnetic biosensor system for detection of E. coli

    KAUST Repository

    Li, Fuquan; Kosel, Jü rgen

    2013-01-01

    This work describes a device for detecting E. coli bacteria by manipulating superparamagnetic beads to a sensing area and immobilizing them in a trapping well. The trapping well replaces the biochemical immobilization layer, which is commonly used

  4. TRIMETHOPRIM-SULFAMETHOXAZOLE RESISTANCE IN SEWAGE ISOLATES OF ESCHERICHIA COLI

    Science.gov (United States)

    Sewage samples from seven locations in the United States were analyzed for Escherichia coli isolates which were resistant to trimethoprim-sulfamethoxazole (SXT). The prevalence rate of SXT resistant organisms varied between the different geographical locales. The majority of th...

  5. Rare Case of Polymicrobial Keratitis With Balantidium coli.

    Science.gov (United States)

    Hazarika, Manali; Pai H, Vijaya; Khanna, Vinay; Reddy, Harish; Tilak, Kriti; Chawla, Kiran

    2016-12-01

    To report a rare case of polymicrobial keratitis due to Balantidium coli and gram-negative bacteria, Pseudomonas aeruginosa and Klebsiella pneumoniae, in a soft contact lens (CL) wearer. We report a case of CL-related keratitis due to B. coli, P. aeruginosa, and K. pneumoniae. The culture of the corneal scrapings, the CL cleaning solution, and the CL revealed the growth of a rare ciliated parasite, B. coli, along with gram-negative bacteria, namely, P. aeruginosa and K. pneumoniae. The patient was successfully treated with topical broad-spectrum antibiotics and intravenous metronidazole. Polymicrobial keratitis has seldom been reported with B. coli as the causative agent. CL wear can be a risk factor for this infection. Treatment with topical antibiotics may not suffice, and the intravenous route of antiprotozoal drugs may be a useful adjunct. Increasing awareness, early diagnosis, and treatment may improve the final visual outcome.

  6. Ischemic colitis or melanosis coli: a case report

    Directory of Open Access Journals (Sweden)

    Nadeem Mohammed

    2007-09-01

    Full Text Available Abstract Background Melanosis Coli is described as black or brown discolouration of the mucosa of the colon. Its a benign condition, which arises from anthraquinone laxative abuse and has no symptoms of its own. The main importance of diagnosing Melanosis Coli correctly lies in the fact that if its extensive, there may be difficulty in differentiating it from ischemic colitis. Case presentation We present a case of extensive Melanosis Coli involving the whole of large bowel that appeared gangrenous. A sub total colectomy was performed on presumed diagnosis of ischemic bowel. Conclusion This report reminds the clinicians that extensive Melanosis Coli may mimic ischemic colitis and thus must be considered as a differential diagnosis.

  7. The Prevalence of Enterhaemorrhagic Escherichia Coli in children ...

    African Journals Online (AJOL)

    EHEC), the pathogenicity of other strains of Escherichia coli and other organisms in children presenting with and without diarrhoea in the hospital. Subjects and Methods: A total of 247 stool samples collected from children aged 1 month to 7 ...

  8. Peptide nucleic acid (PNA) antisense effects in Escherichia coli

    DEFF Research Database (Denmark)

    Good, L; Nielsen, P E

    1999-01-01

    Antisense peptide nucleic acid (PNA) can be used to control cell growth, gene expression and growth phenotypes in the bacteria Escherichia coli. PNAs targeted to the RNA components of the ribosome can inhibit translation and cell growth, and PNAs targeted to mRNA can limit gene expression with gene...... and sequence specificity. In an E. coli cell extract, efficient inhibition is observed when using PNA concentrations in the nanomolar range, whereas micromolar concentrations are required for inhibition in growing cells. A mutant strain of E. coli that is more permeable to antibiotics also is more susceptible...... to antisense PNAs than the wild type. This chapter details methods for testing the antisense activities of PNA in E. coli. As an example of the specific antisense inhibition possible, we show the effects of an anti-beta-galactosidase PNA in comparison to control PNAs. With improvements in cell uptake...

  9. GLYCOSYLATED YGHJ POLYPEPTIDES FROM ENTEROTOXIGENIC ESCHERICHIA COLI (ETEC)

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention relates to glycosylated YghJ polypeptides from or derived from enterotoxigenic Escherichia coli (ETEC) that are immunogenic. In particular, the present invention relates to compositions or vaccines comprising the polypeptides and their application in immunization, vaccination...

  10. Molecular characterization of diarrheagenic Escherichia coli strains from stools samples and food products in Colombia

    OpenAIRE

    Rúgeles, Laura Cristina; Bai, Jing; Martínez, Aída Juliana; Vanegas, María Consuelo; Gómez-Duarte, Oscar Gilberto

    2010-01-01

    The prevalence of diarrheagenic E. coli in childhood diarrhea and the role of contaminated food products in disease transmission in Colombia are largely unknown. The aim of this study is to identify E. coli pathotypes, including E. coli O157:H7, from 108 stool samples from children with acute diarrhea, 38 meat samples and 38 vegetable samples. Multiplex PCR and Bax Dupont systems were used for E. coli pathotype detection. Eighteen (9.8%) E. coli diarrheagenic pathotypes were detected among al...

  11. Analysis of early-onset bloodstream infection due to Escherichia coli infection in premature babies

    OpenAIRE

    Chen, I-Lun; Huang, Hsin-Chun; Wu, Chih-Te; Ou-Yang, Mei-Chen; Chung, Mei-Yung; Chen, Chih-Cheng; Suen, Jau-Ling; Hung, Chih-Hsing

    2017-01-01

    Abstract In early-onset bacteremia among preterm neonates, Escherichia coli (E. coli) is the main pathogen and can cause a high mortality rate. Thus, the predictive factors of mortality and extended-spectrum ?-lactamase (ESBL)-producing E. coli in preterm babies with E. coli early-onset bacteremia were reported. We retrospectively reviewed preterm neonates who had E. coli bacteremia occurring within 3 days after birth between 2004 and 2015. Maternal and perinatal information were collected fr...

  12. Characterization of Climical and Commensal Escherichia coli Isolates from an Integrated Turkey Operation

    OpenAIRE

    Altekruse, Sean Fitzgerald

    2001-01-01

    Pathogenic E. coli infections cause approximately one quarter of disease losses in commercial turkey flocks. A small subgroup of E. coli causes most infections. Epidemiologic studies of this disease have been hindered by a lack of reliable markers to discriminate between pathogenic and fecal E. coli and by the diversity of poultry strains. Reliance on antimicrobials to control E. coli infections has caused widespread antimicrobial resistance. One hundred five clinical E. coli were obtaine...

  13. Metabolic engineering of Escherichia coli for the production of riboflavin

    OpenAIRE

    Lin, Zhenquan; Xu, Zhibo; Li, Yifan; Wang, Zhiwen; Chen, Tao; Zhao, Xueming

    2014-01-01

    Background Riboflavin (vitamin B2), the precursor of the flavin cofactors flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), is used commercially as an animal feed supplement and food colorant. E. coli is a robust host for various genetic manipulations and has been employed for efficient production of biofuels, polymers, amino acids, and bulk chemicals. Thus, the aim of this study was to understand the metabolic capacity of E. coli for the riboflavin production by modification...

  14. Draft Genome Sequence of Escherichia coli K-12 (ATCC 10798).

    Science.gov (United States)

    Dimitrova, Daniela; Engelbrecht, Kathleen C; Putonti, Catherine; Koenig, David W; Wolfe, Alan J

    2017-07-06

    Here, we present the draft genome sequence of Escherichia coli ATCC 10798. E. coli ATCC 10798 is a K-12 strain, one of the most well-studied model microorganisms. The size of the genome was 4,685,496 bp, with a G+C content of 50.70%. This assembly consists of 62 contigs and the F plasmid. Copyright © 2017 Dimitrova et al.

  15. Genes and proteins of Escherichia coli K-12.

    Science.gov (United States)

    Riley, M

    1998-01-01

    GenProtEC is a database of Escherichia coli genes and their gene products, classified by type of function and physiological role and with citations to the literature for each. Also present are data on sequence similarities among E.coli proteins, representing groups of paralogous genes, with PAM values, percent identity of amino acids, length of alignment and percent aligned. GenProtEC can be accessed at the URL http://www.mbl.edu/html/ecoli.html

  16. Predictors Of Non-Escherichia Coli Urinary Tract Infection.

    Science.gov (United States)

    Shaikh, Nader; Wald, Ellen R; Keren, Ron; Gotman, Nathan; Ivanova, Anastasia; Carpenter, Myra A; Moxey-Mims, Marva; Hoberman, Alejandro

    2016-11-01

    We aimed to determine which children are prone to non-Escherichia coli urinary tract infection (UTIs). We included 769 children with UTI. We found that circumcised males, Hispanic children, children without fever and children with grades 3 and 4 vesicoureteral reflux were more likely to have a UTI caused by organisms other than E. coli. This information may guide clinicians in their choice of antimicrobial therapy.

  17. Metabolic and Transcriptional Response to Cofactor Perturbations in Escherichia coli

    DEFF Research Database (Denmark)

    Holm, Anders Koefoed; Blank, L.M.; Oldiges, M.

    2010-01-01

    Metabolic cofactors such as NADH and ATP play important roles in a large number of cellular reactions, and it is of great interest to dissect the role of these cofactors in different aspects of metabolism. Toward this goal, we overexpressed NADH oxidase and the soluble F1-ATPase in Escherichia coli...... of redox and energy metabolism and should help in developing metabolic engineering strategies in E. coli....

  18. The Naive Central Banker

    Directory of Open Access Journals (Sweden)

    Marcelo de Carvalho Griebeler

    2015-09-01

    Full Text Available There has been in some countries a trend of assigning other functions to central banks besides price stability. The most suggested function to be added to monetary authority’s obligations is to pursue economic growth or full employment. In this paper we characterize the behavior and analyse the optimal monetary policy of, what we call, a naive central banker. We describe the naive behavior as one that does face the inflation-unemployment trade-off, but it tries to minimize both variables simultaneously. Our findings, both under discretion and commitment, indicate that the naive central banker delivers lower expected inflation and inflation variance than the benchmark behavior whenever the economy is rigid enough. However, the degree of conservativeness also affects this result, such that the less conservative the naive policymaker, the more rigidity is necessary.

  19. Colloquium on Central Asia

    International Nuclear Information System (INIS)

    2005-01-01

    This colloquium on Azerbaijan was organized by the direction of international relations of the French Senate and the French center of foreign trade (CFCE). This document gathers the interventions of the participants and the debates with the audience following these interventions. The topics treated concern: - the present day political-economical situation of Central Asia countries (problem of borders, relations with Russia and China); - the economies of Central Asia countries: short term problems and medium-term perspectives; - the relations with the European Union (political, economical, trade and investments, perspectives); - the European energy stakes of Caspian sea (oil and gas reserves, development of hydrocarbon resources, exploitation and transport constraints, stakes for Europe and France); - TotalFinaElf company in Central Asia (Kazakhstan, Azerbaijan, enclavement problem); - the economical impacts of the TRACECA pathway (Transport Corridor Europe Caucasus Asia). (J.S.)

  20. Central Station Design Options

    DEFF Research Database (Denmark)

    2011-01-01

    . The work identifies the architecture, sizing and siting of prospective Central Stations in Denmark, which can be located at shopping centers, large car parking lots or gas stations. Central Stations are planned to be integrated in the Danish distribution grid. The Danish island of Bornholm, where a high...... overloading, more reference points might be necessary to represent various transformer loading levels. The subject of safety in Central Station is also addressed. A number of safety rules based on European standards apply to AC charging equipment up to 44 kW. The connection interlock and the automatic de......-energization are identified as fundamental requirements for safety in such a charging station. The connection interlock is a solution which ensures that no power is applied to the DC cable when the EV connector is not connected. The automatic de-energization device ensures that whenever a strain on the cable is detected, e...

  1. The central nervous system

    International Nuclear Information System (INIS)

    Holmes, R.A.

    1984-01-01

    The first section presents a comprehensive evaluation of radionuclide imaging of the central nervous system and provides a comparison of the detection accuracies of radionuclide imaging (RNI) and XCT in certain lesions, realizing that the XCT results may vary when radiocontrast or newer generation XCT scanners are used. Although conventional radionuclide imaging of the central nervous system has experienced no significant changes over the last 7 years except for mild refinements, a new section has been added on positron emission tomography (PET). Most positron radiopharmaceuticals passively cross the intact blood-brain barrier, and their localization has catalyzed renewed interest in our ability to metabolically study and obtain images of the central nervous system. The section on radionuclide cisternography has been rewritten to reflect present day practice and the wider application of XCT in describing conditions affecting the ventricular system

  2. Physicochemical Factors: Impact on Spermagglutination Induced by Escherichia coli

    Directory of Open Access Journals (Sweden)

    Kiranjeet Kaur

    2014-02-01

    Full Text Available Motility is a sensitive parameter of sperm function which is predictive of its fertilization potential in vitro. The decrease in sperm motility may be associated with sperm agglutination and immobilization due to mere presence of bacteria or excretion of bacterial toxic products. Supplementation with various agents like sucrose, mannitol, calcium, and EDTA is well known to improve the sperm motility in vitro. The present study was designed to check any protective role exerted by the addition of different agents on spermatozoal motility against E. coli induced sperm agglutination. 52 semen specimens were screened for the presence of sperm-agglutinating strain of E. coli. Further, influence of various factors, namely, sugars, salts, and chelating agents was studied. Also, the impact of exposure to high temperature and alcohol on sperm-agglutinating efficiency of E. coli was observed. None of the factors could inhibit the sperm agglutination induced by E. coli, except high temperature suggesting the involvement of protein moiety. In addition, it was observed that agglutinating efficiency of E. coli was limited to spermatozoa and RBCs. It may be concluded that sperm-agglutinating property of E. coli is quite stable as various physicochemical factors tested did not show any negative effect on the same except high temperature.

  3. Incidence of Escherichia coli O157:H7 in Thailand

    International Nuclear Information System (INIS)

    Sukhumungoon, P.

    2015-01-01

    Entero hemorrhagic Escherichia coli (EHEC) especially serotype O157:H7 is one of the important food-borne pathogens because it is able to produce crucial toxins Shiga. However, the outbreak of this organism in Thailand has not been reported. Antibody to O157 antigen was detected in some Thai populations and Shiga toxin-producing E. coli were detected in low numbers of clinical specimens. Interestingly, some E. coli that showed positive to O157 fimbriae probe and lack of virulence gene were isolated from certain patients and one isolate of E. coli O157:H7 which possessed stx1, stx2v was detected in a normal child. In addition, the incidence of E. coli O157:H7 strains were monitored by the samples from cattle and retail beef in Thailand although their inability to produce toxins or produce in a low concentration was demonstrated. This review discusses the incidences of E. coli O157 in clinical and environmental samples of Thailand including the transmission possibility of this bacterium across the Thai border through food trade. (author)

  4. The presence of verotoxinogenic E. coli in some foods

    Directory of Open Access Journals (Sweden)

    Bostan K.

    2005-01-01

    Full Text Available In this study 30 samples each of ready-to-cook meatballs and white cheese as well as 96 samples of various ready-to-eat foods, obtained from different sales outlets in Istanbul, were analyzed for the presence of verotoxins (consequently vemtoxigenic E. coli E. coli with the aid of the enzyme immunoassay technique. Additionally, total coli-form and chromogenic E. coli count were determined by cultural methods for all food samples. E. coli growth was detected in all ready-to-cook meatballs (100%, in 27 of the white cheese samples (90% and in 69 of the other ready-to-eat food samples (71.9%. Verotoxins, however, could not be detected in any of the samples examined with the aid of the ELISA technique. The findings of this study indicate a low microbiological quality of the analyzed meatball, white cheese and ready-to-eat food samples; a considerable part of them did not conform to legal standards. However, within the sensitivity limits of the method applied no verotoxinogenic E. coli could be detected.

  5. Ecological and genetic determinants of plasmid distribution in Escherichia coli.

    Science.gov (United States)

    Medaney, Frances; Ellis, Richard J; Raymond, Ben

    2016-11-01

    Bacterial plasmids are important carriers of virulence and antibiotic resistance genes. Nevertheless, little is known of the determinants of plasmid distribution in bacterial populations. Here the factors affecting the diversity and distribution of the large plasmids of Escherichia coli were explored in cattle grazing on semi-natural grassland, a set of populations with low frequencies of antibiotic resistance genes. Critically, the population genetic structure of bacterial hosts was chararacterized. This revealed structured E. coli populations with high diversity between sites and individuals but low diversity within cattle hosts. Plasmid profiles, however, varied considerably within the same E. coli genotype. Both ecological and genetic factors affected plasmid distribution: plasmid profiles were affected by site, E. coli diversity, E. coli genotype and the presence of other large plasmids. Notably 3/26 E. coli serotypes accounted for half the observed plasmid-free isolates indicating that within species variation can substantially affect carriage of the major conjugative plasmids. The observed population structure suggest that most of the opportunities for within species plasmid transfer occur between different individuals of the same genotype and support recent experimental work indicating that plasmid-host coevolution, and epistatic interactions on fitness costs are likely to be important in determining occupancy. © 2016 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  6. Anti E. coli Activity of Herbal Medicines: a Review

    Directory of Open Access Journals (Sweden)

    Nahid Rezaei

    2017-12-01

    Full Text Available Escherichia coli is the gram negative bacilli of Entrobacteriaceae family that commonly found in intestinal infections and many infections outside the intestine, like urinary tract infections (UTI, cholecystitis, wound infections, meningitis, septicemia, pulmonary infections, and many more. Plants are rich sources of bioactive compounds, hence they can be effective in a wide variety of diseases. The pandemic spread of multidrug-resistant (MDR bacteria (i.e., extended-spectrum b-lactamase-producing Enterobacteriaceae (ESBLPE, Carbapenemase-producing Enterobacteriaceae (CPE threaten healthcare Worldwide. The present review is a report of the most effective medicinal plants against E. coli. In this research, the required online database searches were conducted using the key words such as bacteria, E. coli and medicinal plants. Databases of Web of Science, PubMed, Scopus, Google Scholar, and ScienceDirect were explored to find and explore related articles. Since the incidence of E. coli is high, the aim of this study is to identify and report anti E. coli medicinal plants in Iran. The obtained results showed that there were 51 medicinal herbs that could be considered as the main medicinal plants capable of affecting E. coli.

  7. Antibiotic resistance of Verotoxigenic Escherichia coli isolated from vegetables

    Directory of Open Access Journals (Sweden)

    mojtaba boniadian

    2017-01-01

    Full Text Available Introduction: Human gastrointestinal disease caused by verotoxigenic Escherichia coli has been diagnosed for recent decades. Escherichia coli O157:H7 is the most important serotype of verotoxigenic Escherichia coli that cause hemolytic uremic syndrome and hemorrhagic colitis in humans. This study was conducted to determine the occurrence of verotoxigenic E. coli and antibiotic resistance of the isolates from vegetables. Materials and methods: A total of 500 fresh vegetable samples were collected randomly from retail shops in Shahrekord, Iran. E. coli was isolated and identified using bacteriological and biochemical tests. PCR method was used to identify the rbfE, stx1, stx2 and eae genes. Also, antibiotic resistance of the isolates was determined by disk diffusion method. Results: The results represented that among 25 isolates possess virulence genes, 40, 12 and 4% of the isolates contained eaeA, STx2, and both genes, respectively. But none of them contained H7, STx1, and rfbE genes. The antibiotic resistance pattern demonstrated that the isolates were highly resistant to Gentamycin and cefotoxime. Discussion and conclusion: The results of this study showed that the presence of verotoxigenic E.coli in vegetables; and high resistance of the isolates to antibiotics could be hazardous for public health.

  8. Distribution of Diverse Escherichia coli between Cattle and Pasture.

    Science.gov (United States)

    NandaKafle, Gitanjali; Seale, Tarren; Flint, Toby; Nepal, Madhav; Venter, Stephanus N; Brözel, Volker S

    2017-09-27

    Escherichia coli is widely considered to not survive for extended periods outside the intestines of warm-blooded animals; however, recent studies demonstrated that E. coli strains maintain populations in soil and water without any known fecal contamination. The objective of this study was to investigate whether the niche partitioning of E. coli occurs between cattle and their pasture. We attempted to clarify whether E. coli from bovine feces differs phenotypically and genotypically from isolates maintaining a population in pasture soil over winter. Soil, bovine fecal, and run-off samples were collected before and after the introduction of cattle to the pasture. Isolates (363) were genotyped by uidA and mutS sequences and phylogrouping, and evaluated for curli formation (Rough, Dry, And Red, or RDAR). Three types of clusters emerged, viz. bovine-associated, clusters devoid of cattle isolates and representing isolates endemic to the pasture environment, and clusters with both. All isolates clustered with strains of E. coli sensu stricto, distinct from the cryptic species Clades I, III, IV, and V. Pasture soil endemic and bovine fecal populations had very different phylogroup distributions, indicating niche partitioning. The soil endemic population was largely comprised of phylogroup B1 and had a higher average RDAR score than other isolates. These results indicate the existence of environmental E. coli strains that are phylogenetically distinct from bovine fecal isolates, and that have the ability to maintain populations in the soil environment.

  9. Control de la antibióticorresistencia en Escherichia coli : Enfoque farmacológico en el sistema animal-ambiente-hombre

    OpenAIRE

    Marchetti, María Laura

    2013-01-01

    El objetivo central del presente trabajo de Tesis Doctoral fue restablecer in vitro la susceptibilidad antimicrobiana de cepas comensales de Escherichia coli (con fenotipo multirresistente-MDR-) aisladas de explotaciones pecuarias, mediante la asociación de diferentes antimicrobianos con el inhibidor de bombas de eflujo 1-(1-naphthylmethyl)-piperazine (NMP). De esta manera, se pretende contribuir al desarrollo de planes de dosificación de máxima eficacia antimicrobiana minimizando ...

  10. Atmospheres of central stars

    International Nuclear Information System (INIS)

    Hummer, D.G.

    1978-01-01

    The author presents a brief summary of atmospheric models that are of possible relevance to the central stars of planetary nebulae, and then discusses the extent to which these models accord with the observations of both nebulae and central stars. Particular attention is given to the significance of the very high Zanstra temperature implied by the nebulae He II lambda 4686 A line, and to the discrepancy between the Zanstra He II temperature and the considerably lower temperatures suggested by the appearance of the visual spectrum for some of these objects. (Auth.)

  11. Central Bank independence

    Directory of Open Access Journals (Sweden)

    Vasile DEDU

    2012-08-01

    Full Text Available In this paper we present the key aspects regarding central bank’s independence. Most economists consider that the factor which positively influences the efficiency of monetary policy measures is the high independence of the central bank. We determined that the National Bank of Romania (NBR has a high degree of independence. NBR has both goal and instrument independence. We also consider that the hike of NBR’s independence played an important role in the significant disinflation process, as headline inflation dropped inside the targeted band of 3% ± 1 percentage point recently.

  12. Several Centuries of Centrality

    OpenAIRE

    Dana L. Roth

    2015-01-01

    As Carolyn Bertozzi mentioned in her inaugural editorial, the relationship of “Central Science” to “Chemistry” became popularized over 40 years ago with the publication of the first edition of Brown and LeMay’s Chemistry: The Central Science, now in its 13th edition. Yet as late as 2003, Prof. Sason Shaik at The Hebrew University claimed “popularization of chemistry remains scant.” He goes on to share [his] “own experience of popularizing chemistry by delivering the following universal messag...

  13. Central Venous Access

    International Nuclear Information System (INIS)

    Ganeshan, Arul; Warakaulle, Dinuke R.; Uberoi, Raman

    2007-01-01

    Central venous access plays an important role in the management of an ever-increasing population of patients ranging from those that are critically ill to patients with difficult clinical access. Interventional radiologists are key in delivering this service and should be familiar with the wide range of techniques and catheters now available to them. A comprehensive description of these catheters with regard to indications, technical aspects of catheterization, success rates, and associated early and late complications, as well as a review of various published guidelines on central venous catheter insertion are given in this article

  14. Centralized mouse repositories.

    Science.gov (United States)

    Donahue, Leah Rae; Hrabe de Angelis, Martin; Hagn, Michael; Franklin, Craig; Lloyd, K C Kent; Magnuson, Terry; McKerlie, Colin; Nakagata, Naomi; Obata, Yuichi; Read, Stuart; Wurst, Wolfgang; Hörlein, Andreas; Davisson, Muriel T

    2012-10-01

    Because the mouse is used so widely for biomedical research and the number of mouse models being generated is increasing rapidly, centralized repositories are essential if the valuable mouse strains and models that have been developed are to be securely preserved and fully exploited. Ensuring the ongoing availability of these mouse strains preserves the investment made in creating and characterizing them and creates a global resource of enormous value. The establishment of centralized mouse repositories around the world for distributing and archiving these resources has provided critical access to and preservation of these strains. This article describes the common and specialized activities provided by major mouse repositories around the world.

  15. Aggregation of topological motifs in the Escherichia coli transcriptional regulatory network

    Directory of Open Access Journals (Sweden)

    Barabási Albert-László

    2004-01-01

    Full Text Available Abstract Background Transcriptional regulation of cellular functions is carried out through a complex network of interactions among transcription factors and the promoter regions of genes and operons regulated by them.To better understand the system-level function of such networks simplification of their architecture was previously achieved by identifying the motifs present in the network, which are small, overrepresented, topologically distinct regulatory interaction patterns (subgraphs. However, the interaction of such motifs with each other, and their form of integration into the full network has not been previously examined. Results By studying the transcriptional regulatory network of the bacterium, Escherichia coli, we demonstrate that the two previously identified motif types in the network (i.e., feed-forward loops and bi-fan motifs do not exist in isolation, but rather aggregate into homologous motif clusters that largely overlap with known biological functions. Moreover, these clusters further coalesce into a supercluster, thus establishing distinct topological hierarchies that show global statistical properties similar to the whole network. Targeted removal of motif links disintegrates the network into small, isolated clusters, while random disruptions of equal number of links do not cause such an effect. Conclusion Individual motifs aggregate into homologous motif clusters and a supercluster forming the backbone of the E. coli transcriptional regulatory network and play a central role in defining its global topological organization.

  16. Hydrogen production and metabolic flux analysis of metabolically engineered Escherichia coli strains

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seohyoung; Seol, Eunhee; Park, Sunghoon [Department of Chemical and Biochemical Engineering, Pusan National University, Busan 609-735 (Korea); Oh, You-Kwan [Bioenergy Research Center, Korea Institute of Energy Research, Daejeon 305-543 (Korea); Wang, G.Y. [Department of Oceanography, University of Hawaii at Manoa Honolulu, HI 96822 (United States)

    2009-09-15

    Escherichia coli can produce H{sub 2} from glucose via formate hydrogen lyase (FHL). In order to improve the H{sub 2} production rate and yield, metabolically engineered E. coli strains, which included pathway alterations in their H{sub 2} production and central carbon metabolism, were developed and characterized by batch experiments and metabolic flux analysis. Deletion of hycA, a negative regulator for FHL, resulted in twofold increase of FHL activity. Deletion of two uptake hydrogenases (1 (hya) and hydrogenase 2 (hyb)) increased H{sub 2} production yield from 1.20 mol/mol glucose to 1.48 mol/mol glucose. Deletion of lactate dehydrogenase (ldhA) and fumarate reductase (frdAB) further improved the H{sub 2} yield; 1.80 mol/mol glucose under high H{sub 2} pressure or 2.11 mol/mol glucose under reduced H{sub 2} pressure. Several batch experiments at varying concentrations of glucose (2.5-10 g/L) and yeast extract (0.3 or 3.0 g/L) were conducted for the strain containing all these genetic alternations, and their carbon and energy balances were analyzed. The metabolic flux analysis revealed that deletion of ldhA and frdAB directed most of the carbons from glucose to the glycolytic pathway leading to H{sub 2} production by FHL, not to the pentose phosphate pathway. (author)

  17. Inactivation of Escherichia coli in water by pulsed dielectric barrier discharge in coaxial reactor.

    Science.gov (United States)

    Hernández-Arias, A N; Rodríguez-Méndez, B G; López-Callejas, R; Alcántara-Díaz, D; Valencia-Alvarado, R; Mercado-Cabrera, A; Peña-Eguiluz, R; Muñoz-Castro, A E; Barocio, S R; de la Piedad-Beneitez, A

    2012-09-01

    An experimental study of ATCC (American Type Culture Collection) 8739 Escherichia coli bacteria inactivation in water by means of pulsed dielectric barrier discharge (PDBD) atmospheric pressure plasmas is presented. Plasma is generated by an adjustable power source capable of supplying high voltage 25 kV pulses, ∼30 μs long and at a 500 Hz frequency. The process was conducted in a ∼152 cm(3) cylindrical stainless steel coaxial reactor, endowed with a straight central electrode and a gas inlet. The bacterial concentration in water was varied from 10(3) up to 10(8) E. coli cells per millilitre. The inactivation was achieved without gas flow in the order of 82% at 10(8) colony-forming units per millilitre (CFU mL(-1)) concentrations in 600 s. In addition, oxygen was added to the gas supply in order to increase the ozone content in the process, raising the inactivation percentage to the order of 90% in the same treatment time. In order to reach a higher efficiency however, oxygen injection modulation is applied, leading to inactivation percentages above 99.99%. These results are similarly valid for lower bacterial concentrations.

  18. Neutral forces acting on intragenomic variability shape the Escherichia coli regulatory network topology.

    Science.gov (United States)

    Ruths, Troy; Nakhleh, Luay

    2013-05-07

    Cis-regulatory networks (CRNs) play a central role in cellular decision making. Like every other biological system, CRNs undergo evolution, which shapes their properties by a combination of adaptive and nonadaptive evolutionary forces. Teasing apart these forces is an important step toward functional analyses of the different components of CRNs, designing regulatory perturbation experiments, and constructing synthetic networks. Although tests of neutrality and selection based on molecular sequence data exist, no such tests are currently available based on CRNs. In this work, we present a unique genotype model of CRNs that is grounded in a genomic context and demonstrate its use in identifying portions of the CRN with properties explainable by neutral evolutionary forces at the system, subsystem, and operon levels. We leverage our model against experimentally derived data from Escherichia coli. The results of this analysis show statistically significant and substantial neutral trends in properties previously identified as adaptive in origin--degree distribution, clustering coefficient, and motifs--within the E. coli CRN. Our model captures the tightly coupled genome-interactome of an organism and enables analyses of how evolutionary events acting at the genome level, such as mutation, and at the population level, such as genetic drift, give rise to neutral patterns that we can quantify in CRNs.

  19. Nutrient transitions are a source of persisters in Escherichia coli biofilms.

    Directory of Open Access Journals (Sweden)

    Stephanie M Amato

    Full Text Available Chronic and recurrent infections have been attributed to persisters in biofilms, and despite this importance, the mechanisms of persister formation in biofilms remain unclear. The plethora of biofilm characteristics that could give rise to persisters, including slower growth, quorum signaling, oxidative stress, and nutrient heterogeneity, have complicated efforts to delineate formation pathways that generate persisters during biofilm development. Here we sought to specifically determine whether nutrient transitions, which are a common metabolic stress encountered within surface-attached communities, stimulate persister formation in biofilms and if so, to then identify the pathway. To accomplish this, we established an experimental methodology where nutrient availability to biofilm cells could be controlled exogenously, and then used that method to discover that diauxic carbon source transitions stimulated persister formation in Escherichia coli biofilms. Previously, we found that carbon source transitions stimulate persister formation in planktonic E. coli cultures, through a pathway that involved ppGpp and nucleoid-associated proteins, and therefore, tested the functionality of that pathway in biofilms. Biofilm persister formation was also found to be dependent on ppGpp and nucleoid-associated proteins, but the importance of specific proteins and enzymes between biofilm and planktonic lifestyles was significantly different. Data presented here support the increasingly appreciated role of ppGpp as a central mediator of bacterial persistence and demonstrate that nutrient transitions can be a source of persisters in biofilms.

  20. Nutrient transitions are a source of persisters in Escherichia coli biofilms.

    Science.gov (United States)

    Amato, Stephanie M; Brynildsen, Mark P

    2014-01-01

    Chronic and recurrent infections have been attributed to persisters in biofilms, and despite this importance, the mechanisms of persister formation in biofilms remain unclear. The plethora of biofilm characteristics that could give rise to persisters, including slower growth, quorum signaling, oxidative stress, and nutrient heterogeneity, have complicated efforts to delineate formation pathways that generate persisters during biofilm development. Here we sought to specifically determine whether nutrient transitions, which are a common metabolic stress encountered within surface-attached communities, stimulate persister formation in biofilms and if so, to then identify the pathway. To accomplish this, we established an experimental methodology where nutrient availability to biofilm cells could be controlled exogenously, and then used that method to discover that diauxic carbon source transitions stimulated persister formation in Escherichia coli biofilms. Previously, we found that carbon source transitions stimulate persister formation in planktonic E. coli cultures, through a pathway that involved ppGpp and nucleoid-associated proteins, and therefore, tested the functionality of that pathway in biofilms. Biofilm persister formation was also found to be dependent on ppGpp and nucleoid-associated proteins, but the importance of specific proteins and enzymes between biofilm and planktonic lifestyles was significantly different. Data presented here support the increasingly appreciated role of ppGpp as a central mediator of bacterial persistence and demonstrate that nutrient transitions can be a source of persisters in biofilms.

  1. Tiamulin resistance mutations in Escherichia coli.

    Science.gov (United States)

    Böck, A; Turnowsky, F; Högenauer, G

    1982-01-01

    Forty "two-step" and 13 "three-step" tiamulin-resistant mutants of Escherichia coli PR11 were isolated and tested for alteration of ribosomal proteins. Mutants with altered ribosomal proteins S10, S19, L3, and L4 were detected. The S19, L3, and L4 mutants were studied in detail. The L3 and L4 mutations did not segregate from the resistance character in transductional crosses and therefore seem to be responsible for the resistance. Extracts of these mutants also exhibited an increased in vitro resistance to tiamulin in the polyuridylic acid and phage R17 RNA-dependent polypeptide synthesis systems, and it was demonstrated that this was a property of the 50S subunit. In the case of the S19 mutant, genetic analysis showed segregation between resistance and the S19 alteration and therefore indicated that mutation of a protein other than S19 was responsible for the resistance phenotype. The isolated ribosomes of the S19, L3, and L4 mutants bound radioactive tiamulin with a considerably reduced strength when compared with those of wild-type cells. The association constants were lower by factors ranging from approximately 20 to 200. When heated in the presence of ammonium chloride, these ribosomes partially regained their avidity for tiamulin. Images PMID:7050084

  2. Mutagenic DNA repair in Escherichia coli. VII

    International Nuclear Information System (INIS)

    Bridges, B.A.; Mottershead, R.P.

    1978-01-01

    Incubation of E. coli WP2 in the presence of chloramphenicol (CAP) for 90 min before and 60 min after γ-irradiation had no effect on the induction of Trp + mutations. Bacteria that had been treated with CAP for 90 min prior to UV irradiation showed normal or near normal yields of induced mutations to streptomycin or colicin E2 resistance. Most of these mutations lost their photoreversibility (indicating 'fixation') during continued incubation with CAP for a further 60 min after irradiation, during which time neither protein nor DNA synthesis was detectable. It is suggested that CAP-sensitive protein synthesis is not required for mutagenic (error-prone) repair of lesions in pre-existing DNA, arguing against an inducible component in this repair. In contrast the frequency of UV-induced mutations to Trp + (largely at suppressor loci) was drastically reduced by CAP pretreatment, confirming the need for an active replication fork for UV-mutagenesis at these loci. It is known from the work of others that CAP given after UV abolishes mutagenesis at these loci. It is concluded that CAP-sensitive protein synthesis (consistent with a requirement for an inducible function) is necessary for mutagenic repair only in newly-replicated DNA (presumably at daughter strand gaps) and not in pre-existing DNA. The data are consistent with but do not prove the hypothesis that CAP-sensitive and insensitive modes of mutagenesis reflect minor differences in the operation of a single basic mutagenic repair system. (Auth.)

  3. Immunopurification of adenomatous polyposis coli (APC) proteins

    Science.gov (United States)

    2013-01-01

    Background The adenomatous polyposis coli (APC) tumour suppressor gene encodes a 2843 residue (310 kDa) protein. APC is a multifunctional protein involved in the regulation of β-catenin/Wnt signalling, cytoskeletal dynamics and cell adhesion. APC mutations occur in most colorectal cancers and typically result in truncation of the C-terminal half of the protein. Results In order to investigate the biophysical properties of APC, we have generated a set of monoclonal antibodies which enable purification of recombinant forms of APC. Here we describe the characterisation of these anti-APC monoclonal antibodies (APC-NT) that specifically recognise endogenous APC both in solution and in fixed cells. Full-length APC(1–2843) and cancer-associated, truncated APC proteins, APC(1–1638) and APC(1–1311) were produced in Sf9 insect cells. Conclusions Recombinant APC proteins were purified using a two-step affinity approach using our APC-NT antibodies. The purification of APC proteins provides the basis for detailed structure/function analyses of full-length, cancer-truncated and endogenous forms of the protein. PMID:24156781

  4. Treatment of inflammatory bowel disease associated E. coli with ciprofloxacin and E. coli Nissle in the streptomycin-treated mouse intestine

    DEFF Research Database (Denmark)

    Petersen, Andreas Munk; Schjørring, Susanne; Gerstrøm, Sarah Choi

    2011-01-01

    E. coli belonging to the phylogenetic group B2 are linked to Inflammatory Bowel Disease (IBD). Studies have shown that antimicrobials have some effect in the treatment of IBD, and it has been demonstrated that E. coli Nissle has prophylactic abilities comparable to 5-aminosalicylic acid (5-ASA......) therapy in ulcerative colitis. The objective of this study was to test if ciprofloxacin and/or E. coli Nissle could eradicate IBD associated E. coli in the streptomycin-treated mouse intestine....

  5. Production and Purification Immunoglobulin against E. coli in Egg Yolk

    Directory of Open Access Journals (Sweden)

    Mohammadreza Nassiri

    2016-08-01

    Full Text Available Introduction Chicken is the only avian species in which polyclonal antibodies, like IgG is transported from the hen to the egg yolk in a similar manner as the transport of mammalian IgG from the mother to the fetus. Immunoglobulin Y in the chicken is transported to the egg and accumulates in the egg yolk in large quantities. IgY is an egg yolk antibody that has been used widely for treatment and prevention of infections in humans and animal. IgY is used for passive protection of the pathogen infections such as Escherichia coli, bovine and human rotavirus, bovine coronavirus, salmonella, staphylococcus and Pseudomonas. IgY is a promising candidate as an alternative to antibiotics. Eschericha coli strains of serotype O157: H7 belongs to a family of pathogenic E. coli called enterohemorrhagic E. coli (EHEC strains responsible for hemorrhagic colitis, bloody or non-bloody diarrhea, and hemolytic uremic syndrome in humans. This strain of E. coli pathogenises by adhering to host intestinal epithelium and forming bacterial colonies. The purpose of this study was to produce and purify immunoglobulin Y against E. coli O157:H7 and develop specific polyclonal anti E. coli antibody in the egg yolk. Materials and Methods Sixteen-week-old laying hens (Mashhad, Iran were kept in individual cages with food and water ad libitum. Immunization of hens was performed by intramuscularly injecting killed E. coli O157: H7 with an equal volume of Freund’s complete adjuvant into two sides of chest area (Sigma, USA for the first immunization. Two booster immunizations followed up using complete and incomplete Freund’s adjuvants in two weeks interval. Freund’s adjuvant without antigen was injected to the control group. Two weeks after the last injection, the eggs were collected daily for eight weeks, marked and stored at 4 ºC. In order to IgY purification, eggs were collected. Purification of IgY from egg yolk was based on Polson and using PEG6000. Finally, the

  6. Centralized vs. de-centralized multinationals and taxes

    OpenAIRE

    Nielsen, Søren Bo; Raimondos-Møller, Pascalis; Schjelderup, Guttorm

    2005-01-01

    The paper examines how country tax differences affect a multinational enterprise's choice to centralize or de-centralize its decision structure. Within a simple model that emphasizes the multiple conflicting roles of transfer prices in MNEs – here, as a strategic pre-commitment device and a tax manipulation instrument –, we show that (de-)centralized decisions are more profitable when tax differentials are (small) large. Keywords: Centralized vs. de-centralized decisions, taxes, MNEs. ...

  7. Modeling the inactivation of Escherichia coli 0157:H7 and uropathogenic E.coli in ground chicken by high pressure processing and thymol

    Science.gov (United States)

    Disease causing Escherichia coli commonly found in meat and poultry include intestinal pathogenic E. coli (iPEC) as well as extraintestinal types such as the Uropathogenic E. coli (UPEC). In this study we compare the resistance of iPEC (O157:H7) to UPEC in chicken meat using High Pressure Processing...

  8. Lethality prediction for Escherichia coli 0157:H7 and Uropathogenic E. coli in ground chicken treated with high pressure processing and trans-cinnamaldehyde

    Science.gov (United States)

    Pathogenic Escherichia coli, intestinal (O157:H7) as well as extraintestinal types (Uropathogenic E. coli (UPEC)) are commonly found in many foods including chicken meat. In this study we compared the resistance of E. coli O157:H7 to UPEC in chicken meat under the stresses of high hydrostatic pressu...

  9. Modeling the inactivatin of Escherichia coli 0157:H7 and uropathogenic E. coli in ground beef by high pressure processing and citral

    Science.gov (United States)

    Disease causing Escherichia coli commonly found in meat and poultry include intestinal pathogenic E. coli (iPEC) as well as extraintestinal types such as the Uropathogenic E. coli (UPEC). In this study we compared the resistance of iPEC (O157:H7) to UPEC in ground beef using High Pressure Processing...

  10. Central Dogma Goes Digital.

    Science.gov (United States)

    Lin, Yihan; Elowitz, Michael B

    2016-03-17

    In this issue of Molecular Cell, Tay and colleagues (Albayrak et al., 2016) describe a new technique to digitally quantify the numbers of protein and mRNA in the same mammalian cell, providing a new way to look at the central dogma of molecular biology. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Channeling the Central Dogma.

    Science.gov (United States)

    Calabrese, Ronald L

    2014-05-21

    How do neurons and networks achieve their characteristic electrical activity, regulate this activity homeostatically, and yet show population variability in expression? In this issue of Neuron, O'Leary et al. (2014) address some of these thorny questions in this theoretical analysis that starts with the Central Dogma. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. CMS Central Hadron Calorimeter

    OpenAIRE

    Budd, Howard S.

    2001-01-01

    We present a description of the CMS central hadron calorimeter. We describe the production of the 1996 CMS hadron testbeam module. We show the results of the quality control tests of the testbeam module. We present some results of the 1995 CMS hadron testbeam.

  13. Ecodesign in Central America

    NARCIS (Netherlands)

    Crul, M.R.M.

    2003-01-01

    This PhD thesis describes and analyses the change process started by the Ecodesign project in Central America, executed between 1998 and 2002. The project started using the concept and praxis developed in Europe. Nine ecodesign projects were performed in industry, and ecodesign was introduced to

  14. NCEP Central Operations

    Science.gov (United States)

    ) NCO Organizational Chart NOAA's Weather and Climate Operational Supercomputing System is known as Climate Climate Prediction Climate Archives Weather Safety Storm Ready NOAA Central Library Photo Library NCO's MISSION * Execute the NCEP operational model suite - Create climate, weather, ocean, space and

  15. Central oxygen pipeline failure

    African Journals Online (AJOL)

    surgical intensive care unit (ICU), with two patients on full ventilation and ... uncertainty around the cause of the failure and the restoration, .... soon as its level also falls below three tons. Should ... (properly checked and closed prior to each anaesthetic). ... in use at the time of the central oxygen pipeline failure at Tygerberg.

  16. Central American Climatology

    Science.gov (United States)

    1985-04-01

    Central America, as where mean temperatures are relatively warm throughout the year de- so spite seasonal rainfall changes. 75 Elevation, solar angle...November 1982 Control Hidalgo Anos.1952-1963, Republica de Nicaragua, Ministerio de Formento Y O0.PP, Comision Nacional de Energia . Craig, Richard A., The

  17. Occurrence and characterization of Shiga toxin-producing Escherichia coli O157:H7 and other non-sorbitol-fermenting E. coli in cattle and humans in urban areas of Morogoro, Tanzania

    DEFF Research Database (Denmark)

    Lupindu, Athumani M; Olsen, John Elmerdahl; Ngowi, Helena A

    2014-01-01

    Escherichia coli strains such as Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli, enterotoxigenic, attaching, and effacing E. coli, and enteroinvasive E. coli cause diarrhea in humans. Although other serotypes exist, the most commonly reported STEC in outbreaks is O157:H7. A cross-...

  18. Structures of the E. coli translating ribosome with SRP and its receptor and with the translocon.

    Science.gov (United States)

    Jomaa, Ahmad; Boehringer, Daniel; Leibundgut, Marc; Ban, Nenad

    2016-01-25

    Co-translational protein targeting to membranes is a universally conserved process. Central steps include cargo recognition by the signal recognition particle and handover to the Sec translocon. Here we present snapshots of key co-translational-targeting complexes solved by cryo-electron microscopy at near-atomic resolution, establishing the molecular contacts between the Escherichia coli translating ribosome, the signal recognition particle and the translocon. Our results reveal the conformational changes that regulate the latching of the signal sequence, the release of the heterodimeric domains of the signal recognition particle and its receptor, and the handover of the signal sequence to the translocon. We also observe that the signal recognition particle and the translocon insert-specific structural elements into the ribosomal tunnel to remodel it, possibly to sense nascent chains. Our work provides structural evidence for a conformational state of the signal recognition particle and its receptor primed for translocon binding to the ribosome-nascent chain complex.

  19. Efficient Production of γ-GABA Using Recombinant E. coli Expressing Glutamate Decarboxylase (GAD) Derived from Eukaryote Saccharomyces cerevisiae.

    Science.gov (United States)

    Xiong, Qiang; Xu, Zheng; Xu, Lu; Yao, Zhong; Li, Sha; Xu, Hong

    2017-12-01

    γ-Aminobutyric acid (γ-GABA) is a non-proteinogenic amino acid, which acts as a major regulator in the central nervous system. Glutamate decarboxylase (namely GAD, EC 4.1.1.15) is known to be an ideal enzyme for γ-GABA production using L-glutamic acid as substrate. In this study, we cloned and expressed GAD gene from eukaryote Saccharomyces cerevisiae (ScGAD) in E. coli BL21(DE3). This enzyme was further purified and its optimal reaction temperature and pH were 37 °C and pH 4.2, respectively. The cofactor of ScGAD was verified to be either pyridoxal 5'-phosphate (PLP) or pyridoxal hydrochloride. The optimal concentration of either cofactor was 50 mg/L. The optimal medium for E. coli-ScGAD cultivation and expression were 10 g/L lactose, 5 g/L glycerol, 20 g/L yeast extract, and 10 g/L sodium chloride, resulting in an activity of 55 U/mL medium, three times higher than that of using Luria-Bertani (LB) medium. The maximal concentration of γ-GABA was 245 g/L whereas L-glutamic acid was near completely converted. These findings provided us a good example for bio-production of γ-GABA using recombinant E. coli expressing a GAD enzyme derived from eukaryote.

  20. The first 30 years of Shiga toxin-producing Escherichia coli in cattle production: Incidence, preharvest ecology, and management

    Science.gov (United States)

    Of the 700 serotypes of Escherichia coli, most are commensal; however, some range from mildly to highly pathogenic and can cause death. The disease-causing enterovirulent E. coli are classified as: Enterotoxigenic E. coli (ETEC), Enteropathogenic E. coli (EPEC), Enteroinvasive E. coli (EIEC), and ...

  1. Reduction of verotoxigenic Escherichia coli in production of fermented sausages.

    Science.gov (United States)

    Holck, Askild L; Axelsson, Lars; Rode, Tone Mari; Høy, Martin; Måge, Ingrid; Alvseike, Ole; L'abée-Lund, Trine M; Omer, Mohamed K; Granum, Per Einar; Heir, Even

    2011-11-01

    After a number of foodborne outbreaks of verotoxigenic Escherichia coli involving fermented sausages, some countries have imposed regulations on sausage production. For example, the US Food Safety and Inspection Service requires a 5 log(10) reduction of E. coli in fermented products. Such regulations have led to a number of studies on the inactivation of E. coli in fermented sausages by changing processing and post-processing conditions. Several factors influence the survival of E. coli such as pre-treatment of the meat, amount of NaCl, nitrite and lactic acid, water activity, pH, choice of starter cultures and addition of antimicrobial compounds. Also process variables like fermentation temperature and storage time play important roles. Though a large variety of different production processes of sausages exist, generally the reduction of E. coli caused by production is in the range 1-2 log(10). In many cases this may not be enough to ensure microbial food safety. By optimising ingredients and process parameters it is possible to increase E. coli reduction to some extent, but in some cases still other post process treatments may be required. Such treatments may be storage at ambient temperatures, specific heat treatments, high pressure processing or irradiation. HACCP analyses have identified the quality of the raw materials, low temperature in the batter when preparing the sausages and a rapid pH drop during fermentation as critical control points in sausage production. This review summarises the literature on the reduction verotoxigenic E. coli in production of fermented sausages. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Toxicity mechanism of carbon nanotubes on Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Young, Yu-Fu [Department of Materials Science and Engineering, National Tsing-Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Lee, Hui-Ju [Department of Life Science, National Tsing-Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Shen, Yi-Shan; Tseng, Shih-Hao; Lee, Chi-Young [Department of Materials Science and Engineering, National Tsing-Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Tai, Nyan-Hwa, E-mail: nhtai@mx.nthu.edu.tw [Department of Materials Science and Engineering, National Tsing-Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China); Chang, Hwan-You, E-mail: hychang@mx.nthu.edu.tw [Department of Life Science, National Tsing-Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan (China)

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer F-MWCNTs possess higher antibiotic performance than that of the F-SWCNTs. Black-Right-Pointing-Pointer E. coli cells were pierced when incubated with F-MWCNTs and trapped when incubated with F-SWCNTs. Black-Right-Pointing-Pointer The rigidity and moment of CNTs play important role on the antibiotic effect. - Abstract: The influences of carbon nanomaterials on bacteria were investigated using three types of dispersed and functionalized carbon nanomaterials (F-CNMs), viz. functionalized carbon nanopowder (F-CNP), functionalized single-walled carbon nanotubes (F-SWCNTs), and functionalized multi-walled carbon nanotubes (F-MWCNTs). F-CNMs with different aspect ratios were used to study the influence of material configuration on the viability of Escherichia coli (E. coli). Although these materials were functionalized to improve their dispersibility, the original morphologies and chemical properties of the materials were maintained. Traditional bacteria quantitative plating analysis was conducted, and the results of which revealed that the F-CNP and the F-SWCNTs showed a less significant effect on the viability of E. coli, while the F-MWCNTs obviously inhibited cell viability. A Fourier transform infrared spectroscopy and a scanning electron microscopy were used to verify the functionalization of the F-CNMs and to examine the interaction of F-CNMs with E. coli, respectively; in addition, we adopted chemiluminescence assays to measure the concentration of adenosine triphosphate (ATP) released from the damaged cells. The results showed that the ATP of the F-MWCNTs sample is two-fold higher than that of the control, indicating direct piercing of E. coli by F-MWCNTs leads to bacteria death. Furthermore, F-SWCNTs were concluded to have less influence on the viability of E. coli because ultra-long F-SWCNTs used in this study performed less rigidity to pierce the cells.

  3. Toxicity mechanism of carbon nanotubes on Escherichia coli

    International Nuclear Information System (INIS)

    Young, Yu-Fu; Lee, Hui-Ju; Shen, Yi-Shan; Tseng, Shih-Hao; Lee, Chi-Young; Tai, Nyan-Hwa; Chang, Hwan-You

    2012-01-01

    Highlights: ► F-MWCNTs possess higher antibiotic performance than that of the F-SWCNTs. ► E. coli cells were pierced when incubated with F-MWCNTs and trapped when incubated with F-SWCNTs. ► The rigidity and moment of CNTs play important role on the antibiotic effect. - Abstract: The influences of carbon nanomaterials on bacteria were investigated using three types of dispersed and functionalized carbon nanomaterials (F-CNMs), viz. functionalized carbon nanopowder (F-CNP), functionalized single-walled carbon nanotubes (F-SWCNTs), and functionalized multi-walled carbon nanotubes (F-MWCNTs). F-CNMs with different aspect ratios were used to study the influence of material configuration on the viability of Escherichia coli (E. coli). Although these materials were functionalized to improve their dispersibility, the original morphologies and chemical properties of the materials were maintained. Traditional bacteria quantitative plating analysis was conducted, and the results of which revealed that the F-CNP and the F-SWCNTs showed a less significant effect on the viability of E. coli, while the F-MWCNTs obviously inhibited cell viability. A Fourier transform infrared spectroscopy and a scanning electron microscopy were used to verify the functionalization of the F-CNMs and to examine the interaction of F-CNMs with E. coli, respectively; in addition, we adopted chemiluminescence assays to measure the concentration of adenosine triphosphate (ATP) released from the damaged cells. The results showed that the ATP of the F-MWCNTs sample is two-fold higher than that of the control, indicating direct piercing of E. coli by F-MWCNTs leads to bacteria death. Furthermore, F-SWCNTs were concluded to have less influence on the viability of E. coli because ultra-long F-SWCNTs used in this study performed less rigidity to pierce the cells.

  4. Vegetated treatment area (VTAs efficiencies for E. coli and nutrient removal on small-scale swine operations

    Directory of Open Access Journals (Sweden)

    R. Daren Harmel

    2018-06-01

    Full Text Available As small-scale animal feeding operations work to manage their byproducts and avoid regulation, they need practical, cost-effective methods to reduce environmental impact. One such option is using vegetative treatment areas (VTAs with perennial grasses to treat runoff; however, research is limited on VTA effectiveness as a waste management alternative for smaller operations. This study evaluated the efficiencies of VTAs in reducing bacteria and nutrient runoff from small-scale swine operations in three counties in Central Texas. Based on 4 yr of runoff data, the Bell and Brazos VTAs significantly reduced loads and concentrations of E. coli and nutrients (except NO3-N and had treatment efficiencies of 73–94%. Most notably, the Bell VTA reduced loads of E. coli, NH4-N, PO4-P, total N, and total P similar to that of the background (control. In spite of significant reductions, runoff from the Brazos VTA had higher concentrations and loads than the control site, especially following installation of concrete pens and increased pen washing, which produced standing water and increased E. coli and nutrient influx. The Robertson VTA produced fewer significant reductions and had lower treatment efficiencies (29–69%; however, E. coli and nutrient concentrations and loads leaving this VTA were much lower than observed at the Bell and Brazos County sites due to alternative solids management and enclosed pens. Based on these results and previous research, VTAs can be practical, effective waste management alternatives for reducing nutrient and bacteria losses from small-scale animal operations, but only if properly designed and managed. Keywords: Bacteria, Nutrients, Swine manure, Waste management, Water quality

  5. Centrality and Creativity:

    DEFF Research Database (Denmark)

    Andersen, Kristina Vaarst; Lorenzen, Mark

    2009-01-01

    To provide new insights into urban hierarchy, this article brings together one of economic geography’s oldest and most well-established notions with one of its newest and most disputed notions: Christäller’s centrality and Florida’s creative class. Using a novel original database, the article...... compares the distribution of the general population and the creative class across 444 city regions in 8 European countries. It finds that the two groups are both distributed according to the rank-size rule, but exhibit different distinct phases with different slopes. The article argues that the two...... distributions are different because market thresholds for creative services and jobs are lower than thresholds for less specialized services and jobs. The article hence concludes that centrality exerts a strong influence upon urban hierarchies of creativity and that the study of creative urban city hierarchies...

  6. Central American Flying Weather

    Science.gov (United States)

    1985-12-01

    CEILING; VISIBILITY; WIND, PRECIPITATIDNc’--." HAZE, SMOKE, TEMPORALE ; MOUNTAIN WAVE; MILITARY METEOROLOGY. 4k- / ’A. bstract; Asummary of~ing weather...1 The " Temporale " ....................................1 Mountain Waves ......................I...............1 Severe Thunderstorms...charts. The for any part of Central America lies in having: Tactical Pilota.e Chart series , produced by the Df -.nse Mapping Agency, is * A good, basic

  7. The European Central Bank

    OpenAIRE

    Binder, Michael; Wieland, Volker

    2006-01-01

    The establishment of the ECB and with it the launch of the euro has arguably been a unique endeavor in economic history, representing an important experiment in central banking. This note aims to summarize some of the main lessons learned from this experiment and sketch some of the prospects for the ECB. It is written for "The New Palgrave Dictionary of Economics", 2nd edition. JEL Classification: E52, E58

  8. FNAL central email systems

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Jack; Lilianstrom, Al; Pasetes, Ray; Hill, Kevin; /Fermilab

    2004-10-01

    The FNAL Email System is the primary point of entry for email destined for an employee or user at Fermilab. This centrally supported system is designed for reliability and availability. It uses multiple layers of protection to help ensure that: (1) SPAM messages are tagged properly; (2) All mail is inspected for viruses; and (3) Valid mail gets delivered. This system employs numerous redundant subsystems to accomplish these tasks.

  9. Centrally Banked Cryptocurrencies

    OpenAIRE

    Danezis, George; Meiklejohn, Sarah

    2015-01-01

    Current cryptocurrencies, starting with Bitcoin, build a decentralized blockchain-based transaction ledger, maintained through proofs-of-work that also generate a monetary supply. Such decentralization has benefits, such as independence from national political control, but also significant limitations in terms of scalability and computational cost. We introduce RSCoin, a cryptocurrency framework in which central banks maintain complete control over the monetary supply, but rely on a distribut...

  10. Centrally Banked Cryptocurrencies

    OpenAIRE

    Danezis, G.; Meiklejohn, S.

    2016-01-01

    Current cryptocurrencies, starting with Bitcoin, build a decentralized blockchain-based transaction ledger, maintained through proofs-of-work that also serve to generate a monetary supply. Such decentralization has benefits, such as independence from national political control, but also significant limitations in terms of computational costs and scalability. We introduce RSCoin, a cryptocurrency framework in which central banks maintain complete control over the monetary supply, but rely on...

  11. Centralized vs decentralized contests

    OpenAIRE

    Beviá, Carmen; Corchón, Luis C.

    2015-01-01

    We compare two contests, decentralized in which there are several independent contests with non overlapping contestants and centralized in which all contestants fight for a unique prize which is the sum of all prizes in the small contests. We study the relationship between payoffs and efforts between these two contests. The first author acknowledges financial support from ECO2008-04756 (Grupo Consolidado-C), SGR2014-515 and PROMETEO/2013/037. The second author acknowledges financial suppor...

  12. Centralized versus distributed propulsion

    Science.gov (United States)

    Clark, J. P.

    1982-01-01

    The functions and requirements of auxiliary propulsion systems are reviewed. None of the three major tasks (attitude control, stationkeeping, and shape control) can be performed by a collection of thrusters at a single central location. If a centralized system is defined as a collection of separated clusters, made up of the minimum number of propulsion units, then such a system can provide attitude control and stationkeeping for most vehicles. A distributed propulsion system is characterized by more numerous propulsion units in a regularly distributed arrangement. Various proposed large space systems are reviewed and it is concluded that centralized auxiliary propulsion is best suited to vehicles with a relatively rigid core. These vehicles may carry a number of flexible or movable appendages. A second group, consisting of one or more large flexible flat plates, may need distributed propulsion for shape control. There is a third group, consisting of vehicles built up from multiple shuttle launches, which may be forced into a distributed system because of the need to add additional propulsion units as the vehicles grow. The effects of distributed propulsion on a beam-like structure were examined. The deflection of the structure under both translational and rotational thrusts is shown as a function of the number of equally spaced thrusters. When two thrusters only are used it is shown that location is an important parameter. The possibility of using distributed propulsion to achieve minimum overall system weight is also examined. Finally, an examination of the active damping by distributed propulsion is described.

  13. Attachment of Escherichia coli and enterococci to particles in runoff.

    Science.gov (United States)

    Soupir, Michelle L; Mostaghimi, Saied; Dillaha, Theo

    2010-01-01

    Association of Escherichia coli and enterococci with particulates present in runoff from erodible soils has important implications for modeling the fate and transport of bacteria from agricultural sources and in the selection of management practices to reduce bacterial movement to surface waters. Three soils with different textures were collected from the Ap horizon (silty loam, silty clay loam, and loamy fine sand), placed in portable box plots, treated with standard cowpats, and placed under a rainfall simulator. Rainfall was applied to the plots until saturation-excess flow occurred for 30 min, and samples were collected 10, 20, and 30 min after initiation of the runoff event. The attachment of E. coli and enterococci to particles present in runoff was determined by a screen filtration and centrifugation procedure. Percentage of E. coli and enterococci attached to particulates in runoff ranged from 28 to 49%, with few statistically significant differences in attachment among the three soils. Similar partitioning release patterns were observed between E. coli and enterococci from the silty loam (r = 0.57) and silty clay loam soils (r = 0.60). At least 60% of all attached E. coli and enterococci were associated particles within an 8- to 62-microm particle size category. The results indicate that the majority of fecal bacteria attach to and are transported with manure colloids in sediment-laden flow regardless of the soil texture.

  14. Escherichia coli ST131, an Intriguing Clonal Group

    Science.gov (United States)

    Bertrand, Xavier; Madec, Jean-Yves

    2014-01-01

    SUMMARY In 2008, a previously unknown Escherichia coli clonal group, sequence type 131 (ST131), was identified on three continents. Today, ST131 is the predominant E. coli lineage among extraintestinal pathogenic E. coli (ExPEC) isolates worldwide. Retrospective studies have suggested that it may originally have risen to prominence as early as 2003. Unlike other classical group B2 ExPEC isolates, ST131 isolates are commonly reported to produce extended-spectrum β-lactamases, such as CTX-M-15, and almost all are resistant to fluoroquinolones. Moreover, ST131 E. coli isolates are considered to be truly pathogenic, due to the spectrum of infections they cause in both community and hospital settings and the large number of virulence-associated genes they contain. ST131 isolates therefore seem to contradict the widely held view that high levels of antimicrobial resistance are necessarily associated with a fitness cost leading to a decrease in pathogenesis. Six years after the first description of E. coli ST131, this review outlines the principal traits of ST131 clonal group isolates, based on the growing body of published data, and highlights what is currently known and what we need to find out to provide public health authorities with better information to help combat ST131. PMID:24982321

  15. Recent Advances in Understanding Enteric Pathogenic Escherichia coli

    Science.gov (United States)

    Croxen, Matthew A.; Law, Robyn J.; Scholz, Roland; Keeney, Kristie M.; Wlodarska, Marta

    2013-01-01

    SUMMARY Although Escherichia coli can be an innocuous resident of the gastrointestinal tract, it also has the pathogenic capacity to cause significant diarrheal and extraintestinal diseases. Pathogenic variants of E. coli (pathovars or pathotypes) cause much morbidity and mortality worldwide. Consequently, pathogenic E. coli is widely studied in humans, animals, food, and the environment. While there are many common features that these pathotypes employ to colonize the intestinal mucosa and cause disease, the course, onset, and complications vary significantly. Outbreaks are common in developed and developing countries, and they sometimes have fatal consequences. Many of these pathotypes are a major public health concern as they have low infectious doses and are transmitted through ubiquitous mediums, including food and water. The seriousness of pathogenic E. coli is exemplified by dedicated national and international surveillance programs that monitor and track outbreaks; unfortunately, this surveillance is often lacking in developing countries. While not all pathotypes carry the same public health profile, they all carry an enormous potential to cause disease and continue to present challenges to human health. This comprehensive review highlights recent advances in our understanding of the intestinal pathotypes of E. coli. PMID:24092857

  16. Pulsed-Plasma Disinfection of Water Containing Escherichia coli

    Science.gov (United States)

    Satoh, Kohki; MacGregor, Scott J.; Anderson, John G.; Woolsey, Gerry A.; Fouracre, R. Anthony

    2007-03-01

    The disinfection of water containing the microorganism, Escherichia coli (E. coli) by exposure to a pulsed-discharge plasma generated above the water using a multineedle electrode (plasma-exposure treatment), and by sparging the off-gas of the pulsed plasma into the water (off-gas-sparging treatment), is performed in the ambient gases of air, oxygen, and nitrogen. For the off-gas-sparging treatment, bactericidal action is observed only when oxygen is used as the ambient gas, and ozone is found to generate the bactericidal action. For the plasma-exposure treatment, the density of E. coli bacteria decreases exponentially with plasma-exposure time for all the ambient gases. It may be concluded that the main contributors to E. coli inactivation are particle species produced by the pulsed plasma. For the ambient gases of air and nitrogen, the influence of acidification of the water in the system, as a result of pulsed-plasma exposure, may also contribute to the decay of E. coli density.

  17. Inactivation and Gene Expression of a Virulent WastewaterEscherichia coliStrain and the Nonvirulent CommensalEscherichia coliDSM1103 Strain upon Solar Irradiation

    KAUST Repository

    Aljassim, Nada I.; Mantilla-Calderon, David; Wang, Tiannyu; Hong, Pei-Ying

    2017-01-01

    This study examined the decay kinetics and molecular responses of two Escherichia coli strains upon solar irradiation. The first is E. coli PI-7, a virulent and antibiotic-resistant strain that was isolated from wastewater and carries the emerging NDM-1 antibiotic resistance gene. The other strain, E. coli DSM1103, displayed lower virulence and antibiotic resistance than E. coli PI-7. In a buffer solution, E. coli PI-7 displayed a longer lag phase prior to decay and a longer half-life compared with E. coli DSM1103 (6.64 ± 0.63 h and 2.85 ± 0.46 min vs 1.33 ± 0.52 h and 2.04 ± 0.36 min). In wastewater, both E. coli strains decayed slower than they did in buffer. Although solar irradiation remained effective in reducing the numbers of both strains by more than 5-log10 in <24 h, comparative genomics and transcriptomics revealed differences in the genomes and overall regulation of genes between the two E. coli strains. A wider arsenal of genes related to oxidative stress, cellular repair and protective mechanisms were upregulated in E. coli PI-7. Subpopulations of E. coli PI-7 expressed genes related to dormancy and persister cell formation during the late decay phase, which may have accounted for its prolonged persistence. Upon prolonged solar irradiation, both E. coli strains displayed upregulation of genes related to horizontal gene transfer and antibiotic resistance. Virulence functions unique to E. coli PI-7 were also upregulated. Our findings collectively indicated that, whereas solar irradiation is able to reduce total cell numbers, viable E. coli remained and expressed genes that enable survival despite solar treatment. There remains a need for heightened levels of concern regarding risks arising from the dissemination of E. coli that may remain viable in wastewater after solar irradiation.

  18. Inactivation and Gene Expression of a Virulent WastewaterEscherichia coliStrain and the Nonvirulent CommensalEscherichia coliDSM1103 Strain upon Solar Irradiation

    KAUST Repository

    Aljassim, Nada I.

    2017-03-06

    This study examined the decay kinetics and molecular responses of two Escherichia coli strains upon solar irradiation. The first is E. coli PI-7, a virulent and antibiotic-resistant strain that was isolated from wastewater and carries the emerging NDM-1 antibiotic resistance gene. The other strain, E. coli DSM1103, displayed lower virulence and antibiotic resistance than E. coli PI-7. In a buffer solution, E. coli PI-7 displayed a longer lag phase prior to decay and a longer half-life compared with E. coli DSM1103 (6.64 ± 0.63 h and 2.85 ± 0.46 min vs 1.33 ± 0.52 h and 2.04 ± 0.36 min). In wastewater, both E. coli strains decayed slower than they did in buffer. Although solar irradiation remained effective in reducing the numbers of both strains by more than 5-log10 in <24 h, comparative genomics and transcriptomics revealed differences in the genomes and overall regulation of genes between the two E. coli strains. A wider arsenal of genes related to oxidative stress, cellular repair and protective mechanisms were upregulated in E. coli PI-7. Subpopulations of E. coli PI-7 expressed genes related to dormancy and persister cell formation during the late decay phase, which may have accounted for its prolonged persistence. Upon prolonged solar irradiation, both E. coli strains displayed upregulation of genes related to horizontal gene transfer and antibiotic resistance. Virulence functions unique to E. coli PI-7 were also upregulated. Our findings collectively indicated that, whereas solar irradiation is able to reduce total cell numbers, viable E. coli remained and expressed genes that enable survival despite solar treatment. There remains a need for heightened levels of concern regarding risks arising from the dissemination of E. coli that may remain viable in wastewater after solar irradiation.

  19. Phenotypic and molecular detection of BLACTX-M gene extended-spectrum beta-lactamases in escherichia coli and klebsiella pneumoniae of north sumatera isolates

    Science.gov (United States)

    Hasibuan, Mirzan; Suryanto, Dwi; Lia Kusumawati, R.

    2018-03-01

    The application of antibiotics expanded-spectrum third-generation cephalosporin for the treatment of infectious diseases in hospitals is known contribute to increasing resistance due to the presence of the blaCTX-M gene in the bacteria producing ESBLs. This study was aimed to detect ESBLs, isolate phenotype and blaCTX-M genes on Escherichia coli and Klebsiella pneumoniae collected from H. Adam Malik Central Hospital. Phenotypes of the bacterial were detection using Vitek two compact, while the blaCTX-M genes were detection using polymerase chain reaction technique. The results showed that 85 (100%) isolates were ESBLs consisted of 41(48%) of Escherichia coli, and 44 (52%) of Klebsiella pneumoniae, respectively. blaCTX-M genes were detection in 62 (72.94%) of the isolates which 31 (36.47%) were Escherichia coli, and 31 (36.47%) of the isolates were Klebsiella pneumoniae, respectively. This study indicates the high prevalence of blaCTX-M genes in Escherichia coli and Klebsiella pneumoniea causing bacterial antibiotic resistance.

  20. Vaccines for preventing enterotoxigenic Escherichia coli (ETEC) diarrhoea.

    Science.gov (United States)

    Ahmed, Tanvir; Bhuiyan, Taufiqur R; Zaman, K; Sinclair, David; Qadri, Firdausi

    2013-07-05

    Infection with enterotoxigenic Escherichia coli (ETEC) bacteria is a common cause of diarrhoea in adults and children in developing countries and is a major cause of 'travellers' diarrhoea' in people visiting or returning from endemic regions. A killed whole cell vaccine (Dukoral®), primarily designed and licensed to prevent cholera, has been recommended by some groups to prevent travellers' diarrhoea in people visiting endemic regions. This vaccine contains a recombinant B subunit of the cholera toxin that is antigenically similar to the heat labile toxin of ETEC. This review aims to evaluate the clinical efficacy of this vaccine and other vaccines designed specifically to protect people against diarrhoea caused by ETEC infection. To evaluate the efficacy, safety, and immunogenicity of vaccines for preventing ETEC diarrhoea. We searched the Cochrane Infectious Disease Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, LILACS, and http://clinicaltrials.gov up to December 2012. Randomized controlled trials (RCTs) and quasi-RCTs comparing use of vaccines to prevent ETEC with use of no intervention, a control vaccine (either an inert vaccine or a vaccine normally given to prevent an unrelated infection), an alternative ETEC vaccine, or a different dose or schedule of the same ETEC vaccine in healthy adults and children living in endemic regions, intending to travel to endemic regions, or volunteering to receive an artificial challenge of ETEC bacteria. Two authors independently assessed each trial for eligibility and risk of bias. Two independent reviewers extracted data from the included studies and analyzed the data using Review Manager (RevMan) software. We reported outcomes as risk ratios (RR) with 95% confidence intervals (CI). We assessed the quality of the evidence using the GRADE approach. Twenty-four RCTs, including 53,247 participants, met the inclusion criteria. Four studies assessed the protective

  1. Mechanisms of the radioprotective effect of cysteamine in Escherichia coli

    International Nuclear Information System (INIS)

    Korystov, Yu.N.; Vexler, F.B.

    1988-01-01

    The values of the oxygen effect (m) and the maximal protective effect of cysteamine (DMF*) were estimated for four Escherichia coli strains: AB1157 (wild type), AB1886 (uvrA), AB2463 (recA), and p3478 (polA). A correlation made between DMF* and m as well as the kinetics of the increase of DMF with oxygen depletion showed that the protective effect of cysteamine is realized by three mechanisms: (i) anoxia achieved by oxygen reduction, with the DMF varying from 2.2 to 4.2 for different E. coli strains (this protection is the major contribution to the entire mechanism); (ii) lowering of the indirect radiation effect; i.e., for 50 mM cysteamine DMF does not exceed 1.1; and (iii) increase of the efficiency of enzymatic repair. The latter effect of cysteamine is registered only with the wild-type E. coli, the DMF being not less than 1.4

  2. A magnetic biosensor system for detection of E. coli

    KAUST Repository

    Li, Fuquan

    2013-07-01

    This work describes a device for detecting E. coli bacteria by manipulating superparamagnetic beads to a sensing area and immobilizing them in a trapping well. The trapping well replaces the biochemical immobilization layer, which is commonly used in magnetic biosensor systems. A concept exploiting the volume difference between bare magnetic beads and magnetic bead-bioanalyte compounds is utilized to detect E. coli bacteria. Trapped beads are detected by the help of a tunnel magneto-resistive sensor. Frequency modulation is employed, in order to increase the signal-to-noise ratio, enabling the detection of individual superparamagnetic beads of 2.8 μm in diameter. Replacing the biochemical immobilization layer by the trapping well greatly simplifies the detection process. After applying the mixture of E. coli and magnetic beads to the biosensor system, bacteria detection is achieved in a single step, within a few minutes. © 2013 IEEE.

  3. Bactericidal activity of ciprofloxacin upon Escherichia coli and Acinetobacter baumanni.

    Science.gov (United States)

    Zemelman, R; Vejar, C; Bello, H; Domínguez, M; González, G

    1992-01-01

    The mechanisms of bactericidal activity of ciprofloxacin (mechanisms A and B) upon cells of a strain of Escherichia coli and one strain of Acinetobacter baumannii were investigated under different conditions. The killing of E. coli cells by ciprofloxacin was significantly reduced by chloramphenicol, but this antibiotic showed almost no activity upon killing of A. baumannii cells by this quinolone. Similar results were obtained when rifampicin was added to ciprofloxacin. Bactericidal activity of ciprofloxacin upon nondividing cells of E. coli was lower and that upon non-dividing cells of A. baumannii was not affected when compared with activity of ciprofloxacin upon dividing cells of both microorganisms. These results demonstrate that the antibacterial activity of ciprofloxacin upon A. baumannii is independent of protein and ARN synthesis, a fact which suggests that this quinolone exerts only bactericidal mechanism B upon A. baumannii. This finding might explain, at least in part, the lower susceptibility of this microorganism to ciprofloxacin.

  4. Incidence of Escherichia coli in black walnut meats.

    Science.gov (United States)

    Meyer, M T; Vaughn, R H

    1969-11-01

    Examination of commercially shelled black walnut meats showed inconsistent numbers of total aerobic bacteria, coliforms, and Escherichia coli; variation occurred among different meat sizes and within each meat size. The incidence of E. coli on meats of commercially hulled black walnuts depended on the physical condition of the nuts. Apparently tightly sealed ones contained only a few or none, whereas those with visibly separated sutures and spoiled meats yielded the most. This contamination was in part correlated to a hulling operation. Large numbers of E. coli on the husk of the walnuts contaminated the hulling water, subsequently also contaminating the meats by way of separated sutures. Chlorination of the hulling wash water was ineffective. Attempts were made to decontaminate the walnut meats without subsequent deleterious changes in flavor or texture. A treatment in coconut oil at 100 C followed by removal of excess surface oil by centrifugation was best.

  5. INFLUENCE OF DOXORUBICIN ON ADHESIVE PROPERTIES OF E.COLI

    Directory of Open Access Journals (Sweden)

    O.G. Shapoval

    2008-09-01

    Full Text Available Influence ofantineoplastic drug doxorubicin and amikacin, the aminoglycoside family on adhesive activity of Escherichia coli was studied. Antimicrobialactivity(minimum inhibitory concentration-MIC ofboth drugs against experimental strains using serial two-fold dilution method was determined. Susceptibility of E.coli to amikacin in the presence of Sand j MIC doxorubicin was studied. After 10 passages in beef-extract broth with constant and increasing doxorubicin concentrations in the presence of Sand j MIC doxorubicin, the adhesive activity of initial and passage variants according to theirability to absorb human erythrocytes 1(0 Rh+ was determined. Itwas observed that experimental strains were susceptible to amikacin (MIC 1,5-6,2 mkg/ml butwere resistantto doxorubicin (MIC 1000 mkg/ml. Subinhibitory concentrations of this cytostatic (S and j MIC raised the sensitivity of experimental strains to amikacin and differently effected on adhesive activity of passage variants of E.coli.

  6. The redistribution of granulocytes following E. coli endotoxin induced sepsis

    DEFF Research Database (Denmark)

    Toft, P; Lillevang, S T; Tønnesen, Else Kirstine

    1994-01-01

    Infusion of endotoxin elicits granulocytopenia followed by increased numbers of granulocytes in peripheral blood. The purpose of this study was to investigate the redistribution and sequestration of granulocytes in the tissues following E. coli endotoxin induced sepsis. From 16 rabbits granulocytes...... were isolated, labelled with Indium and reinjected intravenously. Eight rabbits received an infusion of E. coli endotoxin 2 micrograms kg-1 while eight received isotonic saline. The redistribution of granulocytes was imaged with a gamma camera and calculated with a connected computer before and 2 and 6...... hours after infusion of endotoxin or saline. Serum cortisol and interleukin-1 beta were measured. In another seven rabbits, respiratory burst activity and degranulation of granulocytes were measured prior to and from 5 min to 6 hours after infusion of E. coli endotoxin 2 micrograms kg-1 BW. Following...

  7. Is Escherichia coli urinary tract infection a zoonosis?

    DEFF Research Database (Denmark)

    Jacobsen, L.; Garneau, P.; Bruant, G.

    2012-01-01

    Recently, it has been suggested that the Escherichia coli causing urinary tract infection (UTI) may come from meat and animals. The purpose was to investigate if a clonal link existed between E. coli from animals, meat and UTI patients. Twenty-two geographically and temporally matched B2 E. coli...... from UTI patients, community-dwelling humans, broiler chicken meat, pork, and broiler chicken, previously identified to exhibit eight virulence genotypes by microarraydetection of approximately 300 genes, were investigated for clonal relatedness by PFGE. Nine isolates were selected and tested...... for in vivo virulence in the mouse model of ascending UTI. UTI and community-dwelling human strains were closely clonally related to meat strains. Several human derived strains were also clonally interrelated. All nine isolates regardless of origin were virulent in the UTI model with positive urine, bladder...

  8. Longitudinal characterization of Escherichia coli in healthy captive nonhuman primates

    Directory of Open Access Journals (Sweden)

    Jonathan B Clayton

    2014-11-01

    Full Text Available The gastrointestinal (GI tracts of nonhuman primates are well known to harbor Escherichia coli, a known commensal of humans and animals. While E. coli is a normal inhabitant of the mammalian gut, it also exists in a number of pathogenic forms or pathotypes, including those with predisposition for the GI tract, as well the urogenital tract. Diarrhea in captive nonhuman primates (NHPs has long been a problem in both zoo settings and research colonies, including the Como Zoo. It is an animal welfare concern, as well as a public health concern. E. coli has not been extensively studied in correlation with diarrhea in captive primates; therefore, a study was performed during the summer of 2009 in collaboration with a zoo in Saint Paul, MN, which was experiencing an increased incidence and severity of diarrhea among their NHP collection. Fresh fecal samples were collected weekly from each member of the primate collection, between June and August of 2009, and E. coli were isolated. A total of 33 individuals were included in the study, representing eight species. E. coli isolates were examined for their genetic relatedness, phylogenetic relationships, plasmid replicon types, virulence gene profiles, and antimicrobial susceptibility profiles. A number of isolates were identified containing virulence genes commonly found in several different E. coli pathotypes, and there was evidence of clonal transmission of isolates between animals and over time. Overall, the manifestation of chronic diarrhea in the Como Zoo primate collection is a complex problem whose solution will require regular screening for microbial agents and consideration of environmental causes. This study provides some insight towards the sharing of enteric bacteria between such animals.

  9. Deactivation of Escherichia coli by the plasma needle

    International Nuclear Information System (INIS)

    Sladek, R E J; Stoffels, E

    2005-01-01

    In this paper we present a parameter study on deactivation of Escherichia coli (E. coli) by means of a non-thermal plasma (plasma needle). The plasma needle is a small-sized (1 mm) atmospheric glow sustained by radio-frequency excitation. This plasma will be used to disinfect heat-sensitive objects; one of the intended applications is in vivo deactivation of dental bacteria: destruction of plaque and treatment of caries. We use E. coli films plated on agar dishes as a model system to optimize the conditions for bacterial destruction. Plasma power, treatment time and needle-to-sample distance are varied. Plasma treatment of E. coli films results in formation of a bacteria-free void with a size up to 12 mm. 10 4 -10 5 colony forming units are already destroyed after 10 s of treatment. Prolongation of treatment time and usage of high powers do not significantly improve the destruction efficiency: short exposure at low plasma power is sufficient. Furthermore, we study the effects of temperature increase on the survival of E. coli and compare it with thermal effects of the plasma. The population of E. coli heated in a warm water bath starts to decrease at temperatures above 40 deg. C. Sample temperature during plasma treatment has been monitored. The temperature can reach up to 60 deg. C at high plasma powers and short needle-to-sample distances. However, thermal effects cannot account for bacterial destruction at low power conditions. For safe and efficient in vivo disinfection, the sample temperature should be kept low. Thus, plasma power and treatment time should not exceed 150 mW and 60 s, respectively

  10. Reproducible gene targeting in recalcitrant Escherichia coli isolates

    Directory of Open Access Journals (Sweden)

    De Greve Henri

    2011-06-01

    Full Text Available Abstract Background A number of allele replacement methods can be used to mutate bacterial genes. For instance, the Red recombinase system of phage Lambda has been used very efficiently to inactivate chromosomal genes in E. coli K-12, through recombination between regions of homology. However, this method does not work reproducibly in some clinical E. coli isolates. Findings The procedure was modified by using longer homologous regions (85 bp and 500-600 bp, to inactivate genes in the uropathogenic E. coli strain UTI89. An lrhA regulator mutant, and deletions of the lac operon as well as the complete type 1 fimbrial gene cluster, were obtained reproducibly. The modified method is also functional in other recalcitrant E. coli, like the avian pathogenic E. coli strain APEC1. The lrhA regulator and lac operon deletion mutants of APEC1 were successfully constructed in the same way as the UTI89 mutants. In other avian pathogenic E. coli strains (APEC3E, APEC11A and APEC16A it was very difficult or impossible to construct these mutants, with the original Red recombinase-based method, with a Red recombinase-based method using longer (85 bp homologous regions or with our modified protocol, using 500 - 600 bp homologous regions. Conclusions The method using 500-600 bp homologous regions can be used reliably in some clinical isolates, to delete single genes or entire operons by homologous recombination. However, it does not invariably show a greater efficiency in obtaining mutants, when compared to the original Red-mediated gene targeting method or to the gene targeting method with 85 bp homologous regions. Therefore the length of the homology regions is not the only limiting factor for the construction of mutants in these recalcitrant strains.

  11. Deactivation of Escherichia coli by the plasma needle

    Energy Technology Data Exchange (ETDEWEB)

    Sladek, R E J; Stoffels, E [Department of Biomedical Engineering, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven (Netherlands)

    2005-06-07

    In this paper we present a parameter study on deactivation of Escherichia coli (E. coli) by means of a non-thermal plasma (plasma needle). The plasma needle is a small-sized (1 mm) atmospheric glow sustained by radio-frequency excitation. This plasma will be used to disinfect heat-sensitive objects; one of the intended applications is in vivo deactivation of dental bacteria: destruction of plaque and treatment of caries. We use E. coli films plated on agar dishes as a model system to optimize the conditions for bacterial destruction. Plasma power, treatment time and needle-to-sample distance are varied. Plasma treatment of E. coli films results in formation of a bacteria-free void with a size up to 12 mm. 10{sup 4}-10{sup 5} colony forming units are already destroyed after 10 s of treatment. Prolongation of treatment time and usage of high powers do not significantly improve the destruction efficiency: short exposure at low plasma power is sufficient. Furthermore, we study the effects of temperature increase on the survival of E. coli and compare it with thermal effects of the plasma. The population of E. coli heated in a warm water bath starts to decrease at temperatures above 40 deg. C. Sample temperature during plasma treatment has been monitored. The temperature can reach up to 60 deg. C at high plasma powers and short needle-to-sample distances. However, thermal effects cannot account for bacterial destruction at low power conditions. For safe and efficient in vivo disinfection, the sample temperature should be kept low. Thus, plasma power and treatment time should not exceed 150 mW and 60 s, respectively.

  12. [Virulence markers of Escherichia coli O1 strains].

    Science.gov (United States)

    Makarova, M A; Kaftyreva, L A; Grigor'eva, N S; Kicha, E V; Lipatova, L A

    2011-01-01

    To detect virulence genes in clinical isolates of Escherichia coli O1 using polymerase chain reaction (PCR). One hundred and twenty strains of E.coli O1 strains isolated from faeces of patients with acute diarrhea (n = 45) and healthy persons (n = 75) were studied. PCR with primers for rfb and fliC genes, which control synthesis of O- and H- antigens respectively, was used. Fourteen virulence genes (pap, aaf, sfa, afa, eaeA, bfpA, ial, hly, cnf, stx1, stx2, lt, st, and aer) were detected by PCR primers. K1-antigen was determined by Pastorex Meningo B/E. coli O1 kit (Bio-Rad). rfb gene controlling O-antigen synthesis in serogroup O1 as well as fliC gene controlling synthesis of H7 and K1 antigens were detected in all strains. Thus all E. coli strains had antigenic structure O1:K1 :H-:F7. Virulence genes aafl, sfa, afa, eaeA, bfpA, ial, hly, cnf, stx1, stx2, lt, and st were not detected. All strains owned pap and aer genes regardless of the presence of acute diarrhea symptoms. It was shown that E. coli O1:KI:H-:F7 strains do not have virulence genes which are characteristic for diarrhea-causing Escherichia. In accordance with the presence of pap and aer genes they could be attributed to uropathogenic Escherichia (UPEC) or avian-pathogenic Escherichia (APEC). It is necessary to detect virulence factors in order to determine E. coli as a cause of intestinal infection.

  13. Novel roles for the AIDA adhesin from diarrheagenic Escherichia coli:

    DEFF Research Database (Denmark)

    Sherlock, Orla; Schembri, Mark; Reisner, A.

    2004-01-01

    Diarrhea-causing Escherichia coli strains are responsible for numerous cases of gastrointestinal disease and constitute a serious health problem throughout the world. The ability to recognize and attach to host intestinal surfaces is an essential step in the pathogenesis of such strains. AIDA...... binds to mammalian cells. Here, we show that AIDA possesses self-association characteristics and can mediate autoaggregation of E. coli cells. We demonstrate that intercellular AIDA-AIDA interaction is responsible for bacterial autoaggregation. Interestingly, AIDA-expressing cells can interact...

  14. Effect of durable γ-radiation on E.Coli

    International Nuclear Information System (INIS)

    Koudela, K.; Drashil, V.

    1990-01-01

    Effect of prolonged low intensity γ-radiation on changes of frequency of reversion mutations was studied in Escherichia Coli. Frequency of His + revertants was shown to depend on growth phase. Cellular DNA absorbed more energy in stationary than DNA in growth phase. K-12 AB2497 strain of Escherichia Coli D-37 comprised about 60 Gy. This dose wasn't absorbed under continuous irradiation at dose rate of 0.21 R/min in 5 hours. The dose rate was considered to be sufficient to induce SOS-system and thus to increase mutations number. 2 refs

  15. DNA microarray analysis of fim mutations in Escherichia coli

    DEFF Research Database (Denmark)

    Schembri, Mark; Ussery, David; Workman, Christopher

    2002-01-01

    Bacterial adhesion is often mediated by complex polymeric surface structures referred to as fimbriae. Type I fimbriae of Escherichia coli represent the archetypical and best characterised fimbrial system. These adhesive organelles mediate binding to D-mannose and are directly associated...... we have used DNA microarray analysis to examine the molecular events involved in response to fimbrial gene expression in E. coli K-12. Observed differential expression levels of the fim genes were in good agreement with our current knowledge of the stoichiometry of type I fimbriae. Changes in fim...

  16. Effects of irradiation on enzymes in E. coli

    Energy Technology Data Exchange (ETDEWEB)

    Geyer, H.

    1962-08-15

    To determine the effects of irradiation on enzymes in Escherichia coli strain Crookes, the influence of x radiation on the content of the coenzyme pyridoxal phosphate was investigated. The method of pyridoxal phosphate assay used was based on the fact that E. coli is able to produce tryptophanase. Enzyme activity was measured by determination of indole produced from tryptophane. Doses of 10,000 and 80,000 r of x radiation were given to resting cells and growing cells. It was found that pyridoxal phosphate production and content were not infiuenced by irradiation. (H.M.G.)

  17. Colisão com o 'efeito estilingue'

    OpenAIRE

    Silveira,Fernando Lang da; Braun,Luci F.M; Braun,Thomas

    2010-01-01

    Abordamos teoricamente a colisão com o 'efeito estilingue' onde um corpo transfere momento linear e energia cinética para um segundo corpo de massa menor, fazendo com que a energia mecânica desse segundo corpo cresça de forma surpreendente. Mostramos que, mesmo quando as colisões são inelásticas, o ganho de energia mecânica pode ser grande. Apresentamos um estudo experimental do interessante efeito realizado a partir de um vídeo. Finalmente discutimos o 'efeito estilingue gravitacional' utili...

  18. Radiosensitization and radioprotection of E. coli by alcohols

    International Nuclear Information System (INIS)

    Worm, K.-H.; Klimczak, U.; Schulte-Frohlinde, D.

    1993-01-01

    The survival of E. coli K12 strain AB1157 and the isogenic repair-deficient mutant E. coli AB2480 (recA13, uvrA6) was measured after γ-irradiation in the presence of various alcohols as well as after incubation and subsequent removal of the alcohols before irradiation. The authors conclude that alcohols protect predominantly by OH radical scavenging. The comparatively small protection of cell survival by the more hydrophobic alcohols can be attributed to the sensitizing effect of these alcohols. (author)

  19. UV irradiation alters deoxynucleoside triphosphate pools in Escherichia coli

    International Nuclear Information System (INIS)

    Das, S.K.; Loeb, L.A.

    1984-01-01

    UV irradiation of exponentially growing Escherichia coli increased intracellular concentration of dATP and dTTP without significantly changing the concentrations of dGTP and dCTP. These selective increases in dATP and dTTP pools are seen in wild-type E. coli K12 and AB1157, as well as in recA and umuC strains, and are proportional to UV dose. The possible significance of these findings with respect to induction of the SOS response and nontargeted mutagenesis are discussed. (orig.)

  20. A stochastic killing system for biological containment of Escherichia coli

    DEFF Research Database (Denmark)

    Klemm, P.; Jensen, Lars Bogø; Molin, Søren

    1995-01-01

    Bacteria with a stochastic conditional lethal containment system have been constructed. The invertible switch promoter located upstream of the fimA gene from Escherichia coli was inserted as expression cassette in front of the Lethal gef gene deleted of its own natural promoter. The resulting...... fusion was placed on a plasmid and transformed to E. coli. The phenotype connected with the presence of such a plasmid was to reduce the population growth rate with increasing significance as the cell growth rate was reduced. In very fast growing cells, there was no measurable effect on growth rate. When...

  1. Antibiotic Resistance Escherichia coli isolated from Faecal of Healthy Human

    OpenAIRE

    , S. Budiarti

    2011-01-01

    The objective of this research was to examine antibiotic resistant of Escherechia coli as intestinal normal şora, isolated from healthy human. The samples were collected from faeces of new born children, children under 3 and 5years-old, and human adult. Bacteria were isolated at Eosin Methylen Blue solid media followed by biochemistry reaction for physiological E.coli identiŞcation. Antibiotic resistant test was carried out using Kirby-Bauer method. The result showed that 95 % bacterial strai...

  2. Genes and proteins of Escherichia coli (GenProtEc).

    Science.gov (United States)

    Riley, M; Space, D B

    1996-01-01

    GenProtEc is a database of Escherichia coli genes and their gene products, classified by type of function and physiological role and with citations to the literature for each. Also present are data on sequence similarities among E.coli proteins with PAM values, percent identity of amino acids, length of alignment and percent aligned. The database is available as a PKZip file by ftp from mbl.edu/pub/ecoli.exe. The program runs under MS-DOS on IMB-compatible machines. GenProtEc can also be accessed through the World Wide Web at URL http://mbl.edu/html/ecoli.html.

  3. FimH-mediated autoaggregation of Escherichia coli

    DEFF Research Database (Denmark)

    Schembri, Mark; Christiansen, G.; Klemm, Per

    2001-01-01

    Autoaggregation is a phenomenon thought to contribute to colonization of mammalian hosts by pathogenic bacteria. Type 1 fimbriae are surface organelles of Escherichia coli that mediate D-mannose-sensitive binding to various host surfaces. This binding is conferred by the minor fimbrial component...... FimH. In this study, we have used random mutagenesis to identify variants of the FimH adhesin that confer the ability of E. coli to autoaggregate and settle from liquid cultures. Three separate autoaggregating clones were identified, all of which contained multiple amino acid changes located within...

  4. DNA repair by the Ada protein of E. coli

    International Nuclear Information System (INIS)

    Karran, P.; Hall, J.

    1988-01-01

    This paper discusses the Ada protein of E. coli which exemplifies the highly specialized nature of the enzymes which have evolved to repair DNA. According to the authors, this protein exhibits not only novel mechanistic features but also provides an apparently unique example of a strategy for controlling gene expression in E. coli. They report that knowledge of the properties and mode of action of the Ada protein has afforded insight into how human cells are affected by alkylating agents, including those used in chemotherapy

  5. Escherichia coli : host interactions in the pathogenesis of canine pyometra

    OpenAIRE

    Henriques, Sofia Correia Rosa de Barros

    2016-01-01

    Tese de Doutoramento em Ciências Veterinárias na Especialidade de Ciências Biológicas e Biomédicas Canine pyometra develops as a result of a complex interaction of etiological and physiopathological factors, such as the virulence and type of the bacteria and the individual host defence mechanisms. Since Escherichia coli is the most common bacterium isolated from uterus of bitches with pyometra, one main objective of this work was to characterize E. coli virulence potential, and...

  6. Solar thermal central receivers

    International Nuclear Information System (INIS)

    Vant-Hull, L.L.

    1993-01-01

    Market issues, environmental impact, and technology issues related to the Solar Central Receiver concept are addressed. The rationale for selection of the preferred configuration and working fluid are presented as the result of a joint utility-industry analysis. A $30 million conversion of Solar One to an external molten salt receiver would provide the intermediate step to a commercial demonstration plant. The first plant in this series could produce electricity at 11.2 cents/kWhr and the seventh at 8.2 cents/kWhr, completely competitive with projected costs of new utility plants in 1992

  7. Central osteosclerosis with trichothiodystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Wakeling, Emma L.; Brady, Angela F. [North West Thames Regional Genetics Service, Kennedy-Galton Centre, Level 8 V, North West London Hospitals NHS Trust, Watford Road, HAI 3UJ, Harrow, Middlesex (United Kingdom); Cruwys, Michele [Department of Paediatrics, Hillingdon Hospital, Hillingdon, Middlesex (United Kingdom); Suri, Mohnish [Clinical Genetics Service, City Hospital, Nottingham (United Kingdom); Aylett, Sarah E. [Neurosciences Unit, Great Ormond Street Hospital for Children NHS Trust, London (United Kingdom); Hall, Christine [Department of Radiology, Great Ormond Street Hospital for Children NHS Trust, London (United Kingdom)

    2004-07-01

    Trichothiodystrophy (TTD) is a rare, autosomal recessive, multisystem disorder associated with defects in nucleotide excision repair. We report a 7-year-old boy with TTD due to mutation in the XPD gene. The patient has classic features of this condition, including brittle, sulphur-deficient hair, ichthyosis, growth retardation and developmental delay. In addition, he has radiological evidence of progressive central osteosclerosis. Although similar radiological findings have previously been reported in a small number of patients, this association is not widely recognised. We review the radiological findings in this and other similar cases and discuss the natural history of these bony changes. (orig.)

  8. Central nervous system tumors

    International Nuclear Information System (INIS)

    Curran, W.J. Jr.

    1991-01-01

    Intrinsic tumors of the central nervous system (CNS) pose a particularly challenging problem to practicing oncologists. These tumors rarely metastasize outside the CNS, yet even histologically benign tumors can be life-threatening due to their local invasiveness and strategic location. The surrounding normal tissues of the nervous system is often incapable of full functional regeneration, therefore prohibiting aggressive attempts to use either complete surgical resection or high doses of irradiation. Despite these limitations, notable achievements have recently been recorded in the management of these tumors

  9. Decentralized central heating

    Energy Technology Data Exchange (ETDEWEB)

    Savic, S.; Hudjera, A.

    1994-08-04

    The decentralized central heating is essentially based on new technical solutions for an independent heating unit, which allows up to 20% collectible energy savings and up to 15% savings in built-in-material. These savings are already made possible by the fact that the elements described under point A are thus eliminated from the classical heating. The thus superfluous made elements are replaced by new technical solutions described under point B - technical problem - and point E - patent claim. The technical solutions described in detail under point B and point E form together a technical unit and are essential parts of the invention protected by the patent. (author)

  10. Central Hypothyroidism in Miniature Schnauzers

    NARCIS (Netherlands)

    Voorbij, Annemarie M W Y; Leegwater, Peter A J; Buijtels, Jenny J C W M; Daminet, Sylvie; Kooistra, Hans S

    2016-01-01

    BACKGROUND: Primary hypothyroidism is a common endocrinopathy in dogs. In contrast, central hypothyroidism is rare in this species. OBJECTIVES: The objective of this article is to describe the occurrence and clinical presentation of central hypothyroidism in Miniature Schnauzers. Additionally, the

  11. THE WIDESPREAD OCCURRENCE OF THE ENTEROHEMOLYSIN GENE EHLYA AMONG ENVIRONMENTAL STRAINS OF ESCHERICHIA COLI

    Science.gov (United States)

    The putative virulence factor enterohemolysin, encoded for by the ehlyA gene, has been closely associated with the pathogenic enterohemorrhagic Escherichia coli (EHEC) group. E. coli isolates from effluents from seven geographically dispersed municipal ...

  12. Effect of simulated microgravity on E. coli K12 MG1655 growth and gene expression

    Data.gov (United States)

    National Aeronautics and Space Administration — This study demonstrates simulated microgravity effects on E. coli K 12 MG1655 when grown on LB medium supplemented with glycerol. The results imply that E. coli...

  13. Escherichia coli Probiotic Strain ED1a in Pigs Has a Limited Impact on the Gut Carriage of Extended-Spectrum-β-Lactamase-Producing E. coli

    Science.gov (United States)

    Mourand, G.; Paboeuf, F.; Fleury, M. A.; Jouy, E.; Bougeard, S.; Denamur, E.

    2016-01-01

    ABSTRACT Four trials were conducted to evaluate the impact of Escherichia coli probiotic strain ED1a administration to pigs on the gut carriage or survival in manure of extended-spectrum-β-lactamase-producing E. coli. Groups of pigs were orally inoculated with strain E. coli M63 carrying the blaCTX-M-1 gene (n = 84) or used as a control (n = 26). In the first two trials, 24 of 40 E. coli M63-inoculated pigs were given E. coli ED1a orally for 6 days starting 8 days after oral inoculation. In the third trial, 10 E. coli M63-inoculated pigs were given either E. coli ED1a or probiotic E. coli Nissle 1917 for 5 days. In the fourth trial, E. coli ED1a was given to a sow and its 12 piglets, and these 12 piglets plus 12 piglets that had not received E. coli ED1a were then inoculated with E. coli M63. Fecal shedding of cefotaxime-resistant Enterobacteriaceae (CTX-RE) was studied by culture, and blaCTX-M-1 genes were quantified by PCR. The persistence of CTX-RE in manure samples from inoculated pigs or manure samples inoculated in vitro with E. coli M63 with or without probiotics was studied. The results showed that E. coli M63 and ED1a were good gut colonizers. The reduction in the level of fecal excretion of CTX-RE in E. coli ED1a-treated pigs compared to that in nontreated pigs was usually less than 1 log10 CFU and was mainly observed during the probiotic administration period. The results obtained with E. coli Nissle 1917 did not differ significantly from those obtained with E. coli ED1a. CTX-RE survival did not differ significantly in manure samples with or without probiotic treatment. In conclusion, under our experimental conditions, E. coli ED1a and E. coli Nissle 1917 could not durably prevent CTX-RE colonization of the pig gut. PMID:27795372

  14. Escherichia coli Probiotic Strain ED1a in Pigs Has a Limited Impact on the Gut Carriage of Extended-Spectrum-β-Lactamase-Producing E. coli.

    Science.gov (United States)

    Mourand, G; Paboeuf, F; Fleury, M A; Jouy, E; Bougeard, S; Denamur, E; Kempf, I

    2017-01-01

    Four trials were conducted to evaluate the impact of Escherichia coli probiotic strain ED1a administration to pigs on the gut carriage or survival in manure of extended-spectrum-β-lactamase-producing E. coli Groups of pigs were orally inoculated with strain E. coli M63 carrying the bla CTX-M-1 gene (n = 84) or used as a control (n = 26). In the first two trials, 24 of 40 E. coli M63-inoculated pigs were given E. coli ED1a orally for 6 days starting 8 days after oral inoculation. In the third trial, 10 E. coli M63-inoculated pigs were given either E. coli ED1a or probiotic E. coli Nissle 1917 for 5 days. In the fourth trial, E. coli ED1a was given to a sow and its 12 piglets, and these 12 piglets plus 12 piglets that had not received E. coli ED1a were then inoculated with E. coli M63. Fecal shedding of cefotaxime-resistant Enterobacteriaceae (CTX-RE) was studied by culture, and bla CTX-M-1 genes were quantified by PCR. The persistence of CTX-RE in manure samples from inoculated pigs or manure samples inoculated in vitro with E. coli M63 with or without probiotics was studied. The results showed that E. coli M63 and ED1a were good gut colonizers. The reduction in the level of fecal excretion of CTX-RE in E. coli ED1a-treated pigs compared to that in nontreated pigs was usually less than 1 log 10 CFU and was mainly observed during the probiotic administration period. The results obtained with E. coli Nissle 1917 did not differ significantly from those obtained with E. coli ED1a. CTX-RE survival did not differ significantly in manure samples with or without probiotic treatment. In conclusion, under our experimental conditions, E. coli ED1a and E. coli Nissle 1917 could not durably prevent CTX-RE colonization of the pig gut. Copyright © 2016 American Society for Microbiology.

  15. Central Banking after the Crisis

    OpenAIRE

    Frederick S. Mishkin

    2013-01-01

    This paper explores where central banking is heading after the recent financial crisis. First it discusses the central bank consensus before the crisis and then outlines the key facts learned from the crisis that require changes in the way central banks conduct their business. Finally, it discusses four main areas in which central banks are altering their policy frameworks: 1) the interaction between monetary and financial stability policies, 2) nonconventional monetary policy, 3) risk manage...

  16. Central ignition scenarios for TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.; Redi, M.H.; Bateman, G.

    1986-03-01

    The possibility of obtaining ignition in TFTR by means of very centrally peaked density profiles is examined. It is shown that local central alpha heating can be made to exceed local central energy losses (''central ignition'') under global conditions for which Q greater than or equal to 1. Time dependent 1-D transport simulations show that the normal global ignition requirements are substantially relaxed for plasmas with peaked density profiles. 18 refs., 18 figs

  17. The central Iowa project.

    Science.gov (United States)

    Allen, H M

    1994-10-01

    This project developed and tested a population-based survey, the HS Form, to examine health and health care in the Central Iowa community. Data from this new collection of proven sets of items were used to compare competing health plans, doctor offices, hospitals, and to develop preliminary norms of the community's insured, in two areas: system performance and health burden. The results showed that the survey: (1) was both feasible and efficient in delivering a comprehensive and generic assessment of consumers and patients; (2) revealed consistent, noteworthy differences between plans and between providers across both sets of criteria; and (3) indicated that there is substantial room for improvement in Central Iowa's health care delivery system from the public's perspective. Recommendations for next steps include: (1) following through on the June 1993 community forum (held to discuss the project's methods and results with local decision makers); (2) broadening the evaluation design to increase sample representativeness; and (3) implementing a pre/post approach to measure changes in plan and provider performance.

  18. Alpha current flow betweenness centrality

    NARCIS (Netherlands)

    Avrachenkov, K.; Litvak, Nelli; Medyanikov, V.; Sokol, M.

    2013-01-01

    A class of centrality measures called betweenness centralities reflects degree of participation of edges or nodes in communication between different parts of the network. The original shortest-path betweenness centrality is based on counting shortest paths which go through a node or an edge. One of

  19. High temperature in combination with UV irradiation enhances horizontal transfer of stx2 gene from E. coli O157:H7 to non-pathogenic E. coli.

    Directory of Open Access Journals (Sweden)

    Wan-Fu Yue

    Full Text Available Shiga toxin (stx genes have been transferred to numerous bacteria, one of which is E. coli O157:H7. It is a common belief that stx gene is transferred by bacteriophages, because stx genes are located on lambdoid prophages in the E. coli O157:H7 genome. Both E. coli O157:H7 and non-pathogenic E. coli are highly enriched in cattle feedlots. We hypothesized that strong UV radiation in combination with high temperature accelerates stx gene transfer into non-pathogenic E. coli in feedlots.E. coli O157:H7 EDL933 strain were subjected to different UV irradiation (0 or 0.5 kJ/m(2 combination with different temperature (22, 28, 30, 32, and 37 °C treatments, and the activation of lambdoid prophages was analyzed by plaque forming unit while induction of Stx2 prophages was quantified by quantitative real-time PCR. Data showed that lambdoid prophages in E. coli O157:H7, including phages carrying stx2, were activated under UV radiation, a process enhanced by elevated temperature. Consistently, western blotting analysis indicated that the production of Shiga toxin 2 was also dramatically increased by UV irradiation and high temperature. In situ colony hybridization screening indicated that these activated Stx2 prophages were capable of converting laboratory strain of E. coli K12 into new Shiga toxigenic E. coli, which were further confirmed by PCR and ELISA analysis.These data implicate that high environmental temperature in combination with UV irradiation accelerates the spread of stx genes through enhancing Stx prophage induction and Stx phage mediated gene transfer. Cattle feedlot sludge are teemed with E. coli O157:H7 and non-pathogenic E. coli, and is frequently exposed to UV radiation via sunlight, which may contribute to the rapid spread of stx gene to non-pathogenic E. coli and diversity of shiga toxin producing E. coli.

  20. Escherichia coli O104 associated with human diarrhea, South Africa, 2004-2011.

    Science.gov (United States)

    Tau, Nomsa P; Meidany, Parastu; Smith, Anthony M; Sooka, Arvinda; Keddy, Karen H

    2012-08-01

    To determine the origin of >4,000 suspected diarrheagenic Escherichia coli strains isolated during 2004-2011 in South Africa, we identified 7 isolates as serotype O104; 5 as enteroaggregative E. coli O104:H4, and 2 as enteropathogenic E. coli O104:non-H4. Pulsed-field gel electrophoresis showed that these isolates were unrelated to the 2011 E. coli O104:H4 outbreak strain from Germany.

  1. Antimicrobial resistance prevalence of pathogenic and commensal Escherichia coli in food-producing animals in Belgium

    OpenAIRE

    Chantziaras, Ilias; Dewulf, Jeroen; Boyen, Filip; Callens, Benedicte; Butaye, Patrick

    2014-01-01

    In this article, detailed studies on antimicrobial resistance to commensal E. coli (in pigs, meat-producing bovines, broiler chickens and veal calves) and pathogenic E. coli (in pigs and bovines) in Belgium are presented for 2011. Broiler chicken and veal calf isolates of commensal E. coli demonstrated higher antimicrobial resistance prevalence than isolates from pigs and bovines. Fifty percent of E. coli isolates from broiler chickens were resistant to at least five antimicrobials, whereas s...

  2. Selective detection of Escherichia coli by imaging of the light intensity transmitted through an optical disk

    Science.gov (United States)

    Shiramizu, Hideyuki; Kuroda, Chiaki; Ohki, Yoshimichi; Shima, Takayuki; Wang, Xiaomin; Fujimaki, Makoto

    2018-03-01

    We have developed an optical disk system for imaging transmitted light from Escherichia coli dispersed on an optical disk. When E. coli was stained using Bismarck brown, the transmittance was found to decrease in images obtained at λ = 405 nm. The results indicate that transmittance imaging is suitable for finding the difference in light intensity between stained and unstained E. coli, whereas the reflectance images were scarcely changed by staining. Therefore, E. coli can be selectively discriminated from abiotic contaminants using transmittance imaging.

  3. Probiotic Mixture Golden Bifido Prevents Neonatal Escherichia coli K1 Translocation via Enhancing Intestinal Defense

    OpenAIRE

    Qing Zeng; Xiaolong He; Santhosh Puthiyakunnon; Hansen Xiao; Zelong Gong; Swapna Boddu; Lecheng Chen; Huiwen Tian; Huiwen Tian; Sheng-He Huang; Sheng-He Huang; Hong Cao

    2017-01-01

    Escherichia coli (E. coli) K1 sepsis and meningitis is a severe infection characterized by high mortality in neonates. Successful colonization and translocation across the intestinal mucosa have been regarded as the critical steps for E. coli K1 sepsis and meningitis. We recently reported that the probiotic mixture, Golden Bifido (containing live Lactobacillus bulgaricus, Bifidobacterium, and Streptococcus thermophilus, LBS) has a preventive role against neonatal E. coli K1 bacteremia and men...

  4. A systematic analysis of TCA Escherichia coli mutants reveals suitable genetic backgrounds for enhanced hydrogen and ethanol production using glycerol as main carbon source.

    Science.gov (United States)

    Valle, Antonio; Cabrera, Gema; Muhamadali, Howbeer; Trivedi, Drupad K; Ratray, Nicholas J W; Goodacre, Royston; Cantero, Domingo; Bolivar, Jorge

    2015-09-01

    Biodiesel has emerged as an environmentally friendly alternative to fossil fuels; however, the low price of glycerol feed-stocks generated from the biodiesel industry has become a burden to this industry. A feasible alternative is the microbial biotransformation of waste glycerol to hydrogen and ethanol. Escherichia coli, a microorganism commonly used for metabolic engineering, is able to biotransform glycerol into these products. Nevertheless, the wild type strain yields can be improved by rewiring the carbon flux to the desired products by genetic engineering. Due to the importance of the central carbon metabolism in hydrogen and ethanol synthesis, E. coli single null mutant strains for enzymes of the TCA cycle and other related reactions were studied in this work. These strains were grown anaerobically in a glycerol-based medium and the concentrations of ethanol, glycerol, succinate and hydrogen were analysed by HPLC and GC. It was found that the reductive branch is the more relevant pathway for the aim of this work, with malate playing a central role. It was also found that the putative C4-transporter dcuD mutant improved the target product yields. These results will contribute to reveal novel metabolic engineering strategies for improving hydrogen and ethanol production by E. coli. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Diarrheagenic Escherichia coli and acute and persistent diarrhea in returned travelers

    NARCIS (Netherlands)

    Schultsz, C.; van den Ende, J.; Cobelens, F.; Vervoort, T.; van Gompel, A.; Wetsteyn, J. C.; Dankert, J.

    2000-01-01

    To determine the role of diarrheagenic Escherichia coli in acute and persistent diarrhea in returned travelers, a case control study was performed. Enterotoxigenic E. coli (ETEC) was detected in stool samples from 18 (10.7%) of 169 patients and 4 (3.7%) of 108 controls. Enteroaggregative E. coli

  6. Diarrhea, Urosepsis and Hemolytic Uremic Syndrome Caused by the Same Heteropathogenic Escherichia coli Strain

    NARCIS (Netherlands)

    Ang, C. Wim; Bouts, Antonia H. M.; Rossen, John W. A.; van der Kuip, Martijn; van Heerde, Marc; Bökenkamp, Arend

    2016-01-01

    We describe an 8-month-old girl with diarrhea, urosepsis and hemolytic uremic syndrome caused by Escherichia coli. Typing of cultured E. coli strains from urine and blood revealed the presence of virulence factors from multiple pathotypes of E. coli. This case exemplifies the genome plasticity of E.

  7. Transmission of F4+ E. coli in groups of early weaned piglets

    NARCIS (Netherlands)

    Geenen, P.L.; Döpfer, D.; Meulen, van der J.; Jong, de M.C.M.

    2005-01-01

    The aim of this study was to estimate transmission parameters of enterotoxigenic F4+ Escherichia coli F4 (F4+ E. coli) in groups of early weaned piglets with F4-receptor-positive (F4R+) and F4-receptor-negative piglets (F4R[minus sign]). Transmission of F4+ E. coli was quantified in four

  8. Detection of Escherichia Coli O157:H7 in Fecal Samples in Meat Goats

    Science.gov (United States)

    Mobley, Ray; Madden, Uford; Brooks-Walter, Alexis

    2004-01-01

    Studies have reported the isolation of Escherichia coli (E. coli)O157:H7 from pork, lamb and poultry products, and from other animals including deer, horses, dogs, birds and humans. There is limited or no information on the presence of the organism in goats. The objectives of this study were to determine if E. coli O157:H7 was naturally occurring…

  9. Attaching and effacing Escherichia coli isolates from Danish children: clinical significance and microbiological characteristics

    DEFF Research Database (Denmark)

    Jensen, C; Ethelberg, S; Olesen, B

    2007-01-01

    This study describes the prevalence, clinical manifestations and microbiological characteristics of attaching and effacing Escherichia coli isolates, i.e., enteropathogenic E. coli (EPEC) belonging to the classical EPEC serotypes, non-EPEC attaching and effacing E. coli (A/EEC) and verocytotoxin...

  10. Mechanisms of antibiotic resistance to enrofloxacin in uropathogenic Escherichia coli in dog

    Science.gov (United States)

    Escherichia coli (E. coli) urinary tract infections (UTIs) are becoming a serious problem both for pets and humans (zoonosis) due to the close contact and to the increasing resistance to antibiotics. Canine E. coli represents a good experimental model useful to study this pathology. Moreover, as des...

  11. Complete genome sequences of Escherichia coli strains 1303 and ECC-1470 isolated from bovine mastitis

    NARCIS (Netherlands)

    Leimbach, Andreas; Poehlein, Anja; Witten, Anika; Scheutz, Flemming; Schukken, Ynte|info:eu-repo/dai/nl/075051907; Daniel, Rolf; Dobrindt, Ulrich

    2016-01-01

    Escherichia coli is the leading causative agent of acute bovine mastitis. Here, we report the complete genome sequence of E. coli O70:H32 strain 1303, isolated from an acute case of bovine mastitis, and E. coli Ont:Hnt strain ECC-1470, isolated from a persistent infection.

  12. Loop-mediated isothermal amplification assay for rapid detection of common strains of Escherichia coli.

    Science.gov (United States)

    Hill, Joshua; Beriwal, Shilpa; Chandra, Ishwad; Paul, Vinod K; Kapil, Aarti; Singh, Tripti; Wadowsky, Robert M; Singh, Vinita; Goyal, Ankur; Jahnukainen, Timo; Johnson, James R; Tarr, Phillip I; Vats, Abhay

    2008-08-01

    We developed a highly sensitive and specific LAMP assay for Escherichia coli. It does not require DNA extraction and can detect as few as 10 copies. It detected all 36 of 36 E. coli isolates and all 22 urine samples (out of 89 samples tested) that had E. coli. This assay is rapid, low in cost, and simple to perform.

  13. prevalence of escherichia coli 0157:h7 in fresh and roasted beef

    African Journals Online (AJOL)

    DR. AMINU

    The prevalence of Enterohemorrhagic Escherichia coli 0157:H7 in 300 fresh beef and 150 roasted beef samples from ... likely cause of E. coli O157:H7 infection is undercooked ground beef. ..... coli O157:H7 in a sheep model. Appl. Environ.

  14. the occurrence of escherichia coli o157:h7 in market and abattoir

    African Journals Online (AJOL)

    user

    Escherichia coli O157:H7 is a newly emerging pathogen frequently associated with the consumption of foods of ... KEY WORDS: E. coli O157:H7, Pathogen, Abattoir, Market, and Infections ..... pathogen. Escherichia coli O157:H7 as a model of.

  15. [Family of ribosomal proteins S1 contains unique conservative domain].

    Science.gov (United States)

    Deriusheva, E I; Machulin, A V; Selivanova, O M; Serdiuk, I N

    2010-01-01

    Different representatives of bacteria have different number of amino acid residues in the ribosomal proteins S1. This number varies from 111 (Spiroplasma kunkelii) to 863 a.a. (Treponema pallidum). Traditionally and for lack of this protein three-dimensional structure, its architecture is represented as repeating S1 domains. Number of these domains depends on the protein's length. Domain's quantity and its boundaries data are contained in the specialized databases, such as SMART, Pfam and PROSITE. However, for the same object these data may be very different. For search of domain's quantity and its boundaries, new approach, based on the analysis of dicted secondary structure (PsiPred), was used. This approach allowed us to reveal structural domains in amino acid sequences of S1 proteins and at that number varied from one to six. Alignment of S1 proteins, containing different domain's number, with the S1 RNAbinding domain of Escherichia coli PNPase elicited a fact that in family of ribosomal proteins SI one domain has maximal homology with S1 domain from PNPase. This conservative domain migrates along polypeptide chain and locates in proteins, containing different domain's number, according to specified pattern. In this domain as well in the S1 domain from PNPase, residues Phe-19, Phe-22, His-34, Asp-64 and Arg-68 are clustered on the surface and formed RNA binding site.

  16. Differential expression of the Escherichia coli autoaggregation factor antigen 43

    DEFF Research Database (Denmark)

    Schembri, Mark; Hjerrild, Louise; Gjermansen, Morten

    2003-01-01

    Antigen 43 (Ag43) is a self-recognizing surface adhesin found in most Escherichia coli strains. Due to its excellent cell-to-cell aggregation characteristics, Ag43 expression confers clumping and fluffing of cells and promotes biofilm formation. Ag43 expression is repressed by the cellular redox...

  17. Antibacterial effects of zinc oxide nanoparticles on Escherichia coli ...

    African Journals Online (AJOL)

    To study the antibacterial mechanisms, atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to observe morphological changes of E. coli K88 treated with 0.8 μg/ml zinc oxide nanoparticles. The results reveal that zinc oxide nanoparticles could damage cell membranes, lead to leakage of ...

  18. Escherichia coli bacteraemia in patients with and without haematological malignancies

    DEFF Research Database (Denmark)

    Olesen, B; Kolmos, H J; Orskov, F

    1998-01-01

    We compared serotypes, virulence factors and susceptibility to antibiotics of Escherichia coli strains isolated from 282 patients with bacteraemia. Thirty-five of these were neutropenic patients with haematological malignancy and 247 were patients with a normal or raised total white blood cell co...

  19. Mathematical model of rhamnolipid production using E.coli bacteria

    Science.gov (United States)

    Adham, Muhammad Fariduddin; Apri, Mochamad; Moeis, Maelita Ramdani

    2018-03-01

    Rhamnolipid is one of biosurfactants that is widely used in many industries. Despite its wide use, production of rhamnolipid usually involves a pathogen that may endanger our health. To tackle this issue, in iGEM (International Genetically Engineered Machine) competition 2015, our team engineered Escherichia coli (E.coli) to produce rhamnolipid. The bacteria were then put into medium containing glucose and lactose. It turned out that bacteria E. coli produced lower rhamnolipid than that by pseudomonas, therefore a good strategy is required to improve their productivity. We present a mathematical model to describe the production of rhamnolipid by the engineered E coli. Using bifurcation analysis, the equilibrium points of the model and their stabilities were analyzed as the amount of lactose was varied. We show that the system produces bistability behavior for some interval values of lactose. From this analysis we found that to guarantee a high production of rhamnolipid, a high level of lactose is required. To maintain the productivity, however, it is sufficient to maintain the lactose level above a certain threshold value.

  20. Effects of recombinant human collagen VI from Escherichia coli on ...

    African Journals Online (AJOL)

    Jane

    2011-07-20

    Jul 20, 2011 ... In this study, we reported the cloning and over expression of a gene coding for human collagen peptide. (CP6) in Escherichia coli and investigated the protective effects of CP6 on UVA-irradiated human skin fibroblasts cells. The collagen peptide (CP6) was highly soluble and the expression level was.

  1. Antibiogram of E. coli serotypes isolated from children aged under ...

    African Journals Online (AJOL)

    Background: Diarrheal disease and its complications remain a major cause of morbidity and mortality in children. The prevalence and antibiogram of E. coli as causative agents of diarrhea vary from region to region, and even within countries in the same geographical area. Objectives: To determine the serotype and ...

  2. Antibiogram of E. coli serotypes isolated from children aged under ...

    African Journals Online (AJOL)

    Antibiogram of E. coli serotypes isolated from children aged under five with acute diarrhea in Bahir Dar town. Ayrikim Adugna1, Mulugeta Kibret1, Bayeh Abera2, Endalkachew Nibret1, Melaku Adal1. 1. Department of Biology, Science College, Bahir Dar University. 2. Department of Microbiology, Parasitology and ...

  3. ENTRAPMENT OF FLUORESCENT E. COLI CELLS IN ALGINATE GEL

    Directory of Open Access Journals (Sweden)

    T. VINTILA

    2009-05-01

    Full Text Available By this experiment we will demonstrate the possibility to obtain genetically modified microbial strains that can be used as markers in different studies. The trait transferred in this study is the fluorescence in UV light expressed by a gene isolated from jellyfish. This gene was insered into a plasmid carrying ampiciline resistance and in the operon for arabinose fermentation. The plasmid was called pGLO. E coli HB101 K-12, ampicillin resistant colonies has been obtained. The colonies on the LB/amp/ara plate fluoresce green under UV light and the transformed colonies can grow on ampicillin. Transformation efficiency = 362 transformed colonies/ μg DNA. The cells where immobilized by entrapment in alginate gel to study the phenomenon involved in cells immobilization. After immobilization in alginate gel, 5x104 cells of E. coli pGLO / capsule and 1,4 x 105 cells of E. coli HB101/capsule has been found. Fluorescent microscopy revealed the presence of pGLO carrying cells into the capsules. After cultivation of alginate capsules containing E. coli in LB broth, and fluorescent microscopy of the capsule sections, several observations of the phenomenon involved in continuous fermentation using biocatalysts in has been made. These cells grow and migrate to the cortical part of the matrix where they are immobilized.

  4. Wastewater as a Source of Carbapenem Resistant Escherichia coli

    Science.gov (United States)

    Clinical studies have reported that the occurrence of carbapenem resistant E. coli is on the rise. This is of concern because carbapenem antibiotics are typically reserved for treating infections caused by bacteria resistant to other classes of antibiotics. Current literature st...

  5. DNA supercoiling depends on the phosphorylation potential in Escherichia coli

    DEFF Research Database (Denmark)

    Van Workum, M.; van Dooren, S.J.M; Oldenburg, N

    1996-01-01

    ATP/ADP ratios were varied in different ways and the degree of negative supercoiling was determined in Escherichia coli. Independent of whether the ATP/ADP ratio was reduced by a shift to anaerobic conditions, by addition of protonophore (dinitrophenol) or by potassium cyanide addition, DNA super...

  6. Effect of visible range electromagnetic radiations on Escherichia coli ...

    African Journals Online (AJOL)

    Background: Escherichia coli is the agent responsible for a range of clinical diseases. With emerging antimicrobial resistance, other treatment options including solar/photo-therapy are becoming increasingly common. Visible Range Radiation Therapy/Colour Therapy is an emerging technique in the field of ...

  7. Properties of in situ Escherichia coli -D-glucuronidase (GUS ...

    African Journals Online (AJOL)

    A study of the activity of Escherichia coli -D-glucuronidase (GUS) in polluted stagnant and running water samples was performed with an objective of assessing the viability of a direct marker enzyme assay as a suitable alternative to membrane filtration for the indication of faecal pollution in water intended for drinking ...

  8. Antibiotic resistance status of Escherichia coli isolated from healthy ...

    African Journals Online (AJOL)

    The research revealed a high level of antibiotic resistance among E. coli. The percentage of resistance observed for the antibiotics included in this study reflected the degree of their respective uses in pig production in the study area. This work further supports the need for prudent use of each of the antibiotics in animal ...

  9. Multiple-Resistant Commensal Escherichia Coli from Nigerian ...

    African Journals Online (AJOL)

    Purpose: The antimicrobial susceptibility and virulence traits of 150 strains of Escherichia coli ... and ethical approval was obtained from the Health .... persist in the guts by virtue of the ability of such ... cases of diarrhoea in Ile-Ife and environs.

  10. Cytokine response to Escherichia coli in gnotobiotic pigs

    Czech Academy of Sciences Publication Activity Database

    Šplíchal, Igor; Šplíchalová, Alla; Trebichavský, Ilja

    2008-01-01

    Roč. 53, č. 2 (2008), s. 161-164 ISSN 0015-5632 R&D Projects: GA ČR GA523/05/0249 Institutional research plan: CEZ:AV0Z50200510 Keywords : germ-free pigs * escherichia coli * cytokine response Subject RIV: EE - Microbiology, Virology Impact factor: 1.172, year: 2008

  11. The significance of E. coli treatment in perinatal period

    Directory of Open Access Journals (Sweden)

    Ljubić Aleksandar D.

    2016-01-01

    Full Text Available Introduction: Bacteriuria of pregnancy is a common condition. Case report: Patient, 30-years, pregnant woman. During pregnancy, E. coli infection recurred in 4 times, applied Cephalexin and Ceftriaxone. The delivery was terminated by CS, GW 38; girl infant, AS 9. After the period of lactation: secretory status - the patient was a secretor of A and H blood type substance; ultrasonography and contrast radiography - presence of the third kidney. The therapy was added by vaccine UroVaxom, and there was no E. coli infection during 2 years follow up period. The Child is now 7 years old girl, having brilliant psychomotorical development. Possible child brain damage, lung damage, mental diseases are the reason for necessity E. coli infection treatment during pregnancy. Conclusion: All pregnant women should be screened for bacteriuria. E. coli is most commonly sensitive to group B antibiotics (cephalexin and amoxicillin, safe to be included in pregnancy. Long-term follow up of infants born from mothers having bacterial infection during pregnancy is necessary.

  12. Escherichia coli as other Enterobacteriaceae: food poisoning and health effects

    Science.gov (United States)

    Many Escherichia coli strains are harmless, and they are an important commensal in the intestinal microflora; however, pathogenic strains also exist. The pathogenic strains can be divided into diarrhea-inducing strains and strains that reside in the intestines but only cause disease in bodily sites...

  13. Escherichia coli and other Enterobacteriaceae: Food poisoning and health effects

    Science.gov (United States)

    The family Enterobactericeae consists of rod-shaped, Gram-negative, facultatively anaerobic, non-spore forming bacteria and also includes the food-borne pathogens, Cronobacter spp., Escherichia coli, Salmonella enterica, Shigella spp., and Yersinia spp. Illness caused by these pathogens is acquired...

  14. Binding of Divalent Magnesium by Escherichia coli Phosphoribosyl Diphosphate Synthetase

    DEFF Research Database (Denmark)

    Willemoës, Martin; Hove-Jensen, Bjarne

    1997-01-01

    The mechanism of binding of the substrates MgATP and ribose 5-phosphate as well as Mg2+ to the enzyme 5-phospho-d-ribosyl a-1-diphosphate synthetase from Escherichia coli has been analyzed. By use of the competive inhibitors of ATP and ribose 5-phosphate binding, a,ß-methylene ATP and (+)-1-a,2-a...

  15. Kwantitatief gevoeligheidsonderzoek met intra- en extramurale isolaten van Escherichia coli

    NARCIS (Netherlands)

    de Neeling AJ; de Jong J; Overbeek BP; de Bruin RW; Dessens-Kroon M; van Klingeren B

    1990-01-01

    Three Dutch laboratories for medical microbiology collected a total number of 1432 strains of Escherichia coli. Of these 995 were obtained from routine samples taken in clinic and policlinic, 290 had been sent spontaneously by general practitioners for microbiological examination and 147 had been

  16. in Escherichia coli with native cholesterol oxidase expressed

    African Journals Online (AJOL)

    The structure and bio-activity of an endogenous cholesterol oxidase from Brevibacterium sp. was compared to the same enzyme exogenously expressed in Escherichia coli BL21 (DE3) with and without N- or C-terminal his-tags. The different proteins were purified with affinity and subtractive protocols. The specific activity of ...

  17. Sequencing of Escherichia coli that cause persistent and transient Mastitis

    Science.gov (United States)

    The genomes of two strains of Escherichia coli that cause bovine mastitis were sequenced. These strains are known to be associated with persistent and transient mastitis: strain ECA-B causes a transient infection, and ECC-M leads to a persistent infection....

  18. Escherichia coli. A sanitary methodology for faecal water pollution tests

    International Nuclear Information System (INIS)

    Bonadonna, L.

    2001-01-01

    Among the traditional indictors of faecal water pollution, Escherichia coli has shown to fit better with the definition of indicator organism. Till now its recovery has been time-consuming and needs confirmation tests. In this report more rapid and direct methods, based on enzymatic reactions, are presented [it

  19. Antibiotic resistance profile of Escherichia coli isolated from five ...

    African Journals Online (AJOL)

    Information on the resistance profiles of clinical and non clinical human bacteria isolates in the developing countries can serve as important means of understanding the human pathogens drug resistance interactions in the zone. Escherichia coli isolated from five geopolitical zones of Nigeria were screened for anti-microbial ...

  20. Modeling base excision repair in Escherichia coli bacterial cells

    International Nuclear Information System (INIS)

    Belov, O.V.

    2011-01-01

    A model describing the key processes in Escherichia coli bacterial cells during base excision repair is developed. The mechanism is modeled of damaged base elimination involving formamidopyrimidine DNA glycosylase (the Fpg protein), which possesses several types of activities. The modeling of the transitions between DNA states is based on a stochastic approach to the chemical reaction description

  1. Occurrence of Escherichia coli in Brassica rapa L. chinensis ...

    African Journals Online (AJOL)

    Low quality water has become valuable resource with restricted or unrestricted use in food production depending on its quality. This study has quantified the occurrence of Escherichia coli in Brassica rapa L. chinensis (Chinese cabbage) vegetables and low quality irrigation water. A total of 106 samples including Chinese ...

  2. Detection and enumeration of Coliforms and Escherichia coli in water

    African Journals Online (AJOL)

    Water samples from eighteen different sources in Nairobi were analyzed for coliform and E. coli content using three microbiological techniques, namely: Multiple tube or Most Probable Number (MPN) technique, Defined Substrate Technique (DST) or Colilert technique and Petrifilm(TM) Plate Count Techniques. All the three ...

  3. Physiological responses of Escherichia coli to far-ultraviolet radiation

    International Nuclear Information System (INIS)

    Swenson, P.A.

    1976-01-01

    The following topics are reviewed: photochemical damage to DNA; measurement of cell survival; DNA repair processes and genetics of radiation sensitivity; degradation of DNA and RNA; biochemical and physiological consequences; reactivation of bacteriophage in Escherichia coli cells; filament formation; influence of growth phase on survival after uv irradiation; and post-uv-irradiation treatment

  4. Production of jet fuel precursor monoterpenoids from engineered Escherichia coli

    DEFF Research Database (Denmark)

    Mendez-Perez, Daniel; Alonso-Gutierrez, Jorge; Hu, Qijun

    2017-01-01

    ). FPP biosynthesis diverts the carbon flux from monoterpene production to C15 products and quinone biosynthesis. In this study, we tested a chromosomal mutation of Escherichia coli's native FPP synthase (IspA) to improve GPP availability for the production of monoterpenes using a heterologous mevalonate...

  5. Genetic Attributes of E. coli Isolates from Chlorinated Drinking Water.

    Science.gov (United States)

    Blyton, Michaela D J; Gordon, David M

    2017-01-01

    Escherichia coli, is intimately associated with both human health and water sanitation. E. coli isolates from water can either be (i) host associated commensals, indicating recent faecal contamination; (ii) diarrheal pathogens or (iii) extra-intestinal pathogens that pose a direct health risk; or (iv) free-living. In this study we genetically characterised 28 E. coli isolates obtained from treated drinking water in south eastern Australia to ascertain their likely source. We used full genome sequencing to assign the isolates to their phylogenetic group and multi-locus sequence type. The isolates were also screened in silico for several virulence genes and genes involved in acquired antibiotic resistance. The genetic characteristics of the isolates indicated that four isolates were likely human pathogens. However, these isolates were not detected in sufficient numbers to present a health risk to the public. An additional isolate was a human associated strain. Nine isolates were water associated free-living strains that were unlikely to pose a health risk. Only 14% of the isolates belonged to the host associated phylogenetic group (B2) and only a single isolate had any antibiotic resistance genes. This suggests that the primary source of the drinking water E. coli isolates may not have been recent human faecal contamination.

  6. Genetic Attributes of E. coli Isolates from Chlorinated Drinking Water.

    Directory of Open Access Journals (Sweden)

    Michaela D J Blyton

    Full Text Available Escherichia coli, is intimately associated with both human health and water sanitation. E. coli isolates from water can either be (i host associated commensals, indicating recent faecal contamination; (ii diarrheal pathogens or (iii extra-intestinal pathogens that pose a direct health risk; or (iv free-living. In this study we genetically characterised 28 E. coli isolates obtained from treated drinking water in south eastern Australia to ascertain their likely source. We used full genome sequencing to assign the isolates to their phylogenetic group and multi-locus sequence type. The isolates were also screened in silico for several virulence genes and genes involved in acquired antibiotic resistance. The genetic characteristics of the isolates indicated that four isolates were likely human pathogens. However, these isolates were not detected in sufficient numbers to present a health risk to the public. An additional isolate was a human associated strain. Nine isolates were water associated free-living strains that were unlikely to pose a health risk. Only 14% of the isolates belonged to the host associated phylogenetic group (B2 and only a single isolate had any antibiotic resistance genes. This suggests that the primary source of the drinking water E. coli isolates may not have been recent human faecal contamination.

  7. The incidence and antibiotics susceptibility of Escherichia coli O157 ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-02-22

    Feb 22, 2010 ... The incidence of Escherichia coli 0157: H7 was assessed in meat samples from slaughtered cattle in. Ibadan metropolis by culturing ... high quality farm to fork wholesome and safe meat for public consumption in Nigeria. Key words: EHEC .... Prevalence and in vitro antimicrobial susceptibility. Trop. Vet. 26.

  8. Prevalence of Escherichia coli virulence genes in patients with ...

    African Journals Online (AJOL)

    In this study, we investigated the prevalence of the virulence genes specific for five major pathogroups of diarrheagenic Escherichia coli (DEC) in primary cultures from diarrhoeagenic patients in Burkina Faso. Methodology: From September 2016 to Mars 2017, a total of 211 faecal samples from diarrhoeagenic patients from ...

  9. Comparative Genomics of Escherichia coli Strains Causing Urinary Tract Infections

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk; Hancock, Viktoria; Schembri, Mark A.

    2011-01-01

    The virulence determinants of uropathogenic Escherichia coli have been studied extensively over the years, but relatively little is known about what differentiates isolates causing various types of urinary tract infections. In this study, we compared the genomic profiles of 45 strains from a range...

  10. Effect of phytoplankton on Escherichia coli survival in laboratory microcosms

    Science.gov (United States)

    Fecal contamination of water sources is an important water quality issue for agricultural irrigation ponds. Escherichia coli is a common microbial indicator used to evaluate recreational and irrigation water quality. Nuisance algae commonly grow in low- or no-flow irrigation water source The objecti...

  11. Expression and purification of recombinant hemoglobin in Escherichia coli

    DEFF Research Database (Denmark)

    Natarajan, Chandrasekhar; Jiang, Xiaoben; Fago, Angela

    2011-01-01

    BACKGROUND: Recombinant DNA technologies have played a pivotal role in the elucidation of structure-function relationships in hemoglobin (Hb) and other globin proteins. Here we describe the development of a plasmid expression system to synthesize recombinant Hbs in Escherichia coli, and we describe...

  12. Prevalence and antibiogram of Escherichia coli O157 isolated from ...

    African Journals Online (AJOL)

    E. coli O157 from bovine carcass swabs and cecal contents were 9.3% and 7.3%, respectively. ..... Frequent use of tetracycline to treat animal dis- eases in ... Project entitled “Pneumonia, diarrhea and mastitis in food animals”. References.

  13. Antibiotic resistant Salmonella and Escherichia coli isolated from ...

    African Journals Online (AJOL)

    Objective: To characterise and investigate antimicrobial resistance of Esherichia coli and salmonella strains isolated from indigenous Gallus gallus in a leading slaughterhouse/market outlet in Nairobi-Kenya. Design: A repeated cross sectional study and based on random sampling was used. Setting: The study was carried ...

  14. Search for Enterohaemorrhagic Escherichia coli O157:H7 and ...

    African Journals Online (AJOL)

    Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 and Salmonella enterica are important zoonotic bacteria responsible for enteric infections in humans. The present study investigated the possible role of kittens in the zoonotic transmission of antimicrobial resistant EHEC O157 and Salmonella enterica to human using ...

  15. Antibiotic Sensitivity Profile of Escherichia coli Isolated from Poultry ...

    African Journals Online (AJOL)

    A cross sectional study involving 300 cloaca swabs from apparently healthy birds from 8 small-medium scale poultry farms in Ibadan Oyo State was carried out. A total of 201 (67%) Escherichia coli isolates were recovered from the birds and they were subjected to in-vitro antibiotic sensitivity test by agar gel diffusion method.

  16. Multidrug resistant enterohaemorrhagic Escherichia coli O157:H7 in ...

    African Journals Online (AJOL)

    Pigeons are commonly seen around human dwellings and in city centres. The movement of these birds from place to place makes them a veritable vehicle for environmental dissemination of pathogens. Enterohaemorrhagic E. coli (EHEC) O157:H7 can cause severe and sometimes fatal gastroenteritis in humans. This study ...

  17. Initiation of ribosomal RNA synthesis in Escherichia coli

    NARCIS (Netherlands)

    Hamming, Jantina

    1981-01-01

    Het E. coli chromosoom is éên lang circulair dubbelstrengs DNA molecuul en beslaat ongeveer 3000 genen. Het enzym RNA polymerase is verantwoordelijk voor de transcriptie in RNA van alle genetische informatie in de ce1. Er zijn 2 soorten transcripten: de ribosomale en transfer RNAs die deel uitmaken

  18. Increasing the permeability of Escherichia coli using MAC13243

    DEFF Research Database (Denmark)

    Muheim, Claudio; Götzke, Hansjörg; Eriksson, Anna U.

    2017-01-01

    molecules that make the outer membrane of Escherichia coli more permeable. We identified MAC13243, an inhibitor of the periplasmic chaperone LolA that traffics lipoproteins from the inner to the outer membrane. We observed that cells were (1) more permeable to the fluorescent probe 1-N...

  19. Molecular characterization of the Escherichia coli asymptomatic bacteriuria strain 83972

    DEFF Research Database (Denmark)

    Klemm, Per; Hancock, Viktoria; Ulett, G.C.

    2006-01-01

    Escherichia coli 83972 is a clinical asymptomatia bacteriuric isolate that is able to colonize the human urinary bladder without inducing an immune response. Here we demonstrate that one of the mechanisms by which this strain has become attenuated is through the mutation of its genes encoding type...

  20. Adsorption kinetics of Escherichia Coli on different Carbon Nanoforms

    Directory of Open Access Journals (Sweden)

    Md. Shamimul Haque Choudhury

    2012-03-01

    Full Text Available Adsorption of Escherichia coli (E. Coli bacterial cells on different carbon nanoforms (i.e. Single walled carbon nanotube (SWCNT, Multiwalled Carbon nanotube (MWCNT, graphite and mixedFullerene aggregates is studied. The diffusivities of pure cultures of E. Coli cells in SWCNT aggregates, MWCN aggregates, Graphite aggregates and Mixed Fullerenes was observed to be 1.5×10-9 cm2/s, 0.55×10-9 cm2/s, 0.8×10-9 cm2/s, and 1.016×10-9 cm2/s, respectively. In addition to batch adsorption studies, optical microscopy studies were also performed. The results suggest that diffusion kinetics ofbacterial cells depends on the concentration and average diameter of the nano-carbon aggregates and also on the type of material used. Diffusivity of E. Coli. in SWCNT was observed to be highest and isabout three times greater than for MWCNT, about two times greater than for graphite and about 1.5 times greater than for Fullerene aggregates. SWCNT seems to be best candidates (amongst the othermaterials studied for adsorption of microorganisms – paying their way for application towards microorganisms filters and for biosensors (where it is desired to simultaneously detect and capture bio-threat agents.

  1. Multiple antimicrobial resistance of Escherichia coli and Salmonella ...

    African Journals Online (AJOL)

    Presumptive isolates were subjected to antimicrobial susceptibility testing using 13 panels of antibiotics for both E. coli and Salmonella spp. Results showed that the overall isolation rate of Salmonella spp. was 12 (11.4%), broiler chickens had higher isolation rate 9 (12.0%) of Salmonella than local chickens. However, the ...

  2. The redistribution of granulocytes following E. coli endotoxin induced sepsis

    DEFF Research Database (Denmark)

    Toft, P; Lillevang, S T; Tønnesen, Else Kirstine

    1994-01-01

    Infusion of endotoxin elicits granulocytopenia followed by increased numbers of granulocytes in peripheral blood. The purpose of this study was to investigate the redistribution and sequestration of granulocytes in the tissues following E. coli endotoxin induced sepsis. From 16 rabbits granulocytes...

  3. Inactivation of Escherichia coli by titanium dioxide photocatalytic oxidation.

    Science.gov (United States)

    Titanium dioxide in the anatase crystalline form was used as a photocatalyst to generate hydroxyl radicals in a flowthrough water reactor. Experiments were performed on pure cultures of Escherichia coli in dechlorinated tap water and a surface water sample to evaluate the disinfe...

  4. Complete Genome Sequence of Enterotoxigenic Escherichia coli Siphophage Seurat.

    Science.gov (United States)

    Doan, Dung P; Lessor, Lauren E; Hernandez, Adriana C; Kuty Everett, Gabriel F

    2015-02-26

    Enterotoxigenic Escherichia coli (ETEC) is one of the leading causes of diarrhea in developing countries. Bacteriophage therapy has the potential to aid in the prevention and treatment of ETEC-related illness. To that end, we present here the complete genome of ETEC siphophage Seurat and describe its major features. Copyright © 2015 Doan et al.

  5. One-step purification of E. coli elongation factor Tu

    DEFF Research Database (Denmark)

    Knudsen, Charlotte Rohde; Clark, Brian F. C.; Degn, B

    1993-01-01

    The tuf A gene, encoding the E. coli elongation factor Tu, was cloned in the pGEX gene fusion system. Upon expression EF-Tu is fused to glutathione-S-transferase serving as a purification handle with affinity for glutathione immobilised on agarose. This allows purification of EF-Tu in a one...

  6. Phenotypic Changes Exhibited by E. coli Cultured in Space

    DEFF Research Database (Denmark)

    Zea, Luis; Larsen, Michael; Estante, Frederico

    2017-01-01

    % in space with respect to the Earth control group. Outer membrane vesicles were observed on the spaceflight samples, but not on the Earth cultures. While E. coli suspension cultures on Earth were homogenously distributed throughout the liquid medium, in space they tended to form a cluster, leaving...

  7. Architecture of the E.coli 70S ribosome

    DEFF Research Database (Denmark)

    Burkhardt, N.; Diedrich, G.; Nierhaus, K.H.

    1997-01-01

    The 70S ribosome from E.coli was analysed by neutron scattering focusing on the shape and the internal protein-RNA-distribution of the complex. Measurements on selectively deuterated 70S particles and free 30S and 50S subunits applying conventional contrast variation and proton-spin contrast...

  8. Interdomain interactions in the mannitol permease of E-coli

    NARCIS (Netherlands)

    Meijberg, W; Schuurman-Wolters, GK; Robillard, GT; Ladbury, E.; Chowdhry, B.Z.

    1998-01-01

    The mannitol permease of E. coli, Enzyme IImannitol, catalyses the concomitant phosphorylation and transport of mannitol across the cytoplasmic membrane. The protein consists of three domains, one N-terminal transmembrane domain (C) and two cytoplasmic domains, A and B. During the catalytic cycle

  9. Protein export in bacillus subtilis and escherichia coli

    NARCIS (Netherlands)

    Dijl, Jan Maarten van

    1990-01-01

    The export of heterologous proteins in Bacillus subtilis and Escherichia coli is often inefficient. Frequently observed problems are: 1) accumulation of the precursor form of the exported protein in the cytoplasm or in the membrane; 2), inefficient or incorrect processing of the precursor; 3),

  10. Escherichia coli and virus isolated from ''sticky kits''

    DEFF Research Database (Denmark)

    Jørgensen, M.; Scheutz, F.; Strandbygaard, Bertel

    1996-01-01

    A total of 121 Escherichia coli strains isolated from 3-week-old mink kits were serotyped and examined for virulence factors. 56 strains were isolated from healthy kits while 65 were from ''sticky kits''. Among these, 34 different serotypes were detected. No difference in serotypes or the presenc...

  11. Orden monetario y bancos centrales Monetary order and Central Banks

    Directory of Open Access Journals (Sweden)

    Aglietta Michel

    1996-06-01

    Full Text Available Con el enfoque evolucionista e institucionalista de la economía de las convenciones francesa, este trabajo analiza el surgimiento histórico de la banca central y la creación institucional del 'arte de la banca central'. El artículo estudia los modelos formales del orden monetario, la banca libre y la banca central, y analiza los eventos históricos que llevaron a que el Banco de Inglaterra inventara el arte de manejar los bancos centrales en conjunción con el aprendizaje colectivo e institucional que lo hizo posible. Aglietta muestra que la banca central no es una creación del Estado sino una creación institucional endógena al sistema de mercado.With the evolutionist and institutionalist focus of the economics of the French conventions, this paper analyzes the historical rise of the central bank and the institutional creation of the 'art of the central bank'. The article studies formal models of the monetary order, free banking and the central bank, and analyzes the historie events that led to the Bank of England inventing the art of managing the central banks, in conjunction with the collective and institutional learning that made it possible. Aglietta shows that the central bank is not a creation of the State, but rather aninstitutional creation endogenous to the market system.

  12. Adult central nervous system

    International Nuclear Information System (INIS)

    Sutton, M.L.

    1985-01-01

    Historically, the adult central nervous system (CNS) was regarded as relatively immune to the effects of ionising radiation, and the recognition of the CNS as a radio-vulnerable structure occurred later than was the case for many other tissues. Increasingly precise knowledge of the time-dose-volume relationships for CNS tolerance has had two important consequences: (1) it has permitted the avoidance of catastrophic and usually lethal late effects in the brain and spinal cord when these tissues are unavoidably irradiated during the treatment of adjacent non-CNS tumours, and (2) it has encouraged referral for irradiation of certain technically benign lesions which, although compatible with prolonged survival, represent a continuing threat to the patient - for example arteriovenous malformations, pituitary adenomas, and some meningiomas. Many of these can now be controlled for very long periods following radiation doses consistent with the long-term functional integrity of the CNS

  13. UA2 central calorimeter

    CERN Multimedia

    The UA2 central calorimeter measured the energy of individual particles created in proton-antiproton collisions. Accurate calibration allowed the W and Z masses to be measured with a precision of about 1%. The calorimeter had 24 slices like this one, each weighing 4 tons. The slices were arranged like orange segments around the collision point. Incoming particles produced showers of secondary particles in the layers of heavy material. These showers passed through the layers of plastic scintillator, generating light which was taken by light guides (green) to the data collection electronics. The amount of light was proportional to the energy of the original particle. The inner 23 cm of lead and plastic sandwiches measured electrons and photons; the outer 80 cm of iron and plastic sandwiches measured strongly interacting hadrons. The detector was calibrated by injecting light through optical fibres or by placing a radioactive source in the tube on the bottom edge.

  14. CENTRAL EUROPE: Austron

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    For many of the countries of Central and Eastern Europe access to international research centres such as CERN, the European Space Agency (ESA), the Institut Laue-Langevin (ILL) or to national centres such as the Rutherford Appleton Laboratory in the UK or DESY in Germany, is hindered by the absence of intermediate research institutions. Since mid-1990 this question has been studied by an 'Austron' Study Group set up under the auspices of the Austrian Academy of Sciences and which cooperates with the so-called 'Pentagonal' initiative of Austria, Czechoslovakia, Hungary, Italy and Yugoslavia to promote cooperation in the area, with which Poland is now associated

  15. Central Accountability System (CLAS)

    International Nuclear Information System (INIS)

    Hairston, L.A.

    1991-01-01

    The Central Accountability System (CLAS) is a high level accountability system that consolidates data from the site's 39 material balance areas (MBA) for reporting to Westinghouse Savannah River Company (WSRC) management, Department of Energy (DOE) and the Nuclear Materials Management and Safeguards System (NMMSS) in Oak Ridge, TN. Development of the system began in 1989 and became operational in April, 1991. The CLAS system enhances data accuracy and accountability records, resulting in increased productivity and time and cost savings. This paper reports that the system is in compliance with DOE Orders and meets NMMSS reporting requirements. WSRC management is provided with the overall status of the site's nuclear material inventory. CLAS gives WSRC a leading edge in accounting technology and enhances good accounting practices

  16. Central America's shrinking forests.

    Science.gov (United States)

    1992-01-01

    This news brief reports that 66% of deforestation in Central America has happened in the past 40 years, based on World Conservation Union (WCU) data. Deforestation is expected to continue. The population of Central America and Mexico grew by 28% between 1977 and 1987. Growth is decreasing but remains high at 2.5% in all countries of the region except Panama. 29 million was the regional population in 1990; the projection is for 63 million by 2025. Population is migrating to urban centers. Forests declined by 13% and croplands increased from 4% to 13% of total land area and pasture land from 2% to 37%. There was an increase in unproductive land from 145 to 24%, i.e., 50% of El Salvador's land had soil degradation as does 30% of Guatemala's. In addition to deforestation and soil degradation, there has been soil erosion leading to sedimentation buildup near dam sites and in rivers, which diminishes hydroelectric power capability. Silting also affects groundwater resources, which impact on a safe drinking water supply. Population growth results in increased demand for fuelwood, urban land, and agricultural land. New techniques practiced widely are needed in order to meet the region's needs or demands. Slowing population growth buys time for adjusting to the necessary changes needed for sustaining the region's population. WCU urges conservation organizations to raise awareness about the role population plays in environmental degradation, and to support efforts to reduce birth rates. Women's status needs to be improved through income-generating projects, for instance, and cooperation is needed between conservation groups and organizations involved with improving maternal and child health.

  17. Central control of thermogenesis.

    Science.gov (United States)

    Clapham, John C

    2012-07-01

    In mammals and birds, conservation of body heat at around 37 °C is vital to life. Thermogenesis is the production of this heat which can be obligatory, as in basal metabolic rate, or it can be facultative such as the response to cold. A complex regulatory system has evolved which senses environmental or core temperature and integrates this information in hypothalamic regions such as the preoptic area and dorsomedial hypothalamus. These areas then send the appropriate signals to generate and conserve heat (or dissipate it). In this review, the importance of the sympathetic nervous system is discussed in relation to its role in basal metabolic rate and adaptive thermogenesis with a particular emphasis to human obesity. The efferent sympathetic pathway does not uniformly act on all tissues; different tissues can receive different levels of sympathetic drive at the same time. This is an important concept in the discussion of the pharmacotherapy of obesity. Despite decades of work the medicine chest contains only one pill for the long term treatment of obesity, orlistat, a lipase inhibitor that prevents the absorption of lipid from the gut and is itself not systemically absorbed. The central controlling system for thermogenesis has many potential intervention points. Several drugs, previously marketed, awaiting approval or in the earlier stages of development may have a thermogenic effect via activation of the sympathetic nervous system at some point in the thermoregulatory circuit and are discussed in this review. If the balance is weighted to the "wrong" side there is the burden of increased cardiovascular risk while a shift to the "right" side, if possible, will afford a thermogenic benefit that is conducive to weight loss maintenance. This article is part of a Special Issue entitled 'Central Control Food Intake' Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. Faecal Escherichia coli from patients with E. coli urinary tract infection and healthy controls who have never had a urinary tract infection

    DEFF Research Database (Denmark)

    Nielsen, Karen L; Dynesen, Pia; Larsen, Preben

    2014-01-01

    Urinary tract infections (UTIs) are primarily caused by Escherichia coli with the patient's own faecal flora acting as a reservoir for the infecting E. coli. Here we sought to characterize the E. coli faecal flora of UTI patients and healthy controls who had never had a UTI. Up to 20 E. coli...... colonies from each rectal swab were random amplified polymorphic DNA (RAPD) typed for clonality, dominance in the sample and correlation to the infecting UTI isolate in patients. Each distinct clone was phylotyped and tested for antimicrobial susceptibility. Eighty-seven per cent of the UTI patients...... carried the infecting strain in their faecal flora, and faecal clones causing UTI were more often dominant in the faecal flora. Patients had a larger diversity of E. coli in their gut flora by carrying more unique E. coli clones compared to controls, and patient faecal clones were more often associated...

  19. Genetic and biochemical analysis of peptide transport in Escherichia coli

    International Nuclear Information System (INIS)

    Andrews, J.C.

    1986-01-01

    E. coli peptide transport mutants have been isolated based on their resistance to toxic tripeptides. These genetic defects were found to map in two distinct chromosomal locations. The transport systems which require expression of the trp-linked opp genes and the oppE gene(s) for activity were shown to have different substrate preferences. Growth of E. coli in medium containing leucine results in increased entry of exogenously supplied tripeptides into the bacterial cell. This leucine-mediated elevation of peptide transport required expression of the trp-linked opp operon and was accompanied by increased sensitivity to toxic tripeptides, by an enhanced capacity to utilize nutritional peptides, and by an increase in both the velocity and apparent steady-state level of L-(U- 14 C)alanyl-L-alanyl-L-alanine accumulation for E. coli grown in leucine-containing medium relative to these parameters of peptide transport measured with bacteria grown in media lacking leucine. Direct measurement of opp operon expression by pulse-labeling experiments demonstrated that growth of E. coli in the presence of leucine resulted in increased synthesis of the oppA-encoded periplasmic binding protein. The transcriptional regulation of the trp-linked opp operon of E. coli was investigated using λ placMu51-generated lac operon fusions. Synthesis of β-galactosidase by strains harboring oppA-lac, oppB-lac, and oppD-lac fusions occurred at a basal level when the fusion-containing strains were grown in minimal medium

  20. How much territory can a single E. coli cell control?

    Directory of Open Access Journals (Sweden)

    Ziad W. El-Hajj

    2015-04-01

    Full Text Available Bacteria have been traditionally classified in terms of size and shape and are best known for their very small size. E. coli cells in particular are small rods, each 1-2 microns. However the size varies with the medium, and faster growing cells are larger because they must have more ribosomes to make more protoplasm per unit time, and ribosomes take up space. Indeed, Maaloe's experiments on how E. coli establishes its size began with shifts between rich and poor media.Recently much larger bacteria have been described, including Epulopiscium fishelsoni at 700 μm and Thiomargarita namibiensisis at 750 μm. These are not only much longer than E. coli cells but also much wider, necessitating considerable intracellular organization. Epulopiscium cells for instance, at 80 μm wide, enclose a large enough volume of cytoplasm to present it with major transport problems.This review surveys E. coli cells much longer than those which grow in nature and in usual lab cultures. These include cells mutated in a single gene (metK which are 2-4x longer than their nonmutated parent. This metK mutant stops dividing when slowly starved of S-adenosylmethionine but continues to elongate to 50 μm and more. FtsZ mutants have been routinely isolated as long cells which form during growth at 42°C. The SOS response is a well-characterized regulatory network that is activated in response to DNA damage and also results in cell elongation. Our champion elongated E. coli is a metK strain with a further, as yet unidentified mutation, which reaches 750 μm with no internal divisions and no increase in width.

  1. Genomic and Phenomic Study of Mammary Pathogenic Escherichia coli

    Science.gov (United States)

    Blum, Shlomo E.; Heller, Elimelech D.; Sela, Shlomo; Elad, Daniel; Edery, Nir; Leitner, Gabriel

    2015-01-01

    Escherichia coli is a major etiological agent of intra-mammary infections (IMI) in cows, leading to acute mastitis and causing great economic losses in dairy production worldwide. Particular strains cause persistent IMI, leading to recurrent mastitis. Virulence factors of mammary pathogenic E. coli (MPEC) involved pathogenesis of mastitis as well as those differentiating strains causing acute or persistent mastitis are largely unknown. This study aimed to identify virulence markers in MPEC through whole genome and phenome comparative analysis. MPEC strains causing acute (VL2874 and P4) or persistent (VL2732) mastitis were compared to an environmental strain (K71) and to the genomes of strains representing different E. coli pathotypes. Intra-mammary challenge in mice confirmed experimentally that the strains studied here have different pathogenic potential, and that the environmental strain K71 is non-pathogenic in the mammary gland. Analysis of whole genome sequences and predicted proteomes revealed high similarity among MPEC, whereas MPEC significantly differed from the non-mammary pathogenic strain K71, and from E. coli genomes from other pathotypes. Functional features identified in MPEC genomes and lacking in the non-mammary pathogenic strain were associated with synthesis of lipopolysaccharide and other membrane antigens, ferric-dicitrate iron acquisition and sugars metabolism. Features associated with cytotoxicity or intra-cellular survival were found specifically in the genomes of strains from severe and acute (VL2874) or persistent (VL2732) mastitis, respectively. MPEC genomes were relatively similar to strain K-12, which was subsequently shown here to be possibly pathogenic in the mammary gland. Phenome analysis showed that the persistent MPEC was the most versatile in terms of nutrients metabolized and acute MPEC the least. Among phenotypes unique to MPEC compared to the non-mammary pathogenic strain were uric acid and D-serine metabolism. This study

  2. Collagen-like proteins in pathogenic E. coli strains.

    Directory of Open Access Journals (Sweden)

    Neelanjana Ghosh

    Full Text Available The genome sequences of enterohaemorrhagic E. coli O157:H7 strains show multiple open-reading frames with collagen-like sequences that are absent from the common laboratory strain K-12. These putative collagens are included in prophages embedded in O157:H7 genomes. These prophages carry numerous genes related to strain virulence and have been shown to be inducible and capable of disseminating virulence factors by horizontal gene transfer. We have cloned two collagen-like proteins from E. coli O157:H7 into a laboratory strain and analysed the structure and conformation of the recombinant proteins and several of their constituting domains by a variety of spectroscopic, biophysical, and electron microscopy techniques. We show that these molecules exhibit many of the characteristics of vertebrate collagens, including trimer formation and the presence of a collagen triple helical domain. They also contain a C-terminal trimerization domain, and a trimeric α-helical coiled-coil domain with an unusual amino acid sequence almost completely lacking leucine, valine or isoleucine residues. Intriguingly, these molecules show high thermal stability, with the collagen domain being more stable than those of vertebrate fibrillar collagens, which are much longer and post-translationally modified. Under the electron microscope, collagen-like proteins from E. coli O157:H7 show a dumbbell shape, with two globular domains joined by a hinged stalk. This morphology is consistent with their likely role as trimeric phage side-tail proteins that participate in the attachment of phage particles to E. coli target cells, either directly or through assembly with other phage tail proteins. Thus, collagen-like proteins in enterohaemorrhagic E. coli genomes may have a direct role in the dissemination of virulence-related genes through infection of harmless strains by induced bacteriophages.

  3. Discovery of Escherichia coli CRISPR sequences in an undergraduate laboratory.

    Science.gov (United States)

    Militello, Kevin T; Lazatin, Justine C

    2017-05-01

    Clustered regularly interspaced short palindromic repeats (CRISPRs) represent a novel type of adaptive immune system found in eubacteria and archaebacteria. CRISPRs have recently generated a lot of attention due to their unique ability to catalog foreign nucleic acids, their ability to destroy foreign nucleic acids in a mechanism that shares some similarity to RNA interference, and the ability to utilize reconstituted CRISPR systems for genome editing in numerous organisms. In order to introduce CRISPR biology into an undergraduate upper-level laboratory, a five-week set of exercises was designed to allow students to examine the CRISPR status of uncharacterized Escherichia coli strains and to allow the discovery of new repeats and spacers. Students started the project by isolating genomic DNA from E. coli and amplifying the iap CRISPR locus using the polymerase chain reaction (PCR). The PCR products were analyzed by Sanger DNA sequencing, and the sequences were examined for the presence of CRISPR repeat sequences. The regions between the repeats, the spacers, were extracted and analyzed with BLASTN searches. Overall, CRISPR loci were sequenced from several previously uncharacterized E. coli strains and one E. coli K-12 strain. Sanger DNA sequencing resulted in the discovery of 36 spacer sequences and their corresponding surrounding repeat sequences. Five of the spacers were homologous to foreign (non-E. coli) DNA. Assessment of the laboratory indicates that improvements were made in the ability of students to answer questions relating to the structure and function of CRISPRs. Future directions of the laboratory are presented and discussed. © 2016 by The International Union of Biochemistry and Molecular Biology, 45(3):262-269, 2017. © 2016 The International Union of Biochemistry and Molecular Biology.

  4. Genetic determinants of heat resistance in Escherichia coli

    Directory of Open Access Journals (Sweden)

    Ryan eMercer

    2015-09-01

    Full Text Available Escherichia coli AW1.7 is a heat resistant food isolate and the occurrence of pathogenic strains with comparable heat resistance may pose a risk to food safety. To identify the genetic determinants of heat resistance, 29 strains of E. coli that differed in their of heat resistance were analyzed by comparative genomics. Strains were classified as highly heat resistant strains, exhibiting a D60-value of more than 6 min; moderately heat resistant strains, exhibiting a D60-value of more than 1 min; or as heat sensitive. A ~14 kb genomic island containing 16 predicted open reading frames encoding putative heat shock proteins and proteases was identified only in highly heat resistant strains. The genomic island was termed the locus of heat resistance (LHR. This putative operon is flanked by mobile elements and possesses >99% sequence identity to genomic islands contributing to heat resistance in Cronobacter sakazakii and Klebsiella pneumoniae. An additional 41 LHR sequences with >87% sequence identity were identified in 11 different species of β- and γ-proteobacteria. Cloning of the full length LHR conferred high heat resistance to the heat sensitive E. coli AW1.7ΔpHR1 and DH5α. The presence of the LHR correlates perfectly to heat resistance in several species of Enterobacteriaceae and occurs at a frequency of 2% of all E. coli genomes, including pathogenic strains. This study suggests the LHR has been laterally exchanged among the β- and γ-proteobacteria and is a reliable indicator of high heat resistance in E. coli.

  5. GENETIC CONTROL OF RESTRICTION AND MODIFICATION IN ESCHERICHIA COLI1

    Science.gov (United States)

    Boyer, Herbert

    1964-01-01

    Boyer, Herbert (Yale University, New Haven, Conn.). Genetic control of restriction and modification in Escherichia coli. J. Bacteriol. 88:1652–1660. 1964.—Bacterial crosses with K-12 strains of Escherichia coli as Hfr donors (Hfr Hayes, Hfr Cavalli, and Hfr P4X-6) and B/r strains of E. coli as F− recipients were found to differ from crosses between K-12 Hfr donors and K-12 F− recipients in two ways: (i) recombinants (leu, pro, lac, and gal) did not appear at discrete time intervals but did appear simultaneously 30 min after matings were initiated, and (ii) the linkage of unselected markers to selected markers was reduced. Integration of a genetic region linked to the threonine locus of K-12 into the B/r genome resulted in a hybrid which no longer gave anomalous results in conjugation experiments. A similar region of the B strain was introduced into the K-12 strain, which then behaved as a typical B F− recipient. These observations are interpreted as the manifestation of host-controlled modification and restriction on the E. coli chromosome. This was verified by experiments on the restriction and modification of the bacteriophage lambda, F-lac, F-gal, and sex-factor, F1. It was found that the genetic region that controlled the mating responses of the K-12 and B/r strains also controlled the modification and restriction properties of these two strains. The genes responsible for the restricting and modifying properties of the K-12 and B strains of E. coli were found to be allelic, linked to each other, and linked to the threonine locus. PMID:14240953

  6. Brote causado por Escherichia coli en Chalco, México

    Directory of Open Access Journals (Sweden)

    Cortés-Ortiz Iliana Alejandra

    2002-01-01

    Full Text Available Objetivo. Identificar el agente causal del brote de diarrea asociado con el desbordamiento del canal de aguas negras en Chalco. Material y métodos. Estudio retrospectivo y transversal, efectuado en el Instituto de Diagnóstico y Referencia Epidemiológicos (InDRE, de la Secretaría de Salud, con 1 550 hisopos rectales para el aislamiento e identificación bioquímica de V. cholerae y enterobacterias, obtenidos de la población del Valle de Chalco, que presentó diarrea y vómito durante el desastre natural acontecido el 31 de mayo de 2000. El análisis de los resultados se efectuó por la diferencia entre las proporciones de dos poblaciones (prueba de Ji cuadrada. Las cepas de E. coli se hibridaron por "colony blot" para los grupos ETEC, EIEC, EPEC y EHEC. Resultados. El 0.45% correspondió a Salmonella: S. agona, S. infantis, S. enteritidis, S. muenchen, S. typhimurium; 0.06% a Shigella flexneri 3a, y 76.6% a E. coli: 62.2% a ETEC (44.6 % con LT, 11.2% con ST, y 44.1% con ambas sondas, 0.84% a EIEC (sonda ial, 0.84% a EPEC (sonda bundle-forming pilus BFP, 0.08% a E. coli enterohemorrágica no-O157:H7 (sonda pCVD419, y 36.02% no hibridó. No se encontró asociación entre E. coli patógena con la edad y género. Conclusiones. Escherichia coli podría ser responsable del brote de diarrea. Es importante conocer el agente etiológico del brote para encaminar las estrategias en el estudio y control sanitario del mismo.

  7. Anaerobic respiration of Escherichia coli in the mouse intestine.

    Science.gov (United States)

    Jones, Shari A; Gibson, Terri; Maltby, Rosalie C; Chowdhury, Fatema Z; Stewart, Valley; Cohen, Paul S; Conway, Tyrrell

    2011-10-01

    The intestine is inhabited by a large microbial community consisting primarily of anaerobes and, to a lesser extent, facultative anaerobes, such as Escherichia coli, which we have shown requires aerobic respiration to compete successfully in the mouse intestine (S. A. Jones et al., Infect. Immun. 75:4891-4899, 2007). If facultative anaerobes efficiently lower oxygen availability in the intestine, then their sustained growth must also depend on anaerobic metabolism. In support of this idea, mutants lacking nitrate reductase or fumarate reductase have extreme colonization defects. Here, we further explore the role of anaerobic respiration in colonization using the streptomycin-treated mouse model. We found that respiratory electron flow is primarily via the naphthoquinones, which pass electrons to cytochrome bd oxidase and the anaerobic terminal reductases. We found that E. coli uses nitrate and fumarate in the intestine, but not nitrite, dimethyl sulfoxide, or trimethylamine N-oxide. Competitive colonizations revealed that cytochrome bd oxidase is more advantageous than nitrate reductase or fumarate reductase. Strains lacking nitrate reductase outcompeted fumarate reductase mutants once the nitrate concentration in cecal mucus reached submillimolar levels, indicating that fumarate is the more important anaerobic electron acceptor in the intestine because nitrate is limiting. Since nitrate is highest in the absence of E. coli, we conclude that E. coli is the only bacterium in the streptomycin-treated mouse large intestine that respires nitrate. Lastly, we demonstrated that a mutant lacking the NarXL regulator (activator of the NarG system), but not a mutant lacking the NarP-NarQ regulator, has a colonization defect, consistent with the advantage provided by NarG. The emerging picture is one in which gene regulation is tuned to balance expression of the terminal reductases that E. coli uses to maximize its competitiveness and achieve the highest possible population in

  8. Succinic acid production by escherichia coli under anaerobic fermentation

    International Nuclear Information System (INIS)

    El Shafey, H.M.; Meleigy, S.A.

    2009-01-01

    The effect of alteration of growth conditions, addition of different sodium salts, and irradiation by gamma rays on succinic acid production by E. coli was studied. Twenty one isolates were obtained from buffalo's rumen, and anaerobic screening of the isolated bacterial strains showed the abilities of seventeen strains to produce succinic acid. The two bacterial strains having highest succinic acid production were identified as escherichia coli SP9 and SP16, and were selected for further studies. Results showed that growth conditions yielded highest succinic acid production for the two isolates were: 72 hours incubation, 37 degree c incubation temperature, initial ph of the fermentation medium 6.0,and 3% (v/v)inoculum size. Addition of 5 mm of nine different sodium salts to the fermentation medium showed stimulating effect on succinic acid production of the nine tried sodium salts, sodium carbonate was found to have the highest enhancing effect, especially if used at 15 mm concentration. Gamma irradiation doses tried were in the range of (0.25-1.50 kGy). An enhancing effect on succinic acid production was shown in the range of 0.25-0.75 kGy with a maximal production at 0.75 kGy (giving 8.36% increase) for e.coli SP9, and in the range of 0.25-1.00 kGy with a maximal production at 1.0 kGy (7.60% increase) for e.coli SP16. higher gamma doses led to a decrease in the enhancing effect. An overall increase in the succinic acid yield of 79.45% and 94.26% for e. coli SP9 and SP16, respectively, was achieved in implicating all optimized factors for succinic acid production in one time

  9. Activation of the Glutamic Acid-Dependent Acid Resistance System in Escherichia coli BL21(DE3 Leads to Increase of the Fatty Acid Biotransformation Activity.

    Directory of Open Access Journals (Sweden)

    Ji-Min Woo

    Full Text Available The biosynthesis of carboxylic acids including fatty acids from biomass is central in envisaged biorefinery concepts. The productivities are often, however, low due to product toxicity that hamper whole-cell biocatalyst performance. Here, we have investigated factors that influence the tolerance of Escherichia coli to medium chain carboxylic acid (i.e., n-heptanoic acid-induced stress. The metabolic and genomic responses of E. coli BL21(DE3 and MG1655 grown in the presence of n-heptanoic acid indicated that the GadA/B-based glutamic acid-dependent acid resistance (GDAR system might be critical for cellular tolerance. The GDAR system, which is responsible for scavenging intracellular protons by catalyzing decarboxylation of glutamic acid, was inactive in E. coli BL21(DE3. Activation of the GDAR system in this strain by overexpressing the rcsB and dsrA genes, of which the gene products are involved in the activation of GadE and RpoS, respectively, resulted in acid tolerance not only to HCl but also to n-heptanoic acid. Furthermore, activation of the GDAR system allowed the recombinant E. coli BL21(DE3 expressing the alcohol dehydrogenase of Micrococcus luteus and the Baeyer-Villiger monooxygenase of Pseudomonas putida to reach 60% greater product concentration in the biotransformation of ricinoleic acid (i.e., 12-hydroxyoctadec-9-enoic acid (1 into n-heptanoic acid (5 and 11-hydroxyundec-9-enoic acid (4. This study may contribute to engineering E. coli-based biocatalysts for the production of carboxylic acids from renewable biomass.

  10. Activation of the Glutamic Acid-Dependent Acid Resistance System in Escherichia coli BL21(DE3) Leads to Increase of the Fatty Acid Biotransformation Activity.

    Science.gov (United States)

    Woo, Ji-Min; Kim, Ji-Won; Song, Ji-Won; Blank, Lars M; Park, Jin-Byung

    The biosynthesis of carboxylic acids including fatty acids from biomass is central in envisaged biorefinery concepts. The productivities are often, however, low due to product toxicity that hamper whole-cell biocatalyst performance. Here, we have investigated factors that influence the tolerance of Escherichia coli to medium chain carboxylic acid (i.e., n-heptanoic acid)-induced stress. The metabolic and genomic responses of E. coli BL21(DE3) and MG1655 grown in the presence of n-heptanoic acid indicated that the GadA/B-based glutamic acid-dependent acid resistance (GDAR) system might be critical for cellular tolerance. The GDAR system, which is responsible for scavenging intracellular protons by catalyzing decarboxylation of glutamic acid, was inactive in E. coli BL21(DE3). Activation of the GDAR system in this strain by overexpressing the rcsB and dsrA genes, of which the gene products are involved in the activation of GadE and RpoS, respectively, resulted in acid tolerance not only to HCl but also to n-heptanoic acid. Furthermore, activation of the GDAR system allowed the recombinant E. coli BL21(DE3) expressing the alcohol dehydrogenase of Micrococcus luteus and the Baeyer-Villiger monooxygenase of Pseudomonas putida to reach 60% greater product concentration in the biotransformation of ricinoleic acid (i.e., 12-hydroxyoctadec-9-enoic acid (1)) into n-heptanoic acid (5) and 11-hydroxyundec-9-enoic acid (4). This study may contribute to engineering E. coli-based biocatalysts for the production of carboxylic acids from renewable biomass.

  11. Quantitative analysis of an engineered CO2-fixing Escherichia coli reveals great potential of heterotrophic CO2 fixation.

    Science.gov (United States)

    Gong, Fuyu; Liu, Guoxia; Zhai, Xiaoyun; Zhou, Jie; Cai, Zhen; Li, Yin

    2015-01-01

    Production of fuels from the abundant and wasteful CO2 is a promising approach to reduce carbon emission and consumption of fossil fuels. Autotrophic microbes naturally assimilate CO2 using energy from light, hydrogen, and/or sulfur. However, their slow growth rates call for investigation of the possibility of heterotrophic CO2 fixation. Although preliminary research has suggested that CO2 fixation in heterotrophic microbes is feasible after incorporation of a CO2-fixing bypass into the central carbon metabolic pathway, it remains unclear how much and how efficient that CO2 can be fixed by a heterotrophic microbe. A simple metabolic flux index was developed to indicate the relative strength of the CO2-fixation flux. When two sequential enzymes of the cyanobacterial Calvin cycle were incorporated into an E. coli strain, the flux of the CO2-fixing bypass pathway accounts for 13 % of that of the central carbon metabolic pathway. The value was increased to 17 % when the carbonic anhydrase involved in the cyanobacterial carbon concentrating mechanism was introduced, indicating that low intracellular CO2 concentration is one limiting factor for CO2 fixation in E. coli. The engineered CO2-fixing E. coli with carbonic anhydrase was able to fix CO2 at a rate of 19.6 mg CO2 L(-1) h(-1) or the specific rate of 22.5 mg CO2 g DCW(-1) h(-1). This CO2-fixation rate is comparable with the reported rates of 14 autotrophic cyanobacteria and algae (10.5-147.0 mg CO2 L(-1) h(-1) or the specific rates of 3.5-23.7 mg CO2 g DCW(-1) h(-1)). The ability of CO2 fixation was created and improved in E. coli by incorporating partial cyanobacterial Calvin cycle and carbon concentrating mechanism, respectively. Quantitative analysis revealed that the CO2-fixation rate of this strain is comparable with that of the autotrophic cyanobacteria and algae, demonstrating great potential of heterotrophic CO2 fixation.

  12. Structure of Escherichia coli UDP-N-acetylmuramoyl:L-alanine ligase (MurC).

    Science.gov (United States)

    Deva, Taru; Baker, Edward N; Squire, Christopher J; Smith, Clyde A

    2006-12-01

    The bacterial cell wall provides essential protection from the external environment and confers strength and rigidity to counteract internal osmotic pressure. Without this layer the cell would be easily ruptured and it is for this reason that biosynthetic pathways leading to the formation of peptidoglycan have for many years been a prime target for effective antibiotics. Central to this pathway are four similar ligase enzymes which add peptide groups to glycan moieties. As part of a program to better understand the structure-function relationships in these four enzymes, the crystal structure of Escherichia coli UDP-N-acetylmuramoyl:L-alanine ligase (MurC) has been determined to 2.6 A resolution. The structure was solved by multiwavelength anomalous diffraction methods from a single selenomethionine-substituted crystal and refined to a crystallographic R factor of 0.212 (R(free) = 0.259). The enzyme has a modular multi-domain structure very similar to those of other members of the mur family of ATP-dependent amide-bond ligases. Detailed comparison of these four enzymes shows that considerable conformational changes are possible. These changes, together with the recruitment of two different N-terminal domains, allow this family of enzymes to bind a substrate which is identical at one end and at the other has the growing peptide tail which will ultimately become part of the rigid bacterial cell wall. Comparison of the E. coli and Haemophilus influenzae structures and analysis of the sequences of known MurC enzymes indicate the presence of a ;dimerization' motif in almost 50% of the MurC enzymes and points to a highly conserved loop in domain 3 that may play a key role in amino-acid ligand specificity.

  13. Purification and cellular localization of wild type and mutated dihydrolipoyltransacetylases from Azotobacter vinelandii and Escherichia coli expressed in E. coli

    NARCIS (Netherlands)

    Schulze, Egbert; Westphal, Adrie H.; Veenhuis, Marten; Kok, Arie de

    1992-01-01

    Wild type dihydrolipoyltransacetylase(E2p)-components from the pyruvate dehydrogenase complex of A. vinelandii or E. coli, and mutants of A. vinelandii E2p with stepwise deletions of the lipoyl domains or the alanine- and proline-rich region between the binding and the catalytic domain have been

  14. Captive wild birds as reservoirs of enteropathogenic E. coli (EPEC) and Shiga-toxin producing E. coli (STEC).

    Science.gov (United States)

    Sanches, Lilian Aparecida; Gomes, Marcelo da Silva; Teixeira, Rodrigo Hidalgo Friciello; Cunha, Marcos Paulo Vieira; Oliveira, Maria Gabriela Xavier de; Vieira, Mônica Aparecida Midolli; Gomes, Tânia Aparecida Tardelli; Knobl, Terezinha

    Psittacine birds have been identified as reservoirs of diarrheagenic Escherichia coli, a subset of pathogens associated with mortality of children in tropical countries. The role of other orders of birds as source of infection is unclear. The aim of this study was to perform the molecular diagnosis of infection with diarrheagenic E. coli in 10 different orders of captive wild birds in the state of São Paulo, Brazil. Fecal samples were analyzed from 516 birds belonging to 10 orders: Accipitriformes, Anseriformes, Columbiformes, Falconiformes, Galliformes, Passeriformes, Pelecaniformes, Piciformes, Psittaciformes and Strigiformes. After isolation, 401 E. coli strains were subjected to multiplex PCR system with amplification of genes eae and bfp (EPEC), stx1 and stx2 for STEC. The results of these tests revealed 23/401 (5.74%) positive strains for eae gene, 16/401 positive strains for the bfp gene (3.99%) and 3/401 positive for stx2 gene (0.75%) distributed among the orders of Psittaciformes, Strigiformes and Columbiformes. None of strains were positive for stx1 gene. These data reveal the infection by STEC, typical and atypical EPEC in captive birds. The frequency of these pathotypes is low and restricted to few orders, but the data suggest the potential public health risk that these birds represent as reservoirs of diarrheagenic E. coli. Copyright © 2017 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  15. Transcriptome of E. coli K1 bound to human brain microvascular endothelial cells

    OpenAIRE

    Xie, Yi; Parthasarathy, Geetha; Di Cello, Francescopaolo; Teng, Ching-Hao; Paul-Satyaseela, Maneesh; Kim, Kwang Sik

    2007-01-01

    Escherichia coli K1 is the most common Gram-negative organism causing neonatal meningitis. Binding to human brain microvascdular endothelial cells (HBMEC) is an essential step for E. coli K1 traversal of the blood-brain barrier. In this study, we examined expression profiles of E. coli K1 strain RS218 during its binding to HBMEC. Comparison of HBMEC-bound E. coli K1 with collagen-bound E. coli revealed more than one hundred genes whose expression patterns were significantly changed in HBMEC-b...

  16. Escherichia coli EDL933 Requires Gluconeogenic Nutrients To Successfully Colonize the Intestines of Streptomycin-Treated Mice Precolonized with E. coli Nissle 1917

    Science.gov (United States)

    Schinner, Silvia A. C.; Mokszycki, Matthew E.; Adediran, Jimmy; Leatham-Jensen, Mary; Conway, Tyrrell

    2015-01-01

    Escherichia coli MG1655, a K-12 strain, uses glycolytic nutrients exclusively to colonize the intestines of streptomycin-treated mice when it is the only E. coli strain present or when it is confronted with E. coli EDL933, an O157:H7 strain. In contrast, E. coli EDL933 uses glycolytic nutrients exclusively when it is the only E. coli strain in the intestine but switches in part to gluconeogenic nutrients when it colonizes mice precolonized with E. coli MG1655 (R. L. Miranda et al., Infect Immun 72:1666–1676, 2004, http://dx.doi.org/10.1128/IAI.72.3.1666-1676.2004). Recently, J. W. Njoroge et al. (mBio 3:e00280-12, 2012, http://dx.doi.org/10.1128/mBio.00280-12) reported that E. coli 86-24, an O157:H7 strain, activates the expression of virulence genes under gluconeogenic conditions, suggesting that colonization of the intestine with a probiotic E. coli strain that outcompetes O157:H7 strains for gluconeogenic nutrients could render them nonpathogenic. Here we report that E. coli Nissle 1917, a probiotic strain, uses both glycolytic and gluconeogenic nutrients to colonize the mouse intestine between 1 and 5 days postfeeding, appears to stop using gluconeogenic nutrients thereafter in a large, long-term colonization niche, but continues to use them in a smaller niche to compete with invading E. coli EDL933. Evidence is also presented suggesting that invading E. coli EDL933 uses both glycolytic and gluconeogenic nutrients and needs the ability to perform gluconeogenesis in order to colonize mice precolonized with E. coli Nissle 1917. The data presented here therefore rule out the possibility that E. coli Nissle 1917 can starve the O157:H7 E. coli strain EDL933 of gluconeogenic nutrients, even though E. coli Nissle 1917 uses such nutrients to compete with E. coli EDL933 in the mouse intestine. PMID:25733524

  17. Enteroaggregative Escherichia coli is the predominant diarrheagenic E. coli pathotype among irrigation water and food sources in South Africa.

    Science.gov (United States)

    Aijuka, Matthew; Santiago, Araceli E; Girón, Jorge A; Nataro, James P; Buys, Elna M

    2018-08-02

    Diarrheagenic E. coli (DEC) has been implicated in foodborne outbreaks worldwide and have been associated with childhood stunting in the absence of diarrhoea. Infection is extraordinarily common, but the routes of transmission have not been determined. Therefore, determining the most prevalent pathotypes in food and environmental sources may help provide better guidance to various stakeholders in ensuring food safety and public health and advancing understanding of the epidemiology of enteric disease. We characterized 205 E. coli strains previously isolated from producer distributor bulk milk (PDBM)(118), irrigation water (48), irrigated lettuce (29) and street vendor coleslaw (10) in South Africa. Enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), enteroaggregative E. coli (EAEC) and diffusely adherent E. coli (DAEC) were sought. We used PCR and partial gene sequencing for all 205 strains while 46 out of 205 that showed poor resolution were subsequently characterized using cell adherence (HeLa cells). PCR and partial gene sequencing of aatA and/or aaiC genes confirmed EAEC (2%, 5 out of 205) as the only pathotype. Phylogenetic analysis of sequenced EAEC strains with E. coli strains in GenBank showing ≥80% nucleotide sequence similarity based on possession of aaiC and aatA generated distinct clusters of strains separated predominantly based on their source of isolation (food source or human stool) suggesting a potential role of virulence genes in source tracking. EAEC 24%, 11 out of 46 strains (PDBM = 15%, irrigation water = 7%, irrigated lettuce = 2%) was similarly the predominant pathotype followed by strains showing invasiveness to HeLa cells, 4%, 2 out of 46 (PDBM = 2%, irrigated lettuce = 2%), among stains characterized using cell adherence. Therefore, EAEC may be the leading cause of DEC associated food and water-borne enteric infection in South Africa. Additionally, solely using molecular based methods targeting virulence

  18. Fecal colonization with P-fimbriated Escherichia coli in newborn children and relation to development of extraintestinal E. coli infections.

    Science.gov (United States)

    Tullus, K

    1987-01-01

    The incidence of E. coli pyelonephritis before the age of one year among the children born at Danderyd Hospital during a ten year period was studied. During the study period, 4 or 5 outbreaks of E. coli pyelonephritis occurred among the children who had previously been staying in the hospital's neonatal ward. These outbreaks seemed to have been caused by nosocomial spread of and fecal colonization with certain virulent E. coli strains among the children staying in the ward during certain periods of time. The strains that were spread in the ward seemed to belong to certain pyelonephritogenic E. coli clones of the serotypes O6:K5, O4:K3 and possibly O6:K2. Although the children became fecally colonized with the strains in the neonatal ward, most fell ill some time after they had left the ward. The mean age at the development of their first pyelonephritis was 3.4 months for the boys and 6.2 months for the girls, who had been cared for in this ward. A correlation between the number of infections and the bed occupancy of the ward could be found (p less than 0.01). The risk for a child staying in the ward during an outbreak to develop pyelonephritis was about 5-10%. There was a baseline incidence rate of 0.6-0.7% during non-epidemic periods. During one of the outbreaks there was also an increased incidence rate of E. coli septicemia among the children staying in the neonatal ward. The predictive value of fecal colonization with P-fimbriated E. coli for the later development of extraintestinal E. coli infections was studied in a 2.5 year prospective study. During this study period there was a baseline incidence rate of 10-20% fecal colonization with P-fimbriated E. coli among the children staying in both the neonatal and maternity wards, interrupted only by minor peaks of colonization with such strains. Length of stay in the neonatal ward and a high bed occupancy of the neonatal ward were statistically correlated to fecal colonization with P-fimbriated E. coli strains (p

  19. Molecular detection and antimicrobial resistance of diarrheagenic Escherichia coli strains isolated from diarrheal cases

    International Nuclear Information System (INIS)

    Aslani, Mehdi M.; Salmanzadeh-Ahrabi, S.; Jafari, F.; Zali, Reza M.; Mani, M.; Alikhani, Yousef M.

    2008-01-01

    Objective was to identify and classify Iranian isolates of diarrheagenic Escherichia coli (E. coli) on the basis of presence of virulence genes and to determine antibiotic susceptibility of isolated strains. The current cross-sectional study was conducted in 2005 at the Pasteur Institute, Tehran, Iran. One hundred and ninety-three diarrheagenic E. coli isolated from diarrheal patients in different regions of Iran were included in current study. Virulence factors genees for diarrheagenic E. coli were detected by polymerase chain reaction. Of the 193 diarrheagenic E. coli detected by PCR, 86(44.5%) were Shiga toxin-producing E. coli (STEC), 74 (38.4%) enteropathogenic E. coli (EPEC), 19 (9.8%) enteroaggregative E. coli and 14 (7.3%) enterotoxigenic E. coli isolates. Susceptibility to 12 clinically important antimicrobial agents was determined for 193 strains of diarrhheagenic E. coli. A high incidence of resistance to tetracycline (63%), ampicillin (62%), streptomycin (56%), amoxicillin/clavulanic acid (44.5%), trimetoprim/sulphamethoxazole (39.5%) and cephalothin (37%) was observed. The STEC and EPEC strains with high resistance to tetracycline and ampicillin but highly susceptible to quinolones are among the most important causative agent of diarrhea in Iran. This study suggests that antimicrobial resistance is wide spread among E. coli strains colonizing Iranian patients. Guidelines for appropriate use of antibiotics in developing countries require updating. (author)

  20. Update of incidence and antimicrobial susceptibility trends of Escherichia coli and Klebsiella pneumoniae isolates from Chinese intra-abdominal infection patients.

    Science.gov (United States)

    Zhang, Hui; Yang, Qiwen; Liao, Kang; Ni, Yuxing; Yu, Yunsong; Hu, Bijie; Sun, Ziyong; Huang, Wenxiang; Wang, Yong; Wu, Anhua; Feng, Xianju; Luo, Yanping; Chu, Yunzhuo; Chen, Shulan; Cao, Bin; Su, Jianrong; Duan, Qiong; Zhang, Shufang; Shao, Haifeng; Kong, Haishen; Gui, Bingdong; Hu, Zhidong; Badal, Robert; Xu, Yingchun

    2017-12-18

    To evaluate in vitro susceptibilities of aerobic and facultative Gram-negative bacterial (GNB) isolates from intra-abdominal infections (IAIs) to 12 selected antimicrobials in Chinese hospitals from 2012 to 2014. Hospital acquired (HA) and community acquired (CA) IAIs were collected from 21 centers in 16 Chinese cities. Extended spectrum beta-lactamase (ESBL) status and antimicrobial susceptibilities were determined at a central laboratory using CLSI broth microdilution and interpretive standards. From all isolated strains the Enterobacteriaceae (81.1%) Escherichia coli accounted for 45.4% and Klebsiella pneumoniae for 20.1%, followed by Enterobacter cloacae (5.2%), Proteus mirabilis (2.1%), Citrobacter freundii (1.8%), Enterobacter aerogenes (1.8%), Klebsiella oxytoca (1.4%), Morganella morganii (1.2%), Serratia marcescens (0.7%), Citrobacter koseri (0.3%), Proteus vulgaris (0.3%) and others (1.0%). Non- Enterobacteriaceae (18.9%) included Pseudomonas aeruginosa (9.8%), Acinetobacter baumannii (6.7%), Stenotrophomonas maltophilia (0.9%), Aeromonas hydrophila (0.4%) and others (1.1%). ESBL-screen positive Escherichia coli isolates (ESBL+) showed a decreasing trend from 67.5% in 2012 to 58.9% in 2014 of all Escherichia coli isolates and the percentage of ESBL+ Klebsiella pneumoniae isolates also decreased from 2012 through 2014 (40.4% to 26.6%), which was due to reduced percentages of ESBL+ isolates in HA IAIs for both bacteria. The overall susceptibilities of all 5160 IAI isolates were 87.53% to amikacin (AMK), 78.12% to piperacillin-tazobactam (TZP) 81.41% to imipenem (IMP) and 73.12% to ertapenem (ETP). The susceptibility of ESBL-screen positive Escherichia coli strains was 96.77%-98.8% to IPM, 91.26%-93.16% to ETP, 89.48%-92.75% to AMK and 84.86%-89.34% to TZP, while ESBL-screen positive Klebsiella pneumoniae strains were 70.56%-80.15% susceptible to ETP, 80.0%-87.5% to IPM, 83.82%-87.06% to AMK and 63.53%-68.38% to TZP within the three year study