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Sample records for coli produces tailor-made

  1. Physical structure and absorption properties of tailor-made porous starch granules produced by selected amylolytic enzymes.

    PubMed

    Jung, Yi-Seul; Lee, Byung-Hoo; Yoo, Sang-Ho

    2017-01-01

    Porous starch granules (PSGs) with various pores and cavity sizes were prepared by amylolysis enzymes. The greatest hydrolysis rate on corn starch granule was observed with α-amylase, followed by gluco- and β-amylases. Temperature increase enhanced glucoamylase reaction rate more drastically than other enzyme treatments. Final hydrolysis level with glucoamylase reached to 66.9%, close to 67.5% of α-amylolysis. The α-amylase-treated PSGs displayed the greatest pore size and ratio of cavity-to-granule diameters. Gelatinization onset temperatures of PSGs increased to 72.1 (α-), 68.7 (β-), and 68.1°C (gluco-amylolysis) after 8 h; enthalpy changes of β- and gluco-amylase-treated PSGs increased to 13.4, and 13.1 J/g but α-amylase-treated one showed slightly reduced value of 8.5 J/g. Water holding capacities of PSGs were 209.7 (α-), 94.6 (β-), and 133.8% (gluco-amylolysis), and the untreated control had 89.1%; oil holding capacities of them showed 304.5, 182.7, and 211.5%, respectively, while the untreated control had 161.8%. Thus, enzyme types and their reaction conditions can be applied to generate desirable cavity and pore sizes in starch granules. This biocatalytic approach could contribute to develop tailor-made PSGs with distinct internal structure for specific uses in wide range of food, pharmaceutical and other industrial applications.

  2. Overproduction of Thermus sp. Strain T2 β-Galactosidase in Escherichia coli and Preparation by Using Tailor-Made Metal Chelate Supports

    PubMed Central

    Pessela, Benevides C. C.; Vian, Alejandro; Mateo, César; Fernández-Lafuente, Roberto; García, José L.; Guisán, José M.; Carrascosa, Alfonso V.

    2003-01-01

    A novel thermostable chimeric β-galactosidase was constructed by fusing a poly-His tag to the N-terminal region of the β-galactosidase from Thermus sp. strain T2 to facilitate its overexpression in Escherichia coli and its purification by immobilized metal-ion affinity chromatography (IMAC). The poly-His tag fusion did not affect the activation, kinetic parameters, and stability of the β-galactosidase. Copper-iminodiacetic acid (Cu-IDA) supports enabled the most rapid adsorption of the His-tagged enzyme, favoring multisubunit interactions, but caused deleterious effects on the enzyme stability. To improve the enzyme purification a selective one-point adsorption was achieved by designing tailor-made low-activated Co-IDA or Ni-IDA supports. The new enzyme was not only useful for industrial purposes but also has become an excellent model to study the purification of large multimeric proteins via selective adsorption on tailor-made IMAC supports. PMID:12676671

  3. Tailor-made synthesis of hydrogels

    SciTech Connect

    Kopecek, J.; Yeh, P.Y.; Kopechkova, P.; Ulbrich, K.

    1993-12-31

    The tailor-made synthesis of hydrogels by crosslinking copolymerization, by crosslinking of polymer precursors, and by polymer-polymer reaction will be analyzed. During the synthesis side-reactions occur resulting in the presence of cycles, unreacted pendant groups, and entanglements in the three dimensional network. The extent of these side-reactions depends on the structure of the crosslinking agent; amount and character of solvent; diffusion control of termination, crosslinking, and eventually propagation; difference in the hydrophilicity of monomer and crosslinking agent, and conversion. Synthesis of biodegradable hydrogels containing degradable sequences in the crosslinks will be used as an example to demonstrate that biorecognition by enzymes depends on the detailed structure of the network.

  4. Recombinant lectins: an array of tailor-made glycan-interaction biosynthetic tools.

    PubMed

    Oliveira, Carla; Teixeira, José A; Domingues, Lucília

    2013-03-01

    Lectins are a heterogeneous group of proteins found in plants, animals and microorganisms, which possess at least one non-catalytic domain that binds reversibly to specific mono- or oligosaccharides. The range of lectins and respective biological activities is unsurprising given the immense diversity and complexity of glycan structures and the multiple modes of interaction with proteins. Recombinant DNA technology has been traditionally used for cloning and characterizing newly discovered lectins. It has also been employed as a means of producing pure and sequence-defined lectins for different biotechnological applications. This review focuses on the production of recombinant lectins in heterologous organisms, and highlighting the Escherichia coli and Pichia pastoris expression systems, which are the most employed. The choice of expression host depends on the lectin. Non-glycosylated recombinant lectins are produced in E. coli and post-translational modified recombinant lectins are produced in eukaryotic organisms, namely P. pastoris and non-microbial hosts such as mammalian cells. Emphasis is given to the applications of the recombinant lectins especially (a) in cancer diagnosis and/or therapeutics, (b) as anti-microbial, anti-viral, and anti-insect molecules or (c) in microarrays for glycome profiling. Most reported applications are from recombinant plant lectins. These applications benefit from the tailor-made design associated with recombinant production and will aid in unraveling the complex biological mechanisms of glycan-interactions, bringing recombinant lectins to the forefront of glycobiology. In conclusion, recombinant lectins are developing into valuable biosynthetic tools for biomedical research.

  5. Tailor-made force fields for crystal-structure prediction.

    PubMed

    Neumann, Marcus A

    2008-08-14

    A general procedure is presented to derive a complete set of force-field parameters for flexible molecules in the crystalline state on a case-by-case basis. The force-field parameters are fitted to the electrostatic potential as well as to accurate energies and forces generated by means of a hybrid method that combines solid-state density functional theory (DFT) calculations with an empirical van der Waals correction. All DFT calculations are carried out with the VASP program. The mathematical structure of the force field, the generation of reference data, the choice of the figure of merit, the optimization algorithm, and the parameter-refinement strategy are discussed in detail. The approach is applied to cyclohexane-1,4-dione, a small flexible ring. The tailor-made force field obtained for cyclohexane-1,4-dione is used to search for low-energy crystal packings in all 230 space groups with one molecule per asymmetric unit, and the most stable crystal structures are reoptimized in a second step with the hybrid method. The experimental crystal structure is found as the most stable predicted crystal structure both with the tailor-made force field and the hybrid method. The same methodology has also been applied successfully to the four compounds of the fourth CCDC blind test on crystal-structure prediction. For the five aforementioned compounds, the root-mean-square deviations between lattice energies calculated with the tailor-made force fields and the hybrid method range from 0.024 to 0.053 kcal/mol per atom around an average value of 0.034 kcal/mol per atom.

  6. Tailor-made polyamide membranes for water desalination.

    PubMed

    Choi, Wansuk; Gu, Joung-Eun; Park, Sang-Hee; Kim, Seyong; Bang, Joona; Baek, Kyung-Youl; Park, Byoungnam; Lee, Jong Suk; Chan, Edwin P; Lee, Jung-Hyun

    2015-01-27

    Independent control of the extrinsic and intrinsic properties of the polyamide (PA) selective layer is essential for designing thin-film composite (TFC) membranes with performance characteristics required for water purification applications besides seawater desalination. Current commercial TFC membranes fabricated via the well-established interfacial polymerization (IP) approach yield materials that are far from ideal because their layer thickness, surface roughness, polymer chemistry, and network structure cannot be separately tailored. In this work, tailor-made PA-based desalination membranes based on molecular layer-by-layer (mLbL) assembly are presented. The mLbL technique enables the construction of an ultrathin and highly cross-linked PA selective layer in a precisely and independently controlled manner. The mLbL-assembled TFC membranes exhibit significant enhancements in performance compared to their IP-assembled counterparts. A maximum sodium chloride rejection of 98.2% is achieved along with over 2.5 times higher water flux than the IP-assembled counterpart. More importantly, this work demonstrates the broad applicability of mLbL in fabricating a variety of PA-based TFC membranes with nanoscale control of the selective layer thickness and roughness independent of the specific polyamide chemistry.

  7. Gasifier feed - Tailor-made from Illinois coals

    SciTech Connect

    Ehrlinger, H.P. III ); Lytle, J.; Frost, R.R.; Lizzio, A.; Kohlenberger, L.; Brewer, K. DESTEC Energy Williams Technology, Illinois Coal Association )

    1992-01-01

    The main purpose of this project is to produce a feedstock from preparation plant fines from an illinois coal that is ideal for a slurry fed, slagging, entrained-flow coal gasifier. The high sulfur content and high Btu value of Illinois coals are particularly advantageous in such a gasifier; preliminary calculations indicate that the increased cost of removing sulfur from the gas from a high sulfur coal is more than offset by the increased revenue from the sale of the elemental sulfur; additionally the high Btu Illinois coal concentrates more energy into the slurry of a given coal to water ratio. The Btu is higher not only because of the higher Btu value of the coal but also because Illinois coal requires less water to produce a pumpable slurry than western coal, i.e., as little as 30--35% water may be used for Illinois coal as compared to approximately 45% for most western coals.

  8. Candida bombicola as a platform organism for the production of tailor-made biomolecules.

    PubMed

    Roelants, Sophie L K W; Saerens, Karen M J; Derycke, Thibaut; Li, Bing; Lin, Yao-Cheng; Van de Peer, Yves; De Maeseneire, Sofie L; Van Bogaert, Inge N A; Soetaert, Wim

    2013-09-01

    The yeast Candida bombicola is capable of producing high amounts (400 g/L) of the biosurfactant sophorolipids. The genetic makeup of this industrially important yeast has recently been uncovered and molecular manipulation techniques have been developed. Hence, all tools for the development of new bioprocesses with C. bombicola are now available. As a proof of concept, the production of two totally different molecules was aimed for: the bioplastic polyhydroxyalkanoate (PHA) and a new-to-nature cellobioselipid-biosurfactant. Integration of the new functionalities at genomic loci necessary for sophorolipid production safeguards the new biomolecules from sophorolipid contamination, while taking advantage of the regulation of the sophorolipid gene cluster. A maximum yield of 2.0% wt/dwt PHA was obtained; furthermore, this is the first time cellobioselipid synthesis by a non-natural producer is reported. We here provided proof of concept that C. bombicola can be transformed into a platform organism for the production of tailor-made biomolecules.

  9. Advanced bacterial polyhydroxyalkanoates: towards a versatile and sustainable platform for unnatural tailor-made polyesters.

    PubMed

    Park, Si Jae; Kim, Tae Wan; Kim, Min Kyung; Lee, Sang Yup; Lim, Sung-Chul

    2012-01-01

    Polyhydroxyalkanoates (PHAs) are biopolyesters that generally consist of 3-, 4-, 5-, and 6-hydroxycarboxylic acids, which are accumulated as carbon and energy storage materials in many bacteria in limited growth conditions with excess carbon sources. Due to the diverse substrate specificities of PHA synthases, the key enzymes for PHA biosynthesis, PHAs with different material properties have been synthesized by incorporating different monomer components with differing compositions. Also, engineering PHA synthases using in vitro-directed evolution and site-directed mutagenesis facilitates the synthesis of PHA copolymers with novel material properties by broadening the spectrum of monomers available for PHA biosynthesis. Based on the understanding of metabolism of PHA biosynthesis, recombinant bacteria have been engineered to produce different types of PHAs by expressing heterologous PHA biosynthesis genes, and by creating and enhancing the metabolic pathways to efficiently generate precursors for PHA monomers. Recently, the PHA biosynthesis system has been expanded to produce unnatural biopolyesters containing 2-hydroxyacid monomers such as glycolate, lactate, and 2-hydroxybutyrate by employing natural and engineered PHA synthases. Using this system, polylactic acid (PLA), one of the major commercially-available bioplastics, can be synthesized from renewable resources by direct fermentation of recombinant bacteria. In this review, we discuss recent advances in the development of the PHA biosynthesis system as a platform for tailor-made polyesters with novel material properties. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Tailor-made finance versus tailor-made care. Can the state strengthen consumer choice in healthcare by reforming the financial structure of long-term care?

    PubMed

    Grit, K; de Bont, A

    2010-02-01

    Policy instruments based on the working of markets have been introduced to empower consumers of healthcare. However, it is still not easy to become a critical consumer of healthcare. The aim of this study is to analyse the possibilities of the state to strengthen the position of patients with the aid of a new financial regime, such as personal health budgets. Data were collected through in-depth interviews with executives, managers, professionals and client representatives of six long-term care institutions. With the introduction of individual budgets the responsibility for budgetary control has shifted from the organisational level to the individual level in the caregiver-client relationship. Having more luxurious care on offer necessitates a stronger demarcation of regular care because organisations cannot simultaneously offer extra care as part of the standard care package. New financial instruments have an impact on the culture of receiving and giving care. Distributive justice takes on new meaning with the introduction of financial market mechanisms in healthcare; the distributing principle of 'need' is transformed into the principle of 'economic demand'. Financial instruments not only act as a countervailing power against providers insufficiently client-oriented, but are also used by providers to reinforce their own positions vis-à-vis demanding clients. Tailor-made finance is not the same as tailor-made care.

  11. Development of Skill Standards and a Tailor-made Education System in TOSHIBA

    NASA Astrophysics Data System (ADS)

    Harashima, Shuji

    Software development for embedded systems such as cellular phone and digital TV systems has become larger in scale while development times have become shorter. More over, the necessary technologies are required to respond more rapidly in line with movements in the sales climate for these products. In such a business environment, skill enhancement for software engineers is highly important. In this paper, we explain a tailor-made education system based on skill standards.

  12. Nanoscale tailor-made membranes for precise and rapid molecular sieve separation.

    PubMed

    Wang, Jing; Zhu, Junyong; Zhang, Yatao; Liu, Jindun; Van der Bruggen, Bart

    2017-03-02

    The precise and rapid separation of different molecules from aqueous, organic solutions and gas mixtures is critical to many technologies in the context of resource-saving and sustainable development. The strength of membrane-based technologies is well recognized and they are extensively applied as cost-effective, highly efficient separation techniques. Currently, empirical-based approaches, lacking an accurate nanoscale control, are used to prepare the most advanced membranes. In contrast, nanoscale control renders the membrane molecular specificity (sub-2 nm) necessary for efficient and rapid molecular separation. Therefore, as a growing trend in membrane technology, the field of nanoscale tailor-made membranes is highlighted in this review. An in-depth analysis of the latest advances in tailor-made membranes for precise and rapid molecule sieving is given, along with an outlook to future perspectives of such membranes. Special attention is paid to the established processing strategies, as well as the application of molecular dynamics (MD) simulation in nanoporous membrane design. This review will provide useful guidelines for future research in the development of nanoscale tailor-made membranes with a precise and rapid molecular sieve separation property.

  13. Selective oxidation of lignocellulosic biomass to formic acid and high-grade cellulose using tailor-made polyoxometalate catalysts.

    PubMed

    Albert, Jakob

    2017-06-27

    The main goal of this project was to identify and optimize tailor-made polyoxometalate catalysts for a fractionated oxidation of lignocellulosic biomass (i.e. wood and residues from sugar or paper industries) to produce formic acid (FA) and high-grade cellulose for further processing e.g. in white biotechnology to provide bio-ethanol. Homogeneous vanadium precursors like sodium metavanadate and vanadyl sulfate as well as Keggin-type polyoxometalates (POMs) and more exotic structures like Anderson-, Wells-Dawson- and Lindqvist-type POMs were screened for the desired catalytic performance. The most promising behaviour was found using the Lindqvist-type POM K5V3W3O19, showing for the first time in the literature a selective oxidation of only hemicellulose and lignin to formic acid, while the cellulose fraction was untrapped. However, this can only be a first step towards the project goal as low product yields were obtained.

  14. Development of a tailor-made bis(oxazolidine)pyridine-metal catalyst for the [3+2] cycloaddition of azomethine imines with propiolates.

    PubMed

    Arai, Takayoshi; Ogino, Yuta; Sato, Toru

    2013-09-14

    A series of bis(oxazolidine)pyridine ligands (the PyBodines) were newly designed and synthesized for the development of a highly efficient, tailor-made catalyst for the [3+2] cycloaddition of azomethine imines with propiolates. The PyBodine(l-Ala)-Cu(OAc)2 catalyst was selected on the basis of solid-phase catalysis/CD-HTS and exhibited high efficiency, producing the (R)-adducts with excellent enantioselectivity.

  15. 77 FR 9888 - Shiga Toxin-Producing Escherichia coli

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-21

    ... program for the six non-O157 STEC, as it already does for E. coli O157:H7. The Agency intended to begin... Food Safety and Inspection Service Shiga Toxin-Producing Escherichia coli in Certain Raw Beef Products... manufacturing trimmings for six non-O157 Shiga toxin-producing Escherichia coli (STEC) serogroups (O26, O45...

  16. The effect of tailor-made additives on crystal growth of methyl paraben: Experiments and modelling

    NASA Astrophysics Data System (ADS)

    Cai, Zhihui; Liu, Yong; Song, Yang; Guan, Guoqiang; Jiang, Yanbin

    2017-03-01

    In this study, methyl paraben (MP) was selected as the model component, and acetaminophen (APAP), p-methyl acetanilide (PMAA) and acetanilide (ACET), which share the similar molecular structure as MP, were selected as the three tailor-made additives to study the effect of tailor-made additives on the crystal growth of MP. HPLC results indicated that the MP crystals induced by the three additives contained MP only. Photographs of the single crystals prepared indicated that the morphology of the MP crystals was greatly changed by the additives, but PXRD and single crystal diffraction results illustrated that the MP crystals were the same polymorph only with different crystal habits, and no new crystal form was found compared with other references. To investigate the effect of the additives on the crystal growth, the interaction between additives and facets was discussed in detail using the DFT methods and MD simulations. The results showed that APAP, PMAA and ACET would be selectively adsorbed on the growth surfaces of the crystal facets, which induced the change in MP crystal habits.

  17. Searching for metastases in ovarian tissue before autotransplantation: a tailor-made approach.

    PubMed

    Hoekman, Ellen J; Smit, Vincent T H B M; Fleming, Timothy P; Louwe, Leonie A; Fleuren, Gert Jan; Hilders, Carina G J M

    2015-02-01

    To exclude minimal residual disease in remaining ovarian tissue after harvesting the ovarian cortex for cryopreservation, by means of a tailor-made approach. Retrospective case series. Hospital laboratory. We evaluated the ovarian and tubal tissue from 47 cancer patients (breast cancer, [non-]Hodgkin lymphoma; osteo-, Ewing, myxoid lipo-, and oropharyngeal synovial sarcoma; cervical, rectal, and esophageal cancer), who had stored ovarian tissue for fertility preservation. Immunohistochemistry (IHC) with tumor-related antibodies and genetic mutation analysis were performed to detect micrometastases by multiple sectioning at three levels of the paraffin-embedded formalin-fixed material. Molecular assays were performed with the use of tissue between these three levels of sectioning. Detection of micrometastases in ovaries. We analyzed 847 ovarian slides to detect isolated tumor cells (ITCs) or micrometastases by IHC. In only one case (1/47) were ITCs detected in the fallopian tube. That patient had an intra-abdominal metastatic esophageal carcinoma. Additional DNA analyses of breast and rectal cancer, Ewing sarcoma, and human papilloma virus in cervical patients did not show evidence of micrometastases in the ovarian tissue. The tailor-made approach consisted of patient-specific tumor markers which were used to search for ovarian micrometastases. We found evidence of metastatic disease within the fallopian tube of a patient with intraperitoneal metastatic esophageal adenocarcinoma. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  18. Development of Thermophilic Tailor-Made Enzyme Mixtures for the Bioconversion of Agricultural and Forest Residues

    PubMed Central

    Karnaouri, Anthi; Matsakas, Leonidas; Topakas, Evangelos; Rova, Ulrika; Christakopoulos, Paul

    2016-01-01

    Even though the main components of all lignocellulosic feedstocks include cellulose, hemicellulose, as well as the protective lignin matrix, there are some differences in structure, such as in hardwoods and softwoods, which may influence the degradability of the materials. Under this view, various types of biomass might require a minimal set of enzymes that has to be tailor-made. Partially defined complex mixtures that are currently commercially used are not adapted to efficiently degrade different materials, so novel enzyme mixtures have to be customized. Development of these cocktails requires better knowledge about the specific activities involved, in order to optimize hydrolysis. The role of filamentous fungus Myceliophthora thermophila and its complete enzymatic repertoire for the bioconversion of complex carbohydrates has been widely proven. In this study, four core cellulases (MtCBH7, MtCBH6, MtEG5, and MtEG7), in the presence of other four “accessory” enzymes (mannanase, lytic polyssacharide monooxygenase MtGH61, xylanase, MtFae1a) and β-glucosidase MtBGL3, were tested as a nine-component cocktail against one model substrate (phosphoric acid swollen cellulose) and four hydrothermally pretreated natural substrates (wheat straw as an agricultural waste, birch, and spruce biomass, as forest residues). Synergistic interactions among different enzymes were determined using a suitable design of experiments methodology. The results suggest that for the hydrolysis of the pure substrate (PASC), high proportions of MtEG7 are needed for efficient yields. MtCBH7 and MtEG7 are enzymes of major importance during the hydrolysis of pretreated wheat straw, while MtCBH7 plays a crucial role in case of spruce. Cellobiohydrolases MtCBH6 and MtCBH7 act in combination and are key enzymes for the hydrolysis of the hardwood (birch). Optimum combinations were predicted from suitable statistical models which were able to further increase hydrolysis yields, suggesting that

  19. Clinical trial on tonal tinnitus with tailor-made notched music training.

    PubMed

    Stein, Alwina; Wunderlich, Robert; Lau, Pia; Engell, Alva; Wollbrink, Andreas; Shaykevich, Alex; Kuhn, Jörg-Tobias; Holling, Heinz; Rudack, Claudia; Pantev, Christo

    2016-03-17

    Tinnitus is a result of hyper-activity/hyper-synchrony of auditory neurons coding the tinnitus frequency, which has developed due to synchronous mass activity owing to the lack of inhibition. We assume that removal of exactly these frequencies from a complex auditory stimulus will cause the brain to reorganize around tonotopic regions coding the tinnitus frequency through inhibition-induced plasticity. Based on this assumption, a novel treatment for tonal tinnitus--tailor-made notched music training (TMNMT)--has been introduced and was tested in this clinical trial. A randomized controlled trial in parallel group design was performed in a double-blinded manner. We included 100 participants with chronic, tonal tinnitus who listened to tailor-made notched music for two hours a day for three consecutive months. Our primary outcome measures were the Tinnitus Handicap Questionnaire and Visual Analog Scales measuring perceived tinnitus loudness, awareness, distress and handicap. Participants rated their tinnitus before and after the training as well as one month after cessation of the training. While no effect was found for the primary outcome measures, tinnitus distress, as measured by the Tinnitus Questionnaire, a secondary outcome measure, developed differently in the two groups. The treatment group showed higher distress scores while the placebo group revealed lower distress scores after the training. However, this effect did not reach significance in post-hoc analysis and disappeared at follow-up measurements. At follow-up, tinnitus loudness in the treatment group was significantly reduced as compared to the control group. Post hoc analysis, accounting for low reliability scores in the Visual Analog Scales, showed a significant reduction of the overall Visual Analog Scale mean score in the treatment group even at the post measurement. This is the first study on TMNMT that was planned and conducted following the CONSORT statement standards for clinical trials. The

  20. Development of Thermophilic Tailor-Made Enzyme Mixtures for the Bioconversion of Agricultural and Forest Residues.

    PubMed

    Karnaouri, Anthi; Matsakas, Leonidas; Topakas, Evangelos; Rova, Ulrika; Christakopoulos, Paul

    2016-01-01

    Even though the main components of all lignocellulosic feedstocks include cellulose, hemicellulose, as well as the protective lignin matrix, there are some differences in structure, such as in hardwoods and softwoods, which may influence the degradability of the materials. Under this view, various types of biomass might require a minimal set of enzymes that has to be tailor-made. Partially defined complex mixtures that are currently commercially used are not adapted to efficiently degrade different materials, so novel enzyme mixtures have to be customized. Development of these cocktails requires better knowledge about the specific activities involved, in order to optimize hydrolysis. The role of filamentous fungus Myceliophthora thermophila and its complete enzymatic repertoire for the bioconversion of complex carbohydrates has been widely proven. In this study, four core cellulases (MtCBH7, MtCBH6, MtEG5, and MtEG7), in the presence of other four "accessory" enzymes (mannanase, lytic polyssacharide monooxygenase MtGH61, xylanase, MtFae1a) and β-glucosidase MtBGL3, were tested as a nine-component cocktail against one model substrate (phosphoric acid swollen cellulose) and four hydrothermally pretreated natural substrates (wheat straw as an agricultural waste, birch, and spruce biomass, as forest residues). Synergistic interactions among different enzymes were determined using a suitable design of experiments methodology. The results suggest that for the hydrolysis of the pure substrate (PASC), high proportions of MtEG7 are needed for efficient yields. MtCBH7 and MtEG7 are enzymes of major importance during the hydrolysis of pretreated wheat straw, while MtCBH7 plays a crucial role in case of spruce. Cellobiohydrolases MtCBH6 and MtCBH7 act in combination and are key enzymes for the hydrolysis of the hardwood (birch). Optimum combinations were predicted from suitable statistical models which were able to further increase hydrolysis yields, suggesting that tailor-made

  1. Exploitation of desilylation chemistry in tailor-made functionalization on diverse surfaces

    NASA Astrophysics Data System (ADS)

    Fu, Yongchun; Chen, Songjie; Kuzume, Akiyoshi; Rudnev, Alexander; Huang, Cancan; Kaliginedi, Veerabhadrarao; Baghernejad, Masoud; Hong, Wenjing; Wandlowski, Thomas; Decurtins, Silvio; Liu, Shi-Xia

    2015-03-01

    Interface engineering to attain a uniform and compact self-assembled monolayer at atomically flat surfaces plays a crucial role in the bottom-up fabrication of organic molecular devices. Here we report a promising and operationally simple approach for modification/functionalization not only at ultraflat single-crystal metal surfaces, M(111) (M=Au, Pt, Pd, Rh and Ir) but also at the highly oriented pyrolytic graphite surface, upon efficient in situ cleavage of trimethylsilyl end groups of the molecules. The obtained self-assembled monolayers are ultrastable within a wide potential window. The carbon-surface bonding on various substrates is confirmed by shell-isolated nanoparticle-enhanced Raman spectroscopy. Application of this strategy in tuning surface wettability is also demonstrated. The most valuable finding is that a combination of the desilylation with the click chemistry represents an efficient method for covalent and tailor-made functionalization of diverse surfaces.

  2. Exploitation of desilylation chemistry in tailor-made functionalization on diverse surfaces.

    PubMed

    Fu, Yongchun; Chen, Songjie; Kuzume, Akiyoshi; Rudnev, Alexander; Huang, Cancan; Kaliginedi, Veerabhadrarao; Baghernejad, Masoud; Hong, Wenjing; Wandlowski, Thomas; Decurtins, Silvio; Liu, Shi-Xia

    2015-03-11

    Interface engineering to attain a uniform and compact self-assembled monolayer at atomically flat surfaces plays a crucial role in the bottom-up fabrication of organic molecular devices. Here we report a promising and operationally simple approach for modification/functionalization not only at ultraflat single-crystal metal surfaces, M(111) (M=Au, Pt, Pd, Rh and Ir) but also at the highly oriented pyrolytic graphite surface, upon efficient in situ cleavage of trimethylsilyl end groups of the molecules. The obtained self-assembled monolayers are ultrastable within a wide potential window. The carbon-surface bonding on various substrates is confirmed by shell-isolated nanoparticle-enhanced Raman spectroscopy. Application of this strategy in tuning surface wettability is also demonstrated. The most valuable finding is that a combination of the desilylation with the click chemistry represents an efficient method for covalent and tailor-made functionalization of diverse surfaces.

  3. Exploitation of desilylation chemistry in tailor-made functionalization on diverse surfaces

    PubMed Central

    Fu, Yongchun; Chen, Songjie; Kuzume, Akiyoshi; Rudnev, Alexander; Huang, Cancan; Kaliginedi, Veerabhadrarao; Baghernejad, Masoud; Hong, Wenjing; Wandlowski, Thomas; Decurtins, Silvio; Liu, Shi-Xia

    2015-01-01

    Interface engineering to attain a uniform and compact self-assembled monolayer at atomically flat surfaces plays a crucial role in the bottom-up fabrication of organic molecular devices. Here we report a promising and operationally simple approach for modification/functionalization not only at ultraflat single-crystal metal surfaces, M(111) (M=Au, Pt, Pd, Rh and Ir) but also at the highly oriented pyrolytic graphite surface, upon efficient in situ cleavage of trimethylsilyl end groups of the molecules. The obtained self-assembled monolayers are ultrastable within a wide potential window. The carbon–surface bonding on various substrates is confirmed by shell-isolated nanoparticle-enhanced Raman spectroscopy. Application of this strategy in tuning surface wettability is also demonstrated. The most valuable finding is that a combination of the desilylation with the click chemistry represents an efficient method for covalent and tailor-made functionalization of diverse surfaces. PMID:25758661

  4. Tailor-made anion-exchange membranes for salinity gradient power generation using reverse electrodialysis.

    PubMed

    Guler, Enver; Zhang, Yali; Saakes, Michel; Nijmeijer, Kitty

    2012-11-01

    Reverse electrodialysis (RED) or blue energy is a non-polluting, sustainable technology for generating power from the mixing of solutions with different salinity, that is, seawater and river water. A concentrated salt solution (e.g., seawater) and a diluted salt solution (e.g., river water) are brought into contact through an alternating series of polymeric anion-exchange membranes (AEMs) and cation-exchange membranes (CEMs), which are either selective for anions or cations. Currently available ion-exchange membranes are not optimized for RED, whereas successful RED operation notably depends on the used ion-exchange membranes. We designed such ion-exchange membranes and for the first time we show the performance of tailor-made membranes in RED. More specifically, we focus on the development of AEMs because these are much more complex to prepare. Herein we propose a safe and more environmentally friendly method and use halogenated polyethers, such as polyepichlorohydrin (PECH) as the starting material. A tertiary diamine (1,4-diazabicyclo[2.2.2]octane, DABCO) was used to introduce the ion-exchange groups by amination and for simultaneous cross-linking of the polymer membrane. Area resistances of the series of membranes ranged from 0.82 to 2.05 Ω cm² and permselectivities from 87 to 90 %. For the first time we showed that tailor-made ion-exchange membranes can be applied in RED. Depending on the properties and especially membrane thickness, application of these membranes in RED resulted in a high power density of 1.27 W m⁻², which exceeds the power output obtained with the commercially available AMX membranes. This shows the potential of the design of ion-exchange membranes for a viable blue energy process. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Shiga toxin-producing Escherichia coli

    PubMed Central

    Etcheverría, Analía Inés; Padola, Nora Lía

    2013-01-01

    Shiga toxin-producing Escherichia coli (STEC) cause hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS) in humans. Outbreaks are linked to bovine food sources. STEC O157:H7 has been responsible for the most severe outbreaks worldwide. However, non-O157 serotypes have emerged as important enteric pathogens in several countries. The main virulence factor of STEC is the production of Shiga toxins 1 and 2. Additional virulence markers are a plasmid-encoded enterohemolysin (ehxA), an autoagglutinating adhesin (Saa), a catalase-peroxidase (katP), an extracellular serine protease (espP), a zinc metalloprotease (stcE), a subtilase cytotoxin (subAB), among others. Other virulence factors are intimin and adhesins that had a roll in the adherence of STEC to bovine colon. This review focuses on the virulence traits of STEC and especially on those related to the adhesion to bovine colon. The known of the interaction between STEC and the bovine host is crucial to develop strategies to control cattle colonization. PMID:23624795

  6. Tailor-made asymmetric PVDF hollow fibers for soluble gas removal

    SciTech Connect

    Li, K.; Kong, J.F.; Wang, D.; Teo, W.K.

    1999-06-01

    Tailor-made polyvinylidene fluoride (PVDF) asymmetric hollow-fiber membranes and their membrane modules were employed for soluble gas removal, such as H{sub 2}S from waste gas streams. This study focused on the techniques of fabricating and characterizing the PVDF asymmetric hollow-fiber membranes and their membrane modules for removal of H{sub 2}S using an aqueous solution containing 10% NaOH. A laminar parabolic velocity profile was used to characterize the flow of the H{sub 2}S gas mixture in the hollow-fiber lumen. Effects of operating conditions and the morphological structures of the membranes on the membrane`s coefficient, k{sub AM}, were examined both theoretically and experimentally. The capabilities of the hollow-fiber membranes developed for removal of H{sub 2}S from waste gas streams were evaluated and compared with conventional symmetric hydrophobic hollow-fiber membranes, such as polypropylene. An analysis of H{sub 2}S transfer across the more developed PVDF membranes reveals that the membrane`s coefficient, k{sub AM}, evaluated from its structure parameters, such as the effective surface porosity and mean radius, agreed well with the experimental data obtained from absorption experiments.

  7. Multiple-antibiotic-resistant Helicobacter pylori infection eradicated with a tailor-made quadruple therapy.

    PubMed

    Nakajima, Shigemi; Inoue, Hisayuki; Inoue, Tetsuya; Maruoka, Yuri

    2012-04-01

    In 2008, a 44-year-old woman with mild epigastralgia diagnosed as having Helicobacter pylori-positive chronic gastritis without peptic ulcer underwent eradication therapy with lansoprazole (LPZ), amoxicillin (AMPC) and clarithromycin (CAM) for 7 days, but it failed, so treatment with rabeprazole, AMPC, and metronidazole (MNZ) for another 7 days was given, but it also failed. She was then prescribed a modified, 14-day sequential therapy of LPZ and AMPC with an increased dose of CAM followed by MNZ supplement, but the infection was still not eradicated. The H. pylori was cultured and examined for antibiotic susceptibility with the agar dilution method and was found to be resistant to CAM, MNZ, and levofloxacin, and non-sensitive to AMPC, namely multiple-antibiotic-resistant, although sensitive to minocycline. The CYP2C19 genotype of the patient was an extensive metabolizer (G681A: G/A, G636A: G/G). In 2010, she gave informed consent for a 14-day, tailor-made, modified classical (or modified high-dose PPI + AMPC) quadruple therapy comprising 30 mg LPZ, 500 mg AMPC and 500 mg bismuth subnitrate, qid, and 100 mg minocycline, bid. Two months later, her urea breath test was negative. Histology and bacterial culture were still negative 1 year after the therapy. She did not have any adverse events during or after the novel therapy, nor did she feel any further epigastralgia.

  8. The concept of "tailor-made", protein-based, outer membrane vesicle vaccines against meningococcal disease.

    PubMed

    Holst, Johan; Feiring, Berit; Naess, Lisbeth M; Norheim, Gunnstein; Kristiansen, Paul; Høiby, E Arne; Bryn, Klaus; Oster, Philipp; Costantino, Paolo; Taha, Muhamed-Kheir; Alonso, Jean-Michel; Caugant, Dominique A; Wedege, Elisabeth; Aaberge, Ingeborg S; Rappuoli, Rino; Rosenqvist, Einar

    2005-03-18

    Protein-based, outer membrane vesicle (OMV) vaccines have previously proven to be efficacious against serogroup B meningococcal disease in Norway and Cuba. Currently, a public health intervention is going on in order to control a serogroup B epidemic in New Zealand. The scale-up and standardization of vaccine production required for controlling the New Zealand epidemic has allowed the establishment of large-scale GMP manufacturing for OMV vaccines. The outcome of this will be licensing of the vaccine in New Zealand and possibly other countries. The availability of licensed OMV vaccines raises the question of whether such vaccines may provide the opportunity to control other outbreaks and epidemics. For instance, such a vaccine could control a localised outbreak of group B meningococci in Normandy, France. "Tailor-made" vaccines, focusing on the sub-capsular antigens may also be considered for use in sub-Saharan Africa for the prevention of the recurrent outbreaks by serogroups A and W135 meningococci. This assumption is based on the epidemiological observation that meningococcal outbreaks in Africa are clonal and are strikingly stable regarding their phenotypic characteristics.

  9. Effect of trehalose coating on basic fibroblast growth factor release from tailor-made bone implants.

    PubMed

    Choi, Sungjin; Lee, Jongil; Igawa, Kazuyo; Suzuki, Shigeki; Mochizuki, Manabu; Nishimura, Ryohei; Chung, Ung-il; Sasaki, Nobuo

    2011-12-01

    Artificial bone implants are often incorporated with osteoinductive factors to facilitate early bone regeneration. Calcium phosphate, the main component in artificial bone implants, strongly binds these factors, and in a few cases, the incorporated proteins are not released from the implant under conditions of physiological pH, thereby leading to reduction in their osteoinductivity. In this study, we coated tailor-made bone implants with trehalose to facilitate the release of basic fibroblast growth factor (bFGF). In an in vitro study, mouse osteoblastic cells were separately cultured for 48 hr in a medium with a untreated implant (T-), trehalose-coated implant (T+), bFGF-incorporated implant (FT-), and bFGF-incorporated implant with trehalose coating (FT+). In the FT+ group, cell viability was significantly higher than that in the other groups (P<0.05). Scanning electron microscopy (SEM) and X-ray diffraction (XRD) revealed that trehalose effectively covered the surface of the artificial bone implant without affecting the crystallinity or the mechanical strength of the artificial bone implant. These results suggest that coating artificial bone implants with trehalose could limit the binding of bFGF to calcium phosphate.

  10. Dry particle coating of polymer particles for tailor-made product properties

    SciTech Connect

    Blümel, C. Schmidt, J. Dielesen, A. Sachs, M. Winzer, B. Peukert, W. Wirth, K.-E.

    2014-05-15

    Disperse polymer powders with tailor-made particle properties are of increasing interest in industrial applications such as Selective Laser Beam Melting processes (SLM). This study focuses on dry particle coating processes to improve the conductivity of the insulating polymer powder in order to assemble conductive devices. Therefore PP particles were coated with Carbon Black nanoparticles in a dry particle coating process. This process was investigated in dependence of process time and mass fraction of Carbon Black. The conductivity of the functionalized powders was measured by impedance spectroscopy. It was found that there is a dependence of process time, respectively coating ratio and conductivity. The powder shows higher conductivities with increasing number of guest particles per host particle surface area, i.e. there is a correlation between surface functionalization density and conductivity. The assembled composite particles open new possibilities for processing distinct polymers such as PP in SLM process. The fundamentals of the dry particle coating process of PP host particles with Carbon Black guest particles as well as the influence on the electrical conductivity will be discussed.

  11. Material efficiency: from top-down steering to tailor-made governance.

    PubMed

    Cramer, Jacqueline

    2013-03-13

    Material efficiency is one of the major challenges facing our society in the twenty-first century. Research can help to understand how we can make the transition towards a material-efficient society. This study focuses on the role of the government in such transition processes. Use is made of literature in the field of public administration and innovation literature, particularly transition management. On the basis of three Dutch examples (plastics, e-waste and bio-energy), the complex system change towards a material-efficient society will be reflected upon. These case studies underline the need for a tailor-made governance approach instead of a top-down government approach to enhance material efficiency in practice. The role of the government is not restricted to formulating policies and then leaving it up to other actors to implement these policies. Instead, it is a continuous interplay between the different actors during the whole implementation process. As such, the government's role is to steer the development in the desired direction and orchestrate the process from beginning to end. In order to govern with a better compass, scientifically underpinned guiding principles and indicators are needed. This is a challenge for researchers both in public administration and in transition management.

  12. Infection by verocytotoxin-producing Escherichia coli.

    PubMed Central

    Karmali, M A

    1989-01-01

    Verocytotoxin (VT)-producing Escherichia coli (VTEC) are a newly recognized group of enteric pathogens which are increasingly being recognized as common causes of diarrhea in some geographic settings. Outbreak studies indicate that most patients with VTEC infection develop mild uncomplicated diarrhea. However, a significant risk of two serious and potentially life-threatening complications, hemorrhagic colitis and the hemolytic uremic syndrome, makes VTEC infection a public health problem of serious concern. The main reservoirs of VTEC appear to be the intestinal tracts of animals, and foods of animal (especially bovine) origin are probably the principal sources for human infection. The term VT refers to a family of subunit exotoxins with high biological activity. Individual VTEC strains elaborate one or both of at least two serologically distinct, bacteriophage-mediated VTs (VT1 and VT2) which are closely related to Shiga toxin and are thus also referred to as Shiga-like toxins. The holotoxins bind to cells, via their B subunits, to a specific receptor which is probably the glycolipid, globotriosyl ceramide (Gb3). Binding is followed by internalization of the A subunit, which, after it is proteolytically nicked and reduced to the A1 fragment, inhibits protein synthesis in mammalian cells by inactivating 60S ribosomal subunits through selective structural modification of 28S ribosomal ribonucleic acid. The mechanism of VTEC diarrhea is still controversial, and the relative roles of locally acting VT and "attaching and effacing adherence" of VTEC to the mucosa have yet to be resolved. There is increasing evidence that hemolytic uremic syndrome and possibly hemorrhagic colitis result from the systemic action of VT on vascular endothelial cells. The role of antitoxic immunity in preventing the systemic complications of VTEC infection is being explored. Antibiotics appear to be contraindicated in the treatment of VTEC infection. The most common VTEC serotype associated

  13. Tailor-Made Distribution of Nanoparticles in Blend Structure toward Outstanding Electromagnetic Interference Shielding.

    PubMed

    Biswas, Sourav; Kar, Goutam Prasanna; Bose, Suryasarathi

    2015-11-18

    Engineering blend structure with tailor-made distribution of nanoparticles is the prime requisite to obtain materials with extraordinary properties. Herein, a unique strategy of distributing nanoparticles in different phases of a blend structure has resulted in >99% blocking of incoming electromagnetic (EM) radiation. This is accomplished by designing a ternary polymer blend structure using polycarbonate (PC), poly(vinylidene fluoride) (PVDF), and poly(methyl methacrylate) (PMMA) to simultaneously improve the structural, electrical, and electromagnetic interference shielding (EMI). The blend structure was made conducting by preferentially localizing the multi-wall nanotubes (MWNTs) in the PVDF phase. By taking advantage of "π-π stacking" MWNTs was noncovalently modified with an imidazolium based ionic liquid (IL). Interestingly, the enhanced dispersion of IL-MWNTs in PVDF improved the electrical conductivity of the blends significantly. While one key requisite to attenuate EM radiation (i.e., electrical conductivity) was achieved using MWNTs, the magnetic properties of the blend structure was tuned by introducing barium ferrite (BaFe) nanoparticles, which can interact with the incoming EM radiation. By suitably modifying the surface of BaFe nanoparticles, we can tailor their localization under the macroscopic processing condition. The precise localization of BaFe nanoparticles in the PC phase, due to nucleophilic substitution reaction, and the MWNTs in the PVDF phase not only improved the conductivity but also facilitated in absorption of the incoming microwave radiation due to synergetic effect from MWNT and BaFe. The shielding effectiveness (SE) was measured in X and Ku band, and an enhanced SE of -37 dB was noted at 18 GHz frequency. PMMA, which acted as an interfacial modifier in PC/PVDF blends further, resulting in a significant enhancement in the mechanical properties besides retaining high SE. This study opens a new avenue in designing mechanically strong

  14. ESBL-producing E. coli in Austrian sewage sludge.

    PubMed

    Reinthaler, Franz Ferdinand; Feierl, Gebhard; Galler, Herbert; Haas, Doris; Leitner, Eva; Mascher, Franz; Melkes, Angelika; Posch, Josefa; Winter, Ingrid; Zarfel, Gernot; Marth, Egon

    2010-03-01

    The aim of this study was to investigate the degree of contamination of sewage sludge with ESBL-producing Escherichia coli strains and the effectiveness of different sewage sludge treatment methods. Monthly sewage sludge samples were collected between January and September 2009 in 5 different sewage treatment plants and tested for the presence of ESBL E. coli. In addition, the number of colony forming units (CFU) of E. coli and coliform bacteria before and after the different sludge treatment methods (aerobic/anaerobic digestion, lime stabilization, and thermal treatment) was investigated. Of the 72 sewage sludge samples investigated, ESBL-positive E. coli were found in 44 (61.1%) sewage sludge samples. The classification of beta-lactamase groups was carried out in 15 strains resulting in the detection of 2 different groups (CTX-M and TEM) of bla genes. All 15 of them had a CTX-M gene and 4 of these strains furthermore carried a TEM gene. With regard to the CFU of E. coli and coliform bacteria, thermal treatment and lime stabilization following dehydration sufficiently reduced pathogen concentrations. The plants using merely stabilization and dehydration showed an increase of E. coli and coliform bacteria and thus also an increase in ESBL-producing E. coli.

  15. Intramammary challenge with Escherichia coli following immunization with a curli-producing Escherichia coli.

    PubMed

    Todhunter, D A; Smith, K L; Hogan, J S; Nelson, L

    1991-03-01

    Holstein and Jersey cattle were immunized with a curli-producing strain of Escherichia coli (pCRL65/A012) or a noncurli-producing strain (pUC18/HB101) to determine differences in resistance to establishment of experimental intramammary infection. Cows (n = 6 per group) were immunized at 14 d prior to drying off, 7 d of involution, and at calving with 3 x 10(10) E. coli in Freund's Incomplete Adjuvant. At 30 d of lactation, one mammary quarter of each cow was infused with a wild strain of E. coli (727). Escherichia coli 727 was isolated from a naturally occurring intramammary infection and produced curli. All challenged quarters became infected, and all cows developed acute clinical mastitis. Geometric mean duration of intramammary infections was 6 d for both immunization groups. All infections were spontaneously eliminated within 10 d. No differences occurred between immunization groups in blood selenium and glutathione peroxidase activity, plasma selenium, number of E. coli 727 isolated from secretion after challenge, rectal temperature and SCC response, clinical status of mammary quarters, or DMI. Reduction in milk production after challenge was greater for cows immunized with E. coli pCRL65/A012. Immunization of dairy cattle with a curli-producing strain of E. coli did not protect against experimental intramammary challenge during lactation.

  16. Synergy Effects in the Chemical Synthesis and Extensions of Multicomponent Reactions (MCRs)-The Low Energy Way to Ultra-Short Syntheses of Tailor-Made Molecules.

    PubMed

    Eckert, Heiner

    2017-02-25

    Several novel methods, catalysts and reagents have been developed to improve organic synthesis. Synergistic effects between reactions, reagents and catalysts can lead to minor heats of reaction and occur as an inherent result of multicomponent reactions (MCRs) and their extensions. They enable syntheses to be performed at a low energy level and the number of synthesis steps to be drastically reduced in comparison with 'classical' two-component reactions, fulfilling the rules of Green Chemistry. The very high potential for variability, diversity and complexity of MCRs additionally generates an extremely diverse range of products, thus bringing us closer to the aim of being able to produce tailor-made and extremely low-cost materials, drugs and compound libraries.

  17. Tailor-made biopolymers porous scaffold fabrication for tissue engineering: application of radiant energy in the form of microwave under vacuum.

    PubMed

    Jaya, S; Durance, T D

    2008-01-01

    Many methods are available for developing three-dimensional porous scaffolds using various polymeric materials for tissue-engineering applications. Each has its own advantages and disadvantages. Some of the available methods and their limitations were discussed briefly. This paper focuses on the scope of novel technology called radiant energy application under vacuum for the fabrication of three-dimensional porous scaffolds for tissue engineering applications. Radiant energy application in the form of microwave under vacuum has been shown to develop and maintain the porous structure in fruits and vegetables after dehydration, which produced the microstructure similar to the freeze dried materials. Same principle of applying radiant energy under vacuum was used on the biopolymeric gels to create tailor-made, porous scaffolds for biomedical purposes. It has many advantages over the other existing methods of scaffold fabrication. This paper also reviews the scaffolds design recently fabricated by the authors using radiant energy under vacuum.

  18. 76 FR 58157 - Shiga Toxin-Producing Escherichia coli

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-20

    ... infections.\\1\\ \\1\\ U.S. Centers for Disease Control and Prevention. 2005. Shiga toxin-producing Escherichia coli (STEC). National Notifiable Diseases Surveillance System (NNDSS), 2005 Case Definition. http://www...) 1422-1429. \\6\\ Centers for Disease Control and Prevention. Bacterial Foodborne and Diarrheal Disease...

  19. Gasifier feed - Tailor-made from Illinois coals. Technical report, December 1, 1991--February 29, 1992

    SciTech Connect

    Ehrlinger, H.P. III; Lytle, J.; Frost, R.R.; Lizzio, A.; Kohlenberger, L.; Brewer, K. |||

    1992-08-01

    The main purpose of this project is to produce a feedstock from preparation plant fines from an illinois coal that is ideal for a slurry fed, slagging, entrained-flow coal gasifier. The high sulfur content and high Btu value of Illinois coals are particularly advantageous in such a gasifier; preliminary calculations indicate that the increased cost of removing sulfur from the gas from a high sulfur coal is more than offset by the increased revenue from the sale of the elemental sulfur; additionally the high Btu Illinois coal concentrates more energy into the slurry of a given coal to water ratio. The Btu is higher not only because of the higher Btu value of the coal but also because Illinois coal requires less water to produce a pumpable slurry than western coal, i.e., as little as 30--35% water may be used for Illinois coal as compared to approximately 45% for most western coals.

  20. Playing and Listening to Tailor-Made Notched Music: Cortical Plasticity Induced by Unimodal and Multimodal Training in Tinnitus Patients

    PubMed Central

    Rudack, Claudia

    2014-01-01

    Background. The generation and maintenance of tinnitus are assumed to be based on maladaptive functional cortical reorganization. Listening to modified music, which contains no energy in the range of the individual tinnitus frequency, can inhibit the corresponding neuronal activity in the auditory cortex. Music making has been shown to be a powerful stimulator for brain plasticity, inducing changes in multiple sensory systems. Using magnetoencephalographic (MEG) and behavioral measurements we evaluated the cortical plasticity effects of two months of (a) active listening to (unisensory) versus (b) learning to play (multisensory) tailor-made notched music in nonmusician tinnitus patients. Taking into account the fact that uni- and multisensory trainings induce different patterns of cortical plasticity we hypothesized that these two protocols will have different affects. Results. Only the active listening (unisensory) group showed significant reduction of tinnitus related activity of the middle temporal cortex and an increase in the activity of a tinnitus-coping related posterior parietal area. Conclusions. These findings indicate that active listening to tailor-made notched music induces greater neuroplastic changes in the maladaptively reorganized cortical network of tinnitus patients while additional integration of other sensory modalities during training reduces these neuroplastic effects. PMID:24895541

  1. Playing and listening to tailor-made notched music: cortical plasticity induced by unimodal and multimodal training in tinnitus patients.

    PubMed

    Pape, Janna; Paraskevopoulos, Evangelos; Bruchmann, Maximilian; Wollbrink, Andreas; Rudack, Claudia; Pantev, Christo

    2014-01-01

    BACKGROUND. The generation and maintenance of tinnitus are assumed to be based on maladaptive functional cortical reorganization. Listening to modified music, which contains no energy in the range of the individual tinnitus frequency, can inhibit the corresponding neuronal activity in the auditory cortex. Music making has been shown to be a powerful stimulator for brain plasticity, inducing changes in multiple sensory systems. Using magnetoencephalographic (MEG) and behavioral measurements we evaluated the cortical plasticity effects of two months of (a) active listening to (unisensory) versus (b) learning to play (multisensory) tailor-made notched music in nonmusician tinnitus patients. Taking into account the fact that uni- and multisensory trainings induce different patterns of cortical plasticity we hypothesized that these two protocols will have different affects. RESULTS. Only the active listening (unisensory) group showed significant reduction of tinnitus related activity of the middle temporal cortex and an increase in the activity of a tinnitus-coping related posterior parietal area. CONCLUSIONS. These findings indicate that active listening to tailor-made notched music induces greater neuroplastic changes in the maladaptively reorganized cortical network of tinnitus patients while additional integration of other sensory modalities during training reduces these neuroplastic effects.

  2. Tailor-made rehabilitation approach using multiple types of hybrid assistive limb robots for acute stroke patients: A pilot study.

    PubMed

    Fukuda, Hiroyuki; Morishita, Takashi; Ogata, Toshiyasu; Saita, Kazuya; Hyakutake, Koichi; Watanabe, Junko; Shiota, Etsuji; Inoue, Tooru

    2016-01-01

    This article investigated the feasibility of a tailor-made neurorehabilitation approach using multiple types of hybrid assistive limb (HAL) robots for acute stroke patients. We investigated the clinical outcomes of patients who underwent rehabilitation using the HAL robots. The Brunnstrom stage, Barthel index (BI), and functional independence measure (FIM) were evaluated at baseline and when patients were transferred to a rehabilitation facility. Scores were compared between the multiple-robot rehabilitation and single-robot rehabilitation groups. Nine hemiplegic acute stroke patients (five men and four women; mean age 59.4 ± 12.5 years; four hemorrhagic stroke and five ischemic stroke) underwent rehabilitation using multiple types of HAL robots for 19.4 ± 12.5 days, and 14 patients (six men and eight women; mean age 63.2 ± 13.9 years; nine hemorrhagic stroke and five ischemic stroke) underwent rehabilitation using a single type of HAL robot for 14.9 ± 8.9 days. The multiple-robot rehabilitation group showed significantly better outcomes in the Brunnstrom stage of the upper extremity, BI, and FIM scores. To the best of the authors' knowledge, this is the first pilot study demonstrating the feasibility of rehabilitation using multiple exoskeleton robots. The tailor-made rehabilitation approach may be useful for the treatment of acute stroke.

  3. Tailor-made hollow silver nanoparticle cages assembled with silver nanoparticles: an efficient catalyst for epoxidation.

    PubMed

    Anandhakumar, S; Sasidharan, M; Tsao, Cheng-Wen; Raichur, Ashok M

    2014-03-12

    A novel approach toward the synthesis of hollow silver nanoparticle (NP) cages built with building blocks of silver NPs by layer-by-layer (LbL) assembly is demonstrated. The size of the NP cage depends on the size of template used for the LbL assembly. The microcages showed a uniform distribution of spherical silver nanoparticles with an average diameter of 20 ± 5 nm, which increased to 40 ± 5 nm when the AgNO3 concentration was increased from 25 to 50 mM. Heat treatment of the polyelectrolyte capsules at 80 °C near their pKa values yielded intact nano/micro cages. These cages produced a higher conversion for the epoxidation of olefins and maintained their catalytic activity even after four successive uses. The nanocages exhibited unique and attractive characteristics for metal catalytic systems, thus offering the scope for further development as heterogeneous catalysts.

  4. Biosynthesis, characterization, and hemostasis potential of tailor-made poly(3-hydroxybutyrate-co-3-hydroxyvalerate) produced by Haloferax mediterranei.

    PubMed

    Han, Jing; Wu, Lin-Ping; Hou, Jing; Zhao, Dahe; Xiang, Hua

    2015-02-09

    We report the biosynthesis of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) random copolymers (R-PHBV) or higher-order copolymers (O-PHBV) in Haloferax mediterranei, with adjustable 3-hydroxyvalerate (3HV) incorporation by cofeeding valerate with glucose. Their microchemical structure, molecular weight and its distribution, and thermal and mechanical properties were characterized by NMR, GPC, DSC, TGA, and universal testing machine, respectively. (13)C NMR studies showed that O-PHBV copolymers consisted of short segments of PHB and PHV covalently linked together with random PHBV segments. Consistently, two Tg were observed in the DSC curves of O-PHBV. The "blocky" feature of O-PHBV enhanced crystallinity percentages and improved Young's modulus. Notably, the film of one O-PHBV copolymer, O-PHBV-1, showed unique foveolar cluster-like surface morphology with high hydrophobicity and roughness, as characterized using static contact angle and SEM and AFM analyses. It also exhibited increased platelet adhesion and accelerated blood clotting. The excellent hemostatic properties endow this copolymer with great potential in wound healing.

  5. Study protocol: Münster tinnitus randomized controlled clinical trial-2013 based on tailor-made notched music training (TMNMT).

    PubMed

    Pantev, Christo; Rudack, Claudia; Stein, Alwina; Wunderlich, Robert; Engell, Alva; Lau, Pia; Wollbrink, Andreas; Shaykevich, Alex

    2014-03-02

    Tinnitus is a result of hyper-activity/hyper-synchrony of auditory neurons coding the tinnitus frequency, which has developed to synchronous mass activity owing the lack of inhibition. We assume that removal of exactly these frequency components from an auditory stimulus will cause the brain to reorganize around tonotopic regions coding the tinnitus frequency. Based on this assumption a novel treatment for tonal tinnitus - tailor-made notched music training (TMNMT) (Proc Natl Acad Sci USA 107:1207-1210, 2010; Ann N Y Acad Sci 1252:253-258, 2012; Frontiers Syst Neurosci 6:50, 2012) has been introduced and will be tested in this clinical trial on a large number of tinnitus patients. A randomized controlled trial (RCT) in parallel group design will be performed in a double-blinded manner. The choice of the intervention we are going to apply is based on two "proof of concept" studies in humans (Proc Natl Acad Sci USA 107:1207-1210, 2010; Ann N Y Acad Sci 1252:253-258, 2012; Frontiers Syst Neurosci 6:50, 2012; PloS One 6(9):e24685, 2011) and on a recent animal study (Front Syst Neurosci 7:21, 2013).The RCT includes 100 participants with chronic, tonal tinnitus who listened to tailor-made notched music (TMNM) for two hours a day for three months. The effect of TMNMT is assessed by the tinnitus handicap questionnaire and visual analogue scales (VAS) measuring perceived tinnitus loudness, distress and handicap. This is the first randomized controlled trial applying TMNMT on a larger number of patients with tonal tinnitus. Our data will verify more securely and reliably the effectiveness of this kind of completely non-invasive and low-cost treatment approach on tonal tinnitus. Current Controlled Trials ISRCTN04840953.

  6. Presence of Shiga toxin-producing Escherichia coli, Enteroinvasive E. coli, Enteropathogenic E. coli, and Enterotoxigenic E. coli on tomatoes from public markets in Mexico.

    PubMed

    Gómez-Aldapa, Carlos A; Torres-Vitela, M Del Refugio; Acevedo-Sandoval, Otilio A; Rangel-Vargas, Esmeralda; Villarruel-López, Angélica; Castro-Rosas, Andjavier

    2013-09-01

    Diarrheagenic Escherichia coli pathotypes (DEP) are important foodborne pathogens in various countries, including Mexico. However, no data exist on the presence of DEP on fresh tomatoes (Solanum lycopericum) from Mexico. The frequency of fecal coliforms (FC), E. coli, and DEP were determined for two tomato varieties. One hundred samples of a saladette tomato variety and 100 samples of a red round tomato variety were collected from public markets in Pachuca, Mexico. Each tomato sample consisted of four whole tomatoes. For the 100 saladette samples, coliform bacterial, FC, E. coli, and DEP were identified in 100, 70, 60, and 10% of samples, respectively. For the 100 red round samples, coliform bacterial, FC, E. coli, and DEP were identified in 100, 75, 65, and 11% of samples, respectively. Identified DEP included Shiga toxin-producing E. coli (STEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC). STEC were isolated from 6% of saladette samples and 5% of red round samples. ETEC were isolated from 3% of saladette samples and 4% of red round samples. EPEC were isolated from 2% of saladette samples and 3% of red round samples, and EIEC were isolated from 1% of saladette samples. Both STEC and ETEC were identified in two saladette samples and 1 red round sample. E. coli O157:H7 was not detected in any STEC-positive samples.

  7. Persistence of non-O157 Shiga Toxin-producing Escherichia coli on fresh produce surfaces

    USDA-ARS?s Scientific Manuscript database

    Introduction: The illnesses attributed to non-O157 Shiga toxin-producing Escherichia coli (STEC) have increased in the past decade with 22 foodborne outbreaks associated with non-O157 STEC. Lettuce and salad bars have been implicated in those outbreaks. Prevalence of the six major non-O157 STEC sero...

  8. Microcin 25, a novel antimicrobial peptide produced by Escherichia coli.

    PubMed Central

    Salomón, R A; Farías, R N

    1992-01-01

    Microcin 25, a peptide antibiotic excreted by an Escherichia coli strain isolated from human feces, was purified to homogeneity and characterized. Composition analysis and data from gel filtration indicated that microcin 25 may contain 20 amino acid residues. It has a blocked amino-terminal end. Microcin synthesis and immunity are plasmid determined, and the antibiotic was produced in minimal medium when the cultures entered the stationary phase of growth. The peptide appears to interfere with cell division, since susceptible cells filamented when exposed to it. This response does not seem to be mediated by the SOS system. Images PMID:1429464

  9. Tinnitus therapy using tailor-made notched music delivered via a smartphone application and Ginko combined treatment: A pilot study.

    PubMed

    Kim, So Young; Chang, Mun Young; Hong, Min; Yoo, Sun-Gil; Oh, Dongik; Park, Moo Kyun

    2017-10-01

    Notched music therapy has been suggested to be effective for relieving tinnitus. We have developed a smartphone application using tailor-made notched music for tinnitus patients. This study aimed to evaluate the effect of this smartphone application on reducing tinnitus. In addition, we investigated the predictive factors for tinnitus treatment outcome using this smartphone application. A total of 26 patients who were chronically distressed by tinnitus with a ≥18 Tinnitus Handicap Inventory (THI) score were recruited from March 2013 to March 2015 (National Clinical Trial (NCT) Identifier Number 01663467). Patients were instructed to listen to tailor-made notched music through our smartphone application for 30-60min per day and were prescribed Ginkgo biloba for 3 months. Treatment outcome was evaluated using the THI, a visual analogue scale that measures the effects of tinnitus in terms of loudness, noticeable time, annoyance, and disruption of daily life. Demographic data, including age, sex, duration of tinnitus, and pre-treatment scores on questionnaires such as the Beck Depression Inventory (BDI), State Trait Anxiety Inventory (TAI), and Pittsburgh Sleep Quality Index (PSQI) scores were compared between the effective and non-effective groups according to the differences between their pre- and post-treatment THI scores. Smartphone application-delivered notched music therapy and Ginko combined treatment improved the THI score from 33.9±18.9 to 23.1±15.2; the effect was particularly marked for the emotional score of the THI. Improvement in the THI score was positively correlated with the initial THI score (P=0.001, adjusted estimated value=0.49, 95% confidence interval=0.25-0.73). Chronic tinnitus patients who underwent smartphone application-delivered notched music therapy and Ginko combined treatment showed improved THI scores, particularly the emotional score of the THI. A smartphone application-delivered therapy and Ginko combined treatment may be more

  10. Beta-Lactamase Producing Escherichia coli Isolates in Imported and Locally Produced Chicken Meat from Ghana

    PubMed Central

    Rasmussen, Mette Marie; Opintan, Japheth A.; Frimodt-Møller, Niels; Styrishave, Bjarne

    2015-01-01

    The use of antibiotics in food animals is of public health concern, because resistant zoonotic pathogens can be transmitted to humans. Furthermore, global trade with food may rapidly spread multi-resistant pathogens between countries and even continents. The purpose of the study was to investigate whether imported chicken meat and meat from locally reared chicken are potential sources for human exposure to multi resistant Escherichia coli isolates. 188 samples from imported and locally produced chicken meat were sampled and analyzed. 153 bacteria isolates were successfully cultured and identified as E. coli using MALDI-ToF. Of these 109 isolates were from meat whereas the remaining 44 were isolated from the cloaca of locally reared live chickens. Antimicrobial susceptibility test was done on the identified E. coli isolates. Additionally, beta-lactamases production (ESBL and/or AmpC) were phenotypically confirmed on all isolates showing resistance to cefpodoxime. Beta-lactamase producing (BLP) E. coli meat isolates were further genotyped. Antimicrobial resistance to four antibiotic markers with highest resistance was detected more frequently in isolates from local chickens compared to imported chickens (tetracycline 88.9% vs. 57.5%, sulphonamide 75.0% vs. 46.6%, ampicillin 69.4% vs. 61.6% and trimethoprim 66.7% vs. 38.4%). Beta-lactamase production was found in 29 E. coli meat isolates, with 56.9% of them being multiple drug resistant (≥ 3). The predominant phylogroup identified was B1 followed by A and D, with similar distribution among the isolates from meat of locally reared chickens and imported chickens. Beta-lactamase producing genotype blaCTX-M-15 (50%; 10/20) was the most frequently drug resistant gene detected. More BLP E. coli isolates were found in imported chicken meat compared to locally reared chickens, demonstrating that these isolates may be spreading through food trade. In conclusion, both imported and locally produced chicken meats are potential

  11. Beta-Lactamase Producing Escherichia coli Isolates in Imported and Locally Produced Chicken Meat from Ghana.

    PubMed

    Rasmussen, Mette Marie; Opintan, Japheth A; Frimodt-Møller, Niels; Styrishave, Bjarne

    2015-01-01

    The use of antibiotics in food animals is of public health concern, because resistant zoonotic pathogens can be transmitted to humans. Furthermore, global trade with food may rapidly spread multi-resistant pathogens between countries and even continents. The purpose of the study was to investigate whether imported chicken meat and meat from locally reared chicken are potential sources for human exposure to multi resistant Escherichia coli isolates. 188 samples from imported and locally produced chicken meat were sampled and analyzed. 153 bacteria isolates were successfully cultured and identified as E. coli using MALDI-ToF. Of these 109 isolates were from meat whereas the remaining 44 were isolated from the cloaca of locally reared live chickens. Antimicrobial susceptibility test was done on the identified E. coli isolates. Additionally, beta-lactamases production (ESBL and/or AmpC) were phenotypically confirmed on all isolates showing resistance to cefpodoxime. Beta-lactamase producing (BLP) E. coli meat isolates were further genotyped. Antimicrobial resistance to four antibiotic markers with highest resistance was detected more frequently in isolates from local chickens compared to imported chickens (tetracycline 88.9% vs. 57.5%, sulphonamide 75.0% vs. 46.6%, ampicillin 69.4% vs. 61.6% and trimethoprim 66.7% vs. 38.4%). Beta-lactamase production was found in 29 E. coli meat isolates, with 56.9% of them being multiple drug resistant (≥ 3). The predominant phylogroup identified was B1 followed by A and D, with similar distribution among the isolates from meat of locally reared chickens and imported chickens. Beta-lactamase producing genotype blaCTX-M-15 (50%; 10/20) was the most frequently drug resistant gene detected. More BLP E. coli isolates were found in imported chicken meat compared to locally reared chickens, demonstrating that these isolates may be spreading through food trade. In conclusion, both imported and locally produced chicken meats are potential

  12. "Click chemistry" in tailor-made polymethacrylates bearing reactive furfuryl functionality: a new class of self-healing polymeric material.

    PubMed

    Kavitha, A Amalin; Singha, Nikhil K

    2009-07-01

    This investigation reports the effective use of the Diels-Alder (DA) reaction, a "click reaction" in the preparation of thermally amendable and self-healing polymeric materials having reactive furfuryl functionality. In this case, the DA and retro-DA (rDA) reactions were carried out between the tailor-made homo- and copolymer of furfuryl methacrylate prepared by atom-transfer radical polymerization and a bismaleimide (BM). The kinetic studies of DA and rDA reactions were carried out using Fourier transform infrared spectroscopy. The DA polymers were insoluble in toluene at room temperature. When the DA polymers were heated at 100 degrees C in toluene, it was soluble. This is because of the cleavage between furfuryl functionality and BM. The chemical cross-link density was determined by the Flory-Rehner equation. The cross-linked polymer showed much greater adhesive strength at room temperature, but the adhesive strength was quite low at higher temperature. The self-healing capability was studied by using scanning electron microscopy analysis. The thermal and dynamic mechanical properties of the thermally amendable cross-linked materials were investigated by thermogravimetric analysis and dynamic mechanical analysis.

  13. Tailor-made cell patterning using a near-infrared-responsive composite gel composed of agarose and carbon nanotubes.

    PubMed

    Koga, Haruka; Sada, Takao; Fujigaya, Tsuyohiko; Nakashima, Naotoshi; Nakazawa, Kohji

    2013-03-01

    Micropatterning is useful for regulating culture environments. We developed a highly efficient near-infrared-(NIR)-responsive gel and established a new technique that enables cell patterning by NIR irradiation. As a new culture substratum, we designed a tissue culture plate that was coated with a composite gel composed of agarose and carbon nanotubes (CNTs). A culture plate coated with agarose only showed no response to NIR irradiation. In contrast, NIR laser irradiation induced heat generation by CNTs; this permitted local solation of the CNT/agarose gel, and consequently, selective cell-adhesive regions were exposed on the tissue culture plate. The solation area was controlled by the NIR intensity, magnification of the object lens and CNT concentration in the gel. Furthermore, we formed circular patterns of HeLa cells and linear patterns of 3T3 cells on the same culture plate through selective and stepwise NIR irradiation of the CNT/agarose gel, and we also demonstrated that individual 3T3 cells migrated along a linear path formed on the CNT/agarose gel by NIR irradiation. These results indicate that our technique is useful for tailor-made cell patterning of stepwise and/or complex cell patterns, which has various biological applications such as stepwise co-culture and the study of cell migration.

  14. Shiga Toxin-Producing Escherichia coli (STEC) in Fresh Produce--A Food Safety Dilemma.

    PubMed

    Feng, Peter

    2014-08-01

    Produce contains high levels of mixed microflora, including coliforms and Escherichia coli, but occasionally pathogens may also be present. Enterotoxigenic E. coli and Shigatoxin-producing E. coli (STEC) have been isolated from various produce types, especially spinach. The presence of STEC in produce is easily detected by PCR for the Shiga toxin (Stx) gene, stx, but this is insufficient for risk analysis. STEC comprises hundreds of serotypes that include known pathogenic serotypes and strains that do not appear to cause severe illness. Moreover, Stx without a binding factor like intimin (encoded by eae) is deemed to be insufficient to cause severe disease. Hence, risk analyses require testing for other virulence or serotype-specific genes. Multiplex PCR enables simultaneous testing of many targets, but, in a mixed flora sample, not all targets detected may be coming from the same cell. The need to isolate and confirm STEC in produce is critical, but it is time- and labor-intensive due to the complexity of the group. Studies showed that only a handful of STEC strains in produce have eae, and most belonged to recognized pathogenic serotypes so are of definite health risks. Several eae-negative strains belonged to serotypes O113:H21 and O91:H21 that historically have caused severe illness and may also be of concern. Most of the other STEC strains in produce, however, are only partially serotyped or are unremarkable serotypes carrying putative virulence factors, whose role in pathogenesis is uncertain, thus making it difficult to assess the health risks of these STEC strains.

  15. Public Health Microbiology of Shiga Toxin-Producing Escherichia coli.

    PubMed

    Caprioli, Alfredo; Scavia, Gaia; Morabito, Stefano

    2014-12-01

    Shiga toxin-producing Escherichia coli (STEC) strains are the only pathogenic group of E. coli that has a definite zoonotic origin, with ruminants and, in particular, cattle being recognized as the major reservoir. Most human STEC infections are food borne, but the routes of transmission include direct contact with animals and a variety of environment-related exposures. Therefore, STEC public health microbiology spans the fields of medical, veterinary, food, water, and environmental microbiology, requiring a "One Health" perspective and laboratory scientists with the ability to work effectively across disciplines. Public health microbiology laboratories play a central role in the surveillance of STEC infections, as well as in the preparedness for responding to outbreaks and in providing scientific evidence for the implementation of prevention and control measures. This article reviews (i) how the integration of surveillance of STEC infections and monitoring of these pathogens in animal reservoirs and potential food vehicles may contribute to their control; (ii) the role of reference laboratories, in both the public health and veterinary and food sectors; and (iii) the public health perspectives, including those related to regulatory issues in both the European Union and the United States.

  16. Treatment of Shiga toxin-producing Escherichia coli infections.

    PubMed

    Davis, T Keefe; McKee, Ryan; Schnadower, David; Tarr, Phillip I

    2013-09-01

    The management of Shiga toxin-producing Escherichia coli (STEC) infections is reviewed. Certain management practices optimize the likelihood of good outcomes, such as avoidance of antibiotics during the pre-hemolytic uremic syndrome phase, admission to hospital, and vigorous intravenous volume expansion using isotonic fluids. The successful management of STEC infections is based on recognition that a patient might have an STEC infection, and appropriate use of the microbiology laboratory. The timeliness of STEC identification cannot be overemphasized, because it avoids therapies prompted by inappropriate additional testing and directs the clinician to focus on effective management strategies. The opportunities during STEC infections to avert the worst outcomes are brief, and this article emphasizes practical matters relevant to making a diagnosis, anticipating the trajectory of illness, and optimizing care. Copyright © 2013 Elsevier Inc. All rights reserved.

  17. Impact of Spectral Notch Width on Neurophysiological Plasticity and Clinical Effectiveness of the Tailor-Made Notched Music Training.

    PubMed

    Wunderlich, Robert; Lau, Pia; Stein, Alwina; Engell, Alva; Wollbrink, Andreas; Rudack, Claudia; Pantev, Christo

    2015-01-01

    Tinnitus, the ringing in the ears that is unrelated to any external source, causes a significant loss in quality of life, involving sleep disturbance and depression for 1 to 3% of the general population. While in the first place tinnitus may be triggered by damage to the inner ear cells, the neural generators of subjective tinnitus are located in central regions of the nervous system. A loss of lateral inhibition, tonotopical reorganization and a gain-increase in response to the sensory deprivation result in hypersensitivity and hyperactivity in certain regions of the auditory cortex. In the tailor-made notched music training (TMNMT) patients listen to music from which the frequency spectrum of the tinnitus has been removed. This evokes strong lateral inhibition from neurons tuned to adjacent frequencies onto the neurons involved in the tinnitus percept. A reduction of tinnitus loudness and tinnitus-related neural activity was achieved with TMNMT in previous studies. As the effect of lateral inhibition depends on the bandwidth of the notch, in the current study we altered the notch width to find the most effective notch width for TMNMT. We compared 1-octave notch width with ½-octave and ¼-octave. Participants chose their favorite music for the training that included three month of two hours daily listening. The outcome was measured by means of standardized questionnaires and magnetoencephalography. We found a general reduction of tinnitus distress in all administered tinnitus questionnaires after the training. Additionally, tinnitus-related neural activity was reduced after the training. Nevertheless, notch width did not have an influence on the behavioral or neural effects of TMNMT. This could be due to a non-linear resolution of lateral inhibition in high frequencies.

  18. Field evaluation of a tailor-made new passive sampler for the determination of NO2 levels in ambient air.

    PubMed

    Ozden, Ozlem; Dogeroglu, Tuncay

    2008-07-01

    This study describes the field evaluation of a tailor-made new glass passive sampler developed for the determination of NO(2), based on the collection on triethanolemine (TEA)-coated fibre filter paper. The sampler has been derived from a Palmes design. The overall uncertainty of the sampler was determined by using Griess-Saltzman ASTM D 1607 standard test method as a reference method. The agreement between the results of the passive sampler and the reference method was +/-7.90% with the correlation coefficient of 0.90. Method precision in terms of coefficient of variance (CV) for three simultaneously applied passive samplers was 8.80%. The uptake rate of NO(2) was found to be 2.49 ml/min in a very good agreement with the value calculated from theory (2.63 ml/min). Sampler detection limit was 1.99 microg/m(3) for an exposure period of 1 week and the sampler can be stored safely for a period of up to 6 weeks before exposure. A comparison of the sampler performance was conducted against a commercially available diffusion tube (Gradko diffusion tube). The results from the applied statistical paired t test indicated that there was no significant difference between the performances of two passive samplers (R (2) > 0.90). Also, another statistical comparison was carried out between the dark and transparent glass passive samplers. The results from the dark-colour sampler were higher than that from the transparent sampler (approximately 25%) during the summer season because of the possible photodegradation of NO(2)-TEA complex.

  19. Enhancing inhibition-induced plasticity in tinnitus--spectral energy contrasts in tailor-made notched music matter.

    PubMed

    Stein, Alwina; Engell, Alva; Lau, Pia; Wunderlich, Robert; Junghoefer, Markus; Wollbrink, Andreas; Bruchmann, Maximilian; Rudack, Claudia; Pantev, Christo

    2015-01-01

    Chronic tinnitus seems to be caused by reduced inhibition among frequency selective neurons in the auditory cortex. One possibility to reduce tinnitus perception is to induce inhibition onto over-activated neurons representing the tinnitus frequency via tailor-made notched music (TMNM). Since lateral inhibition is modifiable by spectral energy contrasts, the question arises if the effects of inhibition-induced plasticity can be enhanced by introducing increased spectral energy contrasts (ISEC) in TMNM. Eighteen participants suffering from chronic tonal tinnitus, pseudo randomly assigned to either a classical TMNM or an ISEC-TMNM group, listened to notched music for three hours on three consecutive days. The music was filtered for both groups by introducing a notch filter centered at the individual tinnitus frequency. For the ISEC-TMNM group a frequency bandwidth of 3/8 octaves on each side of the notch was amplified, additionally, by about 20 dB. Before and after each music exposure, participants rated their subjectively perceived tinnitus loudness on a visual analog scale. During the magnetoencephalographic recordings, participants were stimulated with either a reference tone of 500 Hz or a test tone with a carrier frequency representing the individual tinnitus pitch. Perceived tinnitus loudness was significantly reduced after TMNM exposure, though TMNM type did not influence the loudness ratings. Tinnitus related neural activity in the N1m time window and in the so called tinnitus network comprising temporal, parietal and frontal regions was reduced after TMNM exposure. The ISEC-TMNM group revealed even enhanced inhibition-induced plasticity in a temporal and a frontal cortical area. Overall, inhibition of tinnitus related neural activity could be strengthened in people affected with tinnitus by increasing spectral energy contrast in TMNM, confirming the concepts of inhibition-induced plasticity via TMNM and spectral energy contrasts.

  20. Enhancing Inhibition-Induced Plasticity in Tinnitus – Spectral Energy Contrasts in Tailor-Made Notched Music Matter

    PubMed Central

    Stein, Alwina; Engell, Alva; Lau, Pia; Wunderlich, Robert; Junghoefer, Markus; Wollbrink, Andreas; Bruchmann, Maximilian; Rudack, Claudia; Pantev, Christo

    2015-01-01

    Chronic tinnitus seems to be caused by reduced inhibition among frequency selective neurons in the auditory cortex. One possibility to reduce tinnitus perception is to induce inhibition onto over-activated neurons representing the tinnitus frequency via tailor-made notched music (TMNM). Since lateral inhibition is modifiable by spectral energy contrasts, the question arises if the effects of inhibition-induced plasticity can be enhanced by introducing increased spectral energy contrasts (ISEC) in TMNM. Eighteen participants suffering from chronic tonal tinnitus, pseudo randomly assigned to either a classical TMNM or an ISEC-TMNM group, listened to notched music for three hours on three consecutive days. The music was filtered for both groups by introducing a notch filter centered at the individual tinnitus frequency. For the ISEC-TMNM group a frequency bandwidth of 3/8 octaves on each side of the notch was amplified, additionally, by about 20 dB. Before and after each music exposure, participants rated their subjectively perceived tinnitus loudness on a visual analog scale. During the magnetoencephalographic recordings, participants were stimulated with either a reference tone of 500 Hz or a test tone with a carrier frequency representing the individual tinnitus pitch. Perceived tinnitus loudness was significantly reduced after TMNM exposure, though TMNM type did not influence the loudness ratings. Tinnitus related neural activity in the N1m time window and in the so called tinnitus network comprising temporal, parietal and frontal regions was reduced after TMNM exposure. The ISEC-TMNM group revealed even enhanced inhibition-induced plasticity in a temporal and a frontal cortical area. Overall, inhibition of tinnitus related neural activity could be strengthened in people affected with tinnitus by increasing spectral energy contrast in TMNM, confirming the concepts of inhibition-induced plasticity via TMNM and spectral energy contrasts. PMID:25951605

  1. Impact of Spectral Notch Width on Neurophysiological Plasticity and Clinical Effectiveness of the Tailor-Made Notched Music Training

    PubMed Central

    Wunderlich, Robert; Lau, Pia; Stein, Alwina; Engell, Alva; Wollbrink, Andreas; Rudack, Claudia; Pantev, Christo

    2015-01-01

    Tinnitus, the ringing in the ears that is unrelated to any external source, causes a significant loss in quality of life, involving sleep disturbance and depression for 1 to 3% of the general population. While in the first place tinnitus may be triggered by damage to the inner ear cells, the neural generators of subjective tinnitus are located in central regions of the nervous system. A loss of lateral inhibition, tonotopical reorganization and a gain-increase in response to the sensory deprivation result in hypersensitivity and hyperactivity in certain regions of the auditory cortex. In the tailor-made notched music training (TMNMT) patients listen to music from which the frequency spectrum of the tinnitus has been removed. This evokes strong lateral inhibition from neurons tuned to adjacent frequencies onto the neurons involved in the tinnitus percept. A reduction of tinnitus loudness and tinnitus-related neural activity was achieved with TMNMT in previous studies. As the effect of lateral inhibition depends on the bandwidth of the notch, in the current study we altered the notch width to find the most effective notch width for TMNMT. We compared 1-octave notch width with ½-octave and ¼-octave. Participants chose their favorite music for the training that included three month of two hours daily listening. The outcome was measured by means of standardized questionnaires and magnetoencephalography. We found a general reduction of tinnitus distress in all administered tinnitus questionnaires after the training. Additionally, tinnitus-related neural activity was reduced after the training. Nevertheless, notch width did not have an influence on the behavioral or neural effects of TMNMT. This could be due to a non-linear resolution of lateral inhibition in high frequencies. PMID:26406446

  2. Characterization of CTX-M-14-producing Escherichia coli from food-producing animals

    PubMed Central

    Liao, Xiao-Ping; Xia, Jing; Yang, Lei; Li, Liang; Sun, Jian; Liu, Ya-Hong; Jiang, Hong-Xia

    2015-01-01

    Bacterial resistance to the third-generation cephalosporin antibiotics has become a major concern for public health. This study was aimed to determine the characteristics and distribution of blaCTX-M-14, which encodes an extended-spectrum β-lactamase, in Escherichia coli isolated from Guangdong Province, China. A total of 979 E. coli isolates isolated from healthy or diseased food-producing animals including swine and avian were examined for blaCTX-M-14 and then the blaCTX-M-14 -positive isolates were detected by other resistance determinants [extended-spectrum β-lactamase genes, plasmid-mediated quinolone resistance, rmtB, and floR] and analyzed by phylogenetic grouping analysis, PCR-based plasmid replicon typing, multilocus sequence typing, and plasmid analysis. The genetic environments of blaCTX-M-14 were also determined by PCR. The results showed that fourteen CTX-M-14-producing E. coli were identified, belonging to groups A (7/14), B1 (4/14), and D (3/14). The most predominant resistance gene was blaTEM (n = 8), followed by floR (n = 7), oqxA (n = 3), aac(6′)-1b-cr (n = 2), and rmtB (n = 1). Plasmids carrying blaCTX-M-14 were classified to IncK, IncHI2, IncHI1, IncN, IncFIB, IncF or IncI1, ranged from about 30 to 200 kb, and with insertion sequence of ISEcp1, IS26, or ORF513 located upstream and IS903 downstream of blaCTX-M-14. The result of multilocus sequence typing showed that 14 isolates had 11 STs, and the 11 STs belonged to five groups. Many of the identified sequence types are reported to be common in E. coli isolates associated with extraintestinal infections in humans, suggesting possible transmission of blaCTX-M-14 between animals and humans. The difference in the flanking sequences of blaCTX-M-14 between the 2009 isolates and the early ones suggests that the resistance gene context continues to evolve in E. coli of food producing animals. PMID:26528278

  3. Characterization of CTX-M-14-producing Escherichia coli from food-producing animals.

    PubMed

    Liao, Xiao-Ping; Xia, Jing; Yang, Lei; Li, Liang; Sun, Jian; Liu, Ya-Hong; Jiang, Hong-Xia

    2015-01-01

    Bacterial resistance to the third-generation cephalosporin antibiotics has become a major concern for public health. This study was aimed to determine the characteristics and distribution of bla CTX-M-14, which encodes an extended-spectrum β-lactamase, in Escherichia coli isolated from Guangdong Province, China. A total of 979 E. coli isolates isolated from healthy or diseased food-producing animals including swine and avian were examined for bla CTX-M-14 and then the bla CTX-M-14 -positive isolates were detected by other resistance determinants [extended-spectrum β-lactamase genes, plasmid-mediated quinolone resistance, rmtB, and floR] and analyzed by phylogenetic grouping analysis, PCR-based plasmid replicon typing, multilocus sequence typing, and plasmid analysis. The genetic environments of bla CTX-M-14 were also determined by PCR. The results showed that fourteen CTX-M-14-producing E. coli were identified, belonging to groups A (7/14), B1 (4/14), and D (3/14). The most predominant resistance gene was bla TEM (n = 8), followed by floR (n = 7), oqxA (n = 3), aac(6')-1b-cr (n = 2), and rmtB (n = 1). Plasmids carrying bla CTX-M-14 were classified to IncK, IncHI2, IncHI1, IncN, IncFIB, IncF or IncI1, ranged from about 30 to 200 kb, and with insertion sequence of ISEcp1, IS26, or ORF513 located upstream and IS903 downstream of bla CTX-M-14. The result of multilocus sequence typing showed that 14 isolates had 11 STs, and the 11 STs belonged to five groups. Many of the identified sequence types are reported to be common in E. coli isolates associated with extraintestinal infections in humans, suggesting possible transmission of bla CTX-M-14 between animals and humans. The difference in the flanking sequences of bla CTX-M-14 between the 2009 isolates and the early ones suggests that the resistance gene context continues to evolve in E. coli of food producing animals.

  4. Thermolabile antifreeze protein produced in Escherichia coli for structural analysis.

    PubMed

    Lin, Feng-Hsu; Sun, Tianjun; Fletcher, Garth L; Davies, Peter L

    2012-03-01

    The only hyperactive antifreeze protein (AFP) found to date in fishes is an extreme variant of the 3-kDa, alpha-helical, alanine-rich type I AFP, which is referred to here as type Ih. Purification of the 33-kDa homodimeric AFP Ih from a natural source was hampered by its low levels in fish plasma; by the need to remove the more abundant smaller isoforms; and by its extreme thermolability. Moreover, ice affinity as a purification tool was spoiled by the tendency of fish IgM antibodies to bind to ice in the presence of AFPs. In order to produce enough protein for crystallography we expressed AFP Ih as a recombinant protein in the Arctic Express® strain of Escherichia coli at 12 °C, just below the thermal denaturation temperature of 16-18 °C. His-tags were not useful because they compromised the activity and yield of AFP Ih. But in the absence of fish antibodies we were able to recover 10-mg quantities of the antifreeze protein using two cycles of ice affinity purification followed by anion-exchange chromatography to remove contaminating chaperones. The purified recombinant AFP Ih yielded diffraction-quality crystals with an extremely asymmetrical unit cell. By transferring the genes of the chaperones into a methionine auxotroph we were able to grow this host at low temperatures and produce sufficient selenomethionine-labeled AFP Ih for crystallography.

  5. Resistance of various shiga toxin-producing Escherichia coli to electrolyzed oxidizing water

    USDA-ARS?s Scientific Manuscript database

    The resistance of thirty two strains of Escherichia coli O157:H7 and six major serotypes of non-O157 Shiga toxin- producing E. coli (STEC) plus E. coli O104 was tested against Electrolyzed oxidizing (EO) water using two different methods; modified AOAC 955.16 sequential inoculation method and minim...

  6. Shiga-Like-Toxin-Producing Escherichia coli in Retail Meats and Cattle in Thailand

    DTIC Science & Technology

    1990-04-01

    animals in Thailand. SLT-producing E . coli was isolated from 9% of market beef specimens, from 8 to 28% of fresh beef specimens at slaughterhouses, and...from 11 to 84% of fecal specimens from cattle. Animals were frequently infected with several different SLT-producing E . coli types that hybridized...with either the SLT I, SLT II, or both SLT probes. Of 119 SLT-producing E . coli isolates, 24% hybridized with the SLT I probe, 31% hybridized with the

  7. Epidemiology of urinary tract infections caused by extended-spectrum beta-lactamase-producing Escherichia coli.

    PubMed

    Ena, Javier; Arjona, Francisco; Martínez-Peinado, Carmen; López-Perezagua, Maria Del Mar; Amador, Concepción

    2006-12-01

    To describe the epidemiology of urinary tract infections caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli. We performed three studies: a trend study (1999 to 2004) to assess the evolution and origin of ESBL-producing E. coli isolates from urine samples; a comparison of the susceptibility patterns of ESBL-producing E. coli and a random sample of non-ESBL-producing E. coli isolated in the same interval, and a retrospective chart review to determine the risk factors for acquisition of, and outcomes from, urinary tract infections caused by ESBL-producing E. coli (n = 61) compared with a random sample of non-ESBL-producing E. coli urinary tract infections (n = 61) from patients attending our institution and matched by temporal occurrence. ESBL-producing E. coli significantly increased from 2 (0.20%) to 89 (5.52%) isolates per year (P value for trend = 0.000). Of the 161 patients with urinary tract infections caused by ESBL-producing E. coli, 100 (62%) were attending ambulatory health centers, and 61 (38%) were attending the hospital. ESBL-producing E. coli showed a significant reduction in the susceptibility to most antimicrobials, although carbapenems and fosfomycin retained significant activity. The chart review study showed that previous treatment with fluoroquinolones (odds ratio 12.98, 95% confidence interval 1.81 to 106.51, P = 0.017) and the presence of a urinary catheter (odds ratio 2.64, 95% confidence interval 1.01 to 6.88, P = 0.047) were independent risk factors associated with infections caused by ESBL-producing E. coli. ESBL-producing E. coli is a problem of increasing importance. Our study results may help physicians select appropriate antimicrobial therapy in patients suspected of having urinary tract infections caused by ESBL-producing E. coli.

  8. Behavior of non-O157 Shiga toxin-producing Escherichia coli, enteroinvasive E. coli, enteropathogenic E. coli, and enterotoxigenic E. coli strains on alfalfa sprouts.

    PubMed

    Gómez-Aldapa, Carlos A; Rangel-Vargas, Esmeralda; Torres-Vitela, M Del Refugio; Villarruel-López, Angélica; Castro-Rosas, Javier

    2013-08-01

    Data about the behavior of non-O157 Shiga toxin-producing Escherichia coli (non-O157 STEC), enteroinvasive E. coli (EIEC), enterotoxigenic E. coli (ETEC), and enteropathogenic E. coli (EPEC) on seeds and alfalfa sprouts are not available. The behavior of STEC, EIEC, ETEC, and EPEC was determined during germination and sprouting of alfalfa seeds at 20 ± 2°C and 30 ± 2°C and on alfalfa sprouts at 3 ± 2°C. When alfalfa seeds were inoculated with STEC, EIEC, ETEC, or EPEC strains, all these diarrheagenic E. coli pathotypes (DEPs) grew during germination and sprouting of seeds, reaching counts of approximately 5 and 6 log CFU/g after 1 day at 20 ± 2°C and 30 ± 2°C, respectively. However, when the sprouts were inoculated after 1 day of seed germination and stored at 20 ± 2°C or 30 ± 2°C, no growth was observed for any DEP during sprouting at 20 ± 2°C or 30 ± 2°C for 9 days. Refrigeration reduced significantly (P < 0.0.5) the number of viable DEPs on sprouts after 20 days in storage; nevertheless, these decreases have no practical significance for the safety of the sprouts.

  9. Comparison of non-O157 Shiga toxin-producing E. coli detection systems

    USDA-ARS?s Scientific Manuscript database

    Category: methodology improvements Objective: To identify strengths and weaknesses of commercial Shiga toxin-producing E. coli detection systems and kits in a side by side fashion. Experimental Design: Three commercial Shiga toxin-producing E. coli detection tests (BAX, GDS, and GeneDisc) and two t...

  10. Expansion of Shiga Toxin–Producing Escherichia coli by Use of Bovine Antibiotic Growth Promoters

    PubMed Central

    Kim, Jong-Chul; Chui, Linda; Wang, Yang; Shen, Jianzhong

    2016-01-01

    Antibiotics are routinely used in food-producing animals to promote growth and prevent infectious diseases. We investigated the effects of bovine antibiotic growth promoters (bAGPs) on the propagation and spread of Shiga toxin (Stx)–encoding phages in Escherichia coli. Co-culture of E. coli O157:H7 and other E. coli isolated from cattle in the presence of sublethal concentrations of bAGPs significantly increased the emergence of non-O157, Stx-producing E. coli by triggering the SOS response system in E. coli O157:H7. The most substantial mediation of Stx phage transmission was induced by oxytetracyline and chlortetracycline, which are commonly used in agriculture. bAGPs may therefore contribute to the expansion of pathogenic Stx-producing E. coli. PMID:27088186

  11. Expansion of Shiga Toxin-Producing Escherichia coli by Use of Bovine Antibiotic Growth Promoters.

    PubMed

    Kim, Jong-Chul; Chui, Linda; Wang, Yang; Shen, Jianzhong; Jeon, Byeonghwa

    2016-05-01

    Antibiotics are routinely used in food-producing animals to promote growth and prevent infectious diseases. We investigated the effects of bovine antibiotic growth promoters (bAGPs) on the propagation and spread of Shiga toxin (Stx)-encoding phages in Escherichia coli. Co-culture of E. coli O157:H7 and other E. coli isolated from cattle in the presence of sublethal concentrations of bAGPs significantly increased the emergence of non-O157, Stx-producing E. coli by triggering the SOS response system in E. coli O157:H7. The most substantial mediation of Stx phage transmission was induced by oxytetracyline and chlortetracycline, which are commonly used in agriculture. bAGPs may therefore contribute to the expansion of pathogenic Stx-producing E. coli.

  12. First report of Escherichia coli co-producing NDM-1 and OXA-232.

    PubMed

    Both, Anna; Huang, Jiabin; Kaase, Martin; Hezel, Julia; Wertheimer, Daniel; Fenner, Ines; Günther, Thomas; Grundhoff, Adam; Büttner, Henning; Aepfelbacher, Martin; Rohde, Holger; Hentschke, Moritz

    2016-12-01

    Recently Gram-negative bacteria co-producing multiple carbapenemases have emerged in different parts of the world. We report the first isolation of an Escherichia coli strain co-producing the carbapenemases NDM-1 and OXA-232.

  13. Extended-spectrum β-lactamase-producing Escherichia coli bacteremia: Comparison of pediatric and adult populations.

    PubMed

    Tsai, Wan-Lin; Hung, Chih-Hsin; Chen, Hui-An; Wang, Jiun-Ling; Huang, I-Fei; Chiou, Yee-Hsuan; Chen, Yao-Shen; Lee, Susan Shin-Jung; Hung, Wan-Yu; Cheng, Ming-Fang

    2017-08-31

    The prevalence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is increasing worldwide. This study investigated the clinical features and bacteriology of pediatric patients with ESBL-producing E. coli bacteremia and compared their characteristics with those of adult patients. Clinical and laboratory data from all of the 41 patients aged ≤18 years diagnosed with E. coli bacteremia were collected over 5 years. Patients aged >18 years diagnosed with E. coli bacteremia, matched 1:1 for calendar time, were enrolled as the adult group. All E. coli isolates were tested for their blaCTX-M group and sequence type 131 (ST131). A novel seven-single nucleotide polymorphism-based clonotyping test was applied to detect the septatypes of each isolate. In the adult group, patients with ESBL-producing E. coli bacteremia had more previous hospitalizations and antimicrobial agent use than did those with non-ESBL-producing E. coli bacteremia, but these differences were not found in pediatric group. In the pediatric group, the proportion of isolates producing CTX-M group 9 was higher than that in the adult group (85.7% vs. 42.9%; p < 0.05). Among both groups, there were more E. coli ST131 in ESBL isolates in than there were non-ESBL isolates. The distribution of septatypes was more homogenous in ESBL-producing E. coli among the pediatric patients than among the adult patients. ST131 was the major clone causing E. coli bacteremia in both pediatric and adult populations. The pediatric population demonstrated a higher number of isolates producing CTX-M group 9 with more homogenous septatypes compared with the adult population. Copyright © 2017. Published by Elsevier B.V.

  14. Characterization of biofilms produced by Escherichia coli O157 isolated from cattle hides

    NASA Astrophysics Data System (ADS)

    Milojević, L.; Velebit, B.; Baltić, T.; Nikolić, A.; Mitrović, R.; Đorđević, V.

    2017-09-01

    This study aimed to investigate possibility E. coli O157 from cattle hides to produced biofilms. We had 28 suspect primoisolates and 17 were confirmed to be E. coli O157. Biofilm production test showed that more than 50% of this isolates did not produce biofilm. From the other half of the isolates, 5 of them were weakly adherent, 3 were moderately adherent. Since E. coli O157 are one of the main foodborne hazards in meat processing industry and the discovery that some of them can produce moderately adherent biofilms, request necessity of strict implementation of HACCP procedures to prevent further expansion this pathogen.

  15. Detection and isolation of shiga toxin-producing Escherichia coli (STEC) O104 from sprouts

    USDA-ARS?s Scientific Manuscript database

    E. coli O157:H7 and non-O157 Shiga toxin-producing E. coli (STEC) are food-borne pathogens responsible for severe outbreaks of hemorrhagic colitis, which can lead to hemolytic uremic syndrome and/or death. STEC strains belonging to serogroup O104 have been associated with sporadic cases of illness a...

  16. Surveillance for Shiga toxin-producing Escherichia coli, Michigan, 2001-2005.

    PubMed

    Manning, Shannon D; Madera, Robbie T; Schneider, William; Dietrich, Stephen E; Khalife, Walid; Brown, William; Whittam, Thomas S; Somsel, Patricia; Rudrik, James T

    2007-02-01

    A surveillance system used different detection methods to estimate prevalence of Shiga toxin-producing Escherichia coli during 2003-2005 and 2001-2002. More non-O157 serotypes were detected by enzyme immunoassay than by evaluation of non-sorbitol-fermenting E. coli isolates. We therefore recommend use of enzyme immunoassay and culture-based methods.

  17. Surveillance for Shiga Toxin–producing Escherichia coli, Michigan, 2001–2005

    PubMed Central

    Manning, Shannon D.; Madera, Robbie T.; Schneider, William; Dietrich, Stephen E.; Khalife, Walid; Brown, William; Whittam, Thomas S.; Somsel, Patricia

    2007-01-01

    A surveillance system used different detection methods to estimate prevalence of Shiga toxin–producing Escherichia coli during 2003–2005 and 2001–2002. More non-O157 serotypes were detected by enzyme immunoassay than by evaluation of non-sorbitol–fermenting E. coli isolates. We therefore recommend use of enzyme immunoassay and culture-based methods. PMID:17479902

  18. Complete genome sequence and comparison of two Shiga toxin-producing Escherichia coli O104 isolates

    USDA-ARS?s Scientific Manuscript database

    Shiga toxin-producing Escherichia coli (STEC) O104 strains have been associated with sporadic cases of illness and have caused outbreaks associated with milk and sprouts. E. coli O104:H21 caused an outbreak associated with milk in the U.S. in 1994. In this study, next generation sequencing techno...

  19. Pathogenic Escherichia coli producing Extended-Spectrum β-Lactamases isolated from surface water and wastewater.

    PubMed

    Franz, Eelco; Veenman, Christiaan; van Hoek, Angela H A M; de Roda Husman, Ana; Blaak, Hetty

    2015-09-24

    To assess public health risks from environmental exposure to Extended-Spectrum β-Lactamases (ESBL)-producing bacteria, it is necessary to have insight in the proportion of relative harmless commensal variants and potentially pathogenic ones (which may directly cause disease). In the current study, 170 ESBL-producing E. coli from Dutch wastewater (n = 82) and surface water (n = 88) were characterized with respect to ESBL-genotype, phylogenetic group, resistance phenotype and virulence markers associated with enteroaggregative E. coli (EAEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), extraintesinal E. coli (ExPEC), and Shiga toxin-producing E. coli (STEC). Overall, 17.1% of all ESBL-producing E. coli were suspected pathogenic variants. Suspected ExPECs constituted 8.8% of all ESBL-producing variants and 8.3% were potential gastrointestinal pathogens (4.1% EAEC, 1.8% EPEC, 1.2% EIEC, 1.2% ETEC, no STEC). Suspected pathogens were significantly associated with ESBL-genotype CTX-M-15 (X(2) = 14.7, P < 0.001) and phylogenetic group B2 (X(2) = 23.5, P < 0.001). Finally, 84% of the pathogenic ESBL-producing E. coli isolates were resistant to three or more different classes of antibiotics. In conclusion, this study demonstrates that the aquatic environment is a potential reservoir of E. coli variants that combine ESBL-genes, a high level of multi-drug resistance and virulence factors, and therewith pose a health risk to humans upon exposure.

  20. Characterization of fimbriae produced by enteropathogenic Escherichia coli.

    PubMed Central

    Girón, J A; Ho, A S; Schoolnik, G K

    1993-01-01

    Enteropathogenic Escherichia coli (EPEC) express rope-like bundles of filaments, termed bundle-forming pili (BFP) (J. A. Girón, A. S. Y. Ho, and G. K. Schoolnik, Science 254:710-713, 1991). Expression of BFP is associated with localized adherence to HEp-2 cells and the presence of the EPEC adherence factor plasmid. In this study, we describe the identification of rod-like fimbriae and fibrillae expressed simultaneously on the bacterial surface of three prototype EPEC strains. Upon fimbrial extraction from EPEC B171 (O111:NM), three fimbrial subunits with masses of 16.5, 15.5, and 14.7 kDa were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Their N-terminal amino acid sequence showed homology with F9 and F7(2) fimbriae of uropathogenic E. coli and F1845 of diffuse-adhering E. coli, respectively. The mixture of fimbrial subunits (called FB171) exhibited mannose-resistant agglutination of human erythrocytes only, and this activity was not inhibited by alpha-D-Gal(1-4)-beta-Gal disaccharide or any other described receptor analogs for P, S, F, M, G, and Dr hemagglutinins of uropathogenic E. coli, which suggests a different receptor specificity. Hemagglutination was inhibited by extracellular matrix glycoproteins, i.e., collagen type IV, laminin, and fibronectin, and to a lesser extent by gangliosides, fetuin, and asialofetuin. Scanning electron microscopic studies performed on clusters of bacteria adhering to HEp-2 cells revealed the presence of structures resembling BFP and rod-like fimbriae linking bacteria to bacteria and bacteria to the eukaryotic cell membrane. We suggest a role of these surface appendages in the interaction of EPEC with eukaryotic cells as well as in the overall pathogenesis of intestinal disease caused by EPEC. Images PMID:7901197

  1. Properties of a Clostridium thermocellum Endoglucanase Produced in Escherichia coli

    PubMed Central

    Schwarz, Wolfgang H.; Gräbnitz, Folke; Staudenbauer, Walter L.

    1986-01-01

    A cellulase gene of Clostridium thermocellum was transferred to Escherichia coli by molecular cloning with bacteriophage lambda and plasmid vectors and shown to be indentical with the celA gene. The celA gene product was purified from extracts of plasmid-bearing E. coli cells by heat treatment and chromatography on DEAE-Trisacryl. It was characterized as a thermophilic endo-β-1,4-glucanase, the properties of which closely resemble those of endoglucanase A previously isolated from C. thermocellum supernatants. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis the enzyme purified from E. coli exhibited two protein bands with molecular weights of 49,000 and 52,000. It had a temperature optimum at 75°C and was stable for several hours at 60°C. Endoglucanase activity was optimal between pH 5.5 and 6.5. The enzyme was insensitive against end product inhibition by glucose and cellobiose and remarkably resistant to the denaturing effects of detergents and organic solvents. It was capable of degrading, in addition to cellulosic substrates, glucans with alternating β-1,4 and β-1,3 linkages such as barley β-glucan and lichenan. PMID:16347088

  2. High Emergence of ESBL-Producing E. coli Cystitis: Time to Get Smarter in Cyprus.

    PubMed

    Cantas, Leon; Suer, Kaya; Guler, Emrah; Imir, Turgut

    2015-01-01

    Widespread prevalence of extended-spectrum βeta-lactamase producing Escherichia coli (ESBL-producing E. coli) limits the infection therapeutic options and is a growing global health problem. In this study our aim was to investigate the antimicrobial resistance profile of the E. coli in hospitalized and out-patients in Cyprus. During the period 2010-2014, 389 strains of E. coli were isolated from urine samples of hospitalized and out-patients in Cyprus. ESBL-producing E. coli, was observed in 53% of hospitalized and 44% in out-patients, latest one being in 2014. All ESBL-producing E. coli remained susceptible to amikacin, carbapenems except ertapenem (in-patients = 6%, out-patients = 11%). High emerging ESBL-producing E. coli from urine samples in hospitalized and out-patients is an extremely worrisome sign of development of untreatable infections in the near future on the island. We therefore emphasize the immediate need for establishment of optimal therapy guidelines based on the country specific surveillance programs. The need for new treatment strategies, urgent prescription habit changes and ban of over-the-counter sale of antimicrobials at each segment of healthcare services is also discussed in this research.

  3. Occurrence and phenotypic properties of verotoxin producing Escherichia coli in sporadic cases of gastroenteritis.

    PubMed

    Burnens, A P; Boss, P; Orskov, F; Orskov, I; Schaad, U B; Müller, F; Heinzle, R; Nicolet, J

    1992-07-01

    Five verotoxin producing Escherichia coli strains were detected in 405 patients with infectious gastroenteritis and 3 such strains were detected in 11 patients with the hemolytic uremic syndrome in Switzerland. Production of verotoxin 2 was associated with the latter three strains. Four strains reacted with the probe for the virulence plasmid of Escherichia coli O157:H7, and six reacted with a recently described probe for the eae gene of enteropathogenic Escherichia coli. None of the strains was of serotype O157:H7. The methods available at present for detecting toxins or toxin genes will reliably detect all such verotoxin producing strains.

  4. Emergence of Carbapenemase-Producing Escherichia coli Isolated from Companion Animals in Algeria.

    PubMed

    Yousfi, Massilia; Touati, Abdelaziz; Mairi, Assia; Brasme, Lucien; Gharout-Sait, Alima; Guillard, Thomas; De Champs, Christophe

    2016-06-01

    The emergence and worldwide spread of carbapenemase-producing Enterobacteriaceae is of great concern to public health. The aim of this study was to investigate the occurrence of carbapenemase-producing Escherichia coli in companion animals in Algeria. Two hundred fecal samples were obtained from healthy and diseased dogs and cats in one veterinary office and private owners in Bejaia city, Algeria, during November 2014 to March 2015. Isolates were screened by polymerase chain reaction for the presence of carbapenemase, acquired plasmidic AmpC (pAmpC) and extended-spectrum beta-lactamase genes. Five carbapenemase-producing E. coli isolates were detected including four OXA-48-producing isolates and one isolate producing NDM-5. Coexpression of ESBL and pAmpC genes was observed in these isolates. Phylogenetic grouping revealed that these isolates belonged to A and D phylogroups. The results of this study show that carbapenemase-producing E. coli spread to the companion animals in Algeria.

  5. Tailor-Made Zinc-Finger Transcription Factors Activate FLO11 Gene Expression with Phenotypic Consequences in the Yeast Saccharomyces cerevisiae

    PubMed Central

    Shieh, Jia-Ching; Cheng, Yu-Che; Su, Mao-Chang; Moore, Michael; Choo, Yen; Klug, Aaron

    2007-01-01

    Cys2His2 zinc fingers are eukaryotic DNA-binding motifs, capable of distinguishing different DNA sequences, and are suitable for engineering artificial transcription factors. In this work, we used the budding yeast Saccharomyces cerevisiae to study the ability of tailor-made zinc finger proteins to activate the expression of the FLO11 gene, with phenotypic consequences. Two three-finger peptides were identified, recognizing sites from the 5′ UTR of the FLO11 gene with nanomolar DNA-binding affinity. The three-finger domains and their combined six-finger motif, recognizing an 18-bp site, were fused to the activation domain of VP16 or VP64. These transcription factor constructs retained their DNA-binding ability, with the six-finger ones being the highest in affinity. However, when expressed in haploid yeast cells, only one three-finger recombinant transcription factor was able to activate the expression of FLO11 efficiently. Unlike in the wild-type, cells with such transcriptional activation displayed invasive growth and biofilm formation, without any requirement for glucose depletion. The VP16 and VP64 domains appeared to act equally well in the activation of FLO11 expression, with comparable effects in phenotypic alteration. We conclude that the functional activity of tailor-made transcription factors in cells is not easily predicted by the in vitro DNA-binding activity. PMID:17710146

  6. Tailor-made heart simulation predicts the effect of cardiac resynchronization therapy in a canine model of heart failure.

    PubMed

    Panthee, Nirmal; Okada, Jun-ichi; Washio, Takumi; Mochizuki, Youhei; Suzuki, Ryohei; Koyama, Hidekazu; Ono, Minoru; Hisada, Toshiaki; Sugiura, Seiryo

    2016-07-01

    Despite extensive studies on clinical indices for the selection of patient candidates for cardiac resynchronization therapy (CRT), approximately 30% of selected patients do not respond to this therapy. Herein, we examined whether CRT simulations based on individualized realistic three-dimensional heart models can predict the therapeutic effect of CRT in a canine model of heart failure with left bundle branch block. In four canine models of failing heart with dyssynchrony, individualized three-dimensional heart models reproducing the electromechanical activity of each animal were created based on the computer tomographic images. CRT simulations were performed for 25 patterns of three ventricular pacing lead positions. Lead positions producing the best and the worst therapeutic effects were selected in each model. The validity of predictions was tested in acute experiments in which hearts were paced from the sites identified by simulations. We found significant correlations between the experimentally observed improvement in ejection fraction (EF) and the predicted improvements in ejection fraction (P<0.01) or the maximum value of the derivative of left ventricular pressure (P<0.01). The optimal lead positions produced better outcomes compared with the worst positioning in all dogs studied, although there were significant variations in responses. Variations in ventricular wall thickness among the dogs may have contributed to these responses. Thus CRT simulations using the individualized three-dimensional heart models can predict acute hemodynamic improvement, and help determine the optimal positions of the pacing lead. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Use of Photopolymerization for Genotyping Shiga Toxin-Producing Escherichia coli Recovered from Produce Production Regions in California

    USDA-ARS?s Scientific Manuscript database

    Shiga toxin-producing Escherichia coli (STEC) is a leading cause of foodborne illness worldwide. To evaluate better methods to rapidly detect and genotype STEC strains, the present study employed the use of ampliPHOX, a novel colorimetric detection method based on photopolymerization, for pathogen ...

  8. Characterization of Escherichia coli O157:H7 and other Shiga toxin-producing E. coli serotypes isolated from sheep.

    PubMed Central

    Kudva, I T; Hatfield, P G; Hovde, C J

    1997-01-01

    The isolation and characterization of Escherichia coli O157:H7 and non-O157 Shiga toxin-producing E. coli (STEC) strains from sheep are described. One flock was investigated for E. coli O157:H7 over a 16-month period that spanned two summer and two autumn seasons. Variation in the occurrence of E. coli O157:H7-positive sheep was observed, with animals being culture positive only in the summer months but not in the spring, autumn, or winter. E. coli O157:H7 isolates were distinguished by pulsed-field gel electrophoresis (PFGE) of chromosomal DNA and toxin gene restriction fragment length polymorphism (RFLP) analysis. Ten PFGE patterns and five RFLP patterns, identified among the isolates, showed that multiple E. coli O157:H7 strains were isolated from one flock, that a single animal simultaneously shed multiple E. coli O157:H7 strains, and that the strains shed by individuals changed over time. E. coli O157:H7 was isolated only by selective enrichment culture off 10 g of ovine feces. In contrast, strains of eight STEC serotypes other than O157:H7 were cultured from feces of sheep from a separate flock without enrichment. The predominant non-O157 STEC serotype found was O91:NM (NM indicates nonmotile), and others included O128:NM, O88:NM, O6:H49, and O5:NM. Irrespective of serotype, 98% of the ovine STEC isolates possessed various combinations of the virulence-associated genes for Shiga toxin(s) and the attaching-and-effacing lesion (stx1, stx2, and eae), suggesting their potential for human pathogenicity. The most common toxin-eae genotype was positive for stx1, stx2, and eae. A Vero cell cytotoxicity assay demonstrated that 90% of the representative STEC isolates tested expressed the toxin gene. The report demonstrates that sheep transiently shed a variety of STEC strains, including E. coli O157:H7, that have potential as human pathogens. PMID:9157149

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

    PubMed

    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

    2016-09-09

    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. coli O104:H4 in Europe in 2011. We assessed the opportunities for E. coli carrying the aggR and stx genes to emerge in 'backyard' farms in south-east Asia. Faecal samples collected from 204 chicken farms; 204 farmers and 306 age- and gender-matched individuals not exposed to poultry farming were plated on MacConkey agar plates with and without antimicrobials being supplemented. Sweep samples obtained from MacConkey agar plates without supplemented antimicrobials were screened by multiplex PCR for the detection of the stx1, stx2 and aggR genes. One chicken farm sample each (0.5 %) contained the stx1 and the aggR gene. Eleven (2.4 %) human faecal samples contained the stx1 gene, 2 samples (0.4 %) contained stx2 gene, and 31 (6.8 %) contained the aggR gene. From 46 PCR-positive samples, 205 E. coli isolates were tested for the presence of stx1, stx2, aggR, wzx O104 and fliC H4 genes. None of the isolates simultaneously contained the four genetic markers associated with E. coli O104:H4 epidemic strain (aggR, stx2, wzx O104 and fliC H4 ). Of 34 EAEC, 64.7 % were resistant to 3(rd)-generation cephalosporins. These results indicate that in southern Vietnam, the human population is a more likely reservoir of aggR and stx gene carrying E. coli than the chicken population. However, conditions for transmission of isolates and/or genes between human and animal reservoirs resulting in the emergence of highly virulent E. coli strains are still favorable, given the nature of'backyard' farms in Vietnam.

  10. Antibacterial Activity of Some Plant Extracts Against Extended- Spectrum Beta-Lactamase Producing Escherichia coli Isolates

    PubMed Central

    Saeidi, Saeide; Amini Boroujeni, Negar; Ahmadi, Hassan; Hassanshahian, Mehdi

    2015-01-01

    Background: The extended-spectrum beta-lactamase (ESBL) -producing Escherichia coli isolates make many serious infections, especially urinary tract infections. Objectives: The purpose of this study was to determine the antibacterial activities of some natural plant extracts against ESBL-producing E. coli isolates, which harbor the TEM gene in urine samples of the patients who have urinary tract infections. Materials and Methods: Evaluation has to be exactly determined for both methods of disk diffusion test and polymerase chain reaction (PCR), separately. We evaluated 120 strains of E. coli isolates from the urine culture of the patients in Boo-Ali Hospital (Zahedan, south-eastern Iran) who were suffering from urinary tract infections. The ESBL-producing E. coli isolates were evaluated by disk diffusion test and PCR through TEM gene detection. The minimal inhibitory concentration (MIC) of commonly used antibiotics including ceftazidime, ceftriaxon, amikacin, gentamicin and ciprofloxacin along with the MIC of the alcoholic extract of different natural plants including Myrtus communis L (Myrtaceae), Amaranthus retraflexus (Amaranthaceae), Cyminum cuminum L (Apiaceae), Marrubium vulgare (Laminaceae) and Peganum. harmala (Zygrophyllaceae) against the ESBL-producing E. coli isolates, which harbor the TEM genes, were determined using the microdulition method. Results: Results of this study showed that in disk diffusion method, 80 samples of E. coli produced ESBLs. In PCR method, the TEM gene distribution in the isolated ESBL-producing organisms was 50 (41.6%). Amikacin was the most effective anti-bacterial agent and ciprofloxacin was the least effective against E. coli isolates. All the natural plant extracts mentioned above, especially P. harmala, were effective against the selected isolates of ESBL-producing E. coli. The most frequent ESBL rate producing E. coli isolates (32 out of 50) had MIC of 2.5 mg/mL in ethanol extract of P. harmala. Conclusions: The alcoholic

  11. Characterization of Escherichia coli and other Enterobacteriaceae in producer-distributor bulk milk.

    PubMed

    Ntuli, V; Njage, P M K; Buys, E M

    2016-12-01

    The current study was undertaken to characterize Escherichia coli and other Enterobacteriaceae in raw and pasteurized producer-distributor bulk milk (PDBM). A total of 258 samples were collected from purchase points in 8 provinces in South Africa. The samples were tested for antibiotic residues, phosphatase, total aerobic bacteria, coliforms, and E. coli counts. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry was used for identification of isolates. Escherichia coli isolates were characterized for virulence factors, antimicrobial resistance, serotypes, and presumptive E. coli O157:H7. Antibiotic residues and alkaline phosphatase were detected in 2% of both raw and pasteurized PDBM (n=258) and 21% pasteurized PDBM (n=104) samples, respectively. A total of 729 isolates belonging to 21 genera and 59 species were identified. Escherichia coli, Enterobacter cloacae, Klebsiella oxytoca, and Raoultella ornithinolytica were the most abundant species. Spoilage Enterobacteriaceae species exceeded 50% of the total isolates. Escherichia coli was detected and isolated from 36% of the milk samples. Thirty-one E. coli isolates harbored virulence genes stx1/stx2 and 38% (n=121) were presumptive O157:H7. The prevalence of samples with presumptive shigatoxin producing E. coli was 10%. Antimicrobial-resistant E. coli isolates were detected in 70% of the milk samples with 36% of stx1/stx2 positive E. coli showing multi-drug resistance. Information obtained from the study will be used for modeling the public health risk posed by milkborne pathogens in PDBM, which in many cases is consumed by poor and vulnerable members of the population. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  12. Molecular characteristics of extended-spectrum β-lactamase-producing Escherichia coli in Riyadh: emergence of CTX-M-15-producing E. coli ST131.

    PubMed

    Al-Agamy, Mohamed H; Shibl, Atef M; Hafez, Mohamed M; Al-Ahdal, Mohammad N; Memish, Ziad A; Khubnani, Harish

    2014-01-07

    The prevalence of extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) has increased recently. The aim of this study was to further characterise and to assess the occurrence of ESBL-EC in Riyadh, to use pulsed field gel electrophoresis (PFGE) typing to investigate the epidemiology of ESBL-EC and to determine the prevalence of ST131 in ESBL-EC. A total of 152 E. coli isolates were collected at a tertiary hospital in Riyadh from September 2010 to June 2011. Genotypic and phenotypic methods were used to characterise ESBLs. PFGE was used to determine genetic relatedness. Detection of ST131 and CTX-M-like ESBLs was performed using real-time PCR. Of 152 strains, 31 were positive for ESBLs by phenotypic methods. The blaCTX-M-15 gene was highly prevalent (30/31 strains, 96.77%) among the 31 ESBL-positive E. coli strains. The blaCTX-M-27 gene was detected in one strain. Twenty (64.5%) out of 31 of ESBL-EC were ST131. PFGE revealed 29 different pulsotypes. Our study documented the high prevalence of ESBLs in E. coli isolates, with CTX-M-15 as the predominant ESBL gene. ST131 clone producing CTX-M-15 has a major presence in our hospital. The high prevalence of CTX-M producers was not due to the spread of a single clone. To the best of our knowledge, this study represents the first report of CTX-M-15 and CTX-M-27 β-lactamases and the detection of the ST131 clone in Saudi E. coli isolates.

  13. Dissemination of ESBL-producing Escherichia coli of chicken origin to the nearby river water.

    PubMed

    Gao, Lili; Hu, Jiaqing; Zhang, Xiaodan; Ma, Ruihua; Gao, Jing; Li, Song; Zhao, Miaoqing; Miao, Zengmin; Chai, Tongjie

    2014-01-01

    The dissemination of drug-resistant bacteria from animal farms to aquatic environments can pose a potential threat to public health. In this study, antimicrobial resistance, resistance genes, and genetic similarity of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli of different origins (chicken feces and upstream and downstream river waters) were analyzed to track the spread of drug-resistant bacteria of animals. The results showed that a total of 29 ESBL-producing E. coli were obtained from 258 samples, and isolation rates of the ESBL-producing E. coli from chicken feces and upstream and downstream waters were 10.7% (16/150), 3.7% (1/27), and 14.8% (12/81), respectively. The ESBL-producing E. coli from upstream water was resistant to 7 antibiotics, but isolates from feces and downstream water had a higher resistance rate. In 29 ESBL-producing E. coli, the most common gene was CTX-M and the SHV gene was not detected. Five ESBL-producing isolates from downstream water showed >90% similarity with the fecal isolates, while the only one isolate from upstream water had <70% similarity with fecal isolates. The results suggest that animal farms' effluent, especially the untreated wastewater, could contribute to the spread of resistance genes. © 2014 S. Karger AG, Basel.

  14. Incidence of extended spectrum beta lactamase producing Escherichia coli among patients, healthy individuals and in the environment.

    PubMed

    George, E A; Sankar, S; Jesudasan, M V; Sudandiradoss, C; Nandagopal, B

    2014-01-01

    We investigated the faecal carriage of extended spectrum β-lactamases (ESBL) producing Escherichia coli in different groups of human subjects and in the environment. A total of 363 E. coli strains were isolated from stool samples of patients (n = 77), healthy subjects (n = 170) and from different environmental samples (n = 116). A total of 124 ESBL producing E. coli strains were isolated in this study. The frequency of ESBL producing E. coli was found to be highest (60.3%) among the strains isolated from patients, followed by healthy individuals (38%) and the environment (10.5%). The environment was observed to have a very low number of ESBL producing E. coli.

  15. Structure and mode of action of microcin 7, an antibacterial peptide produced by Escherichia coli.

    PubMed Central

    Garcia-Bustos, J F; Pezzi, N; Mendez, E

    1985-01-01

    Microcin 7 is a small peptide produced and excreted to the culture medium by stationary-phase Escherichia coli cells harboring the pMccC7 plasmid (formerly named pRYC7). This peptide inhibited the growth of the enterobacteria phylogenetically closer to E. coli, apparently by blocking protein biosynthesis. The molecule was degraded with trypsin, and the resulting fragments were purified and sequenced. The results show that microcin 7 is a linear heptapeptide blocked at both ends. PMID:2861788

  16. Production of d-lactate using a pyruvate-producing Escherichia coli strain.

    PubMed

    Akita, Hironaga; Nakashima, Nobutaka; Hoshino, Tamotsu

    2017-07-01

    To generate an organism capable of producing d-lactate, NAD(+)-dependent d-lactate dehydrogenase was expressed in our pyruvate-producing strain, Escherichia coli strain LAFCPCPt-accBC-aceE. After determining the optimal culture conditions for d-lactate production, 18.4 mM d-lactate was produced from biomass-based medium without supplemental mineral or nitrogen sources. Our results show that d-lactate can be produced in simple batch fermentation processes.

  17. Effects of a tailor-made exercise program on exercise adherence and health outcomes in patients with knee osteoarthritis: a mixed-methods pilot study.

    PubMed

    Lee, Fung-Kam Iris; Lee, Tze-Fan Diana; So, Winnie Kwok-Wei

    2016-01-01

    Previous studies showed that exercise intervention was effective in symptoms control of knee osteoarthritis (OA) but poor intervention adherence reduced the exercise effect. It has been suspected that the design of exercise intervention mainly from the health care professionals' perspective could not address the patients' barriers to exercise. Therefore, a tailor-made exercise program which incorporated the patient's perspective in the design was developed and ready for evaluation. This pilot study estimated the effects of a tailor-made exercise program on exercise adherence and health outcomes, and explored the participants' perception and experience of the program. The intervention of this study was a 4-week community-based group exercise program, which required the participants to attend a 1-hour session each week. Thirty-four older people with knee OA were recruited to the program. Mixed-methods study design was used to estimate the effects of this program and explore the participants' perception and experience of the program. Exercise adherence and performance in return-demonstration of the exercise were assessed at 12 weeks after the program. Disease-specific health status (Western Ontario and McMaster Universities Osteoarthritis Index), general health status (12-item Short Form of the Medical Outcome Study Questionnaire), knee range of motion, muscle strength, and endurance of the lower extremities (Timed-Stands Test) were measured at the beginning of the program and 12 weeks after. Six participants were interviewed individually on the 12th week. Thirty-three participants (75.0±7.3 years) completed the one-group pretest and post-test study. The participants' exercise adherence was 91.4%±14.54%, and their correct performance in return-demonstration was 76.7%±21.75%. Most of the participants' health outcomes significantly improved at posttests except the 12-item Short Form of the Medical Outcome Study Questionnaire physical health summary score. The

  18. Effects of a tailor-made exercise program on exercise adherence and health outcomes in patients with knee osteoarthritis: a mixed-methods pilot study

    PubMed Central

    Lee, Fung-Kam Iris; Lee, Tze-Fan Diana; So, Winnie Kwok-Wei

    2016-01-01

    Introduction Previous studies showed that exercise intervention was effective in symptoms control of knee osteoarthritis (OA) but poor intervention adherence reduced the exercise effect. It has been suspected that the design of exercise intervention mainly from the health care professionals’ perspective could not address the patients’ barriers to exercise. Therefore, a tailor-made exercise program which incorporated the patient’s perspective in the design was developed and ready for evaluation. Objectives This pilot study estimated the effects of a tailor-made exercise program on exercise adherence and health outcomes, and explored the participants’ perception and experience of the program. Methods The intervention of this study was a 4-week community-based group exercise program, which required the participants to attend a 1-hour session each week. Thirty-four older people with knee OA were recruited to the program. Mixed-methods study design was used to estimate the effects of this program and explore the participants’ perception and experience of the program. Exercise adherence and performance in return-demonstration of the exercise were assessed at 12 weeks after the program. Disease-specific health status (Western Ontario and McMaster Universities Osteoarthritis Index), general health status (12-item Short Form of the Medical Outcome Study Questionnaire), knee range of motion, muscle strength, and endurance of the lower extremities (Timed-Stands Test) were measured at the beginning of the program and 12 weeks after. Six participants were interviewed individually on the 12th week. Results Thirty-three participants (75.0±7.3 years) completed the one-group pretest and post-test study. The participants’ exercise adherence was 91.4%±14.54%, and their correct performance in return-demonstration was 76.7%±21.75%. Most of the participants’ health outcomes significantly improved at posttests except the 12-item Short Form of the Medical Outcome Study

  19. Metabolic engineering of Escherichia coli to produce gamma-aminobutyric acid using xylose.

    PubMed

    Zhao, Anqi; Hu, Xiaoqing; Wang, Xiaoyuan

    2017-05-01

    Biomass-derived xylose is an economically interesting substrate for the sustainable microbial production of value-added compounds. Escherichia coli could barely use xylose to directly produce gamma-aminobutyric acid. In this study, E. coli strains that could directly produce gamma-aminobutyric acid were developed through the deletion of eight genes sucA, puuE, gabT, gabP, xylA, xylB, waaC, and waaF, and the overexpression of two E. coli genes gadB and gdhA, as well as five Caulobacter crescent genes CcxylA, CcxylB, CcxylC, CcxylD, and CcxylX. Both E. coli strains W3110 and JM109 could directly produce gamma-aminobutyric acid from xylose after either overexpression of the seven genes or deletion of the eight genes. Overexpression of the seven genes of in the multiple deletion mutants further increased gamma-aminobutyric acid production. Among the 28 recombinant E. coli strains constructed in this study, the highest gamma-aminobutyric acid was produced by JWZ08/pWZt7-g3/pWZt7-xyl. JWZ08/pWZt7-g3/pWZt7-xyl could produce 3.95 g/L gamma-aminobutyric acid in flask cultivation, using xylose as the sole carbon source.

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

    PubMed

    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.

  1. [Estimation of the transfer of ESBL-producing Escherichia coli to humans in Germany].

    PubMed

    Sharp, Hannah; Valentin, Lars; Fischer, Jennie; Guerra, Beatriz; Appel, Bernd; Käsbohrer, Annemarie

    2014-01-01

    In 2011 EFSA has evaluated the risk for the consumer caused by ESBL-/AmpC-producing bacteria in food of animal origin and in livestock animals. Human-to-human transfer in hospitals.and in the community was considered as the most relevant route of transmission for ESBL-producing E. coli. ESBL-/AmpC-producing E. coli are in Germany, as in many other Member States of the European Union, widely spread in food of animal origin and in livestock animals. In an assessment of the relevance of livestock animals as reservoir for ESBL-/AmpC-producing E. coli as well as for ESBL-coding resistance genes the heterogeneity of the resistance genes, plasmids and bacteria in animals, foods and humans needs to be considered. In this context, both, the clonal spread of bacteria as well as horizontal transfer of resistance genes, e. g. by plasmids, have to be analyzed. Whereas studies in The Netherlands identified poultry as the most relevant reservoir, the transfer of ESBL-gene carrying plasmids from pigs to the farmers was demonstrated in Denmark. First attempts to quantify the relevance of livestock animals as reservoir for ESBL-producing E. coli in Germany showed, that the proportions of the most frequent ESBL-resistance genes are quite different between animal and human derived E. coli isolates. If in addition properties of the bacterial cells, e.g. resistance to several antibiotic classes are considered, only a small proportion of human isolates showed the same patterns as animal isolates. The results achieved so far demonstrate that certain ESBL-types are prevalent in all livestock populations investigated. Currently, the majority of cases of colonizations with ESBL-producing E. coli among humans cannot be directly linked to livestock and food-producing animals as reservoirs. This reflects that transmission routes are more complex and other reservoirs and sources including human-human interactions have to be taken into consideration.

  2. The application of tailor-made force fields and molecular dynamics for NMR crystallography: a case study of free base cocaine

    PubMed Central

    Neumann, Marcus A.

    2017-01-01

    Motional averaging has been proven to be significant in predicting the chemical shifts in ab initio solid-state NMR calculations, and the applicability of motional averaging with molecular dynamics has been shown to depend on the accuracy of the molecular mechanical force field. The performance of a fully automatically generated tailor-made force field (TMFF) for the dynamic aspects of NMR crystallography is evaluated and compared with existing benchmarks, including static dispersion-corrected density functional theory calculations and the COMPASS force field. The crystal structure of free base cocaine is used as an example. The results reveal that, even though the TMFF outperforms the COMPASS force field for representing the energies and conformations of predicted structures, it does not give significant improvement in the accuracy of NMR calculations. Further studies should direct more attention to anisotropic chemical shifts and development of the method of solid-state NMR calculations. PMID:28250956

  3. Changes in bone regeneration by trehalose coating and basic fibroblast growth factor after implantation of tailor-made bone implants in dogs.

    PubMed

    Choi, Sungjin; Lee, Jongil; Igawa, Kazuyo; Liu, I-Li; Honnami, Muneki; Suzuki, Shigeki; Nishimura, Ryohei; Chung, Ung-Il; Sasaki, Nobuo; Mochizuki, Manabu

    2013-01-01

    In this study, we aimed to determine the effect of trehalose coating and the optimal dose of basic fibroblast growth factor (bFGF), an osteoinductive protein, loaded onto tailor-made bone implants for implant-induced bone formation in vivo. We fabricated tailor-made α-tricalcium phosphate bone implants (11 mm diameter with 2 parallel cylindrical holes). bFGF 0, 1, 10, 100 or 200 μg/implant was incorporated into implants with and without a trehalose coating, and these were subsequently implanted into dogs to correct temporal bone defects of the same size and shape. Four weeks after implantation, we analyzed the bone implants and surrounding tissues by using micro-computed tomography imaging and histological analyses, as well as gross evaluation. No significant difference in new bone formation was observed between implants with and without a trehalose coating at any of the bFGF doses. Bone implants with 100 and 200 μg bFGF showed significantly more new bone formation at the implant site and within the cylindrical holes of the implants than those without bFGF (P<0.05). However, heterotopic bone formation on the skull near the implant was observed in the group that received 200 μg bFGF. These results suggest that 100 μg bFGF is the optimal dose for this implant in dogs, and that the trehalose coating may not be necessary in vivo, probably due to the presence of blood proteins and electrolytes at the implant site.

  4. Molecular homogeneity of heat-stable enterotoxins produced by bovine enterotoxigenic Escherichia coli.

    PubMed Central

    Saeed, A M; Magnuson, N S; Sriranganathan, N; Burger, D; Cosand, W

    1984-01-01

    Heat-stable enterotoxins (STs) from four strains of bovine enterotoxigenic Escherichia coli representing four serogroups were purified to homogeneity by utilizing previously published purification schemata. Biochemical characterization of the purified STs showed that they met the basic criteria for the heat-stable enterotoxins of E. coli. Amino acid analysis of the purified STs revealed that they were peptides of identical amino acid composition. This composition consisted of 18 residues of 10 different amino acids, 6 of which were cysteine. The amino acid composition of the four ST peptides was identical to that reported for the STs of human and porcine E. coli. In addition, complete sequence analysis of two of the ST peptides and partial sequencing of several others revealed strong homology to the sequences of STs from human and porcine E. coli and to the sequence predicted from the last 18 codons of the transposon Tn1681. There was also substantial homology to the sequence predicted from the ST-coding genetic element of human E. coli, which may indicate the existence of identical bioactive configuration among ST peptides of E. coli strains of various host origins. These data support the hypothesis that STs produced by human, bovine, and porcine E. coli are coded by a closely related genetic element which may have originated from a single, widely disseminated transposon. Images PMID:6376355

  5. Thermal inactivation of Escherichia coli 0157:H7 (ECOH) and non-0157 Shiga toxin-producing E.coli (STEC)in mechanically tenderized veal

    USDA-ARS?s Scientific Manuscript database

    We quantified thermal destruction of Shiga toxin-producing Escherichia coli O157:H7 (ECOH) and Shiga toxin-producing non-O157 E. coli (STEC) cells within mechanically tenderized veal cutlets following cooking on an electric skillet. For each of five trials, flattened veal cutlets (ca. 71.6 g; ca. 1/...

  6. Detection and characterization of fecal verotoxin-producing Escherichia coli from healthy cattle.

    PubMed Central

    Montenegro, M A; Bülte, M; Trumpf, T; Aleksić, S; Reuter, G; Bulling, E; Helmuth, R

    1990-01-01

    Verotoxin-producing Escherichia coli isolates from feces of healthy cattle were identified by DNA hybridization with verotoxin 1- and verotoxin 2-specific gene probes. Among 259 animals investigated, 28 (10.8%) were found to carry verotoxin-producing E. coli strains. Characterization of the verotoxin-producing isolates revealed a heterogeneous population in terms of serotype and toxin type. Nearly 40% of the strains belonged to serogroups known to be pathogenic for humans, i.e., O22, O39, O82, O91, O113, O116, O126, and O136. Two isolates from different bulls were identified as serotype O157:H7. Results obtained in this study indicate that cattle may be an important source of verotoxigenic E. coli involved in human disease. Images PMID:2199502

  7. A Tailor-Made City

    ERIC Educational Resources Information Center

    Kahama, Clement George

    1975-01-01

    Dodoma, future capital of Tanzania, is one of the first planned attempts at integrating man in his environment. The four principle elements of the Master Plan include: the residential communities, the national capital central spine, the system of open spaces and the transportation network. (BT)

  8. Teacher Training, Tailor-Made

    ERIC Educational Resources Information Center

    Newman, Katherine

    2009-01-01

    Family Partnerships for Achievement is not a course typical of most master's programs in education. The course was designed with one overriding goal: to prepare teachers to be effective in the Boston Public Schools (BPS). This goal drives every aspect of the Boston Teacher Residency (BTR), a district-based program for teacher training and…

  9. Teacher Training, Tailor-Made

    ERIC Educational Resources Information Center

    Newman, Katherine

    2009-01-01

    Family Partnerships for Achievement is not a course typical of most master's programs in education. The course was designed with one overriding goal: to prepare teachers to be effective in the Boston Public Schools (BPS). This goal drives every aspect of the Boston Teacher Residency (BTR), a district-based program for teacher training and…

  10. Phenotypic and Molecular Characterization of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Bangladesh

    PubMed Central

    Lina, Taslima T.; Khajanchi, Bijay K.; Azmi, Ishrat J.; Islam, Mohammad Aminul; Mahmood, Belal; Akter, Mahmuda; Banik, Atanu; Alim, Rumana; Navarro, Armando; Perez, Gabriel; Cravioto, Alejandro; Talukder, Kaisar A.

    2014-01-01

    Background Resistance to cephalosporins in Enterobacteriaceae is mainly due to the production of extended-spectrum beta-lactamase (ESBL). Little is known about ESBL-producing bacteria in Bangladesh. Therefore, the study presents results of phenotypic and molecular characterization of ESBL-producing Escherichia coli from hospitals in Bangladesh. Methods A total of 339 E. coli isolated from patients with urinary tract and wound infections attending three different medical hospitals in urban and rural areas of Bangladesh between 2003–2007 were screened for ESBL-production by the double disk diffusion test. Isolates with ESBL-phenotype were further characterized by antibiotic susceptibility testing, PCR and sequencing of different β-lactamase and virulence genes, serotyping, and XbaI-macrorestriction followed by pulsed-field gel electrophoresis (PFGE). Results We identified 40 E. coli with ESBL phenotype. These isolates were resistant to ceftriaxone, ceftazidime, cefotaxime, aztreonam, cefepime, and nalidixic acid but remained susceptible to imipenem. All but one isolate were additionally resistant to ciprofloxacin, and 3 isolates were resistant to cefoxitin. ESBL genes of blaCTX-M-1-group were detected in all isolates; blaTEM-type and blaOXA-1-type genes were detected in 33 (82.5%) and 19 (47.5%) isolates, respectively. Virulence genes that are present in diarrhoeagenic E. coli were not found. Class-1 integron was present in 20 (50%) isolates. All the ESBL-producing E. coli isolates harbored plasmids ranging between 1.1 and 120 MDa. PFGE-typing revealed 26 different pulsotypes, but identical pulsotype showed 6 isolates of serotype O25:H4. Conclusion The prevalence of multidrug-resistant ESBL-producing E. coli isolates appears to be high and the majority of the isolates were positive for blaCTX-M. Although there was genetic heterogeneity among isolates, presence of a cluster of isolates belonging to serotype O25:H4 indicates dissemination of the pandemic

  11. Rapid, Multiplexed Characterization of Shiga Toxin-Producing Escherichia coli (STEC) Isolates Using Suspension Array Technology

    PubMed Central

    Carter, John M.; Lin, Andrew; Clotilde, Laurie; Lesho, Matthew

    2016-01-01

    Molecular methods have emerged as the most reliable techniques to detect and characterize pathogenic Escherichia coli. These molecular techniques include conventional single analyte and multiplex PCR, PCR followed by microarray detection, pulsed-field gel electrophoresis (PFGE), and whole genome sequencing. The choice of methods used depends upon the specific needs of the particular study. One versatile method involves detecting serogroup-specific markers by hybridization or binding to encoded microbeads in a suspension array. This molecular serotyping method has been developed and adopted for investigating E. coli outbreaks. The major advantages of this technique are the ability to simultaneously serotype E. coli and detect the presence of virulence and pathogenicity markers. Here, we describe the development of a family of multiplex molecular serotyping methods for Shiga toxin-producing E. coli, compare their performance to traditional serotyping methods, and discuss the cost-benefit balance of these methods in the context of various food safety objectives. PMID:27242670

  12. Metabolic evolution of Escherichia coli strains that produce organic acids

    DOEpatents

    Grabar, Tammy; Gong, Wei; Yocum, R Rogers

    2014-10-28

    This invention relates to the metabolic evolution of a microbial organism previously optimized for producing an organic acid in commercially significant quantities under fermentative conditions using a hexose sugar as sole source of carbon in a minimal mineral medium. As a result of this metabolic evolution, the microbial organism acquires the ability to use pentose sugars derived from cellulosic materials for its growth while retaining the original growth kinetics, the rate of organic acid production and the ability to use hexose sugars as a source of carbon. This invention also discloses the genetic change in the microorganism that confers the ability to use both the hexose and pentose sugars simultaneously in the production of commercially significant quantities of organic acids.

  13. Behavior of enteroaggregative Escherichia coli, non-O157-shiga toxin-producing E. coli, enteroinvasive E. coli, enteropathogenic E. coli and enterotoxigenic E. coli strains on mung bean seeds and sprout.

    PubMed

    Gómez-Aldapa, Carlos A; Rangel-Vargas, Esmeralda; Bautista-De León, Haydee; Vázquez-Barrios, Ma Estela; Gordillo-Martínez, Alberto J; Castro-Rosas, Javier

    2013-09-16

    The behavior of enteroaggregative Escherichia coli (EAEC), non-O157 shiga toxin-producing E. coli (non-O157-STEC), enteroinvasive E. coli (EIEC), enterotoxigenic E. coli (ETEC) and enteropathogenic E. coli (EPEC) on mung bean seeds at 25±2 °C and during germination and sprouting of mung bean seeds at 20±2 ° and 30±2 °C and on mung bean sprouts at 3±2 °C was determined. When mung bean seeds were inoculated with EAEC, non-O157 STEC, EIEC, EPEC or ETEC strains, all these diarrheagenic E. coli pathotypes (DEPs) survived at least 90 days on mung bean seeds at 25±2 °C. All DEPs grew during germination and sprouting of seeds, reaching counts of approximately 5 Log and 7 Log CFU/g after 2 days at 20±2 ° and 30±2 °C, respectively. However, when the sprouts were inoculated after 1 day of seeds germination and stored at 20±2 ° or 30±2 °C, no growth was observed for any DEPs during sprouting at 20±2 °C per 9 d; however, a significant increase in the concentration of DEPs of approximately 0.7 log CFU/g was observed during sprouting at 30±2 °C after 1 day of sprout contamination. Refrigeration reduced the number of viable DEPs strains on sprouts after 10 days in storage; nevertheless, these decreases have no practical significance in the safety of the sprouts. © 2013 Elsevier B.V. All rights reserved.

  14. Molecular Profiling of Shiga Toxin-Producing Escherichia coli and Enteropathogenic E. coli Strains Isolated from French Coastal Environments

    PubMed Central

    Balière, C.; Rincé, A.; Delannoy, S.; Fach, P.

    2016-01-01

    ABSTRACT Shiga toxin-producing Escherichia coli (STEC) and enteropathogenic E. coli (EPEC) strains may be responsible for food-borne infections in humans. Twenty-eight STEC and 75 EPEC strains previously isolated from French shellfish-harvesting areas and their watersheds and belonging to 68 distinguishable serotypes were characterized in this study. High-throughput real-time PCR was used to search for the presence of 75 E. coli virulence-associated gene targets, and genes encoding Shiga toxin (stx) and intimin (eae) were subtyped using PCR tests and DNA sequencing, respectively. The results showed a high level of diversity between strains, with 17 unique virulence gene profiles for STEC and 56 for EPEC. Seven STEC and 15 EPEC strains were found to display a large number or a particular combination of genetic markers of virulence and the presence of stx and/or eae variants, suggesting their potential pathogenicity for humans. Among these, an O26:H11 stx1a eae-β1 strain was associated with a large number of virulence-associated genes (n = 47), including genes carried on the locus of enterocyte effacement (LEE) or other pathogenicity islands, such as OI-122, OI-71, OI-43/48, OI-50, OI-57, and the high-pathogenicity island (HPI). One O91:H21 STEC strain containing 4 stx variants (stx1a, stx2a, stx2c, and stx2d) was found to possess genes associated with pathogenicity islands OI-122, OI-43/48, and OI-15. Among EPEC strains harboring a large number of virulence genes (n, 34 to 50), eight belonged to serotype O26:H11, O103:H2, O103:H25, O145:H28, O157:H7, or O153:H2. IMPORTANCE The species E. coli includes a wide variety of strains, some of which may be responsible for severe infections. This study, a molecular risk assessment study of E. coli strains isolated from the coastal environment, was conducted to evaluate the potential risk for shellfish consumers. This report describes the characterization of virulence gene profiles and stx/eae polymorphisms of E. coli

  15. Coenzyme B12 can be produced by engineered Escherichia coli under both anaerobic and aerobic conditions.

    PubMed

    Ko, Yeounjoo; Ashok, Somasundar; Ainala, Satish Kumar; Sankaranarayanan, Mugesh; Chun, Ah Yeong; Jung, Gyoo Yeol; Park, Sunghoon

    2014-12-01

    Coenzyme B12 (Vitamin B12 ) is one of the most complex biomolecules and an essential cofactor required for the catalytic activity of many enzymes. Pseudomonas denitrificans synthesizes coenzyme B12 in an oxygen-dependent manner using a pathway encoded by more than 25 genes that are located in six different operons. Escherichia coli, a robust and suitable host for metabolic engineering was used to produce coenzyme B12 . These genes were cloned into three compatible plasmids and expressed heterologously in E. coli BL21 (DE3). Real-time PCR, SDS-PAGE analysis and bioassay showed that the recombinant E. coli expressed the coenzyme B12 synthetic genes and successfully produced coenzyme B12 . However, according to the quantitative determination by inductively coupled plasma-mass spectrometry, the amount of coenzyme B12 produced by the recombinant E. coli (0.21 ± 0.02 μg/g cdw) was approximately 13-fold lower than that by P. denitrificans (2.75 ± 0.22 μg/g cdw). Optimization of the culture conditions to improve the production of coenzyme B12 by the recombinant E. coli was successful, and the highest titer (0.65 ± 0.03 μg/g cdw) of coenzyme B12 was obtained. Interestingly, although the synthesis of coenzyme B12 in P. denitrificans is strictly oxygen-dependent, the recombinant E. coli could produce coenzyme B12 under anaerobic conditions. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Escherichia coli O157:H7 and other Shiga toxin-producing E. coli in white veal calves.

    PubMed

    Cristancho, Laura; Johnson, Roger P; McEwen, Scott A; Gyles, Carlton L

    2008-01-01

    The aims of the study were to determine the prevalence of enterohemorrhagic Escherichia coli O157:H7 (EHEC O157) and other Shiga toxin-producing E. coli (STEC) in feces of white veal calves in an operation in Ontario, to evaluate exposure of the calves to EHEC O157, and to investigate the milk replacer diet and antimicrobial resistance as factors that might influence the prevalence of EHEC O157. Feces from three cohorts of 20-21 calves were collected weekly for 20 weeks and processed for isolation of EHEC O157:H7 and detection of STEC by an ELISA. Exposure to EHEC O157 was also investigated by measuring IgG and IgM antibodies to the O157 lipopolysaccharide (O157 Ab) in sera by ELISA. The prevalences of EHEC O157 were 0.17% of 1151 fecal samples and 3.2% of 62 calves, and for STEC were 68% of 1005 fecal samples and 100% of 62 calves. Seroconversion to active IgG and IgM O157 Ab responses in some calves was not associated with isolation of EHEC O157. The milk replacer contained low levels of antibodies to EHEC antigens and without antimicrobial drugs, it did not inhibit the growth of EHEC O157 in vitro. Two E. coli O157:H7 that were isolated were totally drug sensitive whereas 60 commensal E. coli isolates that were examined were highly resistant. Antibodies in milk replacer that might be protective in vivo, and susceptibility to antimicrobial agents in the milk replacer may contribute to the low prevalence of EHEC O157 in white veal calves.

  17. Quantitative PCR measurements of Escherichia coli including shiga toxin-producing E. coli (STEC) in animal feces and environmental waters.

    PubMed

    Ahmed, W; Gyawali, P; Toze, S

    2015-03-03

    Quantitative PCR (qPCR) assays were used to determine the concentrations of E. coli including shiga toxin-producing E. coli (STEC) associated virulence genes (eaeA, stx1, stx2, and hlyA) in ten animal species (fecal sources) and environmental water samples in Southeast Queensland, Australia. The mean Log10 concentrations and standard deviations of E. coli 23S rRNA across fecal sources ranged from 1.3 ± 0.1 (horse) to 6.3 ± 0.4 (cattle wastewater) gene copies at a test concentration of 10 ng of DNA. The differences in mean concentrations of E. coli 23S rRNA gene copies among fecal source samples were significantly different from each other (P < 0.0001). Among the virulence genes, stx2 (25%, 95% CI, 17-33%) was most prevalent among fecal sources, followed by eaeA (19%, 95% CI, 12-27%), stx1 (11%, 95% CI, 5%-17%) and hlyA (8%, 95% CI, 3-13%). The Log10 concentrations of STEC virulence genes in cattle wastewater samples ranged from 3.8 to 5.0 gene copies at a test concentration of 10 ng of DNA. Of the 18 environmental water samples tested, three (17%) were positive for eaeA and two (11%) samples were also positive for the stx2 virulence genes. The data presented in this study will aid in the estimation of quantitative microbial risk assessment (QMRA) from fecal pollution of domestic and wild animals in drinking/recreational water catchments.

  18. Dynamics of CMY-2 producing E. coli in a broiler parent flock.

    PubMed

    Dame-Korevaar, Anita; Fischer, Egil A J; Stegeman, Arjan; Mevius, Dik; van Essen-Zandbergen, Alieda; Velkers, Francisca; van der Goot, Jeanet

    2017-05-01

    Extended-spectrum β-lactamase and plasmid mediated AmpC β-lactamase (ESBL/pAmpC) producing bacteria are resistant to Extended Spectrum Cephalosporins (ESC), and are present in all levels of the broiler production chain. We determined the prevalence, concentration, and persistence of ESBL/pAmpC-Escherichia coli in a broiler parent flock during the rearing and laying period. One-day old chickens were housed in four separate pens. Until week 33 no antibiotics or coccidiostatics were used. During rearing 57 chickens in each pen (n=228), and in the laying period two groups of 33 chickens were individually sampled (n=66). Environmental samples were taken from week 16 onwards. ESBL/pAmpC-E. coli presence was determined by selective culturing. In the samples of week 16-19 the concentration of ESBL/pAmpC-E. coli was determined. All ESC-resistant isolates found were positive for pAmpC gene blaCMY-2 located on IncA/C plasmids, in several E. coli MLST types. CMY-2-E. coli prevalence decreased from 91% (95%CI 86-94%) at day 7 (week 1) to 0% (95%CI 0-5%) in week 21. However, CMY-2-E. coli remained present in the environmental samples during the whole study. CMY-2-E. coli concentration varied between detection limit (<10^3) and 2·10^4 cfu/g faeces. The sharp reduction of CMY-2-E. coli in this broiler parent flock in absence of antibiotics suggests a selective disadvantage of blaCMY-2 on IncA/C plasmids on animal level. The underlying mechanism should be studied further as this may provide new insights on how to reduce ESBL/pAmpC prevalence and transmission in the broiler production chain. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Strain-Level Discrimination of Shiga Toxin-Producing Escherichia coli in Spinach Using Metagenomic Sequencing

    PubMed Central

    Leonard, Susan R.; Mammel, Mark K.; Lacher, David W.; Elkins, Christopher A.

    2016-01-01

    Consumption of fresh bagged spinach contaminated with Shiga toxin-producing Escherichia coli (STEC) has led to severe illness and death; however current culture-based methods to detect foodborne STEC are time consuming. Since not all STEC strains are considered pathogenic to humans, it is crucial to incorporate virulence characterization of STEC in the detection method. In this study, we assess the comprehensiveness of utilizing a shotgun metagenomics approach for detection and strain-level identification by spiking spinach with a variety of genomically disparate STEC strains at a low contamination level of 0.1 CFU/g. Molecular serotyping, virulence gene characterization, microbial community analysis, and E. coli core gene single nucleotide polymorphism (SNP) analysis were performed on metagenomic sequence data from enriched samples. It was determined from bacterial community analysis that E. coli, which was classified at the phylogroup level, was a major component of the population in most samples. However, in over half the samples, molecular serotyping revealed the presence of indigenous E. coli which also contributed to the percent abundance of E. coli. Despite the presence of additional E. coli strains, the serotype and virulence genes of the spiked STEC, including correct Shiga toxin subtype, were detected in 94% of the samples with a total number of reads per sample averaging 2.4 million. Variation in STEC abundance and/or detection was observed in replicate spiked samples, indicating an effect from the indigenous microbiota during enrichment. SNP analysis of the metagenomic data correctly placed the spiked STEC in a phylogeny of related strains in cases where the indigenous E. coli did not predominate in the enriched sample. Also, for these samples, our analysis demonstrates that strain-level phylogenetic resolution is possible using shotgun metagenomic data for determining the genomic relatedness of a contaminating STEC strain to other closely related E

  20. Thermal inactivation of Shiga toxin-producing Escherichia coli cells within veal cordon bleu

    USDA-ARS?s Scientific Manuscript database

    We evaluated the fate of Shiga toxin-producing Escherichia coli (STEC) within mechanically tenderized veal cordon bleu steaks following cooking on a flat-surface, non-stick griddle. Pre-flattened veal cutlets (ca. 75 g; ca. 0.34 cm thick) were purchased from a local vendor and both faces were surfac...

  1. Effect of stress on non-O157 Shiga toxin-producing Escherichia coli

    USDA-ARS?s Scientific Manuscript database

    Non-O157 Shiga toxin-producing E. coli (non-O157 STEC) have emerged as important food-borne pathogens worldwide. Non-O157 STEC serogroups O26, O45, O103, O111, O121, and O145 have been declared as adulterants in beef by the USDA Food Safety and Inspection Service. While documentation is limited, tre...

  2. Shiga toxin-producing Escherichia coli in swine: the public health perspective

    USDA-ARS?s Scientific Manuscript database

    Shiga toxin-producing Escherichia coli (STEC) strains are food-borne pathogens that are an important public health concern. STEC infection is associated with severe clinical diseases in humans, including hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS), which can lead to kidney failure ...

  3. Characterization of shiga toxin subtypes and virulence genes in Porcine shiga toxin-producing Escherichia coli

    USDA-ARS?s Scientific Manuscript database

    Similar to ruminants, swine have been shown to be a reservoir for Shiga toxin-producing Escherichia coli (STEC), and pork products have been linked with outbreaks associated with STEC O157 and O111:H-. STEC strains, isolated in a previous study from fecal samples of late-finisher pigs, belonged to a...

  4. Evaluation of beef trim sampling methods for detection of Shiga toxin-producing Escherichia coli (STEC)

    USDA-ARS?s Scientific Manuscript database

    Presence of Shiga toxin-producing Escherichia coli (STEC) is a major concern in ground beef. Several methods for sampling beef trim prior to grinding are currently used in the beef industry. The purpose of this study was to determine the efficacy of the sampling methods for detecting STEC in beef ...

  5. Effect of environmental stresses on the survival and cytotoxicity of Shiga toxin-producing Escherichia coli

    USDA-ARS?s Scientific Manuscript database

    Shiga toxin producing Escherichia coli (STEC) causes serious illnesses leading to hospitalizations in the United States. Since bacteria exposed to sub-lethal treatment during food processing may exhibit enhanced virulence and resistance to subsequent processing, the present study attempts to investi...

  6. Gamma radiation inactivation of non-0157:H7 shiga-toxin producing Escherichia coli in foods

    USDA-ARS?s Scientific Manuscript database

    Non-O157:H7 serovars of shiga-toxin producing Escherichia coli are emerging foodborne pathogens that have been associated with illness outbreaks and food product recalls on a global basis. Ionizing (gamma) radiation is a nonthermal food safety intervention technology that has been approved for use i...

  7. Secondary Shiga Toxin–Producing Escherichia coli Infection, Japan, 2010–2012

    PubMed Central

    Iyoda, Sunao; Iguchi, Atsushi; Ohnishi, Makoto

    2016-01-01

    To evaluate the potential public health risk caused by secondary Shiga toxin–producing Escherichia coli (STEC) infections in Japan, we investigated the prevalence and characteristics of STEC isolated from healthy adults during 2010–2012. Although prevalence among healthy adults was high, most STEC organisms displayed characteristics rarely found in isolates from symptomatic patients. PMID:27869602

  8. Thermal inactivation of non-0157:H7 Shigatoxin producing Escherichia coli(STEC) on catfish fillets

    USDA-ARS?s Scientific Manuscript database

    Non-O157:H7 Shiga toxin-producing Escherichia coli (non-O157 STEC) strains have emerged as foodborne pathogens caused numerous foodborne illness outbreaks worldwide. Seafood (fish) consumption has significantly increased in recent years and it could be more common for STEC outbreaks due to non-O15...

  9. Classification of shiga toxin-producing escherichia coli (STEC) serotypes with hyperspectral microscope imagery

    USDA-ARS?s Scientific Manuscript database

    Non-O157:H7 Shiga toxin-producing Escherichia coli (STEC) strains such as O26, O45, O103, O111, O121 and O145 are recognized as serious outbreak to cause human illness due to their toxicity. Since a conventional microbiological method for cell counting is laborious and time-consuming process, optica...

  10. Real-time isothermal detection of Shiga toxin-producing Escherichia coli using recombinase polymerase amplification

    USDA-ARS?s Scientific Manuscript database

    Shiga toxin (Stx) producing E. coli (STEC) are a major family of foodborne pathogens of immense public health, zoonotic and economic significance in the US and worldwide. To date, there are no published reports on use of recombinase polymerase amplification (RPA) for STEC detection. The primary goal...

  11. A 7-plex microbead-based immunoassay for serotyping Shiga toxin-producing Escherichia coli

    USDA-ARS?s Scientific Manuscript database

    Serotyping of Shiga toxin-producing Escherichia coli (STEC) has been contingent upon the availability of antisera. Here we describe a 7-plex microbead-based immunoassay to simultaneously serotype seven STEC (i.e., belonging to serogroups O26, O45, O103, O111, O121, O145, and O157) by the Luminex xMA...

  12. Shiga toxin-producing serogroup O91 Escherichia coli strains isolated from food and environmental samples

    USDA-ARS?s Scientific Manuscript database

    Shiga toxin-producing Escherichia coli (STEC) strains of the O91: H21 serotype have caused severe infections, including hemolytic-uremic syndrome. Strains of the O91 serogroup have been isolated from food, animals, and the environment worldwide but are not well characterized. We used a microarray an...

  13. Shiga toxin-producing Escherichia coli: importance, outbreaks, and characterization methods

    USDA-ARS?s Scientific Manuscript database

    Shiga toxin-producing Escherichia coli (STEC) is an enteric pathogen known to cause human gastrointestinal illnesses with diverse clinical manifestations. The varying disease severity, such as the onset of the hemolytic uremic syndrome, has been associated with certain serotypes of STEC and with th...

  14. Shiga toxin-producing escherichia coli: detection, differentiation, and implications for food safety

    USDA-ARS?s Scientific Manuscript database

    All unprocessed food products typically harbor microorganisms. Some foods and the components that go into food production may contain pathogenic microorganisms such as Shiga toxin-producing Escherichia coli (STECs). When consumed, these STECs can cause serious illness or even death. In 2011, an out...

  15. Development of an automated multiplexed immunomagnetic separation system for isolating Shiga toxin-producing Escherichia coli

    USDA-ARS?s Scientific Manuscript database

    In recent years, non-O157 Shiga toxin-producing Escherichia coli(STEC) have become an emerging problem. Efforts have been devoted to facilitating and speeding their detection, however, their isolation from high background microbiota foods remains problematic. To solve this problem, immunomagnetic se...

  16. Antimicrobial efficacy of radiant catalytic ionization against shiga toxin-producing Escherichia coli on inoculated beef

    USDA-ARS?s Scientific Manuscript database

    Introduction: Shiga Toxin-producing Escherichia coli (STEC), as a common foodborne pathogen, may cause severe human hemorrhagic colitis infection. The radiant catalytic ionization (RCI) technology utilizes a combination of UV light and low-level oxidizers such as ozone, hydroxyl radicals, and hydrog...

  17. Epidemiology of Shiga toxin-producing Escherichia coli (STEC) in finishing swine

    USDA-ARS?s Scientific Manuscript database

    Every year, approximately 200,000 cases of illness are estimated to be associated with Shiga toxin-producing Escherichia coli (STEC) in the United States. STEC strains are one of the leading causes of hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS) in humans. Many STEC outbreaks are a...

  18. Molecular Characterization and Epidemiologic Study of NDM-1-Producing Extensively Drug-Resistant Escherichia coli.

    PubMed

    Du, Jia; Li, Bin; Cao, Jianming; Wu, Qing; Chen, Huale; Hou, Yuanbo; Zhang, En; Zhou, Tieli

    2016-07-06

    The emergence and dissemination of NDM-1 (New Delhi metallo-β-lactamase-1)-producing Enterobacteriaceae have resulted in a worldwide public health risk. This study described a high incidence and endemic spread of NDM-1-producing extensively drug-resistant Escherichia coli in a teaching hospital in Zhejiang province, China. We recovered six nonduplicated NDM-1-producing E. coli isolates from May 2014 to August 2014 with positive modified Hodge test and EDTA synergistic test. These isolates were highly resistant to β-lactam antimicrobials, aminoglycosides, and quinolones. PCR and DNA sequences analysis showed that all isolates carried the blaNDM-1, blaSHV-11, aac(6')-ib-cr, and qnrB. Several isolates also harbored blaCTX-M-1, blaCTX-M-9, rmtB, and qnrA. Southern blot confirmed that blaNDM-1 was located on the same ∼55 kb plasmid and conjugation experiments further proved the contransferable characteristic of blaNDM-1. The ompC sequences showed various mutations, which was related to multidrug resistance in E. coli. Pulsed-field gel electrophoresis identified four of six isolates that belonged to the same genotype. Multilocus sequence typing assigned them to ST2, except one strain that belonged to ST594. Our study demonstrated that the resistance-associated genes and the loss of the outer membrane proteins could account for high resistance of NDM-1-producing E. coli to multiple antimicrobial drugs. Both horizontal transfer of IncN and transmission of ST2 were responsible for the spread of drug resistance. These findings highlighted an urgent need to limit the further dissemination of NDM-1-producing E. coli in this region.

  19. Development of a Multiplex PCR Assay for Detection of Shiga Toxin-Producing Escherichia coli, Enterohemorrhagic E. coli, and Enteropathogenic E. coli Strains

    PubMed Central

    Botkin, Douglas J.; Galli, Lucía; Sankarapani, Vinoth; Soler, Michael; Rivas, Marta; Torres, Alfredo G.

    2012-01-01

    Escherichia coli O157:H7 and other pathogenic E. coli strains are enteric pathogens associated with food safety threats and which remain a significant cause of morbidity and mortality worldwide. In the current study, we investigated whether enterohemorrhagic E. coli (EHEC), Shiga toxin-producing E. coli (STEC), and enteropathogenic E. coli (EPEC) strains can be rapidly and specifically differentiated with multiplex PCR (mPCR) utilizing selected biomarkers associated with each strain’s respective virulence genotype. Primers were designed to amplify multiple intimin (eae) and long polar fimbriae (lpfA) variants, the bundle-forming pilus gene bfpA, and the Shiga toxin-encoding genes stx1 and stx2. We demonstrated consistent amplification of genes specific to the prototype EHEC O157:H7 EDL933 (lpfA1-3, lpfA2-2, stx1, stx2, and eae-γ) and EPEC O127:H6 E2348/69 (eae-α, lpfA1-1, and bfpA) strains using the optimized mPCR protocol with purified genomic DNA (gDNA). A screen of gDNA from isolates in a diarrheagenic E. coli collection revealed that the mPCR assay was successful in predicting the correct pathotype of EPEC and EHEC clones grouped in the distinctive phylogenetic disease clusters EPEC1 and EHEC1, and was able to differentiate EHEC1 from EHEC2 clusters. The assay detection threshold was 2 × 104 CFU per PCR reaction for EHEC and EPEC. mPCR was also used to screen Argentinean clinical samples from hemolytic uremic syndrome and diarrheal patients, resulting in 91% sensitivity and 84% specificity when compared to established molecular diagnostic procedures. In conclusion, our mPCR methodology permitted differentiation of EPEC, STEC and EHEC strains from other pathogenic E. coli; therefore, the assay becomes an additional tool for rapid diagnosis of these organisms. PMID:22919600

  20. Identification of indigo-related pigments produced by Escherichia coli containing a cloned Rhodococcus gene.

    PubMed

    Hart, S; Koch, K R; Woods, D R

    1992-01-01

    Pigments produced by Escherichia coli containing a cloned piece of DNA from Rhodococcus sp. ATCC 21145 were extracted in chloroform and separated into blue and pink components. Evidence from TLC, NMR spectroscopy, absorption spectrum analysis and solubility behaviour suggested that the blue pigment was indigo and the pink pigment was indirubin, a structural isomer of indigo. The proposed pathway for pigment production on LB agar involves the conversion of tryptophan to indole by tryptophanase of E. coli and the oxidation of indole to indigo by the product of the cloned Rhodococcus DNA insert.

  1. Cloning and expression of the lepidopteran toxin produced by Bacillus thuringiensis var Sotto in Escherichia coli.

    PubMed

    Rady, M H

    1991-01-01

    During sporulation, Bacillus thuringiensis var. Sotto produces a parasporal crystalline protein which is toxic for the silk-worm, Bombyx mori and the cotton leaf worm, Spodoptera littoralis. The gene coding this crystal protein is present in a single plasmid. The plasmid DNA was isolated, purified and physically mapped using restriction endonuclease enzymes (R.E.). The gene coding the delta-endotoxin was inserted into Escherichia coli-Jm103, using cloning vector pUC8. Transformed E. coli cells were found to synthesize the delta-endotoxin as demonstrated by the pathogenicity of the transformed cells against 4th instar larvae of S. littoralis.

  2. Open-source genomic analysis of Shiga-toxin-producing E. coli O104:H4.

    PubMed

    Rohde, Holger; Qin, Junjie; Cui, Yujun; Li, Dongfang; Loman, Nicholas J; Hentschke, Moritz; Chen, Wentong; Pu, Fei; Peng, Yangqing; Li, Junhua; Xi, Feng; Li, Shenghui; Li, Yin; Zhang, Zhaoxi; Yang, Xianwei; Zhao, Meiru; Wang, Peng; Guan, Yuanlin; Cen, Zhong; Zhao, Xiangna; Christner, Martin; Kobbe, Robin; Loos, Sebastian; Oh, Jun; Yang, Liang; Danchin, Antoine; Gao, George F; Song, Yajun; Li, Yingrui; Yang, Huanming; Wang, Jian; Xu, Jianguo; Pallen, Mark J; Wang, Jun; Aepfelbacher, Martin; Yang, Ruifu

    2011-08-25

    An outbreak caused by Shiga-toxin–producing Escherichia coli O104:H4 occurred in Germany in May and June of 2011, with more than 3000 persons infected. Here, we report a cluster of cases associated with a single family and describe an open-source genomic analysis of an isolate from one member of the family. This analysis involved the use of rapid, bench-top DNA sequencing technology, open-source data release, and prompt crowd-sourced analyses. In less than a week, these studies revealed that the outbreak strain belonged to an enteroaggregative E. coli lineage that had acquired genes for Shiga toxin 2 and for antibiotic resistance.

  3. An outbreak of shiga toxin-producing Escherichia coli infection associated with a school camp.

    PubMed

    McCall, Bradley J; Slinko, Vicki G; Smith, Helen V; Heel, Karen; Culleton, Terry H; Kelk, Virgil R; Stafford, Russell J

    2010-03-01

    In November 2008, a case of Shiga toxin-producing Escherichia coli (STEC) infection was reported to the Brisbane Southside Public Health Unit. The case had participated in a school camp. Subsequent investigations confirmed 5 other asymptomatic cases among camp attendees or visitors. Examination of the camp water supply identified that most water sources had high levels of E. coli and did not meet the Australian Drinking Water Guidelines with STEC isolated from 2 water sources. This outbreak highlights the emerging issue of asymptomatic carriage of STEC and the importance of thorough maintenance and attention to drinking water supplies in the rural and school camp setting.

  4. Developing and optimizing bacteriophage treatment to control enterohemorrhagic Escherichia coli on fresh produce.

    PubMed

    Snyder, Abigail B; Perry, Jennifer J; Yousef, Ahmed E

    2016-11-07

    Bacteriophages are potentially useful in controlling foodborne pathogens on minimally processed products since phage application is a non-destructive treatment. The purpose of this study was to evaluate the efficacy of a newly isolated environmental bacteriophage against enterohemorrhagic Escherichia coli on fresh produce, and optimize the treatment with consideration for potential application. Seven anti E. coli O157:H7 EDL933 bacteriophages were isolated from various sources; the most promising was isolated from municipal wastewater. This isolate (designated as E. coli phage OSY-SP) was propagated with the host, in a growth medium, to a titer of 10(8) PFU/ml. Before inoculation into fresh produce, E. coli phage OSY-SP was incubated with the host bacterium, spent medium was filter-sterilized, and the resulting crude lysate was used as a source of phage inocula for preliminary experiments. For optimized testing, phage in the crude lysate was purified by ultra-centrifugation and resuspension in phosphate-buffered saline. Efficacy of phage treatments was determined as a function of fresh produce type (cut green pepper or spinach leaves), treatment time (2 or 5min rinsing), and temperature of holding treated produce (4°C, 25°, or a combination of both temperatures). Cut green pepper was treated with UV light, to eliminate background microbiota, then spot-inoculated with E. coli O157:H7 EDL933 on cut edges, and the inoculum was allowed to dry. Because of its susceptibility to damage, baby spinach leaves were not subjected to a decontamination treatment. These leaves were inoculated with the green fluorescent protein-labeled E. coli O157:H7 B6-914 to facilitate inoculum enumeration in the presence of background microbiota. Phage suspension was applied to the inoculated fresh produce that was subsequently held for three days under variable storage conditions. The optimized phage treatment decreased the populations of pathogenic E. coli by 2.4-3.0logCFU/g on cut green

  5. Multicentre investigation of carbapenemase-producing Escherichia coli and Klebsiella pneumoniae in German hospitals.

    PubMed

    Kaase, Martin; Schimanski, Sven; Schiller, Reinhold; Beyreiß, Bettina; Thürmer, Alexander; Steinmann, Jörg; Kempf, Volkhard A; Hess, Christina; Sobottka, Ingo; Fenner, Ines; Ziesing, Stefan; Burckhardt, Irene; von Müller, Lutz; Hamprecht, Axel; Tammer, Ina; Wantia, Nina; Becker, Karsten; Holzmann, Thomas; Furitsch, Martina; Volmer, Gabriele; Gatermann, Sören G

    2016-09-01

    Aim of this study was to determine the incidence and molecular epidemiology of carbapenemase-producing Escherichia coli and Klebsiella pneumoniae in Germany. E. coli and K. pneumoniae isolates from clinical samples which were non-susceptible to carbapenems were collected in laboratories serving 20 hospitals throughout Germany from November 2013 to April 2014. The isolates were tested for the presence of carbapenemases by PCR and phenotypic methods and typed by multilocus sequence typing. Risk factors including a previous hospitalization abroad were analysed. Carbapenemases were detected in 24 isolates from 22 patients out of 464,514 admissions. Carbapenemases included OXA-48 (n=14), KPC-2 (n=8) and NDM-1 (n=2). Except for two K. pneumoniae isolates with ST101, all OXA-48 producing strains belonged to different clones. In contrast, half of KPC-2 producing K. pneumoniae were of ST258 and both NDM-1 producing strains were of ST11. Compared to carbapenem-susceptible controls, patients with carbapenemase-producing strains differed by a significantly higher proportion of males, a higher proportion of isolates from wound samples and a more frequent previous stay abroad in univariate analysis. This multicentre study demonstrated an incidence of carbapenemase-producing E. coli and K. pneumoniae from clinical samples in Germany of 0.047 cases per 1000 admissions. OXA-48 was more frequent than KPC-2 and NDM-1 and showed a multiclonal background.

  6. The majority of enteroaggregative Escherichia coli strains produce the E. coli common pilus when adhering to cultured epithelial cells.

    PubMed

    Avelino, Fabiola; Saldaña, Zeus; Islam, Sohidul; Monteiro-Neto, Valerio; Dall'Agnol, Monique; Eslava, Carlos A; Girón, Jorge A

    2010-11-01

    Enteroaggregative Escherichia coli (EAEC) have emerged as a significant worldwide cause of chronic diarrhea in the pediatric population and in HIV patients. The vast majority of EAEC strains do not produce the aggregative adherence fimbriae I-III (AAFs) so far reported and thus, what adherence factors are present in these strains remains unknown. Here, we investigated the prevalence of the chromosomal E. coli common pilus (ECP) genes and ECP production amongst 130 EAEC strains of diverse origin as well as the role of ECP in EAEC adherence. Through multiplex PCR analysis we found that 96% of EAEC strains contained the ecpA structural pilin gene whereas only 3.1% and 5.4% were positive for AAF fimbrial genes aggA or aafA, respectively. Among the ecpA(+) strains, 63% produced ECP when adhering to cultured epithelial cells. An ecpA mutant derived from prototypic strain 042 (AAF/II(+)) was not altered in adherence suggesting that the AAF/II, and not ECP, plays a major role in this strain. In contrast, strain 278-1 (AAF(-)) deleted of the ecpA gene was significantly reduced in adherence to cultured epithelial cells. In all, these data indicate a potential role of ECP in adherence for EAEC strains lacking the known AAFs and that in association with other adhesive determinants, ECP may contribute to their survival and persistence within the host and in the environment.

  7. Bacteriocins produced by L. Fermentum and L. Acidophilus can inhibit cephalosporin resistant e. Coli.

    PubMed

    Riaz, Saba; Kashif Nawaz, Syed; Hasnain, Shahida

    2010-07-01

    Reemerging infections occur due to resistant bacteria. Such infections create restrictions for clinicians and microbiologists in drug selection. Such problems demand new strategies for solution. Use of bacteriocins for this purpose may be fruitful. In the present research work, the inhibitory effects of bactericins on cephalosporin resistant Escherichia coli are used as model system for the control of antibiotic resistant pathogenic bacteria. Cephalosporin resistant Escherichia coli strain was isolated from pus by using conventional methodology. For bacteriocin production, Lactobacilli strains were selected by using selective media. Out of seventy two strains isolated from yogurt, fecal materials of human, chick, parrot and cat, only two strains (strain 45 and strain 52) were found to produce bacteriocins having antimicrobial potential against cephalosporin resistant Escherichia coli. Biochemical characterization showed that strain 45 belonged to group of Lactobacillus fermentum and strain 52 to Lactobacillus acidophilus. Both strains showed maximum growth at 25°C and 35°C respectively. Suitable pH was 5.5 and 6.0 for Lactobacillus fermentum and Lactobacillus acidophilus respectively. Bacteriocins produced by both strains were found stable at 50, 75 and 100°C for 60min. Function of bacteriocin was also not disturbed due to change in pH. These findings suggest that bacteriocin produced by Lactobacillus fermentum and Lactobacillus acidophilus can be used for the infection control of cephalosporin resistant Escherichia coli.

  8. Tailor-made micro-object optical sensor based on mesoporous pellets for visual monitoring and removal of toxic metal ions from aqueous media.

    PubMed

    El-Safty, Sherif A; Shenashen, M A; Shahat, A

    2013-07-08

    Methods for the continuous monitoring and removal of ultra-trace levels of toxic inorganic species (e.g., mercury, copper, and cadmium ions) from aqueous media such as drinking water and biological fluids are essential. In this paper, the design and engineering of a simple, pH-dependent, micro-object optical sensor is described based on mesoporous aluminosilica pellets with an adsorbed dressing receptor (a porphyrinic chelating ligand). This tailor-made optical sensor permits ultra-fast (≤ 60 s), specific, pH-dependent visualization and removal of Cu(2+) , Cd(2+) , and Hg(2+) at sub-picomolar concentrations (∼10(-11) mol dm(-3) ) from aqueous media, including drinking water and a suspension of red blood cells. The acidic active acid sites of the pellets consist of heteroatoms arranged around uniformly shaped pores in 3D nanoscale gyroidal mesostructures densely coated with the chelating ligand. The sensor can be used in batch mode, as well as in a flow-through system in which sampling, target ion recognition and removal, and analysis are integrated in a highly automated and efficient manner. Because the pellets exhibit long-term stability, reproducibility, and versatility over a number of analysis/regeneration cycles, they can be expected to be useful for the fabrication of inexpensive sensor devices for naked-eye detection of toxic pollutants. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Tailor-made ion-imprinted polymer based on functionalized graphene oxide for the preconcentration and determination of trace copper in food samples.

    PubMed

    Liu, Yan; Qiu, Jian; Liu, Zhanchao; Ni, Liang; Jiang, Yinhua; Gong, Chongying; Meng, Xiangguo; Liu, Fangfang; Zhong, Guoxing

    2016-04-01

    A tailor-made Cu(II) ion-imprinted polymer based on large-surface-area graphene oxide sheets has been synthesized for the preconcentration and determination of trace copper from food samples by solid-phase extraction. Attributed to the ultrahigh surface area and hydrophilicity of graphene oxide, the Cu(II) ion-imprinted polymer prepared by the surface ion-imprinting technique exhibited a high binding capacity and a fast adsorption rate under the optimized experimental conditions. In the static adsorption experiments, the maximum adsorption capacity of Cu(II) ion-imprinted polymer is 109.38 mg/g at 25°C, which is much higher than that of the nonimprinted polymer (32.12 mg/g). Meanwhile, the adsorption is very rapid and equilibrium is reached after approximately 30 min. The adsorption mechanism is found to follow Langmuir adsorption model and the pseudo-second-order adsorption process. The Cu(II) ion-imprinted polymer was used for extracting and detecting Cu(II) in food samples combined with graphite flame atomic adsorption spectrometry with high recoveries in the range of 97.6-103.3%. The relative standard deviation and limit of detection of the method were evaluated as 1.2% and 0.37 μg/L, respectively. The results showed that the novel absorbent can be utilized as an effective material for the selective enrichment and determination of Cu(II) from food samples.

  10. Rapid emergence of ESBL producers in E. coli causing urinary and wound infections in Pakistan

    PubMed Central

    Habeeb, Muhammad Asif; Sarwar, Yasra; Ali, Aamir; Salman, Muhammad; Haque, Abdul

    2013-01-01

    Objectives: Production of extended spectrum beta -lactamases (ESBLs) by clinical isolates of pathogenic E. coli is a very serious therapeutic threat. This study was aimed to investigate the prevalence of ESBLs and associated drug resistance in E. coli isolates from urine and pus, and to report the drift from 2005 to 2009-10. Methodology: Among 173 E. coli isolates, 82 were phenotypically detected as ESBL producers by standard cefotaxime / clavulanic acid and ceftazidime / clavulanic acid disc diffusion tests. Antimicrobial resistance of all ESBL producers was assessed by disc diffusion method. Presence of CTX-M, TEM, SHV and OXA groups was investigated by PCR. Results: The prevalence of ESBL producing E. coli increased significantly from 33.7% in 2005 to 60.0% in 2009-10 (urine: 31.8% to 62.9%; pus: 41.1% to 55.5%). Resistance to cefotaxime, ceftazidime, ciprofloxacin, gentamicin, nalidixic acid, ticarcillin-clavulanic acid, and trimethoprim-sulfamethoxazole was above 85% in both sets of isolates. Imipenem and Fosfomycin resistance was non-existent in 2005 but ranged from 3-15% in 2009-10. Remarkable increase from 9.5% to 64.7% in urinary tract isolates and from 0 to 55% in pus isolates was observed in colistin sulphate resistance. The dissemination of genes encoding ESBLs was: CTX-M 3.5%; TEM 10.7%; both CTX-M and TEM 3.5% in 2005, and CTX-M 42.5%; TEM 48.1%; both CTX-M and TEM 29.6% in 2009-10. Conclusions: Our results showed very rapid emergence of multidrug resistant ESBL producing E. coli in Pakistan posing a very serious threat in the treatment of nosocomial and community acquired infections. PMID:24353573

  11. Emission of ESBL/AmpC-producing Escherichia coli from pig fattening farms to surrounding areas.

    PubMed

    von Salviati, Christina; Laube, Henriette; Guerra, Beatriz; Roesler, Uwe; Friese, Anika

    2015-01-30

    The presence of ESBL/AmpC-producing Escherichia coli in livestock such as pigs has been known for some time. However, to date there is little information about the transmission of these resistant bacteria between pig farms and their surroundings. Thus, the aim of this study was to explore this topic by investigating seven German pig fattening farms. Samples from outside (including ground surfaces, ambient air, slurry and digestate from biogas plants) and, in parallel, from inside the pig barns (including pig feces, dust, barn air, flies and mice feces) were examined for ESBL/AmpC-producing E. coli and selected isolates were compared by pulsed-field gel electrophoresis (PFGE) analysis. 14/17 (82.4%) slurry samples and three of four samples of digestate from biogas plants tested positive for ESBL/AmpC-producing E. coli. In the vicinity of the pig barns these resistant bacteria were detected in 14/87 (16.1%) boot swabs taken from various ground surfaces and in 2/36 (6%) ambient air samples. Inside the pig barns, 6/63 (9.5%) barn air samples and a small proportion of flies and mice feces samples were ESBL/AmpC-positive. PFGE analysis proved fecal emission as well as a possible spread via flies, as identical ESBL-E. coli isolates were detected in slurry and on fertilized fields, as well as in flies and pooled feces from inside the barn and slurry. Contaminated slurry presented the major emission source for ESBL/AmpC-producing E. coli in the pig fattening farms, but a spread via the airborne route or via different vectors also seems possible.

  12. Extended-spectrum β-lactamase producing Escherichia coli isolated from wild birds in Saskatoon, Canada.

    PubMed

    Parker, D; Sniatynski, M K; Mandrusiak, D; Rubin, J E

    2016-07-01

    The epidemiology of antimicrobial resistance is extremely complex and involves humans, domestic animals (companion and agricultural) and wildlife. In North America there have been very few investigations targeting antimicrobial-resistant organisms in wildlife. In this study, we characterized the susceptibility of Escherichia coli isolated from 75 birds including great horned owls, crows and American robins from the region of Saskatoon, Canada. The recovery rate of E. coli varied significantly between species from 44·8% of robins to 92% of crows. The majority (88·2%) of colonized birds carried only pan-susceptible organisms. Among isolates resistant to at least one antimicrobial, ampicillin resistance was most commonly identified. Three birds carried multidrug-resistant isolates (resistant to ≥3 drug classes), and extended-spectrum β-lactamase (ESBL)-producing organisms (CTX-M-15 and SHV2a) were grown from two. We identified a significant relationship between the presence of drug-resistant E. coli and an urban (vs rural) origin of the bird. Our findings suggest that crows, due to their ubiquity and high rate of colonization with E. coli, may be efficient targets for future resistance surveillance studies targeting urban wildlife. Antimicrobial resistance is a global problem affecting people and animals. Few investigations describing the presence drug-resistant organisms in wildlife in North America have been published. In this study, resistant Escherichia coli, including extended-spectrum β-lactamase-producing strains, were isolated from wild birds in the Saskatoon region of Canada. We found that the recovery rate of E. coli varied significantly by species and was highest among crows. There was also a significant association between drug resistance and urban vs rural birds. Our results suggest that crows may be a good target for future studies investigating antimicrobial resistance in urban wildlife. © 2016 The Society for Applied Microbiology.

  13. Commensal E. coli Stx2 lysogens produce high levels of phages after spontaneous prophage induction.

    PubMed

    Iversen, Hildegunn; L' Abée-Lund, Trine M; Aspholm, Marina; Arnesen, Lotte P S; Lindbäck, Toril

    2015-01-01

    Enterohemorrhagic E. coli (EHEC) is a food-borne pathogen that causes disease ranging from uncomplicated diarrhea to life-threatening hemolytic uremic syndrome (HUS) and nervous system complications. Shiga toxin 2 (Stx2) is the major virulence factor of EHEC and is critical for development of HUS. The genes encoding Stx2 are carried by lambdoid bacteriophages and the toxin production is tightly linked to the production of phages during lytic cycle. It has previously been suggested that commensal E. coli could amplify the production of Stx2-phages and contribute to the severity of disease. In this study we examined the susceptibility of commensal E. coli strains to the Stx2-converting phage ϕ734, isolated from a highly virulent EHEC O103:H25 (NIPH-11060424). Among 38 commensal E. coli strains from healthy children below 5 years, 15 were lysogenized by the ϕ734 phage, whereas lytic infection was not observed. Three of the commensal E. coli ϕ734 lysogens were tested for stability, and appeared stable and retained the phage for at least 10 cultural passages. When induced to enter lytic cycle by H2O2 treatment, 8 out of 13 commensal lysogens produced more ϕ734 phages than NIPH-11060424. Strikingly, five of them even spontaneously (non-induced) produced higher levels of phage than the H2O2 induced NIPH-11060424. An especially high frequency of HUS (60%) was seen among children infected by NIPH-11060424 during the outbreak in 2006. Based on our findings, a high Stx2 production by commensal E. coli lysogens cannot be ruled out as a contributor to the high frequency of HUS during this outbreak.

  14. Persistence of Escherichia coli O157:H7 in major leafy green producing soils.

    PubMed

    Ma, Jincai; Ibekwe, A Mark; Crowley, David E; Yang, Ching-Hong

    2012-11-06

    Persistence of Escherichia coli O157:H7 in 32 (16 organically managed and 16 conventionally managed) soils from California (CA) and Arizona (AZ) was investigated. Results showed that the longest survival (ttd, time needed to reach detection limit, 100 CFU g(-1) dry soil) of E. coli O157:H7 was observed in the soils from Salinas Valley, CA and in organically managed soils from AZ. Detrended correspondence analysis revealed that the survival profiles in organically managed soils in Yuma, AZ were different from the ones in conventionally managed soils from the same site. Principal component analysis and stepwise regression analysis showed that E. coli O157:H7 survival in soils was negatively correlated with salinity (EC) (P < 0.001), while positively correlated with assimilable organic carbon (AOC) and total nitrogen (TN) (P < 0.01). Pearson correlation analysis revealed that a greater ttd was associated with a larger δ (time needed for first decimal reduction in E. coli population). EC was negatively correlated and TN was positively correlated (P < 0.05) with δ, suggesting that EC and TN likely have a direct impact on ttd. On the other hand, AOC showed a close correlation with p (the shape parameter) that was not directly related to ttd, indicating that AOC might have an indirect effect in the overall survival of E. coli O157:H7 in soils. Our data showed that AOC and EC significantly affected the survival of E. coli O157:H7 in leafy green producing soils and the development of good agricultural practices (manure/composting/irrigation water source management) in the preharvest environment must be followed to minimize foodborne bacterial contamination on fresh produce.

  15. First Report of Klebsiella pneumoniae-Carbapenemase-3-Producing Escherichia coli ST479 in Poland.

    PubMed

    Ojdana, Dominika; Sacha, Paweł; Olszańska, Dorota; Majewski, Piotr; Wieczorek, Piotr; Jaworowska, Jadwiga; Sieńko, Anna; Jurczak, Anna; Tryniszewska, Elżbieta

    2015-01-01

    An increase in the antibiotic resistance among members of the Enterobacteriaceae family has been observed worldwide. Multidrug-resistant Gram-negative rods are increasingly reported. The treatment of infections caused by Escherichia coli and other Enterobacteriaceae has become an important clinical problem associated with reduced therapeutic possibilities. Antimicrobial carbapenems are considered the last line of defense against multidrug-resistant Gram-negative bacteria. Unfortunately, an increase of carbapenem resistance due to the production of Klebsiella pneumoniae carbapenemase (KPC) enzymes has been observed. In this study we describe the ability of E. coli to produce carbapenemase enzymes based on the results of the combination disc assay with boronic acid performed according to guidelines established by the European Community on Antimicrobial Susceptibility Testing (EUCAST) and the biochemical Carba NP test. Moreover, we evaluated the presence of genes responsible for the production of carbapenemases (bla KPC, bla VIM, bla IMP, bla OXA-48) and genes encoding other β-lactamases (bla SHV, bla TEM, bla CTX-M) among E. coli isolate. The tested isolate of E. coli that possessed the bla KPC-3 and bla TEM-34 genes was identified. The tested strain exhibited susceptibility to colistin (0.38 μg/mL) and tigecycline (1 μg/mL). This is the first detection of bla KPC-3 in an E. coli ST479 in Poland.

  16. Immune response in diarrheal patients and asymptomatic carrier with CS6-producing enterotoxigenic Escherichia coli infection.

    PubMed

    Puiprom, Orapim; Chantaroj, Siriporn; Matsuda, Shigeaki; Sawanpanyalert, Pathom; Honda, Takeshi; Iida, Tetsuya; Taniguchi, Tooru

    2012-11-01

    Enterotoxigenic Escherichia coli (ETEC) is one of the major causes of diarrhea in children and travelers in developing countries. ETEC colonization factors (CFs) are virulence determinants considered as protective antigens and major targets for vaccine development against ETEC infections. One of the most prevalent CFs, coli surface antigen 6 (CS6), a non-fimbrial polymeric protein consisting of two major subunits, CssA and CssB, is produced by approximately 25-35% of ETEC worldwide. We could isolate only CS6-producing ETEC strains from two diarrheal patients and one asymptomatic carrier, but we could not detect CssA- or CssB-specific antibodies in the feces and blood of two patients convalescing from natural ETEC infection and of an asymptomatic carrier using western blotting. Therefore, in order to protect against infection with CS6-producing ETEC, protective levels of CS6 immunity should be incorporated in any future vaccines against ETEC.

  17. Molecular characterization of multiresistant Escherichia coli producing or not extended-spectrum β-lactamases

    PubMed Central

    2013-01-01

    Background The prevalence and type of plasmids, resistance genes and integrons carried by two collections of multiresistant E. coli producing or not extended-spectrum β-lactamases have been compared. Rep-PCR was used to determine the clonal relationship of the organisms. Plasmids were classified according to their incompatibility. Class 1 and Class 2 integrons and antibiotic resistance genes were analysed by PCR and sequencing. Results Both collections of organisms contained a large diversity of unrelated strains with some clones distributed in both groups of isolates. Large plasmids were identified in the two groups of organisms. Plasmids with replicons repK and repColE were more frequent among ESBL-producing isolates, while repFIA, repFII and repA/C replicons were more frequent in isolates lacking ESBL. Conjugative plasmids with repK and repA/C replicons coded for CTX-M-14 and CMY-2 β-lactamases, respectively. No significant differences were observed in the distribution of class 1 and class 2 integrons among multiresistant E. coli producing or not ESBL, and dfrA17-ant(3″)-Ie was the cassette arrangement most commonly found. Conclusions In the concrete temporal and geographical context of this study, multiresistant E. coli producing ESBL or other mechanisms of resistance were largely clonally diverse and present some differences in the types of harboured plasmids. Still, some clones were found in both ESBL-producing and –lacking isolates. PMID:23586437

  18. Mild Illness during Outbreak of Shiga Toxin-Producing Escherichia coli O157 Infections Associated with Agricultural Show, Australia.

    PubMed

    Vasant, Bhakti R; Stafford, Russell J; Jennison, Amy V; Bennett, Sonya M; Bell, Robert J; Doyle, Christine J; Young, Jeannette R; Vlack, Susan A; Titmus, Paul; El Saadi, Debra; Jarvinen, Kari A J; Coward, Patricia; Barrett, Janine; Staples, Megan; Graham, Rikki M A; Smith, Helen V; Lambert, Stephen B

    2017-10-01

    During a large outbreak of Shiga toxin-producing Escherichia coli illness associated with an agricultural show in Australia, we used whole-genome sequencing to detect an IS1203v insertion in the Shiga toxin 2c subunit A gene of Shiga toxin-producing E. coli. Our study showed that clinical illness was mild, and hemolytic uremic syndrome was not detected.

  19. Isolation of Shiga Toxin-Producing Escherichia coli from a South American Camelid (Lama guanicoe) with Diarrhea

    PubMed Central

    Mercado, E. C.; Rodríguez, S. M.; Elizondo, A. M.; Marcoppido, G.; Parreño, V.

    2004-01-01

    Shiga toxin-producing Escherichia coli belonging to serotype O26:H11 was isolated from a 2-month-old guanaco with severe watery diarrhea. E. coli colonies carried the stx1 and eae genes, showed localized adherence to HEp-2 cells, and produced enterohemolysin. A serological response to lipopolysaccharide O26 was observed at the onset of diarrhea. PMID:15472347

  20. Biofilm-Forming Abilities of Shiga Toxin-Producing Escherichia coli Isolates Associated with Human Infections

    PubMed Central

    Vogeleer, Philippe; Tremblay, Yannick D. N.; Jubelin, Grégory; Jacques, Mario

    2015-01-01

    Forming biofilms may be a survival strategy of Shiga toxin-producing Escherichia coli to enable it to persist in the environment and the food industry. Here, we evaluate and characterize the biofilm-forming ability of 39 isolates of Shiga toxin-producing Escherichia coli isolates recovered from human infection and belonging to seropathotypes A, B, or C. The presence and/or production of biofilm factors such as curli, cellulose, autotransporter, and fimbriae were investigated. The polymeric matrix of these biofilms was analyzed by confocal microscopy and by enzymatic digestion. Cell viability and matrix integrity were examined after sanitizer treatments. Isolates of the seropathotype A (O157:H7 and O157:NM), which have the highest relative incidence of human infection, had a greater ability to form biofilms than isolates of seropathotype B or C. Seropathotype A isolates were unique in their ability to produce cellulose and poly-N-acetylglucosamine. The integrity of the biofilms was dependent on proteins. Two autotransporter genes, ehaB and espP, and two fimbrial genes, z1538 and lpf2, were identified as potential genetic determinants for biofilm formation. Interestingly, the ability of several isolates from seropathotype A to form biofilms was associated with their ability to agglutinate yeast in a mannose-independent manner. We consider this an unidentified biofilm-associated factor produced by those isolates. Treatment with sanitizers reduced the viability of Shiga toxin-producing Escherichia coli but did not completely remove the biofilm matrix. Overall, our data indicate that biofilm formation could contribute to the persistence of Shiga toxin-producing Escherichia coli and specifically seropathotype A isolates in the environment. PMID:26712549

  1. Biofilm-Forming Abilities of Shiga Toxin-Producing Escherichia coli Isolates Associated with Human Infections.

    PubMed

    Vogeleer, Philippe; Tremblay, Yannick D N; Jubelin, Grégory; Jacques, Mario; Harel, Josée

    2015-12-28

    Forming biofilms may be a survival strategy of Shiga toxin-producing Escherichia coli to enable it to persist in the environment and the food industry. Here, we evaluate and characterize the biofilm-forming ability of 39 isolates of Shiga toxin-producing Escherichia coli isolates recovered from human infection and belonging to seropathotypes A, B, or C. The presence and/or production of biofilm factors such as curli, cellulose, autotransporter, and fimbriae were investigated. The polymeric matrix of these biofilms was analyzed by confocal microscopy and by enzymatic digestion. Cell viability and matrix integrity were examined after sanitizer treatments. Isolates of the seropathotype A (O157:H7 and O157:NM), which have the highest relative incidence of human infection, had a greater ability to form biofilms than isolates of seropathotype B or C. Seropathotype A isolates were unique in their ability to produce cellulose and poly-N-acetylglucosamine. The integrity of the biofilms was dependent on proteins. Two autotransporter genes, ehaB and espP, and two fimbrial genes, z1538 and lpf2, were identified as potential genetic determinants for biofilm formation. Interestingly, the ability of several isolates from seropathotype A to form biofilms was associated with their ability to agglutinate yeast in a mannose-independent manner. We consider this an unidentified biofilm-associated factor produced by those isolates. Treatment with sanitizers reduced the viability of Shiga toxin-producing Escherichia coli but did not completely remove the biofilm matrix. Overall, our data indicate that biofilm formation could contribute to the persistence of Shiga toxin-producing Escherichia coli and specifically seropathotype A isolates in the environment.

  2. Cell-mediated killing of Listeria monocytogenes by leucocin C producing Escherichia coli.

    PubMed

    Liu, S; Takala, T M; Wan, X; Reunanen, J; Saris, P E J

    2013-06-12

    Listeria monocytogenes is a foodborne pathogen causing listeriosis. Listeria in foods can be inhibited with bacteriocins or bacteriocin producing cultures. The aim of this study was to enhance the killing of L. monocytogenes by binding bacteriocin producing Escherichia coli cells to Listeria cells. Antilisterial E. coli was obtained by transferring leucocin C production from Leuconostoc carnosum 4010. For binding of E. coli cells to Listeria cells, the Listeria phage endolysin PlyP35 cell wall binding domain (CBD) was displayed on E. coli cell surface as FliC::CBD chimeric protein in flagella. CBD insertion in flagella was confirmed by Western analysis and enterokinase cleavage. By mixing isolated flagella with L. monocytogenes WSLC 1019 cells, the FliC::CBD flagella was shown to bind to Listeria cells. However, the wild type flagella also attached to Listeria cells masking putative additional binding mediated by the CBD. Yet, the cell-mediated leucocin C killing resulted in two-log reduction of Listeria, whereas the corresponding amount of leucocin C in spent culture medium could only inhibit growth without bacteriocidal effect. Cells binding Listeria and secreting antilisterial peptides may have applications in protection against listeriosis as they kill Listeria better than free antilisterial peptides. Copyright © 2012 Elsevier GmbH. All rights reserved.

  3. Detection of Shiga toxin-producing Escherichia coli in meat marketed in Casablanca (Morocco).

    PubMed

    Badri, S; Fassouane, A; Filliol, I; Hassar, M; Cohen, N

    2011-03-01

    The contamination of meat and meat products with Shiga toxin-producing O157:H7 and non-O157 Escherichia coli (STEC), obtained from markets in Casablanca, Morocco, was investigated. A total of 460 meat and meat products were sampled between March 2004 and July 2006 analysed and 176 strains of E. coli were isolated from these samples. The presence of the stx1, stx2, eae and ehxA genes, recognized as major virulence factors of STEC, was tested in E. coli isolates by polymerase chain reaction (PCR). STEC was detected in 4 (0.9%) samples. The result of serotyping by molecular method showed that two of these STEC isolates corresponded to the serotype O157:H7. The others Shiga toxin-producing E. coli non-O157 corresponded to O6:H21 and O76:H19. The presence of O157:H7 and non-O157 STEC in meat and meat products marketed in Casablanca, Morocco, emphasizes the importance of implementing the Hazard Analysis and Critical Control Point (HACCP) system, as well as the need for implementing, evaluating, and validating antimicrobial interventions to reduce the presence of potential pathogenic microorganisms.

  4. Synthesis of nylon 4 from gamma-aminobutyrate (GABA) produced by recombinant Escherichia coli.

    PubMed

    Park, Si Jae; Kim, Eun Young; Noh, Won; Oh, Young Hoon; Kim, Hye Young; Song, Bong Keun; Cho, Kwang Myung; Hong, Soon Ho; Lee, Seung Hwan; Jegal, Jonggeon

    2013-07-01

    In this study, we developed recombinant Escherichia coli strains expressing Lactococcus lactis subsp. lactis Il1403 glutamate decarboxylase (GadB) for the production of GABA from glutamate monosodium salt (MSG). Syntheses of GABA from MSG were examined by employing recombinant E. coli XL1-Blue as a whole cell biocatalyst in buffer solution. By increasing the concentration of E. coli XL1-Blue expressing GadB from the OD₆₀₀ of 2-10, the concentration and conversion yield of GABA produced from 10 g/L of MSG could be increased from 4.3 to 4.8 g/L and from 70 to 78 %, respectively. Furthermore, E. coli XL1-Blue expressing GadB highly concentrated to the OD₆₀₀ of 100 produced 76.2 g/L of GABA from 200 g/L of MSG with 62.4 % of GABA yield. Finally, nylon 4 could be synthesized by the bulk polymerization using 2-pyrrolidone that was prepared from microbially synthesized GABA by the reaction with Al₂O₃ as catalyst in toluene with the yield of 96 %.

  5. Cytolethal distending toxin-producing Escherichia coli strains causing severe diarrhoea in young Mexican children

    PubMed Central

    Maldonado-Puga, Samantha; Huerta-Cantillo, Jazmin; Chavez-Dueñas, Lucia; Navarro-Garcia, Fernando

    2017-01-01

    Introduction. Cytolethal distending toxins (CDTs), encoded by cdt genes, have DNase activity leading to cellular and nuclear distension, resulting in irreversible cell cycle arrest and apoptosis of target cells. cdt-positive Escherichia coli strains have been isolated from children with diarrhoea. There is, however, scant information on the prevalence and clinical presentation of diarrhoeal disease caused by these strains. Furthermore, toxin production of cdt-positive strains is rarely confirmed. We report five young children with diarrhoea caused by CDT-producing E. coli in whom stools were negative for other bacterial or enteric pathogens. Case presentation. On admission to hospital, all children presented watery diarrhoea with high stool output (range 7–20 stools/24 h); five had fever of 38 °C or more and four presented vomiting. Dehydration was present in four patients, one of whom had hypovolaemic shock; one child also presented hyponatraemia and hypokalaemia. In two children, cdt-positive strains were classified as typical and atypical enteropathogenic E. coli, and the remaining three harboured cdt-positive strains that did not belong to any diarrhoeagenic pathogroup. One cdt-positive strain from each case was characterized by a CDT cytotoxic assay and a cdt type-specific PCR. All strains produced the characteristic cellular intoxication due to CDT. Two strains carried the cdt-I, one cdt-III, one cdt-IV, and one concurrently had cdt-I, cdt-II and cdt-III genes. Conclusion. Our results suggest that CDT-producing E. coli strains are an infrequent, albeit significant, cause of severe diarrhoeal illness in children. Future research should measure the true burden of cdt-positive E. coli diarrhoea among children. PMID:28348804

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

    PubMed Central

    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

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

    PubMed

    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 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. Copyright © 2016 American Society for Microbiology.

  8. Escherichia coli O104:H4 Pathogenesis: an Enteroaggregative E. coli/Shiga Toxin-Producing E. coli Explosive Cocktail of High Virulence.

    PubMed

    Navarro-Garcia, Fernando

    2014-12-01

    A major outbreak caused by Escherichia coli of serotype O104:H4 spread throughout Europe in 2011. This large outbreak was caused by an unusual strain that is most similar to enteroaggregative E. coli (EAEC) of serotype O104:H4. A significant difference, however, is the presence of a prophage encoding the Shiga toxin, which is characteristic of enterohemorrhagic E. coli (EHEC) strains. This combination of genomic features, associating characteristics from both EAEC and EHEC, represents a new pathotype. The 2011 E. coli O104:H4 outbreak of hemorrhagic diarrhea in Germany is an example of the explosive cocktail of high virulence and resistance that can emerge in this species. A total of 46 deaths, 782 cases of hemolytic-uremic syndrome, and 3,128 cases of acute gastroenteritis were attributed to this new clone of EAEC/EHEC. In addition, recent identification in France of similar O104:H4 clones exhibiting the same virulence factors suggests that the EHEC O104:H4 pathogen has become endemically established in Europe after the end of the outbreak. EAEC strains of serotype O104:H4 contain a large set of virulence-associated genes regulated by the AggR transcription factor. They include, among other factors, the pAA plasmid genes encoding the aggregative adherence fimbriae, which anchor the bacterium to the intestinal mucosa (stacked-brick adherence pattern on epithelial cells). Furthermore, sequencing studies showed that horizontal genetic exchange allowed for the emergence of the highly virulent Shiga toxin-producing EAEC O104:H4 strain that caused the German outbreak. This article discusses the role these virulence factors could have in EAEC/EHEC O104:H4 pathogenesis.

  9. In vitro activity of beta-lactam antibiotics against CTX-M-producing Escherichia coli.

    PubMed

    Tärnberg, M; Ostholm-Balkhed, A; Monstein, H-J; Hällgren, A; Hanberger, H; Nilsson, L E

    2011-08-01

    Beta-lactam antibiotics have been discussed as options for the treatment of infections caused by multiresistant extended-spectrum beta-lactamase (ESBL)-producing bacteria if the minimum inhibitory concentration (MIC) is low. The objective of this study was to investigate the in vitro activity of different beta-lactam antibiotics against CTX-M-producing Escherichia coli. A total of 198 isolates of E. coli with the ESBL phenotype were studied. Polymerase chain reaction (PCR) amplification of CTX-M genes and amplicon sequencing were performed. The MICs for amoxicillin-clavulanic acid, aztreonam, cefepime, cefotaxime, ceftazidime, ceftibuten, ertapenem, imipenem, mecillinam, meropenem, piperacillin-tazobactam, and temocillin were determined with the Etest. Susceptibility was defined according to the breakpoints of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). MIC(50) and MIC(90) values were calculated. Isolates from CTX-M group 9 showed higher susceptibility to the beta-lactam antibiotics tested than isolates belonging to CTX-M group 1. More than 90% of the isolates belonging to CTX-M group 9 were susceptible to amoxicillin-clavulanic acid, ceftazidime, ceftibuten, piperacillin-tazobactam, and temocillin. The susceptibility was high to mecillinam, being 91%, regardless of the CTX-M group. All isolates were susceptible to imipenem and meropenem, and 99% to ertapenem. This study shows significant differences in susceptibility to different beta-lactam antibiotics among the CTX-M-producing E. coli isolates and a significant difference for many antibiotics tested between the CTX-M-producing groups 1 and 9. The good in vitro activity of other beta-lactam antibiotics compared to carbapenems indicate that clinical studies are warranted in order to examine the potential role of these beta-lactam antibiotics in the treatment of infections caused by multiresistant ESBL-producing E. coli.

  10. Absence of direct association between coliforms and Escherichia coli in irrigation water and on produce.

    PubMed

    Won, Gayeon; Schlegel, Pamela J; Schrock, Jennifer M; LeJeune, Jeffrey T

    2013-06-01

    Irrigation water is considered a potential source of preharvest pathogen contamination of vegetables. Hence, several organizations have recommended microbiological standards for water used to irrigate edible plants. The purpose of this study was to determine the strength of association between microbial quality indicators (coliforms and Escherichia coli) in irrigation water and on irrigated vegetables. Data analyzed included original results from a cross-sectional study conducted in the Midwestern United States during summer 2009 and information presented in two previously published studies performed in France and Portugal to investigate microbial quality of irrigation water and watered produce. In the cross-sectional study, repetitive PCR (rep-PCR) was used to characterize genetic relatedness of E. coli isolates from water and vegetables. No significant correlations were found between fecal indicators on leafy greens (lettuce and parsley, n = 91) or fruit (tomatoes and green peppers, n = 22) and those found in irrigation water used in the cross-sectional study (P > 0.40) or in the previously published data sets (data set 1: lettuce and waste irrigation water, n = 15, P > 0.40; data set 2: lettuce and irrigation water, n = 32, P = 0.06). Rep-PCR banding patterns of E. coli strains were all distinguishable among the pairs of E. coli isolates recovered from produce and irrigation water on the same farm. From the available data, the concentration of indicator organisms based on a single measure of irrigation water quality was not associated with the presence of these indicators on produce. In the absence of additional information, the use of a single microbial water quality parameter as an indicator of produce safety is of limited value for predicting the safety of the produce.

  11. A simple and low-cost platform technology for producing pexiganan antimicrobial peptide in E. coli.

    PubMed

    Zhao, Chun-Xia; Dwyer, Mirjana Dimitrijev; Yu, Alice Lei; Wu, Yang; Fang, Sheng; Middelberg, Anton P J

    2015-05-01

    Antimicrobial peptides, as a new class of antibiotics, have generated tremendous interest as potential alternatives to classical antibiotics. However, the large-scale production of antimicrobial peptides remains a significant challenge. This paper reports a simple and low-cost chromatography-free platform technology for producing antimicrobial peptides in Escherichia coli (E. coli). A fusion protein comprising a variant of the helical biosurfactant protein DAMP4 and the known antimicrobial peptide pexiganan is designed by joining the two polypeptides, at the DNA level, via an acid-sensitive cleavage site. The resulting DAMP4(var)-pexiganan fusion protein expresses at high level and solubility in recombinant E. coli, and a simple heat-purification method was applied to disrupt cells and deliver high-purity DAMP4(var)-pexiganan protein. Simple acid cleavage successfully separated the DAMP4 variant protein and the antimicrobial peptide. Antimicrobial activity tests confirmed that the bio-produced antimicrobial peptide has the same antimicrobial activity as the equivalent product made by conventional chemical peptide synthesis. This simple and low-cost platform technology can be easily adapted to produce other valuable peptide products, and opens a new manufacturing approach for producing antimicrobial peptides at large scale using the tools and approaches of biochemical engineering.

  12. The discovery of cholera - like enterotoxins produced by Escherichia coli causing secretory diarrhoea in humans

    PubMed Central

    Sack, R. Bradley

    2011-01-01

    Non-vibrio cholera has been recognized as a clinical entity for as long as cholera was known to be caused by Vibrio cholerae. Until 1968, the aetiologic agent of this syndrome was not known. Following a series of studies in patients with non-vibrio cholera it was found that these patients had large concentrations of Escherichia coli in the small bowel and stools which produced cholera toxin-like enterotoxins, and had fluid and electrolyte transport abnormalities in the small bowel similar to patients with documented cholera. Furthermore, these patients developed antibodies to the cholera-like enterotoxin. Later studies showed that these strains, when fed to volunteers produced a cholera-like disease and that two enterotoxins were found to be produced by these organisms: a heat-labile enterotoxin (LT) which is nearly identical to cholera toxin, and a heat-stable enterotoxin (ST), a small molecular weight polypeptide. E. coli that produced one or both of these enterotoxins were designated enterotoxigenic E. coli (ETEC). ETEC are now known not only to cause a severe cholera-like illness, but to be the most common bacterial cause of acute diarrhoea in children in the developing world, and to be the most common cause of travellers’ diarrhoea in persons who visit the developing world. PMID:21415491

  13. Evaluation of the premier EHEC assay for detection of Shiga toxin-producing Escherichia coli.

    PubMed Central

    Kehl, K S; Havens, P; Behnke, C E; Acheson, D W

    1997-01-01

    An enzyme-linked immunosorbent assay for the detection of Shiga toxins (Premier EHEC assay; Meridian Diagnostics, Inc.) was compared to conventional sorbitol-MacConkey culture for the recovery of enterohemorrhagic Escherichia coli. A total of 74 enteric pathogens, including 8 E. coli O157:H7 isolates, were recovered from 974 stool specimens. Two of these specimens were not tested by Premier assaying due to insufficient sample and are not considered in the data analysis. The Premier EHEC assay detected the 6 evaluable specimens which were culture positive for E. coli O157:H7 and identified an additional 10 specimens as containing Shiga toxin. Seven isolates were recovered from these 10 specimens by an immunoblot assay and were confirmed as toxin producers by a cytotoxin assay. Of these seven, four isolates were serotype O157:H7, one was O26:NM, one was O6:H-, and one was O untypeable:H untypeable. Three specimens contained Shiga toxin by both EHEC immunoassaying and cytotoxin testing; however, no cytotoxin-producing E. coli could be recovered. The sorbitol-MacConkey method had a sensitivity and a specificity of 60 and 100%, respectively, while the Premier EHEC assay had a sensitivity and a specificity of 100 and 99.7%, respectively, for E. coli O157:H7 only. The Premier EHEC assay also detected an additional 20% Shiga toxin-producing E. coli (STEC) that were non-O157:H7. Thus, the Premier EHEC assay is a sensitive and specific method for the detection of all STEC isolates. Routine use would improve the detection of E. coli O157:H7 and allow for determination of the true incidence of STEC other than O157:H7. The presence of blood in the stool and/or the ages of the patients were poor predictors of the presence of STEC. Criteria need to be determined which would allow for the cost-effective incorporation of this assay into the routine screen for enteric pathogens in high-risk individuals, especially children. PMID:9230380

  14. Shiga toxin-producing Escherichia coli: a single-center, 11-year pediatric experience.

    PubMed

    Schindler, Emily I; Sellenriek, Patricia; Storch, Gregory A; Tarr, Phillip I; Burnham, Carey-Ann D

    2014-10-01

    The aim of this study was to identify the best practices for the detection of Shiga toxin-producing Escherichia coli (STEC) in children with diarrheal illness treated at a tertiary care center, i.e., sorbitol-MacConkey (SMAC) agar culture, enzyme immunoassay (EIA) for Shiga toxin, or the simultaneous use of both methods. STEC was detected in 100 of 14,997 stool specimens submitted for enteric culture (0.7%), with 65 cases of E. coli O157. Among E. coli O157 isolates, 57 (88%) were identified by both SMAC agar culture and EIA, 6 (9%) by SMAC agar culture alone, and 2 (3%) by EIA alone. Of the 62 individuals with diarrheal hemolytic uremic syndrome (HUS) seen at our institution during the study period, 16 (26%) had STEC isolated from cultures at our institution and 15 (24%) had STEC isolated at other institutions. No STEC was recovered in 31 cases (50%). Of the HUS cases in which STEC was isolated, 28 (90%) were attributable to E. coli O157 and 3 (10%) were attributable to non-O157 STEC. Consistent with previous studies, we have determined that a subset of E. coli O157 infections will not be detected if an agar-based method is excluded from the enteric culture workup; this has both clinical and public health implications. The best practice would be concomitant use of an agar-based method and a Shiga toxin EIA, but a Shiga toxin EIA should not be considered to be an adequate stand-alone test for detection of E. coli O157 in clinical samples. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  15. Shiga Toxin-Producing Escherichia coli O157, England and Wales, 1983-2012.

    PubMed

    Adams, Natalie L; Byrne, Lisa; Smith, Geraldine A; Elson, Richard; Harris, John P; Salmon, Roland; Smith, Robert; O'Brien, Sarah J; Adak, Goutam K; Jenkins, Claire

    2016-04-01

    We evaluated clinical Shiga toxin-producing Escherichia coli O157 infections in England and Wales during 1983-2012 to describe changes in microbiological and surveillance methods. A strain replacement event was captured; phage type (PT) 2 decreased to account for just 3% of cases by 2012, whereas PT8 and PT21/28 strains concurrently emerged, constituting almost two thirds of cases by 2012. Despite interventions to control and reduce transmission, incidence remained constant. However, sources of infection changed over time; outbreaks caused by contaminated meat and milk declined, suggesting that interventions aimed at reducing meat cross-contamination were effective. Petting farm and school and nursery outbreaks increased, suggesting the emergence of other modes of transmission and potentially contributing to the sustained incidence over time. Studies assessing interventions and consideration of policies and guidance should be undertaken to reduce Shiga toxin-producing E. coli O157 infections in England and Wales in line with the latest epidemiologic findings.

  16. Preclinical Evaluation of a Tailor-Made DOTA-Conjugated PSMA Inhibitor with Optimized Linker Moiety for Imaging and Endoradiotherapy of Prostate Cancer.

    PubMed

    Benešová, Martina; Schäfer, Martin; Bauder-Wüst, Ulrike; Afshar-Oromieh, Ali; Kratochwil, Clemens; Mier, Walter; Haberkorn, Uwe; Kopka, Klaus; Eder, Matthias

    2015-06-01

    Despite many advances in the past years, the treatment of metastatic prostate cancer still remains challenging. In recent years, prostate-specific membrane antigen (PSMA) inhibitors were intensively studied to develop low-molecular-weight ligands for imaging prostate cancer lesions by PET or SPECT. However, the endoradiotherapeutic use of these compounds requires optimization with regard to the radionuclide-chelating agent and the linker moiety between chelator and pharmacophore, which influence the overall pharmacokinetic properties of the resulting radioligand. In an effort to realize both detection and optimal treatment of prostate cancer, a tailor-made novel naphthyl-containing DOTA-conjugated PSMA inhibitor has been developed. The peptidomimetic structure was synthesized by solid-phase peptide chemistry and characterized using reversed-phase high-performance liquid chromatography and matrix-assisted laser desorption/ionization mass spectrometry. Subsequent (67/68)Ga and (177)Lu labeling resulted in radiochemical yields of greater than 97% or greater than 99%, respectively. Competitive binding and internalization experiments were performed using the PSMA-positive LNCaP cell line. The in vivo biodistribution and dynamic small-animal PET imaging studies were investigated in BALB/c nu/nu mice bearing LNCaP xenografts. The chemically modified PSMA inhibitor PSMA-617 demonstrated high radiolytic stability for at least 72 h. A high inhibition potency (equilibrium dissociation constant [K(i)] = 2.34 ± 2.94 nM on LNCaP; K(i) = 0.37 ± 0.21 nM enzymatically determined) and highly efficient internalization into LNCaP cells were demonstrated. The small-animal PET measurements showed high tumor-to-background contrasts as early as 1 h after injection. Organ distribution revealed specific uptake in LNCaP tumors and in the kidneys 1 h after injection. With regard to therapeutic use, the compound exhibited a rapid clearance from the kidneys from 113.3 ± 24.4 at 1 h to 2.13

  17. Combining Transcranial Direct Current Stimulation and Tailor-Made Notched Music Training to Decrease Tinnitus-Related Distress – A Pilot Study

    PubMed Central

    Teismann, Henning; Wollbrink, Andreas; Okamoto, Hidehiko; Schlaug, Gottfried; Rudack, Claudia; Pantev, Christo

    2014-01-01

    The central auditory system has a crucial role in tinnitus generation and maintenance. Curative treatments for tinnitus do not yet exist. However, recent attempts in the therapeutic application of both acoustic stimulation/training procedures and electric/magnetic brain stimulation techniques have yielded promising results. Here, for the first time we combined tailor-made notched music training (TMNMT) with transcranial direct current stimulation (tDCS) in an effort to modulate TMNMT efficacy in the treatment of 32 patients with tonal tinnitus and without severe hearing loss. TMNMT is characterized by regular listening to so-called notched music, which is generated by digitally removing the frequency band of one octave width centered at the individual tinnitus frequency. TMNMT was applied for 10 subsequent days (2.5 hours of daily treatment). During the initial 5 days of treatment and the initial 30 minutes of TMNMT sessions, tDCS (current strength: 2 mA; anodal (N = 10) vs. cathodal (N = 11) vs. sham (N = 11) groups) was applied simultaneously. The active electrode was placed on the head surface over left auditory cortex; the reference electrode was put over right supra-orbital cortex. To evaluate treatment outcome, tinnitus-related distress and perceived tinnitus loudness were assessed using standardized tinnitus questionnaires and a visual analogue scale. The results showed a significant treatment effect reflected in the Tinnitus Handicap Questionnaire that was largest after 5 days of treatment. This effect remained significant at the end of follow-up 31 days after treatment cessation. Crucially, tDCS did not significantly modulate treatment efficacy - it did not make a difference whether anodal, cathodal, or sham tDCS was applied. Possible explanations for the findings and functional modifications of the experimental design for future studies (e.g. the selection of control conditions) are discussed. PMID:24587113

  18. Initial experience with a tailor-made simulation and navigation program using a 3-D printer model of kidney transplantation surgery.

    PubMed

    Kusaka, M; Sugimoto, M; Fukami, N; Sasaki, H; Takenaka, M; Anraku, T; Ito, T; Kenmochi, T; Shiroki, R; Hoshinaga, K

    2015-04-01

    Three-dimensional (3-D) printing systems allow for the creation of surgical models mimicking real tissue. We developed a kidney graft and pelvic cavity replica as a patient-specific 3-D model using a 3-D printing system with simultaneous jetting of different materials and subsequently evaluated the usefulness of surgical simulation and navigation of living kidney transplantation. After generating a stereolithographic file of the organ surface based on multidetector computed tomographic data, we created a 3-D organ model using an inkjet 3-D printer and manufactured a pelvic cavity replica using patient-specific data. The patients' individual 3-D printed models were used to plan and guide the surgical procedures for laparoscopic donor nephrectomy and recipient transplantation surgery. The 3-D organ replicas obtained using transparent materials allowed for the creation of models that showed the visceral organs, blood vessels, and other details, thereby overcoming the limitations of conventional image-guided navigation. Our pelvic replicas can be made according to each patient's specific anatomical data, thus representing personalized surgical procedures. This level of detail of the anatomy enables the surgeons and trainees to virtually treat various pelvic conditions before they perform the surgical procedure. The use of these replicas may also reduce the length of the operation and provide better anatomical reference tools for tailor-made simulation and navigation of kidney transplantation surgery, consequently helping to improve training for the operating room staff, students, and trainees. We believe that our sophisticated personalized donor graft and pelvic replications obtained using a 3-D printing system are advantageous for kidney transplantation surgery. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Molecular characteristic of mcr-1 producing Escherichia coli in a Chinese university hospital.

    PubMed

    He, Qing-Wen; Xu, Xiao-Hong; Lan, Fang-Jun; Zhao, Zhi-Chang; Wu, Zhi-Yun; Cao, Ying-Ping; Li, Bin

    2017-04-19

    Colistin has been considered as a last-line treatment option in severe infections caused by multidrug-resistant (MDR) gram-negative pathogens. However, the emergence of the mobile colistin resistance gene (mcr-1) has challenged this viewpoint. The aim of this study is to explore the prevalence of mcr-1 in Escherichia coli (E. coli) in a Chinese teaching hospital, and investigate their molecular characteristics. A total of 700 E. coli isolates were used to screen mcr-1 by PCR and sequencing in a Chinese university hospital from August 2014 to August 2015. Susceptibility test of mcr-1-producing isolates was determined by Vitek -2 Compact system. 26 virulence factors (VFs), phylogenetic groups, Multi-locus sequence typing (MLST), and DNA Fingerprinting (ERIC-PCR) of strains were investigated by PCR. Four (0.6%) mcr-1 producing E. coli isolates were found in this study. The results of antibiotic susceptibility test showed that all four isolates were resistant to colistin, ciprofloxacin, levofloxacin, cefazolin, and trimethoprim/sulfamethoxazole, and were susceptible to amikacin, ertapenem and imipenem. In addition, all 4 isolates exhibited high-level resistance to aztreonam, cefotaxime and gentamicin. The numbers of VFs contained in mcr-1 positive isolates were no more than 4 in our study. MLST result demonstrated that these isolates were assigned to two sequence types: ST156 and ST167. The result of phylogenetic analysis showed that four mcr-1-positive isolates belong to two phylogenetic groups: A and B1 group. ERIC-PCR showed that four mcr-1 positive strains were categorized into three different genotypes. Our study demonstrated a low prevalence of mcr-1 in E. coli clinical isolates in a Chinese teaching hospital, and we have gained insights into the molecular characteristics of these mcr-1-positive strains. Increasing the surveillance of these infections, as well as taking effective infection control measures are urgently needed to take to control the transmission

  20. Shiga Toxin–producing Escherichia coli, New Mexico, USA, 2004–2007

    PubMed Central

    Edge, Karen; Bareta, Joseph

    2009-01-01

    Sporadic infection with Shiga toxin–producing Escherichia coli (STEC) in New Mexico increased from 0.9 cases per 100,000 population (95% confidence interval [CI] 0.5–1.36) in 2004 to 1.7 (95% CI 1.14–2.26) in 2007. Non-O157 STEC was more common in nonwhite residents, children <5 years of age, and urban residents. PMID:19751594

  1. The surveillance of vero cytotoxin-producing Escherichia coli O157 in Wales, 1990 to 1998.

    PubMed

    Chalmers, R M; Parry, S M; Salmon, R L; Smith, R M; Willshaw, G A; Cheasty, T

    1999-01-01

    Population-based surveillance for Vero cytotoxin-producing Escherichia coli (VTEC) O157 has been carried out in Wales since 1990. The annual incidence has remained stable during the 9-year period (mean: 1.6 cases per 100,000 population); the rate is highest in children younger than 5 years of age. Blood in the stool is reported in fewer than half the cases, indicating the importance of screening all fecal specimens for VTEC O157.

  2. Inactivation of shiga toxin-producing Escherichia coli in lean ground beef by gamma irradiation

    USDA-ARS?s Scientific Manuscript database

    Non-O157 serovars of Shiga Toxin-producing Escherichia coli (STEC) are now responsible for over 60% of STEC induced illnesses. The majority of illnesses caused by non-O157:H7 STEC have been due to serogroups O26, O121, O103, O45, O111, and O145, “the big/top six”, which are now considered adulterant...

  3. Shiga toxin-producing Escherichia coli infections associated with hemolytic uremic syndrome, Italy, 1988-2000.

    PubMed

    Tozzi, Alberto E; Caprioli, Alfredo; Minelli, Fabio; Gianviti, Alessandra; De Petris, Laura; Edefonti, Alberto; Montini, Giovanni; Ferretti, Alfonso; De Palo, Tommaso; Gaido, Maurizio; Rizzoni, Gianfranco

    2003-01-01

    The mean annual incidence of hemolytic uremic syndrome in persons producing Escherichia coli (STEC) infection occurred in 73.1% of patients. STEC O157 was the most common serotype, but a considerable number of cases were from infections by non-O157 STEC.

  4. Shiga Toxin–Producing Escherichia coli Infections Associated with Hemolytic Uremic Syndrome, Italy, 1988–2000

    PubMed Central

    Caprioli, Alfredo; Minelli, Fabio; Gianviti, Alessandra; De Petris, Laura; Edefonti, Alberto; Montini, Giovanni; Ferretti, Alfonso; De Palo, Tommaso; Gaido, Maurizio; Rizzoni, Gianfranco

    2003-01-01

    The mean annual incidence of hemolytic uremic syndrome in persons <15 years of age in Italy from 1988 to 2000 was 0.28 per 100,000 population. Laboratory investigations showed that Shiga toxin–producing Escherichia coli (STEC) infection occurred in 73.1% of patients. STEC O157 was the most common serotype, but a considerable number of cases were from infections by non-O157 STEC. PMID:12533290

  5. Virulence characterization of Shiga-toxigenic Escherichia coli isolates from wholesale produce.

    PubMed

    Feng, Peter C H; Councell, Terry; Keys, Christine; Monday, Steven R

    2011-01-01

    The 13 Shiga-toxigenic Escherichia coli (STEC) strains isolated from wholesale spinach and lettuce consisted mostly of serotypes that have not been implicated in illness. Among these strains, however, were two O113:H21 that carried virulence genes common to this pathogenic serotype (stx(2), ehxA, saa, and subAB), suggesting that their presence in ready-to-eat produce may be of health concern.

  6. Multidrug Resistant CTX-M-Producing Escherichia coli: A Growing Threat among HIV Patients in India

    PubMed Central

    Padmavathy, Kesavaram; Padma, Krishnan; Rajasekaran, Sikhamani

    2016-01-01

    Extended Spectrum β-Lactamases (ESBLs) confer resistance to third-generation cephalosporins and CTX-M types have emerged as the most prominent ESBLs worldwide. This study was designed to determine the prevalence of CTX-M positive ESBL-producing urinary E. coli isolates from HIV patients and to establish the association of multidrug resistance, phylogeny, and virulence profile with CTX-M production. A total of 57 ESBL producers identified among 76 E. coli strains isolated from HIV patients from South India were screened for blaCTX-M, AmpC production, multidrug resistance, and nine virulence associated genes (VAGs), fimH, pap, afa/dra, sfa/foc, iutA, fyuA, iroN, usp, and kpsMII. The majority (70.2%) of the ESBL producers harbored blaCTX-M and were AmpC coproducers. Among the CTX-M producers, 47.5% were found to be UPEC, 10% harbored as many as 7 VAGs, and 45% possessed kpsMII. Multidrug resistance (CIPRSXTRGENR) was significantly more common among the CTX-M producers compared to the nonproducers (70% versus 41.2%). However, 71.4% of the multidrug resistant CTX-M producers exhibited susceptibility to nitrofurantoin thereby making it an effective alternative to cephalosporins/fluoroquinolones. The emergence of CTX-M-producing highly virulent, multidrug resistant uropathogenic E. coli is of significant public health concern in countries like India with a high burden of HIV/AIDS. PMID:27123344

  7. Sorbitol non-fermenting shiga toxin-producing Escherichia coli in cattle on smallholdings.

    PubMed

    Islam, M Z; Christensen, J P; Biswas, P K

    2015-01-01

    We investigated faecal samples collected from the rectum of 518 cattle on 371 randomly selected smallholdings in Bangladesh for the presence of sorbitol non-fermenting (SN-F) shiga toxin-producing Escherichia coli (STEC). The SN-F isolates were tested for the presence of rfb O157, stx1, stx2, eae and hlyA genes by polymerase chain reaction (PCR). Seven SN-F isolates lacking these genes were profiled by pulsed-field gel electrophoresis (PFGE) to verify their clonality. SN-F E. coli was identified in 44 [8·5%, 95% confidence interval (CI) 6·4-11·2] samples; of these, 28 (5·4%, 95% CI 3·8-7·7) had shiga toxin-producing strains, although only two carried the rfb O157 gene. Thirteen isolates carried the hlyA gene while 18 harboured the eae gene. Based on PFGE, six pulsotypes were observed among the seven isolates that had no virulence genes. To the best of our knowledge this is the first report on shiga toxin-producing E. coli from direct rectal faecal samples of cattle on smallholdings.

  8. (13)C-metabolic flux analysis for mevalonate-producing strain of Escherichia coli.

    PubMed

    Wada, Keisuke; Toya, Yoshihiro; Banno, Satomi; Yoshikawa, Katsunori; Matsuda, Fumio; Shimizu, Hiroshi

    2017-02-01

    Mevalonate (MVA) is used to produce various useful products such as drugs, cosmetics and food additives. An MVA-producing strain of Escherichia coli (engineered) was constructed by introducing mvaES genes from Enterococcus faecalis. The engineered strain produced 1.84 mmol/gDCW/h yielding 22% (C-mol/C-mol) of MVA from glucose in the aerobic exponential growth phase. The mass balance analysis revealed that the MVA yield of the engineered strain was close to the upper limit at the biomass yield. Since MVA is synthesized from acetyl-CoA using NADPH as a cofactor, the production of MVA affects central metabolism in terms of carbon utilization and NADPH requirements. The reason for this highly efficient MVA production was investigated based on (13)C-metabolic flux analysis. The estimated flux distributions revealed that the fluxes of acetate formation and the TCA cycle in the engineered strain were lower than those in the control strain. Although the oxidative pentose phosphate pathway is considered as the NADPH generating pathway in E. coli, no difference of the flux was observed between the control and engineered strains. The production/consumption balance of NADPH suggested that additional requirement of NADPH for MVA synthesis was obtained from the transhydrogenase reaction in the engineered strain. Comparison between the measured flux distribution and the ideal values for MVA production proposes a strategy for further engineering to improve the MVA production in E. coli.

  9. [Morphologic changes in the intestine of swine after infection with verotoxin-producing Escherichia coli].

    PubMed

    Appel, G; Ewald, C; Heer, A; von Mickwitz, G; Aleksić, S; Rüssmann, H; Meyer, T; Karch, H

    1990-09-01

    Spontaneous morphologic lesions are described in 12 of 66 pigs submitted for necropsy. All 12 pigs were culture positive for Verotoxin-producing E. coli (VTEC). 10 of them were weaned pigs, one a suckling piglet and one a fattening hog. In 6 cases E. coli serovar 0139:H1 and in one case each the serovars 0139:H40; 0138:H-; 0125ac:H27 and 0154:H- were isolated. From the fecal samples of 2 animals E. coli ONT (O-group non typable):H- were cultured. Macroscopically there were cyanosis, edema of the eye lids, catarrhal enteritis and/or colitis as well as edema of the mesentery, swelling of the mesenteric lymph nodes and congestion of the lung to varying degrees. Histopathologic examination of 5 animals was carried out. In 3 animals atrophy and edema of the villi in the jejunum and ileum were discovered. In one animal an additional infection with corona virus was confirmed electron microscopically. Furthermore there was disseminated necrosis of lymphocytes in Peyer's patches of the small intestine and in secondary follicles of the mesenteric lymph nodes. In one of the animals a hemorrhagic-necrotising ileitis, occurred characterized by necrosis of villi and thrombosis of blood vessels in the mucosa. The highest number of VTEC with seven out of twelve animals was found in weaned pigs in association with the E. coli serovar 0139.

  10. Occurrence of generic Escherichia coli, E. coli O157 and Salmonella spp. in water and sediment from leafy green produce farms and streams on the Central California coast.

    PubMed

    Benjamin, Lisa; Atwill, Edward R; Jay-Russell, Michele; Cooley, Michael; Carychao, Diana; Gorski, Lisa; Mandrell, Robert E

    2013-07-01

    Irrigation with water of poor microbiological quality can elevate levels of bacteria on produce. This study aimed to identify climate and management variables associated with generic Escherichia coli in irrigation water on leafy green produce farms and to measure the prevalence of E. coli O157 and Salmonella spp. in irrigation and non-irrigation water sources on these farms. Water and sediment samples collected from various points along irrigation systems, as well as from streams and ponds on farms on the Central California coast between May 27th, 2008 and October 26th, 2010 were cultured for generic E. coli (MPN/100 mL or cfu 100 g) (n=436), E. coli O157 (n=437), and (n=163) Salmonella. Variables were based on grower's management practices, landscape features in proximity to samples (e.g., distance to roads and ranches/livestock), and climate data accessed from an online database. Negative binomial regression models were constructed to test associations between generic E. coli (MPN/100 mL) in water from farms and variables. Arithmetic mean concentration of E. coli for water, not including those from Moore swabs, and sediment samples, was 7.1×10(2) MPN/100 mL and 1.0×10(4) cfu/100 g, respectively. Matched by collection day, E. coli concentration in sediment (cfu/100 g) was typically 10- to 1000-fold higher than the overlying water (MPN/100 mL) for these irrigation systems. Generic E. coli concentration (MPN/100 mL) increased by 60.1% for each 1m/s increase in wind speed and decreased by 3% for each 10 m increase in the distance between the sample location and rangeland. Moore swabs detected a higher proportion of E. coli O157 (13.8%) positive water samples compared to grab samples (1.8%); 1.7% of sediment samples had detectable levels of this pathogen. Interestingly, season was not significantly associated with E. coli O157 presence in water or sediments from produce farms or water sources with public access. Salmonella was detected in 6% (6/96) water and 4.3% (3

  11. Generation of polyclonal antibodies against recombinant human glucocerebrosidase produced in Escherichia coli.

    PubMed

    Novo, Juliana Branco; Oliveira, Maria Leonor Sarno; Magalhães, Geraldo Santana; Morganti, Ligia; Raw, Isaías; Ho, Paulo Lee

    2010-11-01

    Deficiency of the lysosomal glucocerebrosidase (GCR) enzyme results in Gaucher's disease, the most common inherited storage disorder. Treatment consists of enzyme replacement therapy by the administration of recombinant GCR produced in Chinese hamster ovary cells. The production of anti-GCR antibodies has already been described with placenta-derived human GCR that requires successive chromatographic procedures. Here, we report a practical and efficient method to obtain anti-GCR polyclonal antibodies against recombinant GCR produced in Escherichia coli and further purified by a single step through nickel affinity chromatography. The purified GCR was used to immunize BALB/c mice and the induction of anti-GCR antibodies was evaluated by enzyme-linked immunosorbent assay. The specificity of the antiserum was also evaluated by western blot analysis against recombinant GCR produced by COS-7 cells or against endogenous GCR of human cell lines. GCR was strongly recognized by the produced antibodies, either as cell-associated or as secreted forms. The detected molecular masses of 59-66 kDa are in accordance to the expected size for glycosylated GCR. The GCR produced in E. coli would facilitate the production of polyclonal (shown here) and monoclonal antibodies and their use in the characterization of new biosimilar recombinant GCRs coming in the near future.

  12. Diminazene aceturate: an antibacterial agent for Shiga-toxin-producing Escherichia coli O157:H7

    PubMed Central

    Wu, Si-Ying; Park, Gil-Yong; Kim, So-Hee; Hulme, John; An, Seong Soo A

    2016-01-01

    The aim of this study was to investigate the bacteriostatic and bactericidal effects of diminazene aceturate (DA) against five strains of pathogenic bacteria and two strains of nonpathogenic bacteria. The results showed that 5 μg/mL of DA suppressed the growth of pathogenic Escherichia coli by as much as 77% compared with the controls. Enterohemorrhagic E. coli EDL933 (an E. coli O157:H7 strain) was the most sensitive to DA with a minimum inhibitory concentration of 20 μg/mL. Additional investigations showed that DA induced the highest level of intracellular reactive oxygen species in EDL933. A positive correlation between the reactive oxygen species levels and DA concentration was demonstrated. DA (5 μg/mL) was also a potent uncoupler, inducing a stationary phase collapse (70%–75%) in both strains of E. coli O157:H7. Further investigation showed that the collapse was due to the NaCl:DA ratio in the broth and was potassium ion dependent. A protease screening assay was conducted to elucidate the underlying mechanism. It was found that at neutral pH, the hydrolysis of H-Asp-pNA increased by a factor of 2–3 in the presence of DA, implying that DA causes dysregulation of the proton motive force and a decrease in cellular pH. Finally, a commercial verotoxin test showed that DA did not significantly increase toxin production in EDL933 and was a suitable antibacterial agent for Shiga-toxin-producing E. coli. PMID:27789937

  13. Molecular Diversity and Plasmid Analysis of KPC-Producing Escherichia coli.

    PubMed

    Chavda, Kalyan D; Chen, Liang; Jacobs, Michael R; Bonomo, Robert A; Kreiswirth, Barry N

    2016-07-01

    The emergence and spread of Klebsiella pneumoniae carbapenemase (KPC) among Enterobacteriaceae presents a major public health threat to the world. Although not as common as in K. pneumoniae, KPC is also found in Escherichia coli strains. Here, we genetically characterized 9 carbapenem-resistant E. coli strains isolated from six hospitals in the United States and completely sequenced their blaKPC-harboring plasmids. The nine strains were isolated from different geographical locations and belonged to 8 different E. coli sequence types. Seven blaKPC-harboring plasmids belonged to four different known incompatibility groups (IncN, -FIA, -FIIK2, and -FIIK1) and ranged in size from ∼16 kb to ∼241 kb. In this analysis, we also identified two plasmids that have novel replicons: (i) pBK28610, which is similar to p34978-3 with an insertion of Tn4401b, and (ii) pBK31611, which does not have an apparent homologue in the GenBank database. Moreover, we report the emergence of a pKP048-like plasmid, pBK34397, in E. coli in the United States. Meanwhile, we also found examples of interspecies spread of blaKPC plasmids, as pBK34592 is identical to pBK30683, isolated from K. pneumoniae In addition, we discovered examples of acquisition (pBK32602 acquired an ∼46-kb fragment including a novel replication gene, along with Tn4401b and other resistance genes) and/or loss (pKpQIL-Ec has a 14.5-kb deletion compared to pKpQIL-10 and pBK33689) of DNA, demonstrating the plasticity of these plasmids and their rapid evolution in the clinic. Overall, our study shows that the spread of blaKPC-producing E. coli is largely due to horizontal transfer of blaKPC-harboring plasmids and related mobile elements into diverse genetic backgrounds.

  14. Molecular Diversity and Plasmid Analysis of KPC-Producing Escherichia coli

    PubMed Central

    Chavda, Kalyan D.; Chen, Liang; Jacobs, Michael R.; Bonomo, Robert A.

    2016-01-01

    The emergence and spread of Klebsiella pneumoniae carbapenemase (KPC) among Enterobacteriaceae presents a major public health threat to the world. Although not as common as in K. pneumoniae, KPC is also found in Escherichia coli strains. Here, we genetically characterized 9 carbapenem-resistant E. coli strains isolated from six hospitals in the United States and completely sequenced their blaKPC-harboring plasmids. The nine strains were isolated from different geographical locations and belonged to 8 different E. coli sequence types. Seven blaKPC-harboring plasmids belonged to four different known incompatibility groups (IncN, -FIA, -FIIK2, and -FIIK1) and ranged in size from ∼16 kb to ∼241 kb. In this analysis, we also identified two plasmids that have novel replicons: (i) pBK28610, which is similar to p34978-3 with an insertion of Tn4401b, and (ii) pBK31611, which does not have an apparent homologue in the GenBank database. Moreover, we report the emergence of a pKP048-like plasmid, pBK34397, in E. coli in the United States. Meanwhile, we also found examples of interspecies spread of blaKPC plasmids, as pBK34592 is identical to pBK30683, isolated from K. pneumoniae. In addition, we discovered examples of acquisition (pBK32602 acquired an ∼46-kb fragment including a novel replication gene, along with Tn4401b and other resistance genes) and/or loss (pKpQIL-Ec has a 14.5-kb deletion compared to pKpQIL-10 and pBK33689) of DNA, demonstrating the plasticity of these plasmids and their rapid evolution in the clinic. Overall, our study shows that the spread of blaKPC-producing E. coli is largely due to horizontal transfer of blaKPC-harboring plasmids and related mobile elements into diverse genetic backgrounds. PMID:27114279

  15. Factors affecting compost tea as a potential source of Escherichia coli and Salmonella on fresh produce.

    PubMed

    Ingram, D T; Millner, P D

    2007-04-01

    Compost tea (CT) is an unheated on-farm infusion of compost used as a spray or soil drench to promote plant growth and control foliar and root diseases. Because food safety involves all aspects from farm to fork, CT should meet basic microbiological criteria for water quality. This report describes the effects of two CT production processes, aerated and nonaerated, on growth and survival of foodborne pathogens and fecal coliforms. Seven commercially available nutrients used to supplement CT were tested individually and in combination for their effects on the growth of Escherichia coli and Salmonella. Compost containing 10(1) to 10(3) CFU/g initial concentrations of E. coli O157:H7 and Salmonella Enteritidis were used to assess growth and survival responses to aerated CT (36-h preparations) and nonaerated CT (8.5-day preparations). Pathogen and fecal coliform populations were undetectable by 8.5 days in nonaerated CT without nutrient supplements. E. coli O157:H7 decreased to below detection levels in aerated CT at 36 h without the use of supplements. In contrast, the addition of commercially formulated mixtures or combinations of nutrient supplements resulted in growth of E. coli O157: H7, Salmonella, and fecal coliforms by 1 to 4 log CFU/g in both aerated and nonaerated CT. When nutrient supplements were added, aerated CT sustained higher concentrations of E. coli O157:H7, Salmonella, and fecal coliforms than did nonaerated CT. Thus, addition of supplements supports growth of human pathogens from very low initial concentrations in both aerated and nonaerated CT and should be avoided when CT is used on fresh produce.

  16. Characteristics of Shiga Toxin-Producing Escherichia coli O157 in Slaughtered Reindeer from Northern Finland.

    PubMed

    Zweifel, Claudio; Fierz, Lisa; Cernela, Nicole; Laaksonen, Sauli; Fredriksson-Ahomaa, Maria; Stephan, Roger

    2017-03-01

    Fecal samples collected from 470 slaughtered reindeer 6 to 7 months of age were screened by real-time PCR (after enrichment) for Shiga toxin genes (stx) and then for Escherichia coli serogroup O157. Shiga toxin genes were found frequently (>30% of samples), and serogroup O157 was detected in 20% of the stx-positive samples. From these samples, a total of 25 E. coli O157:H(-) isolates (nonmotile but PCR positive for fliCH7) were obtained. Twenty-four of these E. coli O157:H(-) isolates did not ferment sorbitol and originated from one geographic area. These 24 isolates belonged to the multilocus sequence type 11, typical for Shiga toxin-producing E. coli (STEC) O157:H7 and O157:H(-), and harbored genes stx1a, stx2c, eae, and hlyA; the stx2c subtype has been associated with high virulence. In contrast, one E. coli O157:H(-) isolate (multilocus sequence type 11) did ferment sorbitol, lacked Shiga toxin genes, but was positive for eae, hlyA, and sfpA. This isolate closely resembled an STEC that has lost its Shiga toxin genes. Additional examination revealed that reindeer can be colonized by various other STEC isolates; 21 non-O157 STEC isolates belonged to four multilocus sequence types, harbored stx1a (8 isolates) or stx2b (13 isolates), and in the stx2b-positive isolates the recently described new allelic variants (subAB2-2 and subAB2-3) for subtilase cytotoxin were identified. Hence, slaughtered semidomesticated Finnish reindeer might constitute a little known reservoir for STEC O157:H7/H(-) and other serogroups, and the risk of direct or indirect transmission of these pathogens from reindeer to humans and domestic livestock must not be overlooked.

  17. Frequent acquisition of low-virulence strains of ESBL-producing Escherichia coli in travellers.

    PubMed

    Vading, M; Kabir, M H; Kalin, M; Iversen, A; Wiklund, S; Nauclér, P; Giske, C G

    2016-12-01

    International travel is a risk factor for intestinal colonization with ESBL-producing Enterobacteriaceae (EPE). This prospective cohort study focuses on molecular features of and risk factors for travel-acquired EPE. Rectal swabs and survey data were collected from 188 Swedes travelling to four regions of high EPE prevalence. Samples were plated onto selective agars. ESBL producers were determined using phenotypic methods. Molecular characterization regarding virulence factors and phylogenetic grouping of ESBL-producing Escherichia coli was done using PCR. Isolates were also screened for the plasmid-mediated colistin resistance gene mcr-1. Among 175 pre-travel EPE-negative participants, 32% were positive upon return. No carbapenemase-producing Enterobacteriaceae were found, but one CTX-M-producing E. coli harboured mcr-1 (travel to Thailand). Most E. coli strains (43.1%) belonged to phylogroup A and were rarely associated with extraintestinal infections and a few (9.2%) expressed uropathogenicity pap genes. During 10-26 months of follow-up, no clinical infections were observed. Colonization rates varied by visited region: the Indian subcontinent, 49.2%; northern Africa, 44.0%; South-East Asia, 19.1%; and Turkey, 9.5%. Travellers' diarrhoea (OR 2.5, P = 0.04) or antimicrobial treatment during the trip (OR 5.9, P = 0.02) were both independent risk factors for EPE colonization. EPE acquired during travel have seemingly low pathogenicity, possibly indicating a low risk of clinical infection. Pre-travel advice should emphasize avoiding unnecessary antibiotic treatment during travel. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  18. Increasing incidence of carbapenemase-producing Escherichia coli and Klebsiella pneumoniae in Belgian hospitals.

    PubMed

    De Laveleye, M; Huang, T D; Bogaerts, P; Berhin, C; Bauraing, C; Sacré, P; Noel, A; Glupczynski, Y

    2017-01-01

    Carbapenemase-producing Enterobacteriaceae are increasingly reported worldwide. The aim of the study was to determine the incidence and molecular epidemiology of carbapenemase-producing (CP) Escherichia coli and Klebsiella pneumoniae (CP-E/K) in Belgium. Eleven hospital-based laboratories collected carbapenem non-susceptible (CNS) isolates of E. coli and K. pneumoniae detected in clinical specimens from January 2013 to December 2014. All CNS strains were tested for carbapenemase production and typed by multilocus sequence typing (MLST) for a 6-month period as part of the European Survey on Carbapenemase-Producing Enterobacteriaceae in Europe (EuSCAPE) structured survey. In addition, an equal number of carbapenem-susceptible isolates collected were preserved as a control group for risk factor analysis. The overall incidence rate of CP-E/K isolates in hospitals increased from 0.124 in 2013 to 0.223 per 1000 admissions in 2014. From November 2013 to April 2014, 30 CP K. pneumoniae [OXA-48 (n = 16), KPC (n = 13), OXA-427 (n = 1)] and five CP E. coli [OXA-48 (n = 3), NDM (n = 1), OXA-427 (n = 1)] isolates were detected in ten hospitals. The 16 OXA-48-producing K. pneumoniae strains were distributed into eight sequence types (STs), while the 13 KPC-producing K. pneumoniae clustered into three STs dominated by ST512 (n = 7) and ST101 (n = 5). Compared to controls, we observed among CP-E/K carriers significantly higher proportion of males, respiratory origins, previous hospitalization, nosocomial setting, and a significantly lower proportion of bloodstream infections. Our study confirms the rapid spread of CP-E/K in Belgian hospitals and the urgent need for a well-structured and coordinated national surveillance plan in order to limit their dissemination.

  19. Neuropsychological Outcome after Complicated Shiga Toxin–Producing Escherichia coli Infection

    PubMed Central

    Simova, Olga; Weineck, Gabriele; Schuetze, Thorsten; Wegscheider, Karl; Panzer, Ulf; Stahl, Rolf A. K.; Gerloff, Christian; Magnus, Tim

    2014-01-01

    Background The diarrhea associated hemolytic uremic syndrome (HUS) is a major cause of acute uremic failure in children, but not very common in adults. The enterohaemorrhagic Escherichia coli -epidemic in Germany in 2011 affected mostly young and healthy adults. While their immediate deficits have been published, not much is known about the time course and degree of recovery concerning cognitive and behavioral impairment. Methods and Findings Twenty patients with Shiga toxin –producing Escherichia coli infection and neurological symptoms underwent comprehensive neuropsychological assessment 3 months and 1 year after the acute disease. Overall, there was an excellent recovery of cognitive functions. In a detailed neuropsychological analysis no significant deficits could be noticed 1 year after the infection in terms of cognitive function, alertness, executive functions and speech. Interestingly there were no correlations between different indicators for severity of disease (hemoglobin and creatinin levels, days of hospitalization, neurological symptoms and MRI changes) and neuropsychological outcome. However, there were a small number of patients with limitations in every day and professional life even one year after the acute disease. Conclusions Our study does not provide definitive answers regarding risk factors for these limitations. Still since Shiga toxin –producing Escherichia coli infection is a rare condition in adults, the information this study provides is important for the clinical practice. On one hand for consulting patients and on the other to raise the awareness of the physicians to possible long term complains and the consideration of neuropsychological assessment and supportive psychological treatment. PMID:25050708

  20. High genotypic and phenotypic similarity among Shiga toxin-producing Escherichia coli O111 environmental and outbreak strains

    USDA-ARS?s Scientific Manuscript database

    E. coli serogroup O111 is among the six most commonly reported non-O157:H7 Shiga toxin-producing Escherichia coli (STEC), which are emerging foodborne pathogens that have caused numerous outbreaks and sporadic cases of enteric illness in industrialized countries. We have assembled a collection of en...

  1. Shiga toxin-producing Escherichia coli and rectoanal junction persistence in ruminants: a study of bacterial-epithelial interactions.

    USDA-ARS?s Scientific Manuscript database

    Escherichia coli O157:H7 (O157) was the first Shiga toxin-producing E. coli serotype to be associated with bloody diarrhea or hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS) in humans. It has since been implicated in several outbreaks in the U.S. and globally. Non-O157 STEC have not bee...

  2. The polymorphic aggregative phenotype of Shiga toxin-producing Escherichia coli O111 depends on rpoS and curli

    USDA-ARS?s Scientific Manuscript database

    Escherichia coli O111 is an emerging non-O157:H7 Shiga toxin-producing E. coli (STEC). We previously reported that outbreak and environmental, but not sporadic case, strains of STEC O111 share a distinct aggregation phenotype (M. E. Diodati, A. H. Bates, M. B. Cooley, S. Walker, R. E. Mandrell, and ...

  3. Media composition and incubation temperature affect Congo red dye affinity of Shiga toxin-producing Escherichia coli

    USDA-ARS?s Scientific Manuscript database

    Background: Escherichia coli biofilm formation is dependent on curli fimbriae and cellulose, and the expression of both varies among Shiga toxin-producing E. coli (STEC). Curli and cellulose expression are often identified by their affinity for Congo red dye (CR) but media composition and incubation...

  4. Molecular insights into the unique phenotypes exhibited by super shed shiga toxin producing Escherichia coli O157

    USDA-ARS?s Scientific Manuscript database

    Shiga toxin producing Escherichia coli (STEC) serovar O157:H7 is a major foodborne pathogen that can cause bloody diarrhea and life threatening hemolytic uremic syndrome in humans. Asymptomatic cattle are colonized with E. coli O157:H7 at the mucosal interface of the recto-anal junction (RAJ). Sup...

  5. Prevalence of β-Lactamase Producing Escherichia coli from Retail Meat in Turkey.

    PubMed

    Pehlivanlar Önen, Sevda; Aslantaş, Özkan; Şebnem Yılmaz, Ebru; Kürekci, Cemil

    2015-09-01

    Extended spectrum β-lactamase (ESBL) and plasmid-mediated AmpC β-lactamase (pAmpC) producing Escherichia coli have been shown to be present in humans and animals representing a significant problem worldwide. This study aimed to search the presence of ESBL and/or AmpC-producing E. coli in retail meats (chicken and beef) in Turkey. A total of 88 β-lactamase-producing E. coli were isolated from chicken (n = 81/100) and beef meat (n = 7/100) samples and their susceptibility to several antimicrobials were tested using disc diffusion method. E. coli isolates were further characterized for their phylogenetic groups. β-Lactamase encoding (blaTEM , blaSHV , blaOXA , blaCTX-M , and blaAmpC ) and quinolone resistance genes (qnrA, qnrB, qnrS, qepA, and acc(6')-Ib-cr) were also secreened by polymerase chain reaction (PCR). However, in regard to β-lactamase genes, 84 of 88 isolates were positive for blaCTX-M-1 (n = 39), blaCTX-M-3 (n = 5), blaCTX-M-15 (n = 4), blaTEM-1b (n = 2), blaSHV-12 (n = 1), blaCTX-M-1 /blaTEM-1b (n = 10), blaCTX-M-1 /blaTEM-1b /blaSHV-5 (n = 1), blaCTX-M-1 /blaCMY-2 (n = 1) and blaTEM-1b /blaCMY-2 (n = 6), blaCTX-M-15 /blaSHV-12 (n = 1), blaCTX-M-15 /blaTEM-1b (n = 1), blaTEM-1b /blaSHV-12 (n = 1), and blaCMY-2 (n = 12) genes. Resistance to cefuroxime (75.6% and 85.7%), nalidixic acid (89% and 85.7%), tetracycline (91.4% and 100%), streptomycin (40.2% and 100%), and trimethoprim-sulfamethoxazole (36.6% and 85.7%) was observed among strains isolated from chicken and beef, respectively. However, all isolates were found to be susceptible to amikacin, imipenem, and cefepime. Resistance to ampicillin and cefoxitin was significantly linked to blaCMY-2 gene, while there was a significant correlation between CTX-M type ESBL and antimicrobial resistance to cefuroxime and streptomycin (P < 0.05). The results of this study suggest that raw chicken retail meats are highly contaminated with ESBL-producing E. coli implementing a great risk to human health in

  6. Detection of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli in Market-Ready Chickens in Zambia

    PubMed Central

    Chishimba, K.; Hang'ombe, B. M.; Muzandu, K.; Mshana, S. E.; Matee, M. I.; Nakajima, C.; Suzuki, Y.

    2016-01-01

    The frequent administering of antibiotics in the treatment of poultry diseases may contribute to emergence of antimicrobial-resistant strains. The objective of this study was to detect the presence of extended-spectrum β-lactamase- (ESBL-) producing Escherichia coli in poultry in Zambia. A total of 384 poultry samples were collected and analyzed for ESBL-producing Escherichia coli. The cultured E. coli isolates were subjected to antimicrobial susceptibility tests and the polymerase chain reaction for detection of blaCTX-M, blaSHV, and blaTEM genes. Overall 20.1%, 77/384, (95% CI; 43.2–65.5%) of total samples analyzed contained ESBL-producing Escherichia coli. The antimicrobial sensitivity test revealed that 85.7% (66/77; CI: 75.7–92) of ESBL-producing E. coli isolates conferred resistance to beta-lactam and other antimicrobial agents. These results indicate that poultry is a potential reservoir for ESBL-producing Escherichia coli. The presence of ESBL-producing Escherichia coli in poultry destined for human consumption requires strengthening of the antibiotic administering policy. This is important as antibiotic administration in food animals is gaining momentum for improved animal productivity in developing countries such as Zambia. PMID:27190518

  7. Characterization of Extended-Spectrum β-Lactamase-Producing Escherichia coli Isolates from Pigs and Farm Workers.

    PubMed

    Zhang, Hongna; Zhai, Zhenzhen; Li, Qing; Liu, Linghong; Guo, Shuyuan; Li, Qimeng; Yang, Lingling; Ye, Chaoqun; Chang, Weishan; Zhai, Jing

    2016-09-01

    Food-producing animals can serve as reservoirs for extended-spectrum β-lactamase (ESBL)-producing Escherichia coli . The present study aimed to characterize and compare ESBL-carrying E. coli isolates from both pigs and farm workers. Rectal swabs were obtained from 60 pigs on four pig-fattening farms (15 samples per farm), and rectal swabs were taken from 40 farm workers on these farms (10 samples per farm). ESBL-carrying E. coli isolates from the workers and pigs were characterized by ESBL genotype, antibiotic susceptibility, enterobacterial repetitive intergenic consensus type, and multilocus sequence type. ESBL-producing E. coli was detected in 34 (56.7%) of 60 pigs, and 20.0% (8 of 40) of the farm workers were positive for ESBL-producing E. coli . More importantly, ESBL-producing E. coli isolates with the same β-lactamase genes, antibiotic resistance profiles, enterobacterial repetitive intergenic consensus types, and multilocus sequence types were detected in both pigs and workers on the same pig farm. These findings were suggestive for transfer of ESBL-producing E. coli between animals and humans.

  8. Current trends in detecting non-O157 Shiga toxin-producing Escherichia coli in food.

    PubMed

    Wang, Fei; Yang, Qianru; Kase, Julie A; Meng, Jianghong; Clotilde, Laurie M; Lin, Andrew; Ge, Beilei

    2013-08-01

    Non-O157 Shiga toxin-producing Escherichia coli (non-O157 STEC) strains are increasingly recognized as important foodborne pathogens worldwide. Together with E. coli O157:H7, six additional STEC serogroups (O26, O45, O103, O111, O121, and O145) are now regulated as adulterants in certain raw beef products in the United States. However, effective detection and isolation of non-O157 STEC strains from food matrices remain challenging. In the past decade, great attention has been paid to developing rapid and reliable detection methods for STEC in general (targeting common virulence factors) and specific STEC serogroups in particular (targeting serogroup-specific traits). This review summarizes current trends in detecting non-O157 STEC in food, including culture, immunological, and molecular methods, as well as several novel technologies.

  9. A novel fermentation pathway in an Escherichia coli mutant producing succinic acid, acetic acid, and ethanol.

    SciTech Connect

    Donnelly, M. I.; Millard, C. S.; Clark, D. P.; Chen, M. J.; Rathke, J. W.; Southern Illinois Univ.

    1998-04-01

    Escherichia coli strain NZN111, which is unable to grow fermentatively because of insertional inactivation of the genes encoding pyruvate: formate lyase and the fermentative lactate dehydrogenase, gave rise spontaneously to a chromosomal mutation that restored its ability to ferment glucose. The mutant strain, named AFP111, fermented glucose more slowly than did its wild-type ancestor, strain W1485, and generated a very different spectrum of products. AFP111 produced succinic acid, acetic acid, and ethanol in proportions of approx 2:1:1. Calculations of carbon and electron balances accounted fully for the observed products; 1 mol of glucose was converted to 1 mol of succinic acid and 0.5 mol each of acetic acid and ethanol. The data support the emergence in E.coli of a novel succinic acid:acetic acid:ethanol fermentation pathway.

  10. AFA and F17 adhesins produced by pathogenic Escherichia coli strains in domestic animals.

    PubMed

    Le Bouguénec, C; Bertin, Y

    1999-01-01

    AFA and F17 are afimbrial and fimbrial adhesins, respectively, produced by pathogenic Escherichia coli strains in domestic animals. F17-related fimbriae are mainly detected on bovine and ovine E. coli associated with diarrhoea or septicaemia. The F17-G adhesin subunits recognize N-acetyl-D-glucosamine (GlcNAc) receptors present on bovine intestinal cells. Some F17 subtypes also bind to GlcNAc receptors present on human uroepithelial and intestinal Caco-2 cells or to the laminin contained in the basement of mammalian membranes. F17 is often associated with other virulence factors (aerobactin, serum resistance, CNF2 toxin, K99, CS31A or AFA adhesins) on pathogenic E. coli. A cluster of only four genes is required to synthesize functional F17-related fimbrial structures. The hypothesis of multifunctional F17 fimbrial subunits is supported by the fact that: i) the N-terminal part of the adhesin subunit participates in receptor recognition, whereas the C-terminal part is required for biogenesis of the fimbrial filament; and ii) the interaction between structural and adhesin subunits seems to be crucial for the initiation of monomer polymerization. Recently, determinants related to the afa gene clusters from human pathogenic E. coli associated with intestinal and extra-intestinal infections were identified in strains isolated from calves and piglets with diarrhoea and septicaemia. Two afa-related gene clusters, designated afa-7 and afa-8, that encode afimbrial adhesins were cloned and characterized from bovine pathogenic E. coli. These animal afa gene clusters were plasmid and chromosome borne and were expressed by strains that produced other virulence factors such as CNF toxins, F17, PAP and CS31A adhesins. A high frequency of afa-8 and a low prevalence of afa-7 among bovine E. coli isolates were suggested by preliminary epidemiological studies. As with the human afa gene clusters, the animal ones encode an adhesive structure composed of two proteins: AfaE which

  11. Individualized tailor-made dietetic intervention program at schools enhances eating behaviors and dietary habits in obese Hispanic children of low socioeconomic status.

    PubMed

    Elizondo-Montemayor, Leticia; Moreno-Sànchez, Diana; Gutierrez, Norma G; Monsivais-Rodriguez, Fabiola; Martinez, Ubaldo; Lamadrid-Zertuche, Ana C; Hernandez-Torre, Martin M

    2014-01-01

    Hispanic children and those from low-socioeconomic status are predisposed to unhealthy eating habits and obesity. to implement an individualized, face-to-face, parent supported, and school-partnership dietetic intervention to promote healthy eating habits and decrease body mass index. Prospective school year dietetic intervention of 101 obese, Hispanic, low-socioeconomic school-age children representative of Monterrey, Mexico, consisted of anthropometrics, dietetic assessment, energy-restriction tailor-made daily menus, and parental education every three weeks. Student's t-test was used for means comparison. A significant decrease was found in body mass index percentile (96.43 ± 3.32 to 93.42 ± 8.12/P = 0.00) and energy intake/day of -755.7 kcal/day (P = 0.00). Among other energy dense foods with significant decline in servings/day and servings/week were processed meats (3.13 ± 1.43 to 2.19 ± 1.04/P = 0.00 and 5.60 ± 1.75 to 4.37 ± 2.10/P = 0.00, resp.), saturated fat (1.47 ± 1.08 to 0.78 ± 0.79/P = 0.00 and 2.19 ± 2.18 to 1.1 ± 1.36/P = 0.00), sweetened beverages (2.79 ± 1.99 to 1.42 ± 1.21 and 6.21 ± 1.72 to 3.89 ± 2.80/P = 0.00), and desserts and refined-grain bakery (1.99 ± 1.54 to 1.32 ± 1.59 and 2.85 ± 2.54 to 1.57 ± 2.20/P = 0.00). There was a significant increase in servings/day and servings/week of water (2.98 ± 2.02 to 4.91 ± 2.37 and 6.62 ± 2.03 to 6.87 ± 0.91/P = 0.00, resp.) and nutrient dense foods such as fruits (1.31 ± 0.89 to 1.66 ± 0.96 and 3.34 ± 2.24 to 4.28 ± 2.43/P = 0.00) and fish and poultry (3.76 ± 2.15 to 4.54 ± 2.25/P = 0.00). This intervention created healthy eating habits and decreased body mass index in a high risk population. NCT01925976.

  12. PL3 Amidase, a Tailor-made Lysin Constructed by Domain Shuffling with Potent Killing Activity against Pneumococci and Related Species

    PubMed Central

    Blázquez, Blas; Fresco-Taboada, Alba; Iglesias-Bexiga, Manuel; Menéndez, Margarita; García, Pedro

    2016-01-01

    that the structure/function-based domain shuffling approach is a successful method to construct tailor-made endolysins with higher bactericidal activities than their parental enzymes. PMID:27516758

  13. Genome Sequences of 228 Shiga Toxin-Producing Escherichia coli Isolates and 12 Isolates Representing Other Diarrheagenic E. coli Pathotypes

    PubMed Central

    Strockbine, Nancy; Changayil, Shankar; Ranganathan, Satishkumar; Zhao, Kun; Weil, Ryan; MacCannell, Duncan; Sabol, Ashley; Schmidtke, Amber; Martin, Haley; Stripling, Devon; Ribot, Efrain M.; Gerner-Smidt, Peter

    2014-01-01

    Shiga toxin-producing Escherichia coli (STEC) are a common cause for food-borne diarrheal illness outbreaks and sporadic cases. Here, we report the availability of the draft genome sequences of 228 STEC strains representing 32 serotypes with known pulsed-field gel electrophoresis (PFGE) types and epidemiological relationships, as well as 12 strains representing other diarrheagenic E. coli pathotypes. PMID:25103754

  14. Preharvest evaluation of coliforms, Escherichia coli, Salmonella, and Escherichia coli O157:H7 in organic and conventional produce grown by Minnesota farmers.

    PubMed

    Mukherjee, Avik; Speh, Dorinda; Dyck, Elizabeth; Diez-Gonzalez, Francisco

    2004-05-01

    Microbiological analyses of fresh fruits and vegetables produced by organic and conventional farmers in Minnesota were conducted to determine the coliform count and the prevalence of Escherichia coli, Salmonella, and E. coli O157:H7. A total of 476 and 129 produce samples were collected from 32 organic and 8 conventional farms, respectively. The samples included tomatoes, leafy greens, lettuce, green peppers, cabbage, cucumbers, broccoli, strawberries, apples, and seven other types of produce. The numbers of fruits and vegetables was influenced by their availability at participating farms and varied from 11 strawberry samples to 108 tomato samples. Among the organic farms, eight were certified by accredited agencies and the rest reported the use of organic practices. All organic farms used aged or composted animal manure as fertilizer. The average coliform counts in both organic and conventional produce were 2.9 log most probable number per g. The percentages of E. coli-positive samples in conventional and organic produce were 1.6 and 9.7%, respectively. However, the E. coli prevalence in certified organic produce was 4.3%, a level not statistically different from that in conventional samples. Organic lettuce had the largest prevalence of E. coli (22.4%) compared with other produce types. Organic samples from farms that used manure or compost aged less than 12 months had a prevalence of E. coli 19 times greater than that of farms that used older materials. Serotype O157:H7 was not detected in any produce samples, but Salmonella was isolated from one organic lettuce and one organic green pepper. These results provide the first microbiological assessment of organic fruits and vegetables at the farm level.

  15. Transmission of ESBL/AmpC-producing Escherichia coli from broiler chicken farms to surrounding areas.

    PubMed

    Laube, H; Friese, A; von Salviati, C; Guerra, B; Rösler, U

    2014-08-27

    Although previous studies have demonstrated high carriage of ESBL/AmpC-producing Escherichia coli in livestock, especially in broiler chickens, data on emission sources of these bacteria into the environment are still rare. Therefore, this study was designed to systematically investigate the occurrence of ESBL/AmpC-producing E. coli in slurry, air (inside animal houses), ambient air (outside animal houses) and on soil surfaces in the areas surrounding of seven ESBL/AmpC-positive broiler chicken fattening farms, including investigation of the possible spread of these bacteria via the faecal route and/or exhaust air into the environment. Seven German broiler fattening farms were each investigated at three points in time (3-36 h after restocking, 14-18 and 26-35 days after housing) during one fattening period. The occurrence of ESBL/AmpC genes in the investigated samples was confirmed by PCR, detecting blaCTX-M, blaSHV, blaTEM and blaCMY-genes, and, if necessary, by sequencing and/or the disc diffusion method. The results showed a wide spread of ESBL/AmpC-producing E. coli in broiler farms, as well as emissions into the surroundings. 12 out of 14 (86%) slurry samples were positive for ESBL/AmpC-producing E. coli. Additionally, 28.8% (n=23/80) of boot swabs taken from various surfaces in the areas surrounding of the farms as well as 7.5% (n=3/40) of the exhaust air samples turned out to be positive for these microorganisms. Moreover, a small proportion of air samples from inside the barns were ESBL/AmpC-positive. By comparing selected isolates using pulsed field gel electrophoresis, we proved that faecal and airborne transfer of ESBL/AmpC-producing microorganisms from broiler fattening farms to the surrounding areas is possible. Two isolates from farm G2 (slurry and boot swab 50 m downwind), two isolates from farm G3 (slurry and individual animal swab) as well as two isolates from farm G6 (air sample in the barn and air sample 50 m downwind) showed 100% similarity in

  16. Molecular characterization and phylogeny of Shiga toxin-producing E. coli (STEC) from imported beef meat in Malaysia.

    PubMed

    Abuelhassan, Nawal Nouridaim; Mutalib, Sahilah Abdul; Gimba, Fufa Ido; Yusoff, Wan Mohtar

    2016-09-01

    This study aimed at determining the presence and characterization of Escherichia coli and Shiga toxin-producing E. coli (STEC) from imported frozen beef meats. Seventy-four (74) frozen imported beef meat samples from two countries, India (42 samples) and Australia (32 samples), were collected and tested for E. coli. These samples were purchased from the frozen meat sections of five different supermarkets in different locations in Selangor, Malaysia, from April 2012 to October 2014. A total of 222 E. coli strains were isolated from the meat samples; 126 strains were isolated from country A (India), and 96 E. coli strains were from country of origin B (Australia), respectively. A total of 70 E. coli strains were identified and characterized. All E. coli strains were isolated into Fluorocult medium and identified using API 20E kit. All selected E. coli strains were characterized for Shiga toxin genes (stx1 and stx2). All biochemically identified E. coli in this study were further subjected to molecular detection through polymerase chain reaction (PCR) amplification and characterization using 16S ribosomal RNA (rRNA) gene of Shiga toxin-producing E. coli. Of the 70 E. coli strains, 11 strains were positive for both Shiga toxin genes (stx1 and stx2) and 11 (11/70) strains were positive for stx1 gene, while 25 (25/70) strains were positive for stx2 gene. The analysis of 16S rRNA gene of all the E. coli isolates in this study was successfully sequenced and analyzed, and based on sequence data obtained, a phylogenetic tree of the 16S rRNA gene was performed using Clustal W programme in MEGA 6.06 software. Phylogenetic tree showed that the E. coli isolates in our study cluster with the strain of E. coli isolated in other countries, which further confirm that the isolates of E. coli in this study are similar to those obtained in other studies. As a result, all the strains obtained in this study proved to be a strain of pathogenic E. coli, which may cause a serious outbreak

  17. Antibacterial activities of essential oils from Iranian medicinal plants on extended-spectrum β-lactamase-producing Escherichia coli.

    PubMed

    Sharifi-Rad, J; Mnayer, D; Roointan, A; Shahri, F; Ayatollahi, S A M; Sharifi-Rad, M; Molaee, N; Sharifi-Rad, M

    2016-09-19

    The extended-spectrum beta-lactamase (ESBL) -producing Escherichia coli strains can lead to various infections particularly urinary tract infections. The main objective of this investigation was to evaluate the antibacterial activities of essential oils (EOs) from different Iranian medicinal plants against TEM gene positive ESBL-producing E. coli strains isolated from urine samples of patients with urinary tract infections. EOs were extracted using hydrodistillation method. E. coli strains were isolated by different specific Medias. ESBL-producing E. coli strains were isolated from urine samples of patients with urinary tract infections in Shiraz hospital, Iran. Then, ESBL- producing strains were identified using double disk synergy test, phenotypic disc confirmatory test and polymerase chain reaction (PCR) for TEM gene detection. The antibacterial activity of the EOs from different plants (Achillea wilhelmsii C. Koch, Echinophora platyloba DC., Lallemantia royleana, Nepeta persica Boiss., Pulicaria vulgaris Gaertn., Salvia nemorosa, and Satureja intermedia C.A.Mey) and antibiotics against ESBL-producing strains was studied using the microdilution method for the evaluation of the minimum inhibitory concentration (MIC). The 103 out of 295 E. coli strains with 97 (90.65%) TEM gene distributions were identified as ESBL-producing strains. All of the EOs derived from different plants displayed high inhibitory effects against ESBL-producing E. coli strains. The results of our investigations may propose a good treatment option against resistant infectious bacteria.

  18. Whole-Genome Characterization and Strain Comparison of VT2f-Producing Escherichia coli Causing Hemolytic Uremic Syndrome

    PubMed Central

    Michelacci, Valeria; Bondì, Roslen; Gigliucci, Federica; Franz, Eelco; Badouei, Mahdi Askari; Schlager, Sabine; Minelli, Fabio; Tozzoli, Rosangela; Caprioli, Alfredo; Morabito, Stefano

    2016-01-01

    Verotoxigenic Escherichia coli infections in humans cause disease ranging from uncomplicated intestinal illnesses to bloody diarrhea and systemic sequelae, such as hemolytic uremic syndrome (HUS). Previous research indicated that pigeons may be a reservoir for a population of verotoxigenic E. coli producing the VT2f variant. We used whole-genome sequencing to characterize a set of VT2f-producing E. coli strains from human patients with diarrhea or HUS and from healthy pigeons. We describe a phage conveying the vtx2f genes and provide evidence that the strains causing milder diarrheal disease may be transmitted to humans from pigeons. The strains causing HUS could derive from VT2f phage acquisition by E. coli strains with a virulence genes asset resembling that of typical HUS-associated verotoxigenic E. coli. PMID:27584691

  19. An in vitro combined antibiotic/antibody treatment eliminates toxicity from Shiga toxin-producing E. coli

    USDA-ARS?s Scientific Manuscript database

    Background: Treating Shiga toxin-producing Escherichia coli (STEC) gastrointestinal infections is a difficult endeavor. The utility of antibiotics as an STEC treatment is controversial since antibiotic resistance among STEC isolates is widespread and certain antibiotics dramatically increase express...

  20. Prevalence and characteristics of shiga toxin-producing Escherichia coli from healthy cattle in Japan.

    PubMed

    Kobayashi, H; Shimada, J; Nakazawa, M; Morozumi, T; Pohjanvirta, T; Pelkonen, S; Yamamoto, K

    2001-01-01

    The prevalence of Shiga toxin-producing Escherichia coli (STEC) in Japan was examined by using stool samples from 87 calves, 88 heifers, and 183 cows on 78 farms. As determined by screening with stx-PCR, the prevalence was 46% in calves, 66% in heifers, and 69% in cows; as determined by nested stx-PCR, the prevalence was 100% in all animal groups. Of the 962 isolates picked by colony stx hybridization, 92 isolates from 54 farms were characterized to determine their O serogroups, virulence factor genes, and antimicrobial resistance. Of these 92 isolates, 74 (80%) could be classified into O serogroups; 50% of these 74 isolates belonged to O serogroups O8, O26, O84, O113, and O116 and 1 isolate belonged to O serogroup O157. Locus of enterocyte effacement genes were detected in 24% of the isolates, and enterohemorrhagic E. coli (EHEC) hlyA genes were detected in 72% of the isolates. Neither the bundle-forming pilus gene nor the enteropathogenic E. coli adherence factor plasmid was found. STEC strains with characteristics typical of isolates from human EHEC infections, which were regarded as potential EHEC strains, were present on 11.5% of the farms.

  1. Shiga toxin-producing E. coli isolated from sheep in Namibia.

    PubMed

    Madzingira, Oscar

    2016-04-28

    Shiga toxin-producing Escherichia coli (STEC) are an important group of emerging zoonotic pathogens carried in the intestinal tracts of ruminants. They can cause mild diarrhea and fatal disease characterized by hemolytic uremic syndrome, especially in children, the elderly, and immune-compromised individuals. The aim of this study was to determine if sheep harbor STEC. Sheep feces (n = 40), brisket wool (n = 40), and 150 meat samples were collected from the flank (n = 35), rump (n = 35), brisket (n = 20), shank (n = 25), diaphragm (n = 10), and neck (n = 25) of slaughter-age sheep at a high-throughput abattoir and tested for STEC using a combination of culture and real-time polymerase chain reaction techniques. E. coli O103 (5/40) and O145 (5/40) strains were isolated from the feces and E. coli O157:H7 was isolated from brisket wool (10/40) and flank meat (5/35). The results of this study provide the first report of STEC infections in sheep in Namibia. The results of this study show that sheep, like cattle, can shed STEC strains in their feces, which can contaminate meat and expose humans to infections.

  2. Inactivation of Escherichia coli ATCC 11775 in fresh produce using atmospheric pressure cold plasma

    NASA Astrophysics Data System (ADS)

    Bermudez-Aguirre, Daniela; Wemlinger, Erik; Barbosa-Canovas, Gustavo; Pedrow, Patrick; Garcia-Perez, Manuel

    2011-10-01

    Food-borne outbreaks are associated with the presence of pathogenic bacteria in food products such as fresh produce. One of the target microorganisms is Escherichia coli which exhibits resistance to being inactivated with conventional disinfection methods for vegetables. Atmospheric pressure cold plasma (APCP) was tested to disinfect three vegetables with challenge surfaces, lettuce, carrots and tomatoes. The produce was inoculated with the bacteria to reach an initial microbial concentration of 107 cfu/g. Vegetables were initially exposed to the APCP discharges from a needle array at 5.7 kV RMS in argon, processing times of 0.5, 3 and 5 min. Initial results indicate that microbial decontamination is effective on the lettuce (1.2 log reduction) when compared with other vegetables. To claim disinfection, a 3 log reduction or more is needed, which makes APCP treatment very promising technology for decontamination of produce. We propose that with method refinements full disinfection can be achieved using APCP.

  3. Inactivation of Escherichia coli ATCC 11775 in fresh produce using atmospheric pressure cold plasma

    NASA Astrophysics Data System (ADS)

    Bermudez-Aguirre, Daniela; Wemlinger, Erik; Barbosa-Canovas, Gustavo; Pedrow, Patrick; Garcia-Perez, Manuel

    2011-10-01

    Food-borne outbreaks are associated with the presence of pathogenic bacteria in food products such as fresh produce. One of the target microorganisms is Escherichia coli which exhibits resistance to being inactivated with conventional disinfection methods for vegetables. Atmospheric pressure cold plasma (APCP) was tested to disinfect three vegetables with challenge surfaces, lettuce, carrots and tomatoes. The produce was inoculated with the bacteria to reach an initial microbial concentration of 107 cfu/g. Vegetables were initially exposed to the APCP discharges from a needle array at 5.7 kV RMS in argon, processing times of 0.5, 3 and 5 min. Initial results indicate that microbial decontamination is effective on the lettuce (1.2 log reduction) when compared with other vegetables. To claim disinfection, a 3 log reduction or more is needed, which makes APCP treatment very promising technology for decontamination of produce. We propose that with method refinements full disinfection can be achieved using APCP.

  4. Household transmission of NDM-producing E. coli in New Zealand.

    PubMed

    Blakiston, Matthew; Roberts, Sally A; Freeman, Joshua T; Heffernan, Helen

    2017-03-24

    This report describes the introduction of an extensively antibiotic-resistant carbapenemase-producing Escherichia coli into a hospital in Auckland, New Zealand, by a patient who was a household contact of recent travellers to the Indian subcontinent. The carbapenemase was identified as New Delhi metallo-β-lactamase (NDM) and reflects probable household transmission in the context of a recent upsurge in NDM-producing Enterobacteriaceae isolation in New Zealand. The observations in this report suggest that hospital screening practices to identify carbapenemase-producing Enterobacteriaceae (CPE) colonised patients may need to be extended to include travellers to high-risk countries who were not hospitalised during their trip, and possibly also their close contacts.

  5. Mild Illness during Outbreak of Shiga Toxin−Producing Escherichia coli O157 Infections Associated with Agricultural Show, Australia

    PubMed Central

    Stafford, Russell J.; Jennison, Amy V.; Bennett, Sonya M.; Bell, Robert J.; Doyle, Christine J.; Young, Jeannette R.; Vlack, Susan A.; Titmus, Paul; El Saadi, Debra; Jarvinen, Kari A.J.; Coward, Patricia; Barrett, Janine; Staples, Megan; Graham, Rikki M.A.; Smith, Helen V.; Lambert, Stephen B.

    2017-01-01

    During a large outbreak of Shiga toxin−producing Escherichia coli illness associated with an agricultural show in Australia, we used whole-genome sequencing to detect an IS1203v insertion in the Shiga toxin 2c subunit A gene of Shiga toxin−producing E. coli. Our study showed that clinical illness was mild, and hemolytic uremic syndrome was not detected. PMID:28930030

  6. The Microcosm Mediates the Persistence of Shiga Toxin-Producing Escherichia coli in Freshwater Ecosystems

    PubMed Central

    Mauro, Steven A.; Opalko, Hannah; Lindsay, Kyle; Colon, Michael P.

    2013-01-01

    Water is a major route for infection of humans by exotoxin-producing bacteria, including Shiga toxin-producing Escherichia coli (STEC). While STEC has the potential to be present in nearly every type of water source, its distribution is sporadic, and an understanding of factors that govern its emergence and persistence within water is lacking. In this study, we examined the influence of microbe content on STEC persistence in freshwater. We found that depletion of microbes in the water leads to a considerable increase in the persistence of STEC, an effect that can be mitigated by adding grazing protists to the water. STEC strains appear to be more resistant to the impact of grazing protists than E. coli strains that lack the Shiga toxin (stx) gene. Our results demonstrate that the microcosm can dramatically influence the persistence of STEC in aquatic ecosystems and that the overall impact by microbes on STEC strains is fundamentally different from that of non-STEC strains of bacteria. Overall, these results provide insight into why STEC and possibly other exotoxin-producing bacterial pathogens display such variability in abundance, distribution, and persistence in aquatic ecosystems. PMID:23747699

  7. Caffeic acid production enhancement by engineering a phenylalanine over-producing Escherichia coli strain.

    PubMed

    Huang, Qin; Lin, Yuheng; Yan, Yajun

    2013-12-01

    Caffeic acid is a plant-specific phenylpropanoic acid with multiple health-improving effects reported, and its therapeutic derivatives have also been studied throughout the last decade. To meet its market need and achieve high-level production, microbial production of caffeic acid approaches have been developed in metabolically engineered Escherichia coli. In our previous work, we have established the first artificial pathway that realized de novo production of caffeic acid using E. coli endogenous 4-hydroxyphenylacetate 3-hydroxylase (4HP3H). In this work, we exploited the catalytic potential of 4HPA3H in the whole-cell bioconversion study and produced 3.82 g/L (461.12 mg/L/OD) caffeic acid from p-coumaric acid, a direct precursor. We further engineered a phenylalanine over-producer into a tyrosine over-producer and then introduced the artificial pathway. After adjusting the expression strategy and optimizing the inoculants timing, de novo production of caffeic acid reached 766.68 mg/L. Both results from the direct precursor and simple carbon sources represent the highest titers of caffeic acid from microbial production so far.

  8. Prevalence of Salmonella enterica and Shiga toxin-producing Escherichia coli in zoo animals from Chile

    PubMed Central

    Marchant, Paulina; Hidalgo-Hermoso, Ezequiel; Espinoza, Karen

    2016-01-01

    Salmonella (S.) enterica and Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens. Here, we report the prevalence of S. enterica and STEC in feces of 316 zoo animals belonging to 61 species from Chile. S. enterica and STEC strains were detected in 7.5% and 4.4% of animals, respectively. All Salmonella isolates corresponded to the serotype Enteritidis. To the best of our knowledge, this is the first report of S. Enteritidis in the culpeo fox (Lycalopex culpaeus), black-capped capuchin (Sapajus apella) and Peruvian pelican (Pelecanus thagus) and the first STEC report in Thomson's gazelle (Eudorcas thomsonii). PMID:27030195

  9. Prevalence of Salmonella enterica and Shiga toxin-producing Escherichia coli in zoo animals from Chile.

    PubMed

    Marchant, Paulina; Hidalgo-Hermoso, Ezequiel; Espinoza, Karen; Retamal, Patricio

    2016-12-30

    Salmonella (S.) enterica and Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens. Here, we report the prevalence of S. enterica and STEC in feces of 316 zoo animals belonging to 61 species from Chile. S. enterica and STEC strains were detected in 7.5% and 4.4% of animals, respectively. All Salmonella isolates corresponded to the serotype Enteritidis. To the best of our knowledge, this is the first report of S. Enteritidis in the culpeo fox (Lycalopex culpaeus), black-capped capuchin (Sapajus apella) and Peruvian pelican (Pelecanus thagus) and the first STEC report in Thomson's gazelle (Eudorcas thomsonii).

  10. Distribution, Numbers, and Diversity of ESBL-Producing E. coli in the Poultry Farm Environment.

    PubMed

    Blaak, Hetty; van Hoek, Angela H A M; Hamidjaja, Raditijo A; van der Plaats, Rozemarijn Q J; Kerkhof-de Heer, Lianne; de Roda Husman, Ana Maria; Schets, Franciska M

    2015-01-01

    This study aimed to discern the contribution of poultry farms to the contamination of the environment with ESBL-producing Escherichia coli and therewith, potentially to the spread of these bacteria to humans and other animals. ESBL-producing E. coli were detected at all investigated laying hen farms (n = 5) and broiler farms (n = 3) in 65% (46/71) and 81% (57/70) of poultry faeces samples, respectively. They were detected in rinse water and run-off water (21/26; 81%), other farm animals (11/14; 79%), dust (21/35; 60%), surface water adjacent to farms (20/35; 57%), soil (48/87; 55%), on flies (11/73; 15%), and in barn air (2/33; 6%). The highest prevalence and concentrations in the outdoor environment were observed in soil of free-range areas at laying hen farms (100% of samples positive, geometric mean concentration 2.4×10(4) cfu/kg), and surface waters adjacent to broiler farms during, or shortly after, cleaning between production rounds (91% of samples positive, geometric mean concentration 1.9×10(2) cfu/l). The diversity of ESBL-producing E. coli variants with respect to sequence type, phylogenetic group, ESBL-genotype and antibiotic resistance profile was high, especially on broiler farms where on average 16 different variants were detected, and the average Simpson's Indices of diversity (SID; 1-D) were 0.93 and 0.94 among flock and environmental isolates respectively. At laying hen farms on average nine variants were detected, with SIDs of 0.63 (flock isolates) and 0.77 (environmental isolates). Sixty percent of environmental isolates were identical to flock isolates at the same farm. The highest proportions of 'flock variants' were observed in dust (94%), run-off gullies (82%), and barn air (67%), followed by surface water (57%), soil (56%), flies (50%) and other farm animals (35%).The introduction of ESBL-producing E. coli from poultry farms to the environment may pose a health risk if these bacteria reach places where people may become exposed.

  11. Distribution, Numbers, and Diversity of ESBL-Producing E. coli in the Poultry Farm Environment

    PubMed Central

    Blaak, Hetty; van Hoek, Angela H. A. M.; Hamidjaja, Raditijo A.; van der Plaats, Rozemarijn Q. J.; Kerkhof-de Heer, Lianne; de Roda Husman, Ana Maria; Schets, Franciska M.

    2015-01-01

    This study aimed to discern the contribution of poultry farms to the contamination of the environment with ESBL-producing Escherichia coli and therewith, potentially to the spread of these bacteria to humans and other animals. ESBL-producing E. coli were detected at all investigated laying hen farms (n = 5) and broiler farms (n = 3) in 65% (46/71) and 81% (57/70) of poultry faeces samples, respectively. They were detected in rinse water and run-off water (21/26; 81%), other farm animals (11/14; 79%), dust (21/35; 60%), surface water adjacent to farms (20/35; 57%), soil (48/87; 55%), on flies (11/73; 15%), and in barn air (2/33; 6%). The highest prevalence and concentrations in the outdoor environment were observed in soil of free-range areas at laying hen farms (100% of samples positive, geometric mean concentration 2.4×104 cfu/kg), and surface waters adjacent to broiler farms during, or shortly after, cleaning between production rounds (91% of samples positive, geometric mean concentration 1.9×102 cfu/l). The diversity of ESBL-producing E. coli variants with respect to sequence type, phylogenetic group, ESBL-genotype and antibiotic resistance profile was high, especially on broiler farms where on average 16 different variants were detected, and the average Simpson’s Indices of diversity (SID; 1–D) were 0.93 and 0.94 among flock and environmental isolates respectively. At laying hen farms on average nine variants were detected, with SIDs of 0.63 (flock isolates) and 0.77 (environmental isolates). Sixty percent of environmental isolates were identical to flock isolates at the same farm. The highest proportions of ‘flock variants’ were observed in dust (94%), run-off gullies (82%), and barn air (67%), followed by surface water (57%), soil (56%), flies (50%) and other farm animals (35%).The introduction of ESBL-producing E. coli from poultry farms to the environment may pose a health risk if these bacteria reach places where people may become exposed. PMID

  12. Comparison of preservation methods for enterotoxigenic Escherichia coli producing heat-labile enterotoxin.

    PubMed Central

    Yoh, M; Narita, I; Honda, T; Miwatani, T; Nishibuchi, M

    1991-01-01

    Ten strains of enterotoxigenic Escherichia coli producing heat-labile enterotoxin (LT) were preserved under 12 different conditions. After 1 month, 9 months, and 3 years of preservation, the cultures were recovered and examined for LT production. Preservation of the cultures on Dorset Egg Medium at 4 degrees C and preservation by freezing the cell suspensions in tryptic soy broth with 20% glycerol were found to be suitable preservation methods; all strains were alive for 3 years and had a minimum loss of LT production. PMID:1939590

  13. A survey of β-lactamase-producing Escherichia coli in farm animals and raw retail meat in Shizuoka Prefecture, Japan.

    PubMed

    Hiroi, Midori; Harada, Tetsuya; Kawamori, Fumihiko; Takahashi, Naomi; Kanda, Takashi; Sugiyama, Kanji; Masuda, Takashi; Yoshikawa, Yuko; Ohashi, Norio

    2011-01-01

    We surveyed β-lactamase-producing Escherichia coli from farm animals (chickens, pigs, and cattle) and raw retail meat in Shizuoka Prefecture, Japan. In total 305 E. coli isolates, 15 isolates collected from broilers, beef cattle, chicken meat, and pork meat, were found to have β-lactamase genes encoding CTX-M-2, CTX-M-14, CMY-2, SHV-2, and/or TEM-1, whereas 7 possessed mutations in the ampC promoter region. The findings suggest that broilers are more important than other farm animals with regards to the surveillance of β-lactamase-producing E. coli in this region.

  14. Carriage of Escherichia coli Producing CTX-M-Type Extended-Spectrum β-Lactamase in Healthy Vietnamese Individuals

    PubMed Central

    Ueda, Shuhei; Bui, Thi Kim Ngan; Hamamoto, Kouta; Toyosato, Takehiko; Le, Danh Tuyen; Yamamoto, Yoshimasa

    2015-01-01

    Healthy carriage of CTX-M-type extended-spectrum β-lactamase (ESBL)-producing Escherichia coli was examined by thrice collecting fecal samples from the same 199 healthy Vietnamese subjects every 6 months. Using pulsed-field gel electrophoresis (PFGE), identical PFGE patterns throughout the three samplings were not observed, although prevalence of E. coli in the subjects was around 50% in the three samplings. Our results suggested a short carriage period of the CTX-M-type ESBL-producing E. coli in healthy Vietnamese subjects. PMID:26195526

  15. Epidemiological factors associated with ESBL- and non ESBL-producing E. coli causing urinary tract infection in general practice.

    PubMed

    Hertz, Frederik Boëtius; Schønning, Kristian; Rasmussen, Steen Christian; Littauer, Pia; Knudsen, Jenny Dahl; Løbner-Olesen, Anders; Frimodt-Møller, Niels

    2016-01-01

    The purpose of the study was to evaluate how use of antibiotics precedes the presence of ESBL-producing E.coli in general practice. The authors performed a triple-case-control study where three case groups were individually compared to a single control group of uninfected individuals. Urine samples were prospectively collected and retrospective statistical analyses were done. This study included 98 cases with urinary tract infection (UTI) caused by ESBL-producing E. coli, 174 with antibiotic-resistant (non-ESBL) E. coli, 177 with susceptible E. coli and 200 with culture negative urine samples. Case groups had significantly higher use of antibiotics than the control group within 30 days before infection (p < 0.0001). The ESBL group had significantly more hospital admissions than the other case groups (p < 0.05). Hospital admission was an independent risk factor for community onset UTI by ESBL-producing E. coli. Exposure to antibiotics was a risk factor for UTI with E. coli, while prior antibiotic usage was not an indisputable predictor for infection with ESBL-producing E.coli in general practice.

  16. Fusion tags for protein solubility, purification and immunogenicity in Escherichia coli: the novel Fh8 system

    PubMed Central

    Costa, Sofia; Almeida, André; Castro, António; Domingues, Lucília

    2014-01-01

    Proteins are now widely produced in diverse microbial cell factories. The Escherichia coli is still the dominant host for recombinant protein production but, as a bacterial cell, it also has its issues: the aggregation of foreign proteins into insoluble inclusion bodies is perhaps the main limiting factor of the E. coli expression system. Conversely, E. coli benefits of cost, ease of use and scale make it essential to design new approaches directed for improved recombinant protein production in this host cell. With the aid of genetic and protein engineering novel tailored-made strategies can be designed to suit user or process requirements. Gene fusion technology has been widely used for the improvement of soluble protein production and/or purification in E. coli, and for increasing peptide’s immunogenicity as well. New fusion partners are constantly emerging and complementing the traditional solutions, as for instance, the Fh8 fusion tag that has been recently studied and ranked among the best solubility enhancer partners. In this review, we provide an overview of current strategies to improve recombinant protein production in E. coli, including the key factors for successful protein production, highlighting soluble protein production, and a comprehensive summary of the latest available and traditionally used gene fusion technologies. A special emphasis is given to the recently discovered Fh8 fusion system that can be used for soluble protein production, purification, and immunogenicity in E. coli. The number of existing fusion tags will probably increase in the next few years, and efforts should be taken to better understand how fusion tags act in E. coli. This knowledge will undoubtedly drive the development of new tailored-made tools for protein production in this bacterial system. PMID:24600443

  17. Individualized Tailor-Made Dietetic Intervention Program at Schools Enhances Eating Behaviors and Dietary Habits in Obese Hispanic Children of Low Socioeconomic Status

    PubMed Central

    Moreno-Sànchez, Diana; Gutierrez, Norma G.; Lamadrid-Zertuche, Ana C.; Hernandez-Torre, Martin M.

    2014-01-01

    Hispanic children and those from low-socioeconomic status are predisposed to unhealthy eating habits and obesity. Aim. to implement an individualized, face-to-face, parent supported, and school-partnership dietetic intervention to promote healthy eating habits and decrease body mass index. Prospective school year dietetic intervention of 101 obese, Hispanic, low-socioeconomic school-age children representative of Monterrey, Mexico, consisted of anthropometrics, dietetic assessment, energy-restriction tailor-made daily menus, and parental education every three weeks. Student's t-test was used for means comparison. A significant decrease was found in body mass index percentile (96.43 ± 3.32 to 93.42 ± 8.12/P = 0.00) and energy intake/day of −755.7 kcal/day (P = 0.00). Among other energy dense foods with significant decline in servings/day and servings/week were processed meats (3.13 ± 1.43 to 2.19 ± 1.04/P = 0.00 and 5.60 ± 1.75 to 4.37 ± 2.10/P = 0.00, resp.), saturated fat (1.47 ± 1.08 to 0.78 ± 0.79/P = 0.00 and 2.19 ± 2.18 to 1.1 ± 1.36/P = 0.00), sweetened beverages (2.79 ± 1.99 to 1.42 ± 1.21 and 6.21 ± 1.72 to 3.89 ± 2.80/P = 0.00), and desserts and refined-grain bakery (1.99 ± 1.54 to 1.32 ± 1.59 and 2.85 ± 2.54 to 1.57 ± 2.20/P = 0.00). There was a significant increase in servings/day and servings/week of water (2.98 ± 2.02 to 4.91 ± 2.37 and 6.62 ± 2.03 to 6.87 ± 0.91/P = 0.00, resp.) and nutrient dense foods such as fruits (1.31 ± 0.89 to 1.66 ± 0.96 and 3.34 ± 2.24 to 4.28 ± 2.43/P = 0.00) and fish and poultry (3.76 ± 2.15 to 4.54 ± 2.25/P = 0.00). This intervention created healthy eating habits and decreased body mass index in a high risk population. Trial registration number: NCT01925976. PMID:24592170

  18. Intestinal carriage of Extended Spectrum Beta-Lactamase producing E. coli in women with urinary tract infections, Cameroon.

    PubMed

    Djuikoue, Ingrid Cécile; Woerther, Paul-Louis; Toukam, Michel; Burdet, Charles; Ruppé, Etienne; Gonsu, Kamga Hortense; Fokunang, Charles; El Mniai, Assiya; Larissa, Kamgue; Pieme, Anatole Constant; Mboupaing, Mallila Georgia; Kakam, Caroline Mietchop; Fogang, Hervé Kengne; Andremont, Antoine; Ngogang, Jeanne

    2016-10-31

    During the last decade, the prevalence of the intestinal carriage of extended spectrum beta-lactamases - producing Escherichia coli (ESBL-E. coli) has continued to increase worldwide in the community, especially in developing countries. Hence, we undertook a study to determine the ESBL-E. coli fecal carriage rate and the associated risk factors in Cameroonian women. A total of 86 women suspected of community-acquired urinary tract infections (UTI) were included in 10 health structures from May 2011 to April 2012. After filling a questionnaire, they provided a stool sample that was plated on selective media for ESBL producing bacteria. The identification of strains was obtained with mass spectrometry and the antibiotic susceptibility by disk diffusion in agar media. The ESBL type was determined by PCR. The relative abundance of ESBL-E. coli was measured for positive samples. Eventually, the presence of antibiotics in stool was assessed. The carriage rate of ESBL-E. coli was 57/86 (66.3%). Phenotypic and molecular characterization showed that all ESBL-E. coli strains contained group 1 CTX-M enzymes. Multivariate analysis showed that ESBL-E. coli fecal carriage was associated with the presence of antibiotics in stools (p < 0.05). Although not significant, mean ESBL relative abundance tended to be higher in patients with antibiotic exposure. Our results show that the carriage of ESBL-E. coli fecal carriage in women with UTI suspicion from the Cameroonian community is extremely high and associated with recent antibiotic intake.

  19. Behavior of shiga toxin-producing Escherichia coli, enteroinvasive E. coli, enteropathogenic E. coli and enterotoxigenic E. coli strains on whole and sliced jalapeño and serrano peppers.

    PubMed

    Gómez-Aldapa, Carlos A; Rangel-Vargas, Esmeralda; Gordillo-Martínez, Alberto J; Castro-Rosas, Javier

    2014-06-01

    The behavior of enterotoxigenic Escherichia coli (ETEC), enteropathogenic E. coli (EPEC), enteroinvasive E. coli (EIEC) and non-O157 shiga toxin-producing E. coli (non-O157-STEC) on whole and slices of jalapeño and serrano peppers as well as in blended sauce at 25 ± 2 °C and 3 ± 2 °C was investigated. Chili peppers were collected from markets of Pachuca city, Hidalgo, Mexico. On whole serrano and jalapeño stored at 25 ± 2 °C or 3 ± 2 °C, no growth was observed for EPEC, ETEC, EIEC and non-O157-STEC rifampicin resistant strains. After twelve days at 25 ± 2 °C, on serrano peppers all diarrheagenic E. coli pathotypes (DEP) strains had decreased by a total of approximately 3.7 log, whereas on jalapeño peppers the strains had decreased by approximately 2.8 log, and at 3 ± 2 °C they decreased to approximately 2.5 and 2.2 log respectively, on serrano and jalapeño. All E. coli pathotypes grew onto sliced chili peppers and in blended sauce: after 24 h at 25 ± 2 °C, all pathotypes had grown to approximately 3 and 4 log CFU on pepper slices and sauce, respectively. At 3 ± 2 °C the bacterial growth was inhibited. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Efficient preservation in a silicon oxide matrix of Escherichia coli, producer of recombinant proteins.

    PubMed

    Desimone, Martín F; De Marzi, Mauricio C; Copello, Guillermo J; Fernández, Marisa M; Malchiodi, Emilio L; Diaz, Luis E

    2005-10-01

    The aim of this work was to study the use of silicon oxide matrices for the immobilization and preservation of recombinant-protein-producing bacteria. We immobilized Escherichia coli BL21 transformants containing different expression plasmids. One contained DNA coding for a T-cell receptor beta chain, which was expressed as inclusion bodies in the cytoplasm. The other two encoded bacterial superantigens Staphylococcal Enterotoxin G and Streptococcal Superantigen, which were expressed as soluble proteins in the periplasm. The properties of immobilization and storage stability in inorganic matrices prepared from two precursors, silicon dioxide and tetraethoxysilane, were studied. Immobilized E. coli was stored in sealed tubes at 4 and 20 degrees C and the number of viable cells and level of recombinant protein production were analyzed weekly. Different tests showed that the biochemical characteristics of immobilized E. coli remained intact. At both temperatures selected, we found that the number of bacteria in silicon dioxide-derived matrix was of the same order of magnitude (10(9) cfu ml(-1)) as before immobilization, for 2 months. After 2 weeks, cells immobilized in an alkoxide-derived matrix decreased to 10(4) cfu ml(-1) at 4 degrees C, and no viable cells were detected at 20 degrees C. We found that immobilized bacteria could be used as a starter to produce recombinant proteins with yields comparable to those obtained from glycerol stocks: 15 mg l(-1) for superantigens and 2 mg l(-1) for T-cell receptor beta chain. These results contribute to the development of methods for microbial cell preservation under field conditions.

  1. Characterization of extended-spectrum-beta-lactamase-producing Escherichia coli strains involved in maternal-fetal colonization: prevalence of E. coli ST131.

    PubMed

    Birgy, André; Mariani-Kurkdjian, Patricia; Bidet, Philippe; Doit, Catherine; Genel, Nathalie; Courroux, Céline; Arlet, Guillaume; Bingen, Edouard

    2013-06-01

    Maternal-fetal Escherichia coli infections, such as neonatal bacteremia and meningitis, are important causes of morbidity and mortality. From 2006 to 2010, we studied newborns and their mothers who were colonized with E. coli in a French hospital in order to document (i) the epidemiology and genetic characteristics of extended-spectrum-beta-lactamase (ESBL)-producing E. coli strains, (ii) the prevalence of associated virulence genes, (iii) the prevalence of clone sequence type 131 (ST131), and (iv) the genetic relationship among ESBL-producing strains. Among the 2,755 E. coli cultures recovered from vaginal or neonatal samples, 68 were ESBL producers (2.46%). We found a wide diversity of ESBL genes, with the majority being bla(CTX-M-14), bla(CTX-M-1), and bla(CTX-M-15), distributed among the 4 main phylogenetic groups. Genes encoding virulence factors were found in 90.7% of the isolates, with ≥ 2 virulence genes present in 76% of cases. The prevalence of ST131 among ESBL-producing E. coli isolates was 9.4% (6/64). Five of these 6 ST131 isolates possessed bla(CTX-M-15) enzymes (and also were resistant to quinolones), and one possessed bla(CTX-M-2) enzymes. Two possessed virulence genes, suggesting the presence of pathogenicity island IIJ96 (PAI IIJ96)-like domains. Pulsed-field gel electrophoresis (PFGE) revealed a high level of genomic diversity overall, except for 3 closely related isolates belonging to clonal group ST131. Repetitive PCR showed that the six ST131 isolates were closely related to ST131 control strains (>95% similarity). This study shows a high prevalence of ESBL-producing E. coli strains and clonal group ST131 in the French maternal-fetal population. These results suggest a widespread distribution of ESBL enzymes in the community and highlight the early transmission between mothers and neonates. These findings are worrisome, especially for this particularly vulnerable population.

  2. Selective recovery by different culture methods of Shiga toxin-producing Escherichia coli genotypes from a major produce production region in California(Abstract)

    USDA-ARS?s Scientific Manuscript database

    The higher consumption of fresh fruits and vegetables in the United States has corresponded to an increase in the number of outbreaks. More than 45% of the leafy greens-associated outbreaks of Shiga toxin-producing Escherichia coli (STEC) O157:H7 have been linked to produce from California’s central...

  3. A new immunoassay for detecting all subtypes of Shiga toxins produced by Shiga toxin-producing E. coli in ground beef

    USDA-ARS?s Scientific Manuscript database

    Background Shiga toxin (Stx) is a common virulence factor of all Shiga toxin producing E. coli (STEC) that cause a wide spectrum of disease, including hemorrhagic colitis and hemolytic uremic syndrome (HUS). Although several commercial kits are available for detection of Stx produced by STEC, none o...

  4. Investigation of environmental factors on the prevalence of free bacteriophages against Shiga toxin-producing Escherichia coli strains in produce pre-harvest environment in Salinas, California

    USDA-ARS?s Scientific Manuscript database

    Investigation of environmental factors on the prevalence of free bacteriophages against Shiga toxin-producing Escherichia coli strains in produce pre-harvest environment in Salinas, California Yen-Te Liaoa, Irwin Quintelab, Kimberly Nguyena, Alexandra Salvadora, Michael Cooleya, and Vivian C.H. Wu*a...

  5. 76 FR 72331 - Shiga Toxin-Producing Escherichia coli in Certain Raw Beef Products

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-23

    ...) Escherichia coli (E. coli). The document also requested comments regarding the Agency's implementation plans... manufacturing trim and other raw ground beef components, to ensure control of both E. coli O157:H7 and six other serogroups of STEC E. coli (O26, O45, O103, O111, O121, and O145). FSIS has determined that they, as well as...

  6. Competitive Exclusion Reduces Transmission and Excretion of Extended-Spectrum-β-Lactamase-Producing Escherichia coli in Broilers.

    PubMed

    Ceccarelli, Daniela; van Essen-Zandbergen, Alieda; Smid, Bregtje; Veldman, Kees T; Boender, Gert Jan; Fischer, Egil A J; Mevius, Dik J; van der Goot, Jeanet A

    2017-06-01

    Extended-spectrum β-lactamases (ESBLs) and plasmid-mediated AmpC β-lactamases (pAmpC) are enzymes able to hydrolyze a large variety of β-lactam antibiotics, including third-generation cephalosporins and monobactams. Broilers and broiler meat products can be highly contaminated with ESBL- and pAmpC-producing Escherichia coli strains, also known as extended-spectrum cephalosporin (ESC)-resistant E. coli strains, and can be a source for human infections. As few data on interventions to reduce the presence of ESC-resistant E. coli in broilers are available, we used transmission experiments to examine the role of competitive exclusion (CE) on reducing transmission and excretion in broilers. A broiler model to study the transmission of ESC-resistant E. coli was set up. Day-old chickens were challenged with an ESBL-producing E. coli strain isolated from healthy broilers in the Netherlands. Challenged and not challenged chicks were housed together in pairs or in groups, and ESBL-producing E. coli transmission was monitored via selective culturing of cloacal swab specimens. We observed a statistically significant reduction in both the transmission and excretion of ESBL-producing E. coli in chicks treated with the probiotic flora before E. coli challenge compared to the transmission and excretion in untreated controls. In conclusion, our results support the use of competitive exclusion as an intervention strategy to control ESC-resistant E. coli in the field.IMPORTANCE Extended-spectrum β-lactamases (ESBLs) and plasmid-mediated AmpC β-lactamases are a primary cause of resistance to β-lactam antibiotics among members of the family Enterobacteriaceae in humans, animals, and the environment. Food-producing animals are not exempt from this, with a high prevalence being seen in broilers, and there is evidence pointing to a possible foodborne source for human contamination. We investigated the effect of administration of a commercial probiotic product as an intervention to

  7. An Automated Fluorescent PCR Method for Detection of Shiga Toxin-Producing Escherichia coli in Foods

    PubMed Central

    Chen, Shu; Xu, Renlin; Yee, Arlene; Wu, Kai Yuan; Wang, Chang-Ning; Read, Susan; De Grandis, Stephanie A.

    1998-01-01

    An automated fluorescence-based PCR system (a model AG-9600 AmpliSensor analyzer) was investigated to determine whether it could detect Shiga toxin-producing Escherichia coli (STEC). The AmpliSensor PCR assay involves amplification-mediated disruption of a fluorogenic DNA signal duplex (AmpliSensor) that is homologous to conserved target sequences in a 323-bp amplified fragment of Shiga toxin genes stx1, stx2, and stxe. Using the Amplisensor assay, we detected 113 strains of STEC belonging to 50 different serotypes, while 18 strains of non-Shiga-toxin-producing E. coli and 68 strains of other bacteria were not detected. The detection limits of the assay were less than 1 to 5 CFU per PCR mixture when pure cultures of five reference strains were used and 3 CFU per 25 g of food when spiked ground beef samples that were preenriched overnight were used. The performance of the assay was also evaluated by using 53 naturally contaminated meat samples and 48 raw milk samples. Thirty-two STEC-positive samples that were confirmed to be positive by the culture assay were found to be positive when the AmpliSensor assay was used. Nine samples that were found to be positive when the PCR assay was used were culture negative. The system described here is an automated PCR-based system that can be used for detection of all serotypes of STEC in food or clinical samples. PMID:9797267

  8. Shiga Toxin–Producing Escherichia coli O157, England and Wales, 1983–2012

    PubMed Central

    Byrne, Lisa; Smith, Geraldine A.; Elson, Richard; Harris, John P.; Salmon, Roland; Smith, Robert; O’Brien, Sarah J.; Adak, Goutam K.; Jenkins, Claire

    2016-01-01

    We evaluated clinical Shiga toxin–producing Escherichia coli O157 infections in England and Wales during 1983–2012 to describe changes in microbiological and surveillance methods. A strain replacement event was captured; phage type (PT) 2 decreased to account for just 3% of cases by 2012, whereas PT8 and PT21/28 strains concurrently emerged, constituting almost two thirds of cases by 2012. Despite interventions to control and reduce transmission, incidence remained constant. However, sources of infection changed over time; outbreaks caused by contaminated meat and milk declined, suggesting that interventions aimed at reducing meat cross-contamination were effective. Petting farm and school and nursery outbreaks increased, suggesting the emergence of other modes of transmission and potentially contributing to the sustained incidence over time. Studies assessing interventions and consideration of policies and guidance should be undertaken to reduce Shiga toxin–producing E. coli O157 infections in England and Wales in line with the latest epidemiologic findings. PMID:26982243

  9. Association of verotoxin-producing E. coli and verotoxin with hemolytic uremic syndrome.

    PubMed

    Arbus, G S

    1997-03-01

    It has been over 10 years since we first showed an association [1] between classical hemolytic uremic syndrome (hemolytic anemia, thrombocytopenia, and uremia, following a diarrheal prodome) and certain E. coli [1] capable of producing a toxin, initially called verotoxin (VT) because of its cytopathic effect on Vero cells [2] and later Shiga-like toxin (SLT) because of the toxin's close biological and structural similarity to Shiga toxin. Although we initially reported that 75% of children with idiopathic hemolytic uremic syndrome (HUS) [1] had evidence of a verotoxin-producing E. coli (VTEC) [1], a later study showed that over a seven year period (1980-86), of 86 children seen with HUS, 91% had a classical presentation and 88% of these had evidence of a VTEC infection [3]. This paper traces the path of the incriminating organisms (VTEC) from the time of ingestion, up to and including internalization of the toxin into a target cell; in vitro experiments demonstrating the effect of toxin on endothelial cells are included. It is hoped that we might gain a clearer insight into factors that might predispose an individual to contracting HUS. Once a better understanding of the pathogenesis of VTEC associated HUS is known, areas for therapeutic intervention might be realized.

  10. Detection and characterization of Shiga toxin-producing Escherichia coli from seagulls.

    PubMed Central

    Makino, S.; Kobori, H.; Asakura, H.; Watarai, M.; Shirahata, T.; Ikeda, T.; Takeshi, K.; Tsukamoto, T.

    2000-01-01

    Shiga toxin (Stx)-producing Escherichia coli (STEC) strains isolated from a seagull in Japan were examined. A total of 50 faecal samples was collected on a harbour bank in Hokkaido, Japan, in July 1998. Two different STEC strains, whose serotypes were O136:H16 and O153:H-, were isolated from the same individual by PCR screening; both of them were confirmed by ELISA and Vero cell cytotoxicity assay to be producing active Stx2 and Stx1, respectively. They harboured large plasmids, but did not carry the haemolysin or eaeA genes of STEC O157:H7. Based on their plasmid profiles, antibiotic resistance patterns, pulsed-field gel electrophoresis analysis (PFGE), and the stx genes sequences, the isolates were different. Phylogenic analysis of the deduced Stx amino acid sequences demonstrated that the Stx toxins of seagull-origin STEC were closely associated with those of the human-origin, but not those of other animal-origin STEC. In addition, Stx2phi-K7 phage purified from O136 STEC resembled Stx2phi-II from human-origin O157:H7, and was able to convert non-toxigenic E. coli to STEC. These results suggest that birds may be one of the important carriers in terms of the distribution of STEC. PMID:11057959

  11. Investigation of Encephalopathy Caused by Shiga Toxin 2c-Producing Escherichia coli Infection in Mice

    PubMed Central

    Amran, Muhammad Yunus; Fujii, Jun; Suzuki, Satoshi O.; Kolling, Glynis L.; Villanueva, Sharon Y. A. M.; Kainuma, Mosaburo; Kobayashi, Hideyuki; Kameyama, Hideko; Yoshida, Shin-ichi

    2013-01-01

    A large outbreak of Shiga toxin (Stx)-producing enteroaggregative Escherichia coli (EAEC) O104:H4 occurred in northern Germany. From this outbreak, at least 900 patients developed hemolytic uremic syndrome (HUS), resulting in more than 50 deaths. Thirty percent of the HUS patients showed encephalopathy. We previously established a mouse model with encephalopathy associated with blood brain barrier (BBB) damage after oral infection with the Shiga toxin (Stx) 2c-producing Escherichia coli O157: H- strain E32511 (E32511). In this model, we detected high expression of the Stx receptor synthase enzyme, glycosphingolipid globotriaosylceramide (Gb3) synthase, in endothelial cells (ECs) and neurons in the reticular formation of the medulla oblongata by in situ hybridization. Caspase-3 was activated in neurons in the reticular formation of the medulla oblongata and the anterior horn of the spinal cord. Astrocytes (ASTs) were activated in the medulla oblongata and spinal cord, and a decrease in aquaporin 4 around the ECs suggested that BBB integrity was compromised directly by Stx2c or through the activation of ASTs. We also report the effectiveness of azithromycin (AZM) in our model. Moreover, AZM strongly inhibited the release of Stx2c from E32511 in vitro. PMID:23516588

  12. Detection and isolation of Shiga toxin-producing Escherichia coli (STEC) O104 from sprouts.

    PubMed

    Baranzoni, Gian Marco; Fratamico, Pina M; Rubio, Fernando; Glaze, Thomas; Bagi, Lori K; Albonetti, Sabrina

    2014-03-03

    Shiga toxin-producing Escherichia coli (STEC) strains belonging to serogroup O104 have been associated with sporadic cases of illness and have caused outbreaks associated with milk and sprouts. An outbreak that occurred in Europe in 2011 linked to fenugreek sprouts was caused by E. coli O104:H4 that had characteristics of an enteroaggregative E. coli (EAEC) but carried the gene that encoded for Shiga toxin 2. In this study, methods were developed for detection of this enteroaggregative STEC O104, as well as STEC O104 in sprouts. Multiplex PCR assays for enteroaggregative STEC O104:H4 targeted the stx2, aggR, and wzx104 genes, and for STEC O104 targeted the stx1-2, ehxA, and wzx104 genes. After incubating artificially contaminated sprouts at 4 °C for 48 h and overnight enrichment in modified buffered peptone water with pyruvate supplemented with three antibiotics (mBPWp), the pathogens were detected in all samples inoculated at a level of ca. 100CFU/25 g. Several samples inoculated at lower concentrations of ca. 10CFU/25 g were negative by the PCR assays, and this could have been due to cells not surviving or not being able to recover after the stress treatment at 4 °C for 48 h. For isolation of the pathogens, immunomagnetic separation (IMS) using magnetic beads coated with antibodies against O104 were employed, and this was followed by plating the beads onto mRBA and CHROMagar STEC O104 for isolation of E. coli O104:H4 and mRBA and CHROMagar STEC for isolation of E. coli O104:H7. Presumptive colonies were confirmed by agglutination using latex particles attached to antibodies against serogroup O104 and by the multiplex PCR assays. The methodologies described in this study for detection of enteroaggregative STEC O104:H4 and STEC O104 include the use of IMS and latex reagents for serogroup O104, and they enhance the ability to detect and isolate these pathogens from sprouts and potentially other foods, as well. Published by Elsevier B.V.

  13. Tigecycline treatment of infection caused by KPC-producing Escherichia coli in a pediatric patient

    PubMed Central

    2013-01-01

    Tigecycline shows great antimicrobial activity against both Gram-positive and Gram-negative bacteria, and has been considered to be an appropriate choice in controlling infection caused by multi-drug resistant (MDR) pathogens, such as carbapenemase-producing Enterobacteriaceae (CPE). Although many clinical trials evaluate the efficacy and safety of tigecycline on adults, rare reports recommend tigecycline to treat pediatric patient. In this study, we presented a clinical case with tigecycline as an anti-infectious agent on a 14-year-old child who was suffering from infection of intraperitoneal abscess caused by Klebsiella pneumoniae carbapenemases (KPC)-producing Escherichia coli with extreme drug resistant profile. By accessing the clinical outcome and efficacy of the patient, and the side effects of tigecycline, our research explored the documented experience of tigecycline on controlling infection caused by CPE isolate in children. PMID:23941473

  14. Overview of the purification of recombinant proteins produced in Escherichia coli.

    PubMed

    Wingfield, Paul T

    2003-02-01

    The updated version of this unit presents an overview of recombinant protein purification with special emphasis on proteins expressed in E. coli. The first section deals with information pertinent to protein purification that can be derived from translation of the cDNA sequence. This is followed by a discussion of common problems associated with bacterial protein expression. A flow chart summarizes approaches for establishing solubility and localization of bacterially produced proteins. Purification strategies for both soluble and insoluble proteins are also reviewed. A section on glycoproteins produced in bacteria in the nonglycosylated state is included to emphasize that, although they may not be useful for in vivo studies, such proteins are well suited for structural studies. Finally, protein handling, scale and aims of purification, and specialized equipment needed for recombinant protein purification and characterization are discussed. The methodologies and approaches described here are essentially suitable for laboratory-scale operations.

  15. 60Co irradiation of Shiga toxin (Stx)-producing Escherichia coli induces Stx phage.

    PubMed

    Yamamoto, Tatsuo; Kojio, Seiichi; Taneike, Ikue; Nakagawa, Saori; Iwakura, Nobuhiro; Wakisaka-Saito, Noriko

    2003-05-16

    Shiga toxin (Stx)-producing Escherichia coli (STEC), an important cause of hemolytic uremic syndrome, was completely killed by (60)Co irradiation at 1 x l0(3) gray (1 kGy) or higher. However, a low dose of irradiation (0.1-0.3 kGy) markedly induced Stx phage from STEC. Stx production was observed in parallel to the phage induction. Inactivation of Stx phage required a higher irradiation dose than that for bacterial killing. Regarding Stx, cytotoxicity was susceptible to irradiation, but cytokine induction activity was more resistant than Stx phage. The findings suggest that (1). although (60)Co irradiation is an effective means to kill the bacteria, it does induce Stx phage at a lower irradiation dose, with a risk of Stx phage transfer and emergence of new Stx-producing strains, and (2). irradiation differentially inactivates some activities of Stx.

  16. [The directed modification of Escherichia coli MG1655 to obtain histidine-producing mutants].

    PubMed

    Doroshenko, V G; Lobanov, A O; Fedorina, E A

    2013-01-01

    Strain MG 1655+hisGr hisL'-Delta, purR, which produces histidine with a weight yield of approximately 12% from glucose, was constructed through directed chromosomal modifications of the laboratory Escherichia coli strain MG 1655+, which has a known genome sequence. A feedback-resistant ATP-phosphoribosyl transferase encoded by the mutant hisGr (E271 K) was the main determinant of histidine production. A further increase in histidine production was achieved by the expression enhance of a mutant his operon containing hisGr through the deleting attenuator region (hisL'-Delta). An increase in the expression of the wildtype his operon did not result in histidine accumulation. Deletion of the transcriptional regulator gene purR increased the biomass produced and maintained the level of histidine production per cell under the fermentation conditions used.

  17. Attaching and effacing Escherichia coli and Shiga toxin-producing E. coli in children with acute diarrhoea and controls in Teresina/PI, Brazil.

    PubMed

    Nunes, Maria do Rosário Conceição Moura; Magalhães, Paula Prazeres; Macêdo, Antônio da Silva; Franco, Roger Teixeira; Penna, Francisco José; Mendes, Edilberto Nogueira

    2012-01-01

    This 3.5-year prospective study was conducted to ascertain the level of attaching and effacing Escherichia coli (AEEC) associated diarrhoea in children from Teresina, a northeastern state of Brazil. Passed faecal specimens from 400 patients (250 with and 150 without diarrhoea) up to 60 months of age attending from 2004 to 2007 at two public hospitals were investigated. Conventional microbiology methods and PCR were employed. Escherichia coli was isolated from 390 children, 240 of them with diarrhoea. A total of 117 AEEC strains were cultivated from specimens from 63 children, 37 with and 26 without diarrhoea. No association between AEEC and diarrhoea was observed. Atypical enteropathogenic E. coli (a-EPEC) (79.4%) was more commonly found than typical EPEC (t-EPEC). Association between EPEC and EPEC subtypes and diarrhoea was not detected. Mixed infection by t-EPEC and a-EPEC and infection by Shiga toxin-producing E. coli (STEC) were rare. Enteropathogenic E. coli was more common in males and in children aged less than 12 months. Correlation between serotyping and PCR results was 0.19. High resistance rates of AEEC to ampicillin, cephalotin, and trimethoprim-sulfamethoxazole were found. In conclusion, EPEC is very common in children with diarrhoea and controls in the population we studied, with a-EPEC predominating. This diarrhoeagenic E. coli (DEC) pathotype is more common in infant males and is resistant to drugs frequently used in clinical practice.

  18. Characterization of Shiga toxin subtypes and virulence genes in porcine Shiga toxin-producing Escherichia coli

    DOE PAGES

    Baranzoni, Gian Marco; Fratamico, Pina M.; Gangiredla, Jayanthi; ...

    2016-04-21

    Similar to ruminants, swine have been shown to be a reservoir for Shiga toxin-producing Escherichia coli (STEC), and pork products have been linked with outbreaks associated with STEC O157 and O111:H-. STEC strains, isolated in a previous study from fecal samples of late-finisher pigs, belonged to a total of 56 serotypes, including O15:H27, O91:H14, and other serogroups previously associated with human illness. The isolates were tested by polymerase chain reaction (PCR) and a high-throughput real-time PCR system to determine the Shiga toxin (Stx) subtype and virulence-associated and putative virulence-associated genes they carried. Select STEC strains were further analyzed using amore » Minimal Signature E. coli Array Strip. As expected, stx2e (81%) was the most common Stx variant, followed by stx1a (14%), stx2d (3%), and stx1c (1%). The STEC serogroups that carried stx2d were O15:H27, O159:H16 and O159:H-. Similar to stx2a and stx2c, the stx2d variant is associated with development of hemorrhagic colitis and hemolytic uremic syndrome, and reports on the presence of this variant in STEC strains isolated from swine are lacking. Moreover, the genes encoding heat stable toxin (estIa) and enteroaggregative E. coli heat stable enterotoxin-1 (astA) were commonly found in 50 and 44% of isolates, respectively. The hemolysin genes, hlyA and ehxA, were both detected in 7% of the swine STEC strains. Although the eae gene was not found, other genes involved in host cell adhesion, including lpfAO113 and paa were detected in more than 50% of swine STEC strains, and a number of strains also carried iha, lpfAO26, lpfAO157, fedA, orfA, and orfB. Furthermore, the present work provides new insights on the distribution of virulence factors among swine STEC strains and shows that swine may carry Stx1a-, Stx2e-, or Stx2d-producing E. coli with virulence gene profiles associated with human infections.« less

  19. Characterization of Shiga Toxin Subtypes and Virulence Genes in Porcine Shiga Toxin-Producing Escherichia coli

    PubMed Central

    Baranzoni, Gian Marco; Fratamico, Pina M.; Gangiredla, Jayanthi; Patel, Isha; Bagi, Lori K.; Delannoy, Sabine; Fach, Patrick; Boccia, Federica; Anastasio, Aniello; Pepe, Tiziana

    2016-01-01

    Similar to ruminants, swine have been shown to be a reservoir for Shiga toxin-producing Escherichia coli (STEC), and pork products have been linked with outbreaks associated with STEC O157 and O111:H-. STEC strains, isolated in a previous study from fecal samples of late-finisher pigs, belonged to a total of 56 serotypes, including O15:H27, O91:H14, and other serogroups previously associated with human illness. The isolates were tested by polymerase chain reaction (PCR) and a high-throughput real-time PCR system to determine the Shiga toxin (Stx) subtype and virulence-associated and putative virulence-associated genes they carried. Select STEC strains were further analyzed using a Minimal Signature E. coli Array Strip. As expected, stx2e (81%) was the most common Stx variant, followed by stx1a (14%), stx2d (3%), and stx1c (1%). The STEC serogroups that carried stx2d were O15:H27, O159:H16 and O159:H-. Similar to stx2a and stx2c, the stx2d variant is associated with development of hemorrhagic colitis and hemolytic uremic syndrome, and reports on the presence of this variant in STEC strains isolated from swine are lacking. Moreover, the genes encoding heat stable toxin (estIa) and enteroaggregative E. coli heat stable enterotoxin-1 (astA) were commonly found in 50 and 44% of isolates, respectively. The hemolysin genes, hlyA and ehxA, were both detected in 7% of the swine STEC strains. Although the eae gene was not found, other genes involved in host cell adhesion, including lpfAO113 and paa were detected in more than 50% of swine STEC strains, and a number of strains also carried iha, lpfAO26, lpfAO157, fedA, orfA, and orfB. The present work provides new insights on the distribution of virulence factors among swine STEC strains and shows that swine may carry Stx1a-, Stx2e-, or Stx2d-producing E. coli with virulence gene profiles associated with human infections. PMID:27148249

  20. Tailor-made Au@Ag core-shell nanoparticle 2D arrays on protein-coated graphene oxide with assembly enhanced antibacterial activity

    NASA Astrophysics Data System (ADS)

    Wang, Huiqiao; Liu, Jinbin; Wu, Xuan; Tong, Zhonghua; Deng, Zhaoxiang

    2013-05-01

    Water-dispersible two-dimensional (2D) assemblies of Au@Ag core-shell nanoparticles are obtained through a highly selective electroless silver deposition on pre-assembled gold nanoparticles on bovine serum albumin (BSA)-coated graphene oxide (BSA-GO). While neither BSA-GO nor AuNP-decorated BSA-GO shows any antibacterial ability, the silver-coated GO@Au nanosheets (namely GO@Au@Ag) exhibit an enhanced antibacterial activity against Gram-negative Escherichia coli (E. coli) bacteria, superior to unassembled Au@Ag nanoparticles and even ionic Ag. Such an improvement may be attributed to the increased local concentration of silver nanoparticles around a bacterium and a polyvalent interaction with the bacterial surface. In addition, the colloidal stability of this novel nano-antimicrobial against the formation of random nanoparticle aggregates guarantees a minimized activity loss of the Au@Ag nanoparticles. The antibacterial efficacy of GO@Au@Ag is less sensitive to the existence of Cl-, in comparison with silver ions, providing another advantage for wound dressing applications. Our research unambiguously reveals a strong and very specific interaction between the GO@Au@Ag nanoassembly and E. coli, which could be an important clue toward a rational design, synthesis and assembly of innovative and highly active antibacterial nanomaterials.

  1. Clonal spread and interspecies transmission of clinically relevant ESBL-producing Escherichia coli of ST410--another successful pandemic clone?

    PubMed

    Schaufler, Katharina; Semmler, Torsten; Wieler, Lothar H; Wöhrmann, Michael; Baddam, Ramani; Ahmed, Niyaz; Müller, Kerstin; Kola, Axel; Fruth, Angelika; Ewers, Christa; Guenther, Sebastian

    2016-01-01

    Clinically relevant extended-spectrum beta-lactamase (ESBL)-producing multi-resistant Escherichia coli have been on the rise for years. Initially restricted to mostly a clinical context, recent findings prove their prevalence in extraclinical settings independent of the original occurrence of antimicrobial resistance in the environment. To get further insights into the complex ecology of potentially clinically relevant ESBL-producing E. coli, 24 isolates from wild birds in Berlin, Germany, and 40 ESBL-producing human clinical E. coli isolates were comparatively analyzed. Isolates of ST410 occurred in both sample groups (six). In addition, three ESBL-producing E. coli isolates of ST410 from environmental dog feces and one clinical dog isolate were included. All 10 isolates were clonally analyzed showing almost identical macrorestriction patterns. They were chosen for whole-genome sequencing revealing that the whole-genome content of these 10 E. coli isolates showed a very high genetic similarity, differing by low numbers of single nucleotide polymorphisms only. This study gives initial evidence for a recent interspecies transmission of a new successful clone of ST410 E. coli between wildlife, humans, companion animals and the environment. The results underline the zoonotic potential of clinically relevant multi-resistant bacteria found in the environment as well as the mandatory nature of the 'One Health' approach.

  2. Study of antimicrobial resistance due to extended spectrum beta-lactamase-producing Escherichia coli in healthy broilers of Jabalpur

    PubMed Central

    Shrivastav, Arpita; Sharma, R. K.; Sahni, Y. P.; Shrivastav, Neeraj; Gautam, Vidhi; Jain, Sachin

    2016-01-01

    Aim: To study the prevalence of antimicrobial resistance due to extended spectrum beta-lactamase (ESBL)-producing Escherichia coli in samples collected from the ceca of healthy broilers of poultry sale outlets (PSOs) Jabalpur. Materials and Methods: A total of 400 cecal swab samples were taken randomly from freshly slaughtered poultry of 39 PSOs located at four different zones or areas of Jabalpur and were screened for the presence of ESBL-producing E. coli using standard methods. Further they were characterized phenotypically by standard methods. Results: All the 400 samples were screened for E. coli producing ESBL enzyme. Among the samples positive for E. coli 135 were positive for ESBL E. coli giving an overall prevalence of 33.5%. Conclusion: This study related to the prevalence of ESBL-producing E. coli in healthy broilers in Jabalpur is indicative of antibiotic resistance prevalent in the healthy birds which are used for human consumption as well. It also signifies resistance prevalent against beta-lactam antibiotics including third and fourth generations of cephalosporins. PMID:27956778

  3. Detection of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli on flies at poultry farms.

    PubMed

    Blaak, Hetty; Hamidjaja, Raditijo A; van Hoek, Angela H A M; de Heer, Lianne; de Roda Husman, Ana Maria; Schets, Franciska M

    2014-01-01

    In the Netherlands, extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli bacteria are highly prevalent in poultry, and chicken meat has been implicated as a source of ESBL-producing E. coli present in the human population. The current study describes the isolation of ESBL-producing E. coli from house flies and blow flies caught at two poultry farms, offering a potential alternative route of transmission of ESBL-producing E. coli from poultry to humans. Overall, 87 flies were analyzed in 19 pools. ESBL-producing E. coli bacteria were detected in two fly pools (10.5%): a pool of three blow flies from a broiler farm and a pool of eight house flies from a laying-hen farm. From each positive fly pool, six isolates were characterized and compared with isolates obtained from manure (n = 53) sampled at both farms and rinse water (n = 10) from the broiler farm. Among six fly isolates from the broiler farm, four different types were detected with respect to phylogenetic group, sequence type (ST), and ESBL genotype: A0/ST3519/SHV-12, A1/ST10/SHV-12, A1/ST58/SHV-12, and B1/ST448/CTX-M-1. These types, as well as six additional types, were also present in manure and/or rinse water at the same farm. At the laying-hen farm, all fly and manure isolates were identical, carrying blaTEM-52 in an A1/ST48 genetic background. The data imply that flies acquire ESBL-producing E. coli at poultry farms, warranting further evaluation of the contribution of flies to dissemination of ESBL-producing E. coli in the community.

  4. Detection of Extended-Spectrum Beta-Lactamase (ESBL)-Producing Escherichia coli on Flies at Poultry Farms

    PubMed Central

    Hamidjaja, Raditijo A.; van Hoek, Angela H. A. M.; de Heer, Lianne; de Roda Husman, Ana Maria; Schets, Franciska M.

    2014-01-01

    In the Netherlands, extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli bacteria are highly prevalent in poultry, and chicken meat has been implicated as a source of ESBL-producing E. coli present in the human population. The current study describes the isolation of ESBL-producing E. coli from house flies and blow flies caught at two poultry farms, offering a potential alternative route of transmission of ESBL-producing E. coli from poultry to humans. Overall, 87 flies were analyzed in 19 pools. ESBL-producing E. coli bacteria were detected in two fly pools (10.5%): a pool of three blow flies from a broiler farm and a pool of eight house flies from a laying-hen farm. From each positive fly pool, six isolates were characterized and compared with isolates obtained from manure (n = 53) sampled at both farms and rinse water (n = 10) from the broiler farm. Among six fly isolates from the broiler farm, four different types were detected with respect to phylogenetic group, sequence type (ST), and ESBL genotype: A0/ST3519/SHV-12, A1/ST10/SHV-12, A1/ST58/SHV-12, and B1/ST448/CTX-M-1. These types, as well as six additional types, were also present in manure and/or rinse water at the same farm. At the laying-hen farm, all fly and manure isolates were identical, carrying blaTEM-52 in an A1/ST48 genetic background. The data imply that flies acquire ESBL-producing E. coli at poultry farms, warranting further evaluation of the contribution of flies to dissemination of ESBL-producing E. coli in the community. PMID:24162567

  5. Virus-like particle of Macrobrachium rosenbergii nodavirus produced in Spodoptera frugiperda (Sf9) cells is distinctive from that produced in Escherichia coli.

    PubMed

    Kueh, Chare Li; Yong, Chean Yeah; Masoomi Dezfooli, Seyedehsara; Bhassu, Subha; Tan, Soon Guan; Tan, Wen Siang

    2016-11-14

    Macrobrachium rosenbergii nodavirus (MrNV) is a virus native to giant freshwater prawn. Recombinant MrNV capsid protein has been produced in Escherichia coli, which self-assembled into virus-like particles (VLPs). However, this recombinant protein is unstable, degrading and forming heterogenous VLPs. In this study, MrNV capsid protein was produced in insect Spodoptera frugiperda (Sf9) cells through a baculovirus system. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) revealed that the recombinant protein produced by the insect cells self-assembled into highly stable, homogenous VLPs each of approximately 40 nm in diameter. Enzyme-linked immunosorbent assay (ELISA) showed that the VLPs produced in Sf9 cells were highly antigenic and comparable to those produced in E. coli. In addition, the Sf9 produced VLPs were highly stable across a wide pH range (2-12). Interestingly, the Sf9 produced VLPs contained DNA of approximately 48 kilo base pairs and RNA molecules. This study is the first report on the production and characterization of MrNV VLPs produced in a eukaryotic system. The MrNV VLPs produced in Sf9 cells were about 10 nm bigger and had a uniform morphology compared with the VLPs produced in E. coli. The insect cell production system provides a good source of MrNV VLPs for structural and immunological studies as well as for host-pathogen interaction studies. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 2016.

  6. Comparative Genomics and stx Phage Characterization of LEE-Negative Shiga Toxin-Producing Escherichia coli

    PubMed Central

    Steyert, Susan R.; Sahl, Jason W.; Fraser, Claire M.; Teel, Louise D.; Scheutz, Flemming; Rasko, David A.

    2012-01-01

    Infection by Escherichia coli and Shigella species are among the leading causes of death due to diarrheal disease in the world. Shiga toxin-producing E. coli (STEC) that do not encode the locus of enterocyte effacement (LEE-negative STEC) often possess Shiga toxin gene variants and have been isolated from humans and a variety of animal sources. In this study, we compare the genomes of nine LEE-negative STEC harboring various stx alleles with four complete reference LEE-positive STEC isolates. Compared to a representative collection of prototype E. coli and Shigella isolates representing each of the pathotypes, the whole genome phylogeny demonstrated that these isolates are diverse. Whole genome comparative analysis of the 13 genomes revealed that in addition to the absence of the LEE pathogenicity island, phage-encoded genes including non-LEE encoded effectors, were absent from all nine LEE-negative STEC genomes. Several plasmid-encoded virulence factors reportedly identified in LEE-negative STEC isolates were identified in only a subset of the nine LEE-negative isolates further confirming the diversity of this group. In combination with whole genome analysis, we characterized the lambdoid phages harboring the various stx alleles and determined their genomic insertion sites. Although the integrase gene sequence corresponded with genomic location, it was not correlated with stx variant, further highlighting the mosaic nature of these phages. The transcription of these phages in different genomic backgrounds was examined. Expression of the Shiga toxin genes, stx1 and/or stx2, as well as the Q genes, were examined with quantitative reverse transcriptase polymerase chain reaction assays. A wide range of basal and induced toxin induction was observed. Overall, this is a first significant foray into the genome space of this unexplored group of emerging and divergent pathogens. PMID:23162798

  7. 2′-Deoxyribonolactone lesion produces G→A transitions in Escherichia coli

    PubMed Central

    Faure, Virginie; Constant, Jean-François; Dumy, Pascal; Saparbaev, Murat

    2004-01-01

    2′-Deoxyribonolactone (dL) is a C1′-oxidized abasic site damage generated by a radical attack on DNA. Numerous genotoxic agents have been shown to produce dL including UV and γ-irradiation, ene-dye antibiotics etc. At present the biological consequences of dL present in DNA have been poorly documented, mainly due to the lack of method for introducing the lesion in oligonucleotides. We have recently designed a synthesis of dL which allowed investigation of the mutagenicity of dL in Escherichia coli by using a genetic reversion assay. The lesion was site-specifically incorporated in a double-stranded bacteriophage vector M13G*1, which detects single-base-pair substitutions at position 141 of the lacZα gene by a change in plaque color. In E.coli JM105 the dL-induced reversion frequency was 4.7 × 10–5, similar to that of the classic abasic site 2′-deoxyribose (dR). Here we report that a dL residue in a duplex DNA codes mainly for thymidine. The processing of dL in vivo was investigated by measuring lesion-induced mutation frequencies in DNA repair deficient E.coli strains. We showed a 32-fold increase in dL-induced reversion rate in AP endonuclease deficient (xth nfo) mutant compared with wild-type strain, indicating that the Xth and Nfo AP endonucleases participate in dL repair in vivo. PMID:15159441

  8. Functional and phylogenetic analysis of ureD in Shiga toxin-producing Escherichia coli.

    PubMed

    Steyert, Susan R; Rasko, David A; Kaper, James B

    2011-02-01

    Enterohemorrhagic Escherichia coli (EHEC) is a food-borne pathogen that can cause severe health complications and utilizes a much lower infectious dose than other E. coli pathotypes. Despite having an intact ure locus, ureDABCEFG, the majority of EHEC strains are phenotypically urease negative under tested conditions. Urease activity potentially assists with survival fitness by enhancing acid tolerance during passage through the stomach or by aiding with colonization in either human or animal reservoirs. Previously, in the EHEC O157:H7 Sakai strain, a point mutation in ureD, encoding a urease chaperone protein, was identified, resulting in a substitution of an amber stop codon for glutamine. This single nucleotide polymorphism (SNP) is observed in the majority of EHEC O157:H7 isolates and correlates with a negative urease phenotype in vitro. We demonstrate that the lack of urease activity in vitro is not solely due to the amber codon in ureD. Our analysis has identified two additional SNPs in ureD affecting amino acid positions 38 and 205, in both cases determining whether the encoded amino acid is leucine or proline. Phylogenetic analysis based on Ure protein sequences from a variety of urease-encoding bacteria demonstrates that the proline at position 38 is highly conserved among Gram-negative bacteria. Experiments reveal that the L38P substitution enhances urease enzyme activity; however, the L205P substitution does not. Multilocus sequence typing analysis for a variety of Shiga toxin-producing E. coli isolates combined with the ureD sequence reveals that except for a subset of the O157:H7 strains, neither the in vitro urease-positive phenotype nor the ureD sequence is phylogenetically restricted.

  9. Characterization of Extended-Spectrum-β-Lactamases Produced by Escherichia coli Strains Isolated from Dogs in Poland.

    PubMed

    Rzewuska, Magdalena; Stefańska, Ilona; Kizerwetter-Swida, Magdalena; Chrobak-Cmiel, Dorota; Szczygielska, Paulina; Leśniak, Monika; Binek, Marian

    2015-01-01

    Escherichia coli is a common cause of infections in companion animals. In recent years the increasing prevalence of resistance to β-lactams, including extended-spectrum cephalosporins, antimicrobials frequently used in small animal veterinary practice, was observed in canine isolates of E. coli. The aim of this study was to detect and to characterize extended-spectrum β-lactamases (ESBLs) produced by E. coli isolated from diseased dogs in Poland. Four isolates out of 119 studied (3.4%) were ESBL-positive. They harbored the bla(SHV-12), bla(CTX-M-15), and bla(TEM-116) genes. This study provides the first report of the occurrence of ESBL-producing E. coli in dogs in Poland.

  10. Occurrence of Escherichia coli, Campylobcter, Salmonella and Shiga-Toxin Producing E. coli in Norwegian Primary Strawberry Production.

    PubMed

    Johannessen, Gro S; Eckner, Karl F; Heiberg, Nina; Monshaugen, Marte; Begum, Mumtaz; Økland, Marianne; Høgåsen, Helga R

    2015-06-17

    The aim of this study was to investigate the bacteriological quality of strawberries at harvest and to study risk factors such as irrigation water, soil and picker's hand cleanliness. Four farms were visited during the harvest season in 2012. Samples of strawberries, irrigation water, soil and hand swabs were collected and analyzed for E. coli, Campylobacter, Salmonella and STEC Although fecal indicators and pathogens were found in environmental samples, only one of 80 samples of strawberries was positive for E. coli (1.0 log10 cfu/g) and pathogens were not detected in any of the strawberry samples. The water samples from all irrigation sources were contaminated with E. coli in numbers ranging from 0 to 3.3 log10 cfu/g. Campylobacter (8/16 samples) and Salmonella (1/16 samples) were isolated from samples with high numbers of E. coli. The water samples collected from a lake had lower numbers of E. coli than the samples from rivers and a stream. The present study indicated continuous background contamination in the primary production environment. Although the background contamination was not reflected on the strawberries tested here, the results must be interpreted with caution due to the limited number of samples.

  11. Occurrence of Escherichia coli, Campylobcter, Salmonella and Shiga-Toxin Producing E. coli in Norwegian Primary Strawberry Production

    PubMed Central

    Johannessen, Gro S.; Eckner, Karl F.; Heiberg, Nina; Monshaugen, Marte; Begum, Mumtaz; Økland, Marianne; Høgåsen, Helga R.

    2015-01-01

    The aim of this study was to investigate the bacteriological quality of strawberries at harvest and to study risk factors such as irrigation water, soil and picker’s hand cleanliness. Four farms were visited during the harvest season in 2012. Samples of strawberries, irrigation water, soil and hand swabs were collected and analyzed for E. coli, Campylobacter, Salmonella and STEC Although fecal indicators and pathogens were found in environmental samples, only one of 80 samples of strawberries was positive for E. coli (1.0 log10 cfu/g) and pathogens were not detected in any of the strawberry samples. The water samples from all irrigation sources were contaminated with E. coli in numbers ranging from 0 to 3.3 log10 cfu/g. Campylobacter (8/16 samples) and Salmonella (1/16 samples) were isolated from samples with high numbers of E. coli. The water samples collected from a lake had lower numbers of E. coli than the samples from rivers and a stream. The present study indicated continuous background contamination in the primary production environment. Although the background contamination was not reflected on the strawberries tested here, the results must be interpreted with caution due to the limited number of samples. PMID:26090606

  12. Method for the detection of priority Shiga toxin-producing Escherichia coli in beef trim.

    PubMed

    Huszczynski, George; Gauthier, Martine; Mohajer, Sam; Gill, Alexander; Blais, Burton

    2013-10-01

    A method has been developed for the detection in beef trim of priority Shiga toxin-producing E. coli (STEC) strains, defined as E. coli possessing the virulence factors stx1 and/or stx2 and intimin (eae), with O serogroups O26, O45, O103, O111, O121, O145, or O157. The method is based on recovery of the target bacteria by overnight enrichment in a broth optimized for recovery of O157 and non-O157 STEC, followed by screening using multiplex PCR techniques targeting (i) stx1, stx2, and eae (STE PCR) and (ii) gene sequences associated with the seven priority O serogroups (Poly O PCR), and then direct plating of broth samples positive in both STE and Poly O PCR onto Rainbow agar. Colonies on agar media were screened batchwise for STEC by the STE PCR, and presumptive isolates were characterized using a multiplex PCR and cloth-based hybridization array system targeting key virulence and O serogroup-specific markers. Using one representative strain of each priority O serogroup individually inoculated in beef trim samples, the method exhibited a limit of detection approaching 1 to 2 viable STEC cells per 65 g. None of the uninoculated trim samples produced positive results with either of the screening PCR procedures or on analysis of colonies recovered on plating media. STEC-negative samples were readily identified by screening PCR within 24 h, with a turnaround time of fewer than 4 days for confirmation of positives. The inclusivity and exclusivity characteristics of the screening PCR techniques were verified using a total of 65 different priority STEC strains: 24 nonpriority STEC, 15 non-STEC bacteria, and only those strains bearing the targeted characteristics produced screening PCR-positive results.

  13. Characterization of Shiga toxin – producing Escherichia coli infections in beef feeder calves and the effectiveness of a prebiotic in alleviating Shiga toxin - producing Escherichia coli infections

    PubMed Central

    2013-01-01

    Background In the less-sensitive mouse model, Shiga toxin-producing Escherichia coli (STEC) challenges result in shedding that reflect the amount of infection and the expression of virulence factors such as Shiga toxins (Stx). The purpose of this study was to characterize the contribution of STEC diversity and Stx expression to shedding in beef feeder calves and to evaluate the effectiveness of a prebiotic, Celmanax®, to alleviate STEC shedding. Fecal samples were collected from calves at entry and after 35 days in the feedlot in spring and summer. STECs were evaluated using selective media, biochemical profile, serotyping and Stx detection. Statistical analysis was performed using repeated measures ANOVA and logistic regression. Results At entry, non-O157 STEC were dominant in shedding calves. In spring, 21%, 14% and 14% of calves acquired O157, non-O157 and mixed STEC infections, respectively. In contrast, 45%, 48% and 46% of calves in summer acquired O157, non-O157 and mixed STEC infections, respectively. Treatment with a prebiotic, Celmanax®, in spring significantly reduced 50% of the O157 STEC infections, 50% of the non-O157 STEC infections and 36% of the STEC co-infections (P = 0.037). In summer, there was no significant effect of the prebiotic on STEC infections. The amount of shedding at entry was significantly related to the number and type of STECs present and Stx expression (r2 = 0.82). The same relationship was found for shedding at day 35 (r2 = 0.85), but it was also related to the number and type of STECs present at entry. Stx - producing STEC infections resulted in 100 to 1000 × higher shedding in calves compared with Stx-negative STECs. Conclusions STEC infections in beef feeder calves reflect the number and type of STECs involved in the infection and STEC expression of Stx. Application of Celmanax® reduced O157 and non-O157 STEC shedding by calves but further research is required to determine appropriate dosages to manage STEC

  14. Draft Genome Sequence of Extended-Spectrum-β-Lactamase-Producing Escherichia coli Strain CCUG 62462, Isolated from a Urine Sample

    PubMed Central

    Johnning, Anna; Jakobsson, Hedvig E.; Boulund, Fredrik; Salvà-Serra, Francisco; Åhrén, Christina; Kristiansson, Erik

    2016-01-01

    The draft genome sequence has been determined for an extended-spectrum-β-lactamase (ESBL)-producing (blaCTX-M-15) Escherichia coli strain (CCUG 62462), composed of 119 contigs and a total size of 5.27 Mb. This E. coli is serotype O25b and sequence type 131, a pandemic clonal group, causing worldwide antimicrobial-resistant infections. PMID:27979938

  15. Effects of stresses on the growth and Cytotoxicity of Shiga-Toxin producing Escherichia coli in ground beef and spinach

    USDA-ARS?s Scientific Manuscript database

    The objectives of this study were to examine the effect of stresses on the growth and cytotoxicity of pathogenic Escherichia coli in beef and spinach. A mixture of three strains of Shiga toxin-producing E. coli (STEC) O157:H7 or four strains of non-O157 STEC O26:H11, O103:H1, O104:H4, and O145:NM wa...

  16. Molecular Epidemiology and Genome Dynamics of New Delhi Metallo-β-Lactamase-Producing Extraintestinal Pathogenic Escherichia coli Strains from India

    PubMed Central

    Ranjan, Amit; Shaik, Sabiha; Mondal, Agnismita; Nandanwar, Nishant; Hussain, Arif; Semmler, Torsten; Kumar, Narender; Tiwari, Sumeet K.; Jadhav, Savita; Wieler, Lothar H.

    2016-01-01

    The global dissemination and increasing incidence of carbapenem-resistant, Gram-negative organisms have resulted in acute public health concerns. Here, we present a retrospective multicenter study on molecular characterization of metallo-β-lactamase (MBL)-producing clinical Escherichia coli isolates recovered from extraintestinal infections in two hospitals in Pune, India. We screened a large sample size of 510 E. coli isolates for MBL production wherein we profiled their molecular determinants, antimicrobial resistance phenotypes, functional virulence properties, genomic features, and transmission dynamics. Approximately 8% of these isolates were MBL producers, the majority of which were of the NDM-1 (69%) type, followed by NDM-5 (19%), NDM-4 (5.5%), and NDM-7 (5.5%). MBL producers were resistant to all antibiotics tested except for colistin, fosfomycin, and chloramphenicol, which were effective to various extents. Plasmids were found to be an effective means of dissemination of NDM genes and other resistance traits. All MBL producers adhered to and invaded bladder epithelial (T24) cells and demonstrated significant serum resistance. Genomic analysis of MBL-producing E. coli isolates revealed higher resistance but a moderate virulence gene repertoire. A subset of NDM-1-positive E. coli isolates was identified as dominant sequence type 101 (ST101) while two strains belonging to ST167 and ST405 harbored NDM-5. A majority of MBL-producing E. coli strains revealed unique genotypes, suggesting that they were clonally unrelated. Overall, the coexistence of virulence and carbapenem resistance in clinical E. coli isolates is of serious concern. Moreover, the emergence of NDM-1 among the globally dominant E. coli ST101 isolates warrants stringent surveillance and control measures. PMID:27600040

  17. The Molecular Epidemiology of Resistance in Cefotaximase-Producing Escherichia coli Clinical Isolates from Dublin, Ireland.

    PubMed

    Burke, Liam; Humphreys, Hilary; Fitzgerald-Hughes, Deirdre

    2016-10-01

    In view of continued high clinical prevalence of infections involving extended-spectrum β-lactamase (ESBL)-producing Escherichia coli, this study sought to characterise the blaCTX-M genes, their associated mobile genetic elements and the integrons present in 100 ESBL-producing E. coli isolates collected in a Dublin hospital and associated community healthcare facilities. Polymerase chain reaction (PCR) mapping and sequencing was used to detect blaCTX-M alleles, their associated insertion sequences (ISs) and class 1 and 2 integrons in the collection. ESBL plasmids were characterised by PCR-based replicon typing and replicon sequence typing (RST). Cefotaximases were harboured by 94% of isolates (66 blaCTX-M-15, 8 blaCTX-M-14, 7 blaCTX-M-1, 4 blaCTX-M-3, 3 blaCTX-M-9, 2 blaCTX-M-27, 2 blaCTX-M-55, 1 blaCTX-M-32 and 1 blaCTX-M-2). An ISEcp1 promoter was linked to a group 1 blaCTX-M gene in 45% of isolates. A further 34% of isolates contained blaCTX-M-15 downstream of IS26, an arrangement typical of epidemic UK strain A. Class 1 integrons were found in 66% of isolates, most carrying trimethoprim/aminoglycoside resistance genes. CTX-M plasmids were primarily of multireplicon IncF or IncI1 type, but IncN and unidentified types were also found. Novel IncF RSTs F1:A-:B-, F45:A1:B-, F45:A4:B- and a novel IncI1 sequence type, ST159, were identified. CTX-M plasmids and integrons resembled those identified recently in animal isolates from Ireland and Western Europe. The molecular epidemiology of CTX-M-producing E. coli in Dublin suggests that horizontal spread of mobile genetic elements contributes to antimicrobial resistant human infections. Further investigations into whether animals or animal products represent an important local reservoir for these elements are warranted.

  18. [Hemolytic uremic syndrome caused by Shiga-toxin-producing Escherichia coli].

    PubMed

    Loirat, Chantal

    2013-01-01

    Every year in France, approximately one hundred children, aged from 6 months to 3 years, develop hemolytic uremic syndrome (HUS) secondary to Shiga toxin-producing Escherichia coli (STEC) infection, mostly the O157:H7 serotype. Except during outbreaks, STEC-HUS is less frequent in adults. The main route of transmission is the consumption of undercooked ground beef or unpasteurized dairy products, or household contacts with STEC diarrhea. Mortality is 1 to 2%. Half of patients require dialysis at the acute phase, the majority will recover normal renal function but approximately 30% will suffer renal sequelae. The risk of sequelae is important if the duration of anuria has been more than 5 days. Treatment of STEC-HUS is mostly supportive. The efficacy of plasma exchanges is not demonstrated and that of eculizumab, a complement blocker, especially in case of central nervous system or cardiac involvement, uncertain. Prevention of STEC-HUS relies on simple methods, often unknown of parents of young children, with the French general population being scarcely informed. However, the surveillance of STEC-infections/HUS by the Institut de veille sanitaire and the Reference Center for E. coli infections allows the early detection of outbreaks and their source of contamination. This prevents the emergence of new cases by withdrawing the suspected food from the market and diffusing the information to the population (return of suspected food).

  19. ppGpp and cytotoxicity diversity in Shiga toxin-producing Escherichia coli (STEC) isolates.

    PubMed

    Stella, A E; Luz Hessel DA Cunha, D; Piazza, R M F; Spira, B

    2017-08-01

    Shiga toxin-producing Escherichia coli (STEC) is a known food pathogen, which main reservoir is the intestine of ruminants. The abundance of different STEC lineages in nature reflect a heterogeneity that is characterised by the differential expression of certain genotypic characteristics, which in turn are influenced by the environmental conditions to which the microorganism is exposed. Bacterial homeostasis and stress response are under the control of the alarmone guanosine tetraphosphate (ppGpp), which intrinsic levels varies across the E. coli species. In the present study, 50 STEC isolates from healthy sheep were evaluated regarding their ppGpp content, cytotoxicity and other relevant genetic and phenotypic characteristics. We found that the level of ppGpp and cytotoxicity varied considerably among the examined strains. Isolates that harboured the stx2 gene were the least cytotoxic and presented the highest levels of ppGpp. All stx2 isolates belonged to phylogroup A, while strains that carried stx1 or both stx1 and stx2 genes pertained to phylogroup B1. All but two stx2 isolates belonged to the stx2b subtype. Strains that belonged to phylogroup B1 displayed on average low levels of ppGpp and high cytotoxicity. Overall, there was a negative correlation between cytotoxicity and ppGpp.

  20. Purification and characterization of a Shigella conjugate vaccine, produced by glycoengineering Escherichia coli.

    PubMed

    Ravenscroft, Neil; Haeuptle, Micha A; Kowarik, Michael; Fernandez, Fabiana S; Carranza, Paula; Brunner, Andreas; Steffen, Michael; Wetter, Michael; Keller, Sacha; Ruch, Corina; Wacker, Michael

    2016-01-01

    Shigellosis remains a major cause of diarrheal disease in developing countries and causes substantial morbidity and mortality in children. Glycoconjugate vaccines consisting of bacterial surface polysaccharides conjugated to carrier proteins are the most effective vaccines for controlling invasive bacterial infections. Nevertheless, the development of a multivalent conjugate vaccine to prevent Shigellosis has been hampered by the complex manufacturing process as the surface polysaccharide for each strain requires extraction, hydrolysis, chemical activation and conjugation to a carrier protein. The use of an innovative biosynthetic Escherichia coli glycosylation system substantially simplifies the production of glycoconjugates. Herein, the Shigella dysenteriae type 1 (Sd1) O-polysaccharide is expressed and its functional assembly on an E. coli glycosyl carrier lipid is demonstrated by HPLC analysis and mass spectrometry. The polysaccharide is enzymatically conjugated to specific asparagine residues of the carrier protein by co-expression of the PglB oligosaccharyltransferase and the carrier protein exotoxin A (EPA) from Pseudomonas aeruginosa. The extraction and purification of the Shigella glycoconjugate (Sd1-EPA) and its detailed characterization by the use of physicochemical methods including NMR and mass spectrometry is described. The report shows for the first time that bioconjugation provides a newly developed and improved approach to produce an Sd1 glycoconjugate that can be characterized using state-of-the-art techniques. In addition, this generic process together with the analytical methods is ideally suited for the production of additional Shigella serotypes, allowing the development of a multivalent Shigella vaccine.

  1. Escherichia coli Sequence Type 131 H30 Is the Main Driver of Emerging Extended-Spectrum-β-Lactamase-Producing E. coli at a Tertiary Care Center.

    PubMed

    Johnson, James R; Johnston, Brian; Thuras, Paul; Launer, Bryn; Sokurenko, Evgeni V; Miller, Loren G

    2016-01-01

    The H30 strain of Escherichia coli sequence type 131 (ST131-H30) is a recently emerged, globally disseminated lineage associated with fluoroquinolone resistance and, via its H30Rx subclone, the CTX-M-15 extended-spectrum beta-lactamase (ESBL). Here, we studied the clonal background and resistance characteristics of 109 consecutive recent E. coli clinical isolates (2015) and 41 historical ESBL-producing E. coli blood isolates (2004 to 2011) from a public tertiary care center in California with a rising prevalence of ESBL-producing E. coli isolates. Among the 2015 isolates, ST131, which was represented mainly by ST131-H30, was the most common clonal lineage (23% overall). ST131-H30 accounted for 47% (8/17) of ESBL-producing, 47% (14/30) of fluoroquinolone-resistant, and 33% (11/33) of multidrug-resistant isolates. ST131-H30 also accounted for 53% (8/14) of dually fluoroquinolone-resistant, ESBL-producing isolates, with the remaining 47% comprised of diverse clonal groups that contributed a single isolate each. ST131-H30Rx, with CTX-M-15, was the major ESBL producer (6/8) among ST131-H30 isolates. ST131-H30 and H30Rx also dominated (46% and 37%, respectively) among the historical ESBL-producing isolates (2004 to 2011), without significant temporal shifts in relative prevalence. Thus, this medical center's recently emerging ESBL-producing E. coli strains, although multiclonal, are dominated by ST131-H30 and H30Rx, which are the only clonally expanded fluoroquinolone-resistant, ESBL-producing lineages. Measures to rapidly and effectively detect, treat, and control these highly successful lineages are needed. IMPORTANCE The ever-rising prevalence of resistance to first-line antibiotics among clinical Escherichia coli isolates leads to worse clinical outcomes and higher health care costs, thereby creating a need to discover its basis so that effective interventions can be developed. We found that the H30 subset within E. coli sequence type 131 (ST131-H30) is

  2. Bet-hedging in bacteriocin producing Escherichia coli populations: the single cell perspective

    PubMed Central

    Bayramoglu, Bihter; Toubiana, David; van Vliet, Simon; Inglis, R. Fredrik; Shnerb, Nadav; Gillor, Osnat

    2017-01-01

    Production of public goods in biological systems is often a collaborative effort that may be detrimental to the producers. It is therefore sustainable only if a small fraction of the population shoulders the cost while the majority reap the benefits. We modelled this scenario using Escherichia coli populations producing colicins, an antibiotic that kills producer cells’ close relatives. Colicin expression is a costly trait, and it has been proposed that only a small fraction of the population actively expresses the antibiotic. Colicinogenic populations were followed at the single-cell level using time-lapse microscopy, and showed two distinct, albeit dynamic, subpopulations: the majority silenced colicin expression, while a small fraction of elongated, slow-growing cells formed colicin-expressing hotspots, placing a significant burden on expressers. Moreover, monitoring lineages of individual colicinogenic cells showed stochastic switching between expressers and non-expressers. Hence, colicin expressers may be engaged in risk-reducing strategies—or bet-hedging—as they balance the cost of colicin production with the need to repel competitors. To test the bet-hedging strategy in colicin-mediated interactions, competitions between colicin-sensitive and producer cells were simulated using a numerical model, demonstrating a finely balanced expression range that is essential to sustaining the colicinogenic population. PMID:28165017

  3. Bet-hedging in bacteriocin producing Escherichia coli populations: the single cell perspective

    NASA Astrophysics Data System (ADS)

    Bayramoglu, Bihter; Toubiana, David; van Vliet, Simon; Inglis, R. Fredrik; Shnerb, Nadav; Gillor, Osnat

    2017-02-01

    Production of public goods in biological systems is often a collaborative effort that may be detrimental to the producers. It is therefore sustainable only if a small fraction of the population shoulders the cost while the majority reap the benefits. We modelled this scenario using Escherichia coli populations producing colicins, an antibiotic that kills producer cells’ close relatives. Colicin expression is a costly trait, and it has been proposed that only a small fraction of the population actively expresses the antibiotic. Colicinogenic populations were followed at the single-cell level using time-lapse microscopy, and showed two distinct, albeit dynamic, subpopulations: the majority silenced colicin expression, while a small fraction of elongated, slow-growing cells formed colicin-expressing hotspots, placing a significant burden on expressers. Moreover, monitoring lineages of individual colicinogenic cells showed stochastic switching between expressers and non-expressers. Hence, colicin expressers may be engaged in risk-reducing strategies—or bet-hedging—as they balance the cost of colicin production with the need to repel competitors. To test the bet-hedging strategy in colicin-mediated interactions, competitions between colicin-sensitive and producer cells were simulated using a numerical model, demonstrating a finely balanced expression range that is essential to sustaining the colicinogenic population.

  4. Prevalence and characteristics of ESBL-producing E. coli in Dutch recreational waters influenced by wastewater treatment plants.

    PubMed

    Blaak, Hetty; de Kruijf, Patrick; Hamidjaja, Raditijo A; van Hoek, Angela H A M; de Roda Husman, Ana Maria; Schets, Franciska M

    2014-07-16

    Outside health care settings, people may acquire ESBL-producing bacteria through different exposure routes, including contact with human or animal carriers or consumption of contaminated food. However, contact with faecally contaminated surface water may also represent a possible exposure route. The current study investigated the prevalence and characteristics of ESBL-producing Escherichia coli in four Dutch recreational waters and the possible role of nearby waste water treatment plants (WWTP) as contamination source. Isolates from recreational waters were compared with isolates from WWTP effluents, from surface water upstream of the WWTPs, at WWTP discharge points, and in connecting water bodies not influenced by the studied WWTPs. ESBL-producing E. coli were detected in all four recreational waters, with an average concentration of 1.3 colony forming units/100ml, and in 62% of all samples. In surface waters not influenced by the studied WWTPs, ESBL-producing E. coli were detected in similar concentrations, indicating the existence of additional ESBL-E. coli contamination sources. Isolates with identical ESBL-genes, phylogenetic background, antibiotic resistance profiles, and sequence type, were obtained from effluent and different surface water sites in the same watershed, on the same day; occasionally this included isolates from recreational waters. Recreational waters were identified as a potential exposure source of ESBL-producing E. coli. WWTPs were shown to contribute to the presence of these bacteria in surface waters, but other (yet unidentified) sources likely co-contribute. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Clonal diversity of extended-spectrum beta-lactamase producing Escherichia coli isolates in fecal samples of wild animals.

    PubMed

    Cristóvão, Filipe; Alonso, Carla Andrea; Igrejas, Gilberto; Sousa, Margarida; Silva, Vanessa; Pereira, José Eduardo; Lozano, Carmen; Cortés-Cortés, Gerardo; Torres, Carmen; Poeta, Patrícia

    2017-03-01

    The clonal diversity of extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli isolates from nine different species of wild animals from distinct regions of Portugal and Spain and their content in replicon plasmids were analyzed. Among the initial 53 ESBL-producing E. coli isolates that were studied (from previous studies), 28 were selected, corresponding to different animal origins with distinct ESBL types and pulsed-field gel electrophoresis (PFGE) patterns. These 28 isolates produced different ESBLs ascribed to the following families: CTX-M, SHV and TEM. The isolates were classified into three phylogenetic groups: B1 (n = 11), A (n = 10) and D (n = 7). The seven E. coli of phylogroup D were then typed by multilocus sequence typing and ascribed to four distinct sequence types: ST117, ST115, ST2001 and ST69. The clonal diversity and relationship between isolates was studied by PFGE. Lastly, the plasmids were analyzed according to their incompatibility group using the PCR-based-replicon-typing scheme. A great diversity of replicon types was identified, with up to five per isolate. Most of the CTX-M-1 and SHV-12 producing E. coli isolates carried IncI1 or IncN replicons. The diversity of ESBL-producing E. coli isolates in wild animals, which can be disseminated in the environment, emphasizes the environmental and health problems that we face nowadays. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Growth of Escherichia coli O157:H7, Non-O157 Shiga Toxin-Producing Escherichia coli , and Salmonella in Water and Hydroponic Fertilizer Solutions.

    PubMed

    Shaw, Angela; Helterbran, Kara; Evans, Michael R; Currey, Christopher

    2016-12-01

    The desire for local, fresh produce year round is driving the growth of hydroponic growing systems in the United States. Many food crops, such as leafy greens and culinary herbs, grown within hydroponics systems have their root systems submerged in recirculating nutrient-dense fertilizer solutions from planting through harvest. If a foodborne pathogen were introduced into this water system, the risk of contamination to the entire crop would be high. Hence, this study was designed to determine whether Escherichia coli O157:H7, non-O157 Shiga toxin-producing E. coli , and Salmonella were able to survive and reproduce in two common hydroponic fertilizer solutions and in water or whether the bacteria would be killed or suppressed by the fertilizer solutions. All the pathogens grew by 1 to 6 log CFU/ml over a 24-h period, depending on the solution. E. coli O157:H7 reached higher levels in the fertilizer solution with plants (3.12 log CFU/ml), whereas non-O157 Shiga toxin-producing E. coli and Salmonella reached higher levels in the fertilizer solution without plants (1.36 to 3.77 log CFU/ml). The foodborne pathogens evaluated here survived for 24 h in the fertilizer solution, and populations grew more rapidly in these solutions than in plain water. Therefore, human pathogens entering the fertilizer solution tanks in hydroponic systems would be expected to rapidly propagate and spread throughout the system and potentially contaminate the entire crop.

  7. Extended-Spectrum Beta-Lactamases Producing E. coli in Wildlife, yet Another Form of Environmental Pollution?

    PubMed Central

    Guenther, Sebastian; Ewers, Christa; Wieler, Lothar H.

    2011-01-01

    Wildlife is normally not exposed to clinically used antimicrobial agents but can acquire antimicrobial resistant bacteria through contact with humans, domesticated animals and the environment, where water polluted with feces seems to be the most important vector. Escherichia coli, an ubiquitous commensal bacterial species colonizing the intestinal tract of mammals and birds, is also found in the environment. Extended-spectrum beta-lactamases producing E. coli (ESBL-E. coli) represent a major problem in human and veterinary medicine, particular in nosocomial infections. Additionally an onset of community-acquired ESBL-E. coli infections and an emergence in livestock farming has been observed in recent years, suggesting a successful transmission as well as persistence of ESBL-E. coli strains outside clinical settings. Another parallel worldwide phenomenon is the spread of ESBL-E. coli into the environment beyond human and domesticated animal populations, and this seems to be directly influenced by antibiotic practice. This might be a collateral consequence of the community-onset of ESBL-E. coli infections but can result (a) in a subsequent colonization of wild animal populations which can turn into an infectious source or even a reservoir of ESBL-E. coli, (b) in a contribution of wildlife to the spread and transmission of ESBL-E. coli into fragile environmental niches, (c) in new putative infection cycles between wildlife, domesticated animals and humans, and (d) in problems in the medical treatment of wildlife. This review aims to summarize the current knowledge on ESBL-E. coli in wildlife, in turn underlining the need for more large scale investigations, in particular sentinel studies to monitor the impact of multiresistant bacteria on wildlife. PMID:22203818

  8. Risk Factors for Sporadic Shiga Toxin–producing Escherichia coli Infections in Children, Argentina1

    PubMed Central

    Rivas, Marta; Sosa-Estani, Sergio; Rangel, Josefa; Caletti, Maria G.; Vallés, Patricia; Roldán, Carlos D.; Balbi, Laura; Marsano de Mollar, Maria C.; Amoedo, Diego; Miliwebsky, Elizabeth; Chinen, Isabel; Hoekstra, Robert M.; Mead, Paul

    2008-01-01

    We evaluated risk factors for sporadic Shiga toxin–producing Escherichia coli (STEC) infection among children in Argentina. We conducted a prospective case–control study in 2 sites and enrolled 150 case-patients and 299 controls. The median age of case-patients was 1.8 years; 58% were girls. Serotype O157:H7 was the most commonly isolated STEC. Exposures associated with infection included eating undercooked beef, living in or visiting a place with farm animals, and contact with a child <5 years of age with diarrhea. Protective factors included the respondent reporting that he or she always washed hands after handling raw beef and the child eating more than the median number of fruits and vegetables. Many STEC infections in children could be prevented by avoiding consumption of undercooked beef, limiting exposure to farm animals and their environment, not being exposed to children with diarrhea, and washing hands after handling raw beef. PMID:18439359

  9. Shiga Toxin–producing Escherichia coli Serotype O78:H– in Family, Finland, 2009

    PubMed Central

    Lienemann, Taru; Salo, Eeva; Rimhanen-Finne, Ruska; Rönnholm, Kai; Taimisto, Mari; Hirvonen, Jari J.; Tarkka, Eveliina; Kuusi, Markku

    2012-01-01

    Shiga toxin–producing Escherichia coli (STEC) is a pathogen that causes gastroenteritis and bloody diarrhea but can lead to severe disease, such as hemolytic uremic syndrome (HUS). STEC serotype O78:H– is rare among humans, and infections are often asymptomatic. We detected a sorbitol-fermenting STEC O78:H–stx1c:hlyA in blood and fecal samples of a 2-week-old boy who had bacteremia and HUS and in fecal samples of his asymptomatic family members. The phenotypic and genotypic characteristics and the virulence properties of this invasive STEC were investigated. Our findings demonstrate that contrary to earlier suggestions, STEC under certain conditions can invade the human bloodstream. Moreover, this study highlights the need to implement appropriate diagnostic methods for identifying the whole spectrum of STEC strains associated with HUS. PMID:22469631

  10. Longitudinal Monitoring of Extended-Spectrum-Beta-Lactamase/AmpC-Producing Escherichia coli at German Broiler Chicken Fattening Farms

    PubMed Central

    Friese, A.; von Salviati, C.; Guerra, B.; Käsbohrer, A.; Kreienbrock, L.; Roesler, U.

    2013-01-01

    Antimicrobial resistance of Escherichia coli to modern beta-lactam antibiotics due to the production of extended-spectrum beta-lactamases (ESBL) and/or plasmid-mediated AmpC beta-lactamases (AmpC) represents an emerging and increasing resistance problem that dramatically limits therapeutic options in both human and veterinary medicine. The presence of ESBL/AmpC genes in commensal E. coli from food-producing animals like broilers may pose a human health hazard. However, there are no data available concerning the prevalence of ESBL/AmpC-producing E. coli in German broiler flocks using selective methods. In this longitudinal study, samples were taken from seven conventional broiler fattening farms at three different times within one fattening period. Various samples originating from the animals as well as from their direct environment in the barn were investigated for the occurrence of ESBL/AmpC-producing E. coli. Average detection levels of 51, 75, and 76% in animal samples collected during the three samplings in the course of the fattening period demonstrate a colonization of even 1-day-old chicks, as well as a continuous significant (P < 0.001) increase in prevalence thereafter. The detection frequencies in housing environmental samples were relatively high, with an increase over time, and ranged between 54.2 and 100%. A total of 359 E. coli isolates were characterized by PCR and partly via the disc diffusion method. This study shows that prevalence of ESBL/AmpC-producing E. coli increases during the fattening period of the broiler flocks examined. Both colonized day-old chicks and contaminated farm environments could represent significant sources of ESBL/AmpC-producing E. coli in German broiler fattening farms. PMID:23747697

  11. Longitudinal monitoring of extended-spectrum-beta-lactamase/AmpC-producing Escherichia coli at German broiler chicken fattening farms.

    PubMed

    Laube, H; Friese, A; von Salviati, C; Guerra, B; Käsbohrer, A; Kreienbrock, L; Roesler, U

    2013-08-01

    Antimicrobial resistance of Escherichia coli to modern beta-lactam antibiotics due to the production of extended-spectrum beta-lactamases (ESBL) and/or plasmid-mediated AmpC beta-lactamases (AmpC) represents an emerging and increasing resistance problem that dramatically limits therapeutic options in both human and veterinary medicine. The presence of ESBL/AmpC genes in commensal E. coli from food-producing animals like broilers may pose a human health hazard. However, there are no data available concerning the prevalence of ESBL/AmpC-producing E. coli in German broiler flocks using selective methods. In this longitudinal study, samples were taken from seven conventional broiler fattening farms at three different times within one fattening period. Various samples originating from the animals as well as from their direct environment in the barn were investigated for the occurrence of ESBL/AmpC-producing E. coli. Average detection levels of 51, 75, and 76% in animal samples collected during the three samplings in the course of the fattening period demonstrate a colonization of even 1-day-old chicks, as well as a continuous significant (P < 0.001) increase in prevalence thereafter. The detection frequencies in housing environmental samples were relatively high, with an increase over time, and ranged between 54.2 and 100%. A total of 359 E. coli isolates were characterized by PCR and partly via the disc diffusion method. This study shows that prevalence of ESBL/AmpC-producing E. coli increases during the fattening period of the broiler flocks examined. Both colonized day-old chicks and contaminated farm environments could represent significant sources of ESBL/AmpC-producing E. coli in German broiler fattening farms.

  12. Shiga toxin-producing Escherichia coli (STEC) O22:H8 isolated from cattle reduces E. coli O157:H7 adherence in vitro and in vivo.

    PubMed

    Martorelli, L; Albanese, A; Vilte, D; Cantet, R; Bentancor, A; Zolezzi, G; Chinen, I; Ibarra, C; Rivas, M; Mercado, E C; Cataldi, A

    2017-09-01

    Shiga toxin-producing Escherichia coli (STEC) are a group of bacteria responsible for food-associated diseases. Clinical features include a wide range of symptoms such as diarrhea, hemorrhagic colitis and the hemolytic uremic syndrome (HUS), a life-threatening condition. Our group has observed that animals naturally colonized with STEC strains of unknown serotype were not efficiently colonized with E. coli O157:H7 after experimental infection. In order to assess the basis of the interference, three STEC strains were isolated from STEC persistently-colonized healthy cattle from a dairy farm in Buenos Aires, Argentina. The three isolated strains are E. coli O22:H8 and carry the stx1 and stx2d genes. The activatable activity of Stx2d was demonstrated in vitro. The three strains carry the adhesins iha, ehaA and lpfO113. E. coli O22:H8 formed stronger biofilms in abiotic surface than E. coli O157:H7 (eae+, stx2+) and displayed a more adherent phenotype in vitro towards HeLa cells. Furthermore, when both serotypes were cultured together O22:H8 could reduce O157:H7 adherence in vitro. When calves were intragastrically pre-challenged with 10(8) CFU of a mixture of the three STEC strains and two days later challenged with the same dose of the strain E. coli O157:H7 438/99, the shedding of the pathogen was significantly reduced. These results suggest that E. coli O22:H8, a serotype rarely associated with human illness, might compete with O157:H7 at the bovine recto-anal junction, making non-O157 carrying-calves less susceptible to O157:H7 colonization and shedding of the bacteria to the environment. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Real-time isothermal detection of Shiga toxin-producing Escherichia coli using recombinase polymerase amplification.

    PubMed

    Murinda, Shelton E; Ibekwe, A Mark; Zulkaffly, Syaizul; Cruz, Andrew; Park, Stanley; Razak, Nur; Paudzai, Farah Md; Ab Samad, Liana; Baquir, Khairul; Muthaiyah, Kokilah; Santiago, Brenna; Rusli, Amirul; Balkcom, Sean

    2014-07-01

    Shiga toxin-producing Escherichia coli (STEC) are a major family of foodborne pathogens of public health, zoonotic, and economic significance in the United States and worldwide. To date, there are no published reports on use of recombinase polymerase amplification (RPA) for STEC detection. The primary goal of this study was to assess the potential application of RPA in detection of STEC. This study focused on designing and evaluating RPA primers and fluorescent probes for isothermal (39°C) detection of STEC. Compatible sets of candidate primers and probes were designed for detection of Shiga toxin 1 and 2 (Stx1 and 2), respectively. The sets were evaluated for specificity and sensitivity against STEC (n=12) of various stx genotypes (stx1/stx2, stx1, or stx2, respectively), including non-Stx-producing E. coli (n=28) and other genera (n=7). The primers and probes that were designed targeted amplification of the subunit A moiety of stx1 and stx2. The assay detected STEC in real time (within 5-10 min at 39°C) with high sensitivity (93.5% vs. 90%; stx1 vs. stx2), specificity (99.1% vs. 100%; stx1 vs. stx2), and predictive value (97.9% for both stx1 vs. stx2). Limits of detection of ∼ 5-50 colony-forming units/mL were achieved in serially diluted cultures grown in brain heart infusion broth. This study successfully demonstrated for the first time that RPA can be used for isothermal real-time detection of STEC.

  14. Emergence of KPC-2-producing Escherichia coli isolates in an urban river in Harbin, China.

    PubMed

    Xu, Guofeng; Jiang, Yue; An, Wei; Wang, Hongdong; Zhang, Xiuying

    2015-09-01

    Three KPC-2-producing Escherichia coli (E1, E2, and E3) were recovered from water samples of an urban river in the city of Harbin, China. Antimicrobial susceptibility was determined by broth microdilution. Molecular characterization and genetic relatedness of the isolates were determined by polymerase chain reaction (PCR), pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and PCR-directed phylotyping. Plasmids were analyzed by conjugation, S1-PFGE, Southern blotting and PCR-based replicon typing (PBRT). The genetic environment of the bla KPC-2 gene was determined using PCR and sequencing. PCR analyses revealed that the E1 isolate carried the bla KPC-2, bla CMY-2, bla TEM-1, bla CTX-M-14, and qnrB2 genes and belonged to sequence type ST410, phylogenetic type A; the E2 isolate was assigned to ST131-B2 and carried the bla KPC-2, bla TEM-1, bla CTX-M-3, bla DHA-1, aac(6')-Ib-cr, and qnrS1 genes; while the E3 isolate was of ST648-D and possessed bla KPC-2, bla TEM-1, bla OXA-1, bla CTX-M-15, armA, and aac(6')-Ib-cr genes. PFGE demonstrated that each of the three KPC-2-producing E. coli isolates exhibited an individual XbaI patterns. The bla KPC-2 gene was located on plasmids of 60-140 kb with IncA/C, IncN, or non-typeable replicon types. The genetic environment of bla KPC-2 of the three strains was consistent with the genetic structure of bla KPC-2 on the plasmid pKP048.

  15. Mexican unpasteurised fresh cheeses are contaminated with Salmonella spp., non-O157 Shiga toxin producing Escherichia coli and potential uropathogenic E. coli strains: A public health risk.

    PubMed

    Guzman-Hernandez, Rosa; Contreras-Rodriguez, Araceli; Hernandez-Velez, Rosa; Perez-Martinez, Iza; Lopez-Merino, Ahide; Zaidi, Mussaret B; Estrada-Garcia, Teresa

    2016-11-21

    Fresh cheeses are a main garnish of Mexican food. Consumption of artisanal fresh cheeses is very common and most of them are made from unpasteurised cow milk. A total of 52 fresh unpasteurised cheeses of five different types were purchased from a variety of suppliers from Tabasco, Mexico. Using the most probable number method, 67% and 63% of samples were positive for faecal coliforms and E. coli, respectively; revealing their low microbiological quality. General hygienic conditions and practices of traditional cheese manufacturers were poor; most establishments had unclean cement floors, all lacked windows and doors screens, and none of the food-handlers wore aprons, surgical masks or bouffant caps. After analysing all E. coli isolates (121 strains) for the presence of 26 virulence genes, results showed that 9 (17%) samples were contaminated with diarrheagenic E. coli strains, 8 harboured non-O157 Shiga toxin producing E. coli (STEC), and one sample contained both STEC and diffusely adherent E. coli strains. All STEC strains carried the stx1 gene. Potential uropathogenic E. coli (UPEC) strains were isolated from 15 (29%) samples; the most frequent gene combination was fimA-agn43. Two samples were contaminated with Salmonella. The results demonstrated that unpasteurised fresh cheeses produced in Tabasco are of poor microbiological quality and may frequently harbour foodborne pathogens. Food safety authorities in Mexico need to conduct more rigorous surveillance of fresh cheeses. Furthermore, simple and inexpensive measures as establishing programs emphasizing good hand milking practices and hygienic manufacturing procedures may have a major effect on improving the microbiological quality of these food items. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Use of ramification amplification assay for detection of Escherichia coli O157:H7 and other E. coli Shiga toxin-producing strains.

    PubMed

    Li, Fan; Zhao, Chunyan; Zhang, Wandi; Cui, Shenghui; Meng, Jianghong; Wu, Josephine; Zhang, David Y

    2005-12-01

    Escherichia coli O157:H7 and other Shiga toxin-producing E. coli (STEC) strains are important human pathogens that are mainly transmitted through the food chain. These pathogens have a low infectious dose and may cause life-threatening illnesses. However, detection of this microorganism in contaminated food or a patient's stool specimens presents a diagnostic challenge because of the low copy number in the sample. Often, a more sensitive nucleic acid amplification method, such as PCR, is required for rapid detection of this microorganism. Ramification amplification (RAM) is a recently introduced isothermal DNA amplification technique that utilizes a circular probe for target detection and achieves exponential amplification through the mechanism of primer extension, strand displacement, and ramification. In this study, we synthesized a circular probe specific for the Shiga toxin 2 gene (stx(2)). Our results showed that as few as 10 copies of stx(2) could be detected, indicating that the RAM assay was as sensitive as conventional PCR. We further tested 33 isolates of E coli O157:H7, STEC, Shigella dysenteriae, and nonpathogenic E. coli by RAM assay. Results showed that all 27 STEC isolates containing the stx(2) gene were identified by RAM assay, while S. dysenteriae and nonpathogenic E. coli isolates were undetected. The RAM results were 100% in concordance with those of PCR. Because of its simplicity and isothermal amplification, the RAM assay could be a useful method for detecting STEC in food and human specimens.

  17. Rapid Identification and Differentiation of Clinical Isolates of Enteropathogenic Escherichia coli (EPEC), Atypical EPEC, and Shiga Toxin-Producing Escherichia coli by a One-Step Multiplex PCR Method

    PubMed Central

    Müller, Daniel; Hagedorn, Peter; Brast, Sabine; Heusipp, Gerhard; Bielaszewska, Martina; Friedrich, Alexander W.; Karch, Helge; Schmidt, M. Alexander

    2006-01-01

    Enteropathogenic Escherichia coli (EPEC), atypical enteropathogenic E. coli, and Shiga toxin-producing E. coli differ in their virulence factor profiles, clinical manifestations, and prognosis, and they require different therapeutic measures. We developed and evaluated a robust multiplex PCR to identify these pathogroups based on sequences complementary to escV, bfpB, stx1, and stx2. PMID:16825399

  18. Contact precautions for preventing nosocomial transmission of ESBL-producing Escherichia coli - a point/counterpoint review.

    PubMed

    Tschudin-Sutter, Sarah; Lucet, Jean-Christophe; Mutters, Nico T; Tacconelli, Evelina; Zahar, Jean Ralph; Harbarth, Stephan

    2017-04-03

    Contact precautions have been recommended for hospitalized patients colonized or infected with extendend-spectrum beta-lactamase (ESBL)-producing Escherichia coli. Despite such recommendations, a steady, worldwide increase of ESBL-E. coli has been reported. We discuss arguments in favor and against contact precautions for ESBL- E.coli-carriers.Healthcare settings with high ESBL-E.coli colonization pressure, extended hospital stay and close contact between vulnerable patients may serve as amplification platform further accelerating transmission. However, the evidence base for justifying the implementation of contact precautions for all ESBL-E.coli carriers remains weak.Until more high-level evidence is available, we support the attitude that hospitals and countries should carefully evaluate their decision on whether to implement contact precautions for ESBL-E.coli carriers. It is likely that a large majority of patients and wards do not need to rely on contact precautions for preventing nosocomial ESBL-E.coli transmission in non-epidemic settings, without harming patient-safety, providing sufficient compliance with standard precautions and ongoing surveillance. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  19. ESBL-producing Escherichia coli and Klebsiella pneumoniae: The most prevalent clinical isolates obtained between 2005 and 2012 in Mexico.

    PubMed

    Barrios, Humberto; Garza-Ramos, Ulises; Mejia-Miranda, Ilse; Reyna-Flores, Fernando; Sánchez-Pérez, Alejandro; Mosqueda-García, Dalila; Silva-Sanchez, Jesus

    2017-07-21

    To identify the prevalence of ESBL genes in the principal group of Enterobacteriaceae causing nosocomial infections and to identify the phylogenetic group in Escherichia coli isolates. There were collected 1084 ESBL-producing Enterobacteriaceae isolates during 2005-2012 from adult patients from 14 hospitals and corresponding to eight states and five regions (SE, S, N, W and NW) in Mexico. The CTX-M-(CTX-M-1 group), SHV-, TLA- and GES-type ESBLs genes were screened. The respective alleles were determined in the most of ESBLs genes. In E. coli isolates selected were used to identify the phylogenetic group. The ESBL-producing Escherichia coli and Klebsiella pneumoniae corresponded the most prevalent clinical isolates. CTX-M-type ESBLs genes were the most common, followed by SHV-type, GES-type and the ESBLs TLA-1 gene. The allelic frequency showed to CTX-M-15 ESBL the most prevalent, followed by the SHV-12, SHV-5 and GES-1, GES-19 in the GES family. Among ESBL-producing E. coli isolates the phylogenetic groups A and D were the most common ones. The present study showed an epidemiological change in terms of bacterial species, placing E. coli as the most frequently isolated bacteria among ESBL-producing Enterobacteriaceae in Mexico, followed by K. pneumoniae. This frequency is accompanied by a high frequency of ESBL CTX-M-15. Copyright © 2017 International Society for Chemotherapy of Infection and Cancer. Published by Elsevier Ltd. All rights reserved.

  20. Enhancement of crystallinity of cellulose produced by Escherichia coli through heterologous expression of bcsD gene from Gluconacetobacter xylinus.

    PubMed

    Sajadi, Elaheh; Babaipour, Valiollah; Deldar, Ali Asghar; Yakhchali, Bagher; Fatemi, Seyed Safa-Ali

    2017-09-01

    To evaluate the crystallinity index of the cellulose produced by Escherichia coli Nissle 1917 after heterologous expression of the cellulose synthase subunit D (bcsD) gene of Gluconacetobacter xylinus BPR2001. The bcsD gene of G. xylinus BPR2001 was expressed in E. coli and its protein product was visualized using SDS-PAGE. FTIR analysis showed that the crystallinity index of the cellulose produced by the recombinants was 0.84, which is 17% more than that of the wild type strain. The increased crystallinity index was also confirmed by X-ray diffraction analysis. The cellulose content was not changed significantly after over-expressing the bcsD. The bcsD gene can improve the crystalline structure of the bacterial cellulose but there is not any significant difference between the amounts of cellulose produced by the recombinant and wild type E. coli Nissle 1917.

  1. Investigation of environmental factors on the prevalence of free bacteriophages against Shiga toxin-producing Escherichia coli strains in produce pre-harvest environment in Salinas, California

    USDA-ARS?s Scientific Manuscript database

    Shiga toxin-producing E. coli (STEC) strains, commensal to gastrointestinal tracts of ruminants or other animals, have been associated with serious human illnesses and high mortality among immunocompromised populations. Along with the detection of STEC strains from fecal-contaminated environments su...

  2. Whole genome sequencing of diverse Shiga toxin-producing and non-producing Escherichia coli strains reveals a variety of virulence and novel antibiotic resistance plasmids

    USDA-ARS?s Scientific Manuscript database

    The genomes of a diverse set of Shiga toxin-producing E. coli strains and the presence of 38 plasmids among all the isolates were determined. Among the novel plasmids found, there were eight that encoded resistance genes to antibiotics, including aminoglycosides, carbapenems, penicillins, cephalosp...

  3. Incidence of acute prostatitis caused by extended-spectrum beta-lactamase-producing Escherichia coli after transrectal prostate biopsy.

    PubMed

    Ozden, Ender; Bostanci, Yakup; Yakupoglu, Kamil Y; Akdeniz, Ekrem; Yilmaz, Ali F; Tulek, Necla; Sarikaya, Saban

    2009-07-01

    To study the clinical and bacteriologic picture of acute prostatitis caused by extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli after transrectal ultrasound-guided prostate biopsy. The retrospective data from 1339 patients who had undergone transrectal ultrasound-guided biopsy from November 2003 to June 2008 were reviewed. An automatic biopsy gun with an 18-gauge needle was used to obtain 10-core biopsies for first biopsies and > or =12-core for repeat biopsies. These patients had received 500 mg ciprofloxacin orally twice daily for 5 days, beginning 24 hours before biopsy. All biopsies were performed as outpatient procedures. Of the 1339 patients, 28 (2.1%) had acute bacterial prostatitis detected after transrectal ultrasound-guided prostate biopsy. Acute prostatitis occurred after the first biopsy in 15 patients (1.3%) and after repeat biopsy in 13 (6.8%). The patients had developed infective symptoms a mean of 3 days after transrectal ultrasound-guided prostate biopsy. Of the 28 patients, 17 (61%) had positive urine and/or blood cultures, including E. coli in 14. Of the 14 patients, 6 had acute prostatitis caused by ESBL-producing E. coli. Bacteria isolated from urine were tested for drug susceptibility to a wide range of antibiotics. All patients with ESBL-producing E. coli were treated with imipenem. The bacteria detected in these urine cultures were resistant to ciprofloxacin, ceftriaxone, sulbactam/ampicillin, and cefazolin. Imipenem and piperacillin-tazobactam were the most active agents against ESBL-producing E. coli. ESBL-producing isolates had a significant reduction in activity for most antimicrobial agents, including fluoroquinolones and amikacin. The prompt initiation of effective antimicrobial treatment is essential in patients with ESBL-producing E. coli, and empirical decisions must be determined by knowledge of the local distribution of pathogens and their susceptibility.

  4. Identification and assessment of the effects of yeast decarboxylases expressed in Escherichia coli for producing higher alcohols.

    PubMed

    Su, H; Zhao, Y; Zhao, H; Wang, M; Li, Q; Jiang, J; Lu, Q

    2014-07-01

    To contribute to the improvement of methods for the regulation and production of higher alcohols using micro-organisms, we assessed the yields achieved using 10 decarboxylase genes from three different yeast species (Saccharomyces cerevisiae, Candida tropicalis and Pichia pastoris) by cloning them into vectors and overexpressing them in Escherichia coli hosts of different genotypes. Genes that produced the greatest yields in higher alcohol production were further assessed for the catalytic effects of the decarboxylase enzymes in the different E. coli hosts. A major metabolic pathway is structured via overexpressing a series of five genes, to detect the effect of decarboxylase on the production of higher alcohols. Results suggested that these genes can facilitate production of specific types of higher alcohols by diverse types of E. coli. We also showed that they play direct roles in the metabolic pathways that lead to production of higher alcohols in E. coli. The gene ARO10 from S. cerevisiae produced the highest yields for producing isobutanol and isopentanol in the host JM109. Significant differences were found in the types of higher alcohols and yields produced within the same host, for the genes PAD1, GAD1, SPE1 from S. cerevisiae. Similar results were observed for the genes ODC1 and gadB from Candida tropicalis and P. pastoris, respectively. Investigation of these genes for identification of the key enzymatic steps or regulatory pathways involved in the Ehrlich metabolic network to produce higher alcohols is paramount for producing biofuels. The selected genes are promising targets for the development of improved production strains. This is the first published assessment of the effects of decarboxylases from different yeast species that were expressed in E. coli, for the production of higher alcohols. Our results provide guidance for future studies about the use of yeast enzymes for transforming or constructing a new metabolic pathway utilizing E. coli for the

  5. Ciprofloxacin-resistant, CTX-M-15-producing Escherichia coli ST131 clone in extraintestinal infections in Italy.

    PubMed

    Cerquetti, M; Giufrè, M; García-Fernández, A; Accogli, M; Fortini, D; Luzzi, I; Carattoli, A

    2010-10-01

    Quinolone and β-lactam resistance mechanisms and clonal relationships were characterized among Escherichia coli isolates resistant to ciprofloxacin and extended-spectrum cephalosporins associated with human extra-intestinal infections in Rome. The E. coli. ST131 clone was found to be prevalent. This clone invariably carried a specific pattern of substitutions in the topoisomerase genes and all isolates but one produced CTX-M-15. One ST131 isolate produced SHV-12. The new ST131 variant described here is of particular concern because it combines fluoroquinolone resistance and chromosomally encoded CTX-M-15.

  6. Whole genome sequencing of ESBL-producing Escherichia coli isolated from patients, farm waste and canals in Thailand.

    PubMed

    Runcharoen, Chakkaphan; Raven, Kathy E; Reuter, Sandra; Kallonen, Teemu; Paksanont, Suporn; Thammachote, Jeeranan; Anun, Suthatip; Blane, Beth; Parkhill, Julian; Peacock, Sharon J; Chantratita, Narisara

    2017-09-06

    Tackling multidrug-resistant Escherichia coli requires evidence from One Health studies that capture numerous potential reservoirs in circumscribed geographic areas. We conducted a survey of extended β-lactamase (ESBL)-producing E. coli isolated from patients, canals and livestock wastewater in eastern Thailand between 2014 and 2015, and analyzed isolates using whole genome sequencing. The bacterial collection of 149 isolates consisted of 84 isolates from a single hospital and 65 from the hospital sewer, canals and farm wastewater within a 20 km radius. E. coli ST131 predominated the clinical collection (28.6%), but was uncommon in the environment. Genome-based comparison of E. coli from infected patients and their immediate environment indicated low genetic similarity overall between the two, although three clinical-environmental isolate pairs differed by ≤ 5 single nucleotide polymorphisms. Thai E. coli isolates were dispersed throughout a phylogenetic tree containing a global E. coli collection. All Thai ESBL-positive E. coli isolates were multidrug resistant, including high rates of resistance to tobramycin (77.2%), gentamicin (77.2%), ciprofloxacin (67.8%) and trimethoprim (68.5%). ESBL was encoded by six different CTX-M elements and SHV-12. Three isolates from clinical samples (n = 2) or a hospital sewer (n = 1) were resistant to the carbapenem drugs (encoded by NDM-1, NDM-5 or GES-5), and three isolates (clinical (n = 1) and canal water (n = 2)) were resistant to colistin (encoded by mcr-1); no isolates were resistant to both carbapenems and colistin. Tackling ESBL-producing E. coli in this setting will be challenging based on widespread distribution, but the low prevalence of resistance to carbapenems and colistin suggests that efforts are now required to prevent these from becoming ubiquitous.

  7. Occurrence of carbapenemase-producing Klebsiella pneumoniae and Escherichia coli in the European survey of carbapenemase-producing Enterobacteriaceae (EuSCAPE): a prospective, multinational study.

    PubMed

    Grundmann, Hajo; Glasner, Corinna; Albiger, Barbara; Aanensen, David M; Tomlinson, Chris T; Andrasević, Arjana Tambić; Cantón, Rafael; Carmeli, Yehuda; Friedrich, Alexander W; Giske, Christian G; Glupczynski, Youri; Gniadkowski, Marek; Livermore, David M; Nordmann, Patrice; Poirel, Laurent; Rossolini, Gian M; Seifert, Harald; Vatopoulos, Alkiviadis; Walsh, Timothy; Woodford, Neil; Monnet, Dominique L

    2017-02-01

    Gaps in the diagnostic capacity and heterogeneity of national surveillance and reporting standards in Europe make it difficult to contain carbapenemase-producing Enterobacteriaceae. We report the development of a consistent sampling framework and the results of the first structured survey on the occurrence of carbapenemase-producing Klebsiella pneumoniae and Escherichia coli in European hospitals. National expert laboratories recruited hospitals with diagnostic capacities, who collected the first ten carbapenem non-susceptible clinical isolates of K pneumoniae or E coli and ten susceptible same-species comparator isolates and pertinent patient and hospital information. Isolates and data were relayed back to national expert laboratories, which made laboratory-substantiated information available for central analysis. Between Nov 1, 2013, and April 30, 2014, 455 sentinel hospitals in 36 countries submitted 2703 clinical isolates (2301 [85%] K pneumoniae and 402 (15%) E coli). 850 (37%) of 2301 K pneumoniae samples and 77 (19%) of 402 E coli samples were carbapenemase (KPC, NDM, OXA-48-like, or VIM) producers. The ratio of K pneumoniae to E coli was 11:1. 1·3 patients per 10 000 hospital admissions had positive clinical specimens. Prevalence differed greatly, with the highest rates in Mediterranean and Balkan countries. Carbapenemase-producing K pneumoniae isolates showed high resistance to last-line antibiotics. This initiative shows an encouraging commitment by all participants, and suggests that challenges in the establishment of a continent-wide enhanced sentinel surveillance for carbapenemase-producing Enterobacteriaeceae can be overcome. Strengthening infection control efforts in hospitals is crucial for controlling spread through local and national health care networks. European Centre for Disease Prevention and Control. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Characterization of Extended-Spectrum-Beta-Lactamase-Producing Escherichia coli Strains Involved in Maternal-Fetal Colonization: Prevalence of E. coli ST131

    PubMed Central

    Birgy, André; Mariani-Kurkdjian, Patricia; Bidet, Philippe; Doit, Catherine; Genel, Nathalie; Courroux, Céline; Bingen, Edouard

    2013-01-01

    Maternal-fetal Escherichia coli infections, such as neonatal bacteremia and meningitis, are important causes of morbidity and mortality. From 2006 to 2010, we studied newborns and their mothers who were colonized with E. coli in a French hospital in order to document (i) the epidemiology and genetic characteristics of extended-spectrum-beta-lactamase (ESBL)-producing E. coli strains, (ii) the prevalence of associated virulence genes, (iii) the prevalence of clone sequence type 131 (ST131), and (iv) the genetic relationship among ESBL-producing strains. Among the 2,755 E. coli cultures recovered from vaginal or neonatal samples, 68 were ESBL producers (2.46%). We found a wide diversity of ESBL genes, with the majority being blaCTX-M-14, blaCTX-M-1, and blaCTX-M-15, distributed among the 4 main phylogenetic groups. Genes encoding virulence factors were found in 90.7% of the isolates, with ≥2 virulence genes present in 76% of cases. The prevalence of ST131 among ESBL-producing E. coli isolates was 9.4% (6/64). Five of these 6 ST131 isolates possessed blaCTX-M-15 enzymes (and also were resistant to quinolones), and one possessed blaCTX-M-2 enzymes. Two possessed virulence genes, suggesting the presence of pathogenicity island IIJ96 (PAI IIJ96)-like domains. Pulsed-field gel electrophoresis (PFGE) revealed a high level of genomic diversity overall, except for 3 closely related isolates belonging to clonal group ST131. Repetitive PCR showed that the six ST131 isolates were closely related to ST131 control strains (>95% similarity). This study shows a high prevalence of ESBL-producing E. coli strains and clonal group ST131 in the French maternal-fetal population. These results suggest a widespread distribution of ESBL enzymes in the community and highlight the early transmission between mothers and neonates. These findings are worrisome, especially for this particularly vulnerable population. PMID:23515552

  9. Expanded spectrum β-lactamase producing Escherichia coli isolated from chickens with colibacillosis in Egypt.

    PubMed

    El-Shazly, D A; Nasef, S A; Mahmoud, F F; Jonas, Daniel

    2017-07-01

    Throughout the world, expanded spectrum β-lactamases (ESBL) are increasing among clinical isolates of Enterobacteriaceae, both in humans and animals. Unfortunately, there is a paucity of data on ESBL or Ampicillin class C β-lactamase (AmpC) in Egypt, although antimicrobial consumption is high in this developing country. This study aims to characterize the resistance mechanisms to expanded spectrum cephalosporins among resistant veterinary Escherichia coli isolates in Egypt. We investigated 50 clinical multi-resistant E. coli strains isolated from 20 chicken farms for production of ESBL or AmpC. Antibiotic susceptibility was tested by Clinical and Laboratory Standards Institute (CLSI) disk diffusion and ESBL confirmatory tests. PCR and sequencing were performed to screen for plasmid mediated ESBL genes and genes encoding AmpC β-lactamases. All the isolates were phylogentically classified, investigated for harboring class 1 integrons, and genotyped by amplified fragment length polymorphism (AFLP). Three strains showed ESBL and 6 strains AmpC phenotypic patterns, respectively, with confirmed ESBL genes of blaTEM-57, blaSHV-12, blaCTX-M-14, and blaCMY-2 for AmpC producing strains. All ESBL strains belonged to phylogroup D with different clones isolated from different flocks, while most of the AmpC strains belonged to phylogroup B1 (4/6) and were assigned to the same genotype distributed in 2 different farms. Class 1 integrons were disseminated in 60% of all tested strains and in 100% of ESBL and AmpC strains. These results highlight the antimicrobial resistance problem in Egypt, caused in all probability by unwise use of antimicrobials in animal husbandry. The results call for a nationwide surveillance program to monitor antimicrobial resistance. © 2017 Poultry Science Association Inc.

  10. Evaluation of eight agar media for the isolation of shiga toxin-Producing Escherichia coli.

    PubMed

    Gill, Alexander; Huszczynski, George; Gauthier, Martine; Blais, Burton

    2014-01-01

    The growth characteristics of 96 shiga toxin-producing Escherichia coli (STEC) strains representing 36 different O-types (including priority O types O26, O45, O103, O111, O121, O145 and O157) on commercial and in-house agar media were studied. The ability of the strains to grow on agar media with varying selective supplement formulations was evaluated using MacConkey Agar (MAC); Rainbow® Agar O157 (RBA); Rainbow® Agar O157 with manufacturer-recommended selective supplements (RBA-NT); Rainbow® Agar O157 with USDA-recommended selective supplements (RBA-USDA); CHROMagar STEC™ (CH STEC); Tryptone Bile agar containing cefixime and tellurite (TBA-CT); Tryptone Bile agar containing cefixime, tellurite, eosin and methylene blue (TBA-EM); and VTEC agar. All of the strains were able to grow on MAC, RBA and VTEC agar, whereas a number of strains (including some non-O157 priority O types) were unable to grow on the highly selective media CH STEC, RBA-NT, RBA-USDA, TBA-EM and TBA-CT. Only RBA-NT and CH STEC exhibited significant inhibition of background flora from ground beef enrichment. Significant inhibition of background flora from beef trim enrichment was observed with RBA-NT, RBA-USDA, CH STEC, TBA-EM and VTEC agar. With exception of E. coli O157, several different colony morphologies were observed on the differential plating media among strains of the same O type, indicating that this colony morphology is not a reliable means of identifying target STEC. These results suggest that an approach to maximize the recovery of target STEC from beef enrichment cultures is dual plating on lesser (RBA, MAC, VTEC agar) and more highly (RBA-NT, CH STEC) selective agars. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  11. Phylogenetic relationships of Shiga toxin-producing Escherichia coli isolated from Peruvian children

    PubMed Central

    Contreras, C. A.; Ruiz, J.; Lacher, D. W.; Rivera, F. P.; Saenz, Y.; Chea-Woo, E.; Zavaleta, N.; Gil, A. I.; Lanata, C. F.; Huicho, L.; Maves, R. C.; Torres, C.; DebRoy, C.; Cleary, T. G.

    2011-01-01

    The aim of this study was to determine the prevalence, virulence factors (stx, eae, ehxA and astA) and phylogenetic relationships [PFGE and multilocus sequence typing (MLST)] of Shiga toxin-producing Escherichia coli (STEC) strains isolated from four previous cohort studies in 2212 Peruvian children aged <36 months. STEC prevalence was 0.4 % (14/3219) in diarrhoeal and 0.6 % (15/2695) in control samples. None of the infected children developed haemolytic uraemic syndrome (HUS) or other complications of STEC. stx1 was present in 83 % of strains, stx2 in 17 %, eae in 72 %, ehxA in 59 % and astA in 14 %. The most common serotype was O26 : H11 (14 %) and the most common seropathotype was B (45 %). The strains belonged mainly to phylogenetic group B1 (52 %). The distinct combinations of alleles across the seven MLST loci were used to define 13 sequence types among 19 STEC strains. PFGE typing of 20 STEC strains resulted in 19 pulsed-field patterns. Comparison of the patterns revealed 11 clusters (I–XI), each usually including strains belonging to different serotypes; one exception was cluster VI, which gathered exclusively seven strains of seropathotype B, clonal group enterohaemorrhagic E. coli (EHEC) 2 and phylogenetic group B1. In summary, STEC prevalence was low in Peruvian children with diarrhoea in the community setting. The strains were phylogenetically diverse and associated with mild infections. However, additional studies are needed in children with bloody diarrhoea and HUS. PMID:21292859

  12. [An effective scheme to produce recombinant uracil-DNA glycosylase of Escherichia coli for PCR diagnostics].

    PubMed

    Dmitrochenko, A E; Turiianskaia, O M; Gilep, A A; Usanov, S A; Iantsevich, A V

    2014-01-01

    An effective scheme has been developed to produce recombinant uracil-DNA glycosylase of Escherichia coli K12 intended to be used for PCR diagnostics, making it possible to achieve a high yield of the end product using a two-stage purification. The gene encoding this enzyme was cloned into the pCWori vector within the same reading frame with six residues of histidine in the C-erminal sequence. Using this vector and the E. coli DH5alpha, a host-vector expression system has been developed and conditions for protein synthesis have been optimized. To purify the protein, metal affinity chromatography with further dialysis was used to remove imidazole. The enzyme yield was no less than 60 mg of the end protein per 1 L of the culture medium. The concordance between amino acid sequences of the recombinant and native enzymes was proved by peptide mass fingerprinting and mass spectrometry. A rapid test to determine the activity of the enzyme preparation was suggested. It was found that the activity of 1.0 mg of the recombinant protein is no less than 3 x 10(3) units. The recombinant enzyme was most stable at pH 8.0 and an ionic strength of the solution equal to 200 mM; it lost its activity completely for 10 min at 60 degrees C. Storage during 1 h at 20 degrees C resulted in the loss of no more than 30% of activity. In the enzyme preparation, the activity of DNase was absent. The free energy of the unfolding of the protein globule of the recombinant uracil-DNA glycosylase is 23.1 +/- 0.2 kJ/mol. The data obtained indicate that the recombinant enzyme may be recommended for use in PCR diagnostics to prevent the appearance of false positive results caused by pollution of the reaction mixture by products of the preceding reactions.

  13. Molecular characterization of integrons in clinical isolates of betalactamase-producing Escherichia coli and Klebsiella pneumoniae in Iran.

    PubMed

    Zeighami, Habib; Haghi, Fakhri; Hajiahmadi, Fahimeh

    2015-06-01

    Integrons are considered to play a significant role in the evolution and spread of antibiotic resistance genes. A total of 349 clinical isolates of Escherichia coli and Klebsiella pneumoniae were investigated for molecular characterization of integrons and betalactamases. Antimicrobial susceptibility testing was also performed as the Clinical and Laboratory Standards Institute (CLSI) guidelines. The frequency of extended spectrum betalactamases (ESBL) or metallo-betalactamases (MBL)-producing isolates, patient demographics, and the susceptibility to various antimicrobial agents were described. BlaCTX-M was the most frequently detected betalactamase in all isolates. Moreover, MBL producing K. pneumoniae carried blaIMP and blaVIM at 100 and 41·6%, respectively but no MBL-positive E. coli was detected. Class 1 integrons were more frequent among E. coli and K. pneumoniae isolates in comparison with class 2 integrons and the frequency of intI2 in K. pneumoniae was significantly higher than E. coli isolates. Five different resistance gene arrays were identified among class 1 integrons. Dihydrofolate reductase (dfrA) and aminoglycoside adenyltransferase (aad) gene cassettes were found to be predominant in the class 1 integrons. These results indicate that class 1 integrons are widespread among ESBL-producing isolates of K. pneumoniae and E. coli and appropriate surveillance and control measures are essential to prevent further dissemination of these elements among Enterobacteriaceae in our country.

  14. High-virulence CMY-2- and CTX-M-2-producing avian pathogenic Escherichia coli strains isolated from commercial turkeys.

    PubMed

    da Silva, Ketrin Cristina; Cunha, Marcos Paulo Vieira; Cerdeira, Louise; de Oliveira, Maria Gabriela Xavier; de Oliveira, Mirela Caroline Vilela; Gomes, Cleise Ribeiro; Lincopan, Nilton; Knöbl, Terezinha; Moreno, Andrea Micke

    2017-01-01

    This study reports the high-virulence phylogenetic backgrounds of CMY-2- and CTX-M-2-producing avian pathogenic Escherichia coli strains isolated from turkeys sent to slaughter and condemned by airsacculitis in Brazil. Among 300 air sac samples, seven E. coli strains produced plasmid-mediated CMY-2-type AmpC, of which three carried also the blaCTX-M-2 Extended Spectrum Beta-Lactamase encoding gene. Interestingly, the transfer of the blaCMY-2 gene was positive for three E. coli strains, being associated with the presence of IncI1 plasmids. The complete sequence of the representative pJB10 plasmid revealed that the blaCMY-2 gene was within a transposon-like element in the classical genetic environment consisting of tnpA-blaCMY-2-blc-sugE structure. This plasmid with 94-kb belonged to the sequence type (ST) 12 among IncI1 plasmids, which has been associated with the worldwide spread of blaCMY-2 among Salmonella enterica and E. coli. Furthermore, to the best of our knowledge, this is the first complete sequence of a CMY-2-encoding plasmid derived from an Escherichia coli isolated from food-producing animals in Latin America.

  15. Short communication: Detection of Shiga toxin-producing Escherichia coli (STEC) in healthy cattle and pigs in Lima, Peru.

    PubMed

    Rivera, F P; Sotelo, E; Morales, I; Menacho, F; Medina, A M; Evaristo, R; Valencia, R; Carbajal, L; Ruiz, J; Ochoa, T J

    2012-03-01

    The aim of this study was to determine the prevalence of Shiga toxin-producing Escherichia coli (STEC) in cattle and pigs as a possible STEC reservoir in Lima, Peru. One hundred and fourteen cattle and 112 pigs from 10 and 4 farms, respectively, were studied. Five E. coli colonies per culture were studied by a multiplex real-time PCR to identify Shiga toxin-producing (stx1, stx2, eaeA), enterotoxigenic (lt, st), enteropathogenic (eaeA), enteroinvasive (ipaH), enteroaggregative (aggR), and diffusely adherent E. coli (daaD). Shiga toxin-producing E. coli were isolated from 16 cattle (14%) but none from pigs. stx1 was found in all bovine isolates, 11 of which also carried eaeA genes (69%); only 1 sample had both stx1 and stx2. Thirteen stx-positive strains were classified as Shiga-toxigenic (81%) using an enzymatic immunoassay, 2 STEC strains were from serogroup O157 (13%), and 7 were sorbitol negative (44%). Enteropathogenic E. coli were detected more frequently in cattle (18%, 20/114) than in pigs (5%, 6/112). To our knowledge, this is the first study on the prevalence of STEC in farms animals in Peru using molecular methods. Further studies are needed in a large number of farms to determine the relevance of these findings and its consequences for public health. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  16. [Construction of butanol-producing pathway from Clostridium saccharobutylicum in Escherichia coli JM109 (DE3) and its fermentation].

    PubMed

    Li, Jin; Han, Ruizhi; Xu, Guochao; Dong, Jinjun; Ni, Ye

    2015-11-04

    ] Several key genes (thlA, bcs-operon/crt-bcd1 -etfB2-fixB2-hbd and adhE) in butanol pathway from Clostridium saccharobutylicum DSM13864 were cloned, and a butanol-producing Escherichia coli strain was successfully constructed. Using genome of Clostridium saccharobutylicum DSM13864 as template, the key genes in butanol synthesis pathway were amplified, the recombinant plasmids pETDuet-bcs and pRSFDuet-thlA-adhE were constructed. Then the resultant plasmids were transformed into E. coli JM109 (DE3) to obtain E. coli BUT1 for butanol production, under the semi-anaerobic condition. Effects of different mediums on butanol production were studied. The recombinant E. coli was capable of producing butanol (25.4 mg/L) under semi-anaerobic fermentation. After optimization on the fermentation medium, butanol titer reached 34.1 mg/L. Butanol production by recombinant E. coli harboring exogenous butanol-producing pathway from Clostridium saccharobutylicum provides a feasible solution to overcome the hurdles in traditional butanol production approach by Clostridia.

  17. Comparable High Rates of Extended-Spectrum-Beta-Lactamase-Producing Escherichia coli in Birds of Prey from Germany and Mongolia

    PubMed Central

    Guenther, Sebastian; Aschenbrenner, Katja; Stamm, Ivonne; Bethe, Astrid; Semmler, Torsten; Stubbe, Annegret; Stubbe, Michael; Batsajkhan, Nyamsuren; Glupczynski, Youri; Wieler, Lothar H.; Ewers, Christa

    2012-01-01

    Frequent contact with human waste and liquid manure from intensive livestock breeding, and the increased loads of antibiotic-resistant bacteria that result, are believed to be responsible for the high carriage rates of ESBL-producing E. coli found in birds of prey (raptors) in Central Europe. To test this hypothesis against the influence of avian migration, we initiated a comparative analysis of faecal samples from wild birds found in Saxony-Anhalt in Germany and the Gobi-Desert in Mongolia, regions of dissimilar human and livestock population characteristics and agricultural practices. We sampled a total of 281 wild birds, mostly raptors with primarily north-to-south migration routes. We determined antimicrobial resistance, focusing on ESBL production, and unravelled the phylogenetic and clonal relatedness of identified ESBL-producing E. coli isolates using multi-locus sequence typing (MLST) and macrorestriction analyses. Surprisingly, the overall carriage rates (approximately 5%) and the proportion of ESBL-producers among E. coli (Germany: 13.8%, Mongolia: 10.8%) were similar in both regions. Whereas blaCTX-M-1 predominated among German isolates (100%), blaCTX-M-9 was the most prevalent in Mongolian isolates (75%). We identified sequence types (STs) that are well known in human and veterinary clinical ESBL-producing E. coli (ST12, ST117, ST167, ST648) and observed clonal relatedness between a Mongolian avian ESBL-E. coli (ST167) and a clinical isolate of the same ST that originated in a hospitalised patient in Europe. Our data suggest the influence of avian migratory species in the transmission of ESBL-producing E. coli and challenge the prevailing assumption that reducing human influence alone invariably leads to lower rates of antimicrobial resistance. PMID:23300857

  18. Comparable high rates of extended-spectrum-beta-lactamase-producing Escherichia coli in birds of prey from Germany and Mongolia.

    PubMed

    Guenther, Sebastian; Aschenbrenner, Katja; Stamm, Ivonne; Bethe, Astrid; Semmler, Torsten; Stubbe, Annegret; Stubbe, Michael; Batsajkhan, Nyamsuren; Glupczynski, Youri; Wieler, Lothar H; Ewers, Christa

    2012-01-01

    Frequent contact with human waste and liquid manure from intensive livestock breeding, and the increased loads of antibiotic-resistant bacteria that result, are believed to be responsible for the high carriage rates of ESBL-producing E. coli found in birds of prey (raptors) in Central Europe. To test this hypothesis against the influence of avian migration, we initiated a comparative analysis of faecal samples from wild birds found in Saxony-Anhalt in Germany and the Gobi-Desert in Mongolia, regions of dissimilar human and livestock population characteristics and agricultural practices. We sampled a total of 281 wild birds, mostly raptors with primarily north-to-south migration routes. We determined antimicrobial resistance, focusing on ESBL production, and unravelled the phylogenetic and clonal relatedness of identified ESBL-producing E. coli isolates using multi-locus sequence typing (MLST) and macrorestriction analyses. Surprisingly, the overall carriage rates (approximately 5%) and the proportion of ESBL-producers among E. coli (Germany: 13.8%, Mongolia: 10.8%) were similar in both regions. Whereas bla(CTX-M-1) predominated among German isolates (100%), bla(CTX-M-9) was the most prevalent in Mongolian isolates (75%). We identified sequence types (STs) that are well known in human and veterinary clinical ESBL-producing E. coli (ST12, ST117, ST167, ST648) and observed clonal relatedness between a Mongolian avian ESBL-E. coli (ST167) and a clinical isolate of the same ST that originated in a hospitalised patient in Europe. Our data suggest the influence of avian migratory species in the transmission of ESBL-producing E. coli and challenge the prevailing assumption that reducing human influence alone invariably leads to lower rates of antimicrobial resistance.

  19. Virulence characteristics of Shiga toxin-producing Escherichia coli from raw meats and clinical samples.

    PubMed

    Hoang Minh, Son; Kimura, Etsuko; Hoang Minh, Duc; Honjoh, Ken-ichi; Miyamoto, Takahisa

    2015-03-01

    Shiga toxin producing Escherichia coli (STEC) are dangerous foodborne pathogens. Foods are considered as important sources for STEC infection in human. In this study, STEC contamination of raw meats was investigated and the virulence factors of 120 clinical STEC strains characterized. STEC was detected in 4.4% of tested samples. Among 25 STEC strains from meats, five strains (20%) were positive for the eae gene, which encodes intimin, an important binding protein of pathogenic STEC. The remaining strains (80%) were eae-negative. However, 28% of them possessed the saa gene, which encodes STEC agglutinating adhesin. The ehxA gene encoding for enterohemolysin was found in 75% of the meat strains and the subAB gene, the product is of which subtilase cytotoxin, was found in 32% of these strains. The stx2a gene, a subtype of Shiga toxin gene (stx), was the most prevalent subtype among the identified meat STEC bacteria. None of the meat STEC was O157:H7 serotype. Nevertheless, 92% of them produced Shiga toxin (Stx). Among 120 clinical STEC strains, 30% and 70% strains harbored single and multiple stx subtypes, respectively. Most clinical STEC bacteria possessed eae (90.8%) and ehxA (96.7%) genes and 92.5% of them showed Stx productivity. Our study shows that some raw meat samples contain non-O157 STEC bacteria and some strains have virulence factors similar to those of clinical strains. © 2015 The Societies and Wiley Publishing Asia Pty Ltd.

  20. Detection of shiga-toxin producing E. coli (STEC) in leafy greens sold at local retail markets in Alexandria, Egypt.

    PubMed

    Khalil, Rowaida K S; Gomaa, Mohamed A E; Khalil, Mahmoud I M

    2015-03-16

    Leafy green vegetables, a popular and an indispensable ingredient of the daily menus of Egyptians' diets, currently presents a great concern in terms of microbiological hazards. To the best of our knowledge, this is the first report that provides scientific evidence for prevalence of shiga-toxigenic Escherichia coli (STEC) in leafy greens sold at open air local retail markets and superstores in the Egyptian environment. A total of 486 conventional and organic leafy green samples that are eaten raw were collected from different areas in Alexandria, evaluated for total E. coli counts (ECCs), and screened for E. coli O157:H7 using conventional and molecular methods. Recovery of E. coli (≥10(2)CFU/g) from all studied types of leafy greens was indicative of fecal contamination. Total ECCs in conventional samples ranged from 5.47 to 2.56 log CFU/g. Based on their inability to ferment sorbitol on CT-SMAC media, 26 presumptive E. coli O157 isolates were detected in 71.4% (270/378) of the studied conventional samples. From all studied organic samples, only 2 types (organic cabbage and parsley, 16.7%) were contaminated with presumptive E. coli O157. All 28 isolates were further serotyped as E. coli O157 by latex agglutination test, and biochemically confirmed as E. coli. Multiplex PCR assays confirmed the ability of 21.4% (6/28) of the E. coli O157 strains to produce shiga-toxins (Stxs), and their virulence markers were as follows: stx1, 66.6% (4/6); stx2, 50% (3/6); stx1/stx2, 16.7% (1/6); eaeA, 83.3% (5/6); and hlyA, 16.7% (1/6). Only 2 strains recovered from conventional and organic parsley could possibly be classified as E. coli O157:H7 based on the presence of stx-genes (either stx1 or stx2 or both). Results of the present research highlight that high E. coli loads, together with recovery of STEC O157 isolates could pose serious health risks to the produce consumers. This emphasizes the urgent need for health authorities to value and utilize the existing knowledge to

  1. High Prevalence of ST131 Isolates Producing CTX-M-15 and CTX-M-14 among Extended-Spectrum-β-Lactamase-Producing Escherichia coli Isolates from Canada ▿

    PubMed Central

    Peirano, Gisele; Richardson, David; Nigrin, Jana; McGeer, Allison; Loo, Vivian; Toye, Baldwin; Alfa, Michelle; Pienaar, Colette; Kibsey, Pamela; Pitout, Johann D. D.

    2010-01-01

    Phenotypic and genotypic methods were used to characterize extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli isolated in 2007 from 11 different Canadian medical centers. Of the 209 ESBL-producing E. coli isolates tested, 148 (71%) produced CTX-M-15, 17 (8%) produced CTX-M-14, 5 (2%) produced CTX-M-3, and 1 produced CTX-M-27. Overall, 96 (46%) of the ESBL producers belonged to clonal complex ST131, with the highest prevalence in Brampton, Calgary, and Winnipeg. ST131 is an important cause of community onset urinary tract infections due to ESBL-producing E. coli across Canada. PMID:20047913

  2. High Prevalence of Non-ST131 CTX-M-15-Producing Escherichia coli in Healthy Cattle in Lebanon.

    PubMed

    Diab, Mohamad; Hamze, Monzer; Madec, Jean-Yves; Haenni, Marisa

    2017-03-01

    Extended-Spectrum Beta-Lactamases (ESBL)-producing Escherichia coli have disseminated in both humans and animals worldwide. However, the ESBL epidemiology in these two reservoirs differs markedly, with CTX-M-15 frequently found in humans and CTX-M-1 preferentially found in animals. Our goal was to estimate the prevalence of fecal carriage of ESBL producers in cattle from 31 farms in Lebanon and to characterize the responsible enzymes. This prevalence was high (26/31, 84% of ESBL-positive farms), with a majority of isolates producing CTX-M-15 (27/40, 67.5%). Strikingly, this distribution is reminiscent of the human ESBL epidemiology, even though none of the bovine isolates belonged to the ST131 human clone. This is the first report of ESBL-producing E. coli in animals in Lebanon. Our data rather suggest the spread of CTX-M-15 plasmids in different E. coli backgrounds. Nonetheless, some CTX-M-15-producing E. coli clones found here have already been reported from animal, human, or environmental sources.

  3. Use of the Escherichia coli Identification Microarray for Characterizing the Health Risks of Shiga Toxin-Producing Escherichia coli Isolated from Foods.

    PubMed

    Lacher, David W; Gangiredla, Jayanthi; Patel, Isha; Elkins, Christopher A; Feng, Peter C H

    2016-10-01

    More than 470 serotypes of Shiga toxin-producing Escherichia coli (STEC) have been identified, but not all cause severe illness in humans. Most STEC that cause severe diseases can adhere to epithelial cells, produce specific stx subtypes, and belong to certain serotypes; therefore, these traits appear to be critical STEC risk factors. However, testing for these traits is labor intensive, and serotyping is inadequate because of extensive variations among E. coli O and H antigen types. In the present study, the E. coli identification microarray, which tests for over 40,000 E. coli gene targets, was examined for its potential to quickly characterize STEC strains. Analysis of 47 E. coli isolates, including 31 STEC isolates, recovered from 39 foods revealed that the microarray effectively determined the presence or absence of adherence genes and identified the specific eae allele in 3 isolates. The array identified most of the stx subtypes carried by all the isolates but had some difficulties in discerning between stx2a, stx2c, and stx2d because of the genetic similarities of these subtypes. The array determined the O and H types of 68 and 96% of the isolates, respectively, and although most serotypes were unremarkable, a few known pathogenic serotypes were also found. These selected STEC traits provided a scientific basis for assessing the potential health risks of STEC strains and also showed the importance of H typing in determining health risks. However, the diversity of the STEC group, the complexity of virulence mechanisms, and the variation in pathotypes among strains continue to pose challenges to assessing the potential of STEC strains to cause severe illness.

  4. Epidemiology of extended-spectrum beta-lactamase (ESBL) producing Escherichia coli in Japan: Characteristics of community-associated versus healthcare-associated ESBL E. coli.

    PubMed

    Hayakawa, Kayoko; Nagamatsu, Maki; Mezaki, Kazuhisa; Sugiki, Yuko; Kutsuna, Satoshi; Takeshita, Nozomi; Yamamoto, Kei; Mawatari, Momoko; Fujiya, Yoshihiro; Ohmagari, Norio

    2017-02-01

    Data on community-associated extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (CA-ESBLEC) infections in Japan are scarce. We compared the clinical and microbiological epidemiology of CA-ESBLEC infections with that of healthcare-associated-ESBLEC infections among 76 patients with ESBLEC infections. We identified a high prevalence (26%) of CA-ESBLEC infections in Japan; only a small proportion (15%) of patients with CA-ESBLEC infections had recent exposure to antibiotics.

  5. Acid Resistance and molecular characterization of Escherichia coli O157:H7 and different non-O157 Shiga toxin-producing E. coli serogroups

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to compare the acid resistance (AR) of seven non-O157 Shiga toxin-producing E. coli (STEC) strains belonging to serogroups O26, O45, O103, O104, O111, O121 and O145 with O157:H7 STEC isolated from various sources in 400 mM acetic acid solutions (AAS) at pH 3.2 and 30°...

  6. Acid resistance and molecular characterization of Escherichia coli O157:H7 and different Non-O157 shiga toxin-producing E. coli serogroups

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to compare the acid resistance (AR) of non-O157 Shiga toxin-producing Escherichia coli (STEC) strains belonging to serogroups O26, O45, O103, O104, O111, O121, and O145 with O157:H7 STEC isolated from various sources in 400 mM acetic acid solutions (AAS) at pH 3.2 and...

  7. Bactericidal Effect of Selected Antidiarrhoeal Medicinal Plants on Intracellular Heat-Stable Enterotoxin-Producing Escherichia coli

    PubMed Central

    Birdi, Tannaz J.; Brijesh, S.; Daswani, Poonam G.

    2014-01-01

    Diarrhoeal diseases due to enterotoxigenic Escherichia coli continue to be a cause of global concern. Medicinal plants have been gaining popularity as promising antidiarrhoeal agents. In the present study, four antidiarrhoeal plants, viz. Aegle marmelos, Cyperus rotundus, Psidium guajava and Zingiber officinale were screened against a heat-stable toxin-producing enterotoxigenic E. coli strain. Decoctions of these plants were studied for their effect on intracellular killing of the bacterial strain using murine monocytic cell line, J774. [3H] thymidine release assay was used to evaluate the apoptotic/necrotic effect. All plants at concentrations <1% enhanced intracellular killing of the bacteria by J774 cells. However, at higher concentrations, the decoctions induced apoptosis in J774 cells. The study demonstrates that these plants could control diarrhoea caused by heat-stable toxin-producing enterotoxigenic E. coli through their immunomodulatory effect. PMID:25035535

  8. Clinical spectrum of urine cultures positive for ESBL-producing Escherichia coli in hospitalized patients and impact on antibiotic use.

    PubMed

    Lepeule, R; Leflon-Guibout, V; Vanjak, D; Zahar, J-R; Lafaurie, M; Besson, C; Lefort, A

    2014-12-01

    We wanted to describe the clinical features associated with urinalysis positive for ESBL-producing Escherichia coli and their impact on antibiotic use. We performed a prospective observational study in 13 French hospitals of the Paris area for 3 consecutive months. We included all patients with urine cultures positive for ESBL-producing E. coli. One hundred and seventeen of the 218 patients (54%) presented with asymptomatic bacteriuria, 31 (14%) with cystitis, and 70 (32%) with a parenchymal infection. Nineteen patients with asymptomatic bacteriuria (16%) received antibiotics. Forty-one with parenchymal infections (59%) received a carbapenem. A carbapenem alternative could have been used in every patient treated with a carbapenem, according to antibiotic susceptibility testing results. Urinary tract infections accounted for 46% of E. coli ESBL positive urinalysis. Fifty percent of parenchymal infections were treated with a carbapenem. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  9. Recurrent extended-spectrum beta-lactamase-producing Escherichia coli urinary tract infection due to an infected intrauterine device

    PubMed Central

    Hui, Chee-Kin

    2014-01-01

    The use of intrauterine devices (IUDs) have been widespread since the 1960s. In 2002, the World Health Organization estimated that approximately 160 million women worldwide use IUDs. However, IUDs are associated with short-term complications such as vaginal bleeding, pelvic discomfort, dyspareunia and pelvic infection. Herein, we report the case of a woman who had recurrent urinary tract infection (UTI) due to the use of an IUD, even after treatment. The patient developed four episodes of UTI within a seven-month period after IUD insertion. During each episode of UTI, extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli (E. coli) was cultured from the patient's midstream urine. The IUD was finally removed, and culture of the removed IUD was positive for ESBL-producing E. coli. An infected IUD as a source of recurrent UTI should be considered in women with IUD in situ who develop recurrent UTI even after treatment. PMID:24154554

  10. Extended spectrum β-lactamase producing Escherichia coli and Klebsiella pneumoniae: critical tools for antibiotic resistance pattern.

    PubMed

    Padmini, Nagarajan; Ajilda, Antony Alex Kennedy; Sivakumar, Natesan; Selvakumar, Gopal

    2017-04-11

    Drug resistance is a phenomenon where by an organism becomes fully or partially resistant to drugs or antibiotics being used against it. Antibiotic resistance poses an exacting intimidation for people with underlying medical immune conditions or weakened immune systems. Infections caused by the enzyme extended spectrum β-lactamase (ESBL) producing multi drug resistance (MDR) Enterobacteriaceae especially Escherichia coli and Klebsiella pneumoniae are resistant to a broad range of beta lactams, including third generation cephalosporins. Among all the pathogens, these two MDR E. coli and K. pneumoniae have emerged as one of the world's greatest health threats in past two decades. The nosocomial infections caused by these ESBL producing MDR E. coli and K. pneumoniae complicated the therapy and limit treatment options.

  11. Value of passive immune hemolysis for detection of heat-labile enterotoxin produced by enterotoxigenic Escherichia coli.

    PubMed Central

    Tsukamoto, T; Kinoshita, Y; Taga, S; Takeda, Y; Miwatani, T

    1980-01-01

    The method of passive immune hemolysis of Evans and Evans (Infect. Immun. 16:604-609, 1977) for detection of heat-labile enterotoxin produced by enterotoxigenic Escherichia coli was modified. A total of 373 strains of E. coli were tested by this method using materials obtained by treating the cells with polymyxin B and rabbit antiserum against cholera enterotoxin, purified by affinity gel column coupled with purified cholera enterotoxin, in N-hydroxyethylpiperazine-N'-2-ethanesulfonic acid buffer (pH 6.7). The results correlated very well with those obtained in an assay with Chinese hamster ovary cells. It is concluded that passive immune hemolysis is useful as a routine clinical method for identifying E. coli strains that produce heat-labile enterotoxin. PMID:7031077

  12. CTX-M-15 Extended-Spectrum β-Lactamase in a Shiga Toxin-Producing Escherichia coli Isolate of Serotype O111:H8

    PubMed Central

    Haenni, Marisa; Saras, Estelle; Auvray, Frédéric; Forest, Karine; Oswald, Eric; Madec, Jean-Yves

    2012-01-01

    We report the discovery of a CTX-M-15-producing Escherichia coli (STEC) of serogroup O111:H8, a major serotype responsible for human enterohemorrhagic Escherichia coli (EHEC) infections. In line with the recent CTX-M-15/O104:H4 E. coli outbreak, these data may reflect an accelerating spread of resistance to expanded-spectrum cephalosporins within the E. coli population, including STEC isolates. PMID:22156432

  13. [Trend of detection of cefotaxime-resistant Escherichia coli and clinical features of bloodstream infection due to extended-spectrum β-lactamase producing Escherichia coli in a general hospital].

    PubMed

    Tarumoto, Norihito; Nobe, Masako; Uchida, Masatsugu; Maesaki, Shigefumi; Tanaka, Masahiko

    2014-12-01

    Recently, the community pandemic infections of cefotaxime (CTX)-M type extended-spectrum β-lactamase (ESBL) producing bacteria, which is mostly resistant to CTX, has been well-known as major problems. When the ESBL-confirmation test cannot be done, CTX-resistant Escherichia coli might be used as the alternation method of infectious control. We investigated tendency of third-generation cephalosporin resistant E. coli and the clinical features of bloodstream infections (BSI) due to ESBL producing E. coli in our hospital, which has no department of microbial examination. We examined the trend of detection of CTX-resistant E. coli isolates from clinical samples from January 2009 to November 2013, and antimicrobial use density (AUD) of third-generation cephalosporins in the same period, and the clinical features of BSI of ESBL-producing E. coli. As a result, the percentages of CTX-resistant E. coli in all E. coli were 5.4% in inpatient and 3.9% in outpatient in 2009, but 32.8% and 17.8% in 2013, respectively. Additionally, AUD had increased from 20.6 in 2009 to 28.9 in 2013. In BSI due to E. coli, the clinical features which were male, bedridden patient and using urethral catheter, central venous catheter, chronic renal failure were significantly in the cases of ESBL-producing E. coli (n=8), compared to non-ESBL producing E. coli (n=32).

  14. Orally fed seeds producing designer IgAs protect weaned piglets against enterotoxigenic Escherichia coli infection

    PubMed Central

    Virdi, Vikram; Coddens, Annelies; De Buck, Sylvie; Millet, Sam; Goddeeris, Bruno Maria; Cox, Eric; De Greve, Henri; Depicker, Ann

    2013-01-01

    Oral feed-based passive immunization can be a promising strategy to prolong maternal lactogenic immunity against postweaning infections. Enterotoxigenic Escherichia coli (ETEC)-caused postweaning diarrhea in piglets is one such infection that may be prevented by oral passive immunization and might avert recurrent economic losses to the pig farming industry. As a proof of principle, we designed anti-ETEC antibodies by fusing variable domains of llama heavy chain-only antibodies (VHHs) against ETEC to the Fc part of a porcine immunoglobulin (IgG or IgA) and expressed them in Arabidopsis thaliana seeds. In this way, four VHH-IgG and four VHH-IgA antibodies were produced to levels of about 3% and 0.2% of seed weight, respectively. Cotransformation of VHH-IgA with the porcine joining chain and secretory component led to the production of light-chain devoid, assembled multivalent dimeric, and secretory IgA-like antibodies. In vitro analysis of all of the antibody-producing seed extracts showed inhibition of bacterial binding to porcine gut villous enterocytes. However, in the piglet feed-challenge experiment, only the piglets receiving feed containing the VHH-IgA–based antibodies (dose 20 mg/d per pig) were protected. Piglets receiving the VHH-IgA–based antibodies in the feed showed a progressive decline in shedding of bacteria, significantly lower immune responses corroborating reduced exposure to the ETEC pathogen, and a significantly higher weight gain compared with the piglets receiving VHH-IgG producing (dose 80 mg/d per pig) or wild-type seeds. These results stress the importance of the antibody format in oral passive immunization and encourage future expression of these antibodies in crop seeds. PMID:23801763

  15. Comparison of Extended-Spectrum β-Lactamase-Producing Escherichia coli Isolates from Drinking Well Water and Pit Latrine Wastewater in a Rural Area of China

    PubMed Central

    Gao, Yanxia

    2016-01-01

    The present study was conducted to gain insights into the occurrence and characteristics of extended-spectrum beta-lactamase- (ESBL-) producing Escherichia coli (E. coli) from drinking well water in the rural area of Laiwu, China, and to explore the role of the nearby pit latrine as a contamination source. ESBL-producing E. coli from wells were compared with isolates from pit latrines in the vicinity. The results showed that ESBL-producing E. coli isolates, with the same antibiotic resistance profiles, ESBL genes, phylogenetic group, plasmid replicon types, and enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) fingerprints, were isolated from well water and the nearby pit latrine in the same courtyard. Therefore, ESBL-producing E. coli in the pit latrine may be a likely contributor to the presence of ESBL-producing E. coli in rural well water. PMID:27965975

  16. Virulence markers of Shiga-like toxin-producing Escherichia coli strains originating from healthy domestic animals of different species.

    PubMed Central

    Beutin, L; Geier, D; Zimmermann, S; Karch, H

    1995-01-01

    Shiga-like toxin (verotoxin)-producing strains of Escherichia coli (SLTEC) originating from healthy cattle, sheep, goats, pigs, cats, and dogs were investigated for properties which are related to virulence of E. coli for humans. The slt-II (Shiga-like toxin II) and slt-IIc genes were frequent in SLTEC from healthy cattle and dogs but were rarely found in SLTEC from other animals. The slt-IIe gene was detected only in porcine SLTEC. SLTEC from goats and SLTEC from sheep were found to carry different SLT-II determinants which were not further characterized genetically. Sixty (28.8%) of 208 SLTEC from healthy animals showed diffuse adherence to HEp-2 cells. However, none of the strains was positive for genes specific for the local adherence (eaf), diffuse adherence (daa), or enteroaggregative (EAggEC) E. coli type. Only 3 (1.4%) of the 208 SLTEC were positive for attaching and effacing E. coli (eae) sequences. The enterohemolytic phenotype was present in 128 of the 208 SLTEC. Almost all enterohemolytic animal SLTEC were found to carry DNA sequences specific for the plasmid-encoded enterohemorrhagic E. coli hemolysin of E. coli O157. Bacteriophage-associated enterohemolysin (Ehly1 and Ehly2)-specific sequences were detected only in 14.4% of the 208 SLTEC and were linked with certain serotypes. The SLTEC from healthy animals constitute a very heterogeneous group of E. coli, and many of these strains appeared to be specific for their hosts. The absence of eae sequences in most animal SLTEC could indicate that these strains are less virulent for humans than the classical eae-positive enterohemorrhagic E. coli types. PMID:7538509

  17. [Bacteraemia due to Escherichia coli producing extended-spectrum beta-lactamases (ESBL): clinical relevance and today's insights].

    PubMed

    García-Hernández, Ana Maria; García-Vázquez, Elisa; Hernández-Torres, Alicia; Ruiz, Joaquín; Yagüe, Genoveva; Herrero, José Antonio; Gómez, Joaquín

    2011-06-01

    Antibiotic resistance is an old problem with new face as the rate of infections due to multidrug resistant bacteria is higher everyday and the number of new antibiotics to overwhelm the problem is becoming smaller. E. coli is the most frequent agent causing nosocomial or community-acquired bacteraemia being in our country 10% of them extended-spectrum beta-lactamases (ESBL) producing E. coli isolates. Nowadays the number of community- acquired or health-related infections caused by these ESBL producing E. coli is increasing. CTX-M has also become the most frequent ESBL compared to other enzymes. The role of these enzymes as a virulence factor increasing mortality in patients with bacteraemia due to E. coli is not well defined. The relevance of ESBL-E. coli seems to be related with the higher frequency of inadequate treatment and therefore the importance of identifying factors or features that might predict that the patient's infection is due to one of these isolates. In terms of prevention and control of infection measures, the role of patient's isolation is not clear but a proper prescription of antibiotics and antibiotic control policies are probably important to reduce the problem.

  18. Thermal inactivation of Shiga toxin-producing Escherichia coli within cubed beef steaks following cooking on a griddle

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to quantify thermal inactivation of Shiga toxin-producing Escherichia coli (STEC) cells within knitted/cubed beef steaks following cooking on a non-stick griddle. Both faces of each beef cutlet (ca. 64 g; ca. 8.5 cm L X 10.5 cm W X 0.75 cm H) were surface inoculated (...

  19. Rapid detection of E. coli produced shiga-like toxins by lateral flow immunoassay in multiple food matrices

    USDA-ARS?s Scientific Manuscript database

    Shiga toxigenic E. coli (STEC) produce shiga-like toxins (Stx) that can cause human disease and death. The STEC serotype O157:H7 is a well-recognized foodborne contaminant and effective detection methods have been established. However, the emergence of non-O157 STEC strains has necessitated the deve...

  20. Outbreak of non-O157 Shiga toxin-producing Escherichia coli infection from consumption of beef sausage.

    PubMed

    Ethelberg, Steen; Smith, Birgitte; Torpdahl, Mia; Lisby, Morten; Boel, Jeppe; Jensen, Tenna; Nielsen, Eva Møller; Mølbak, Kåre

    2009-04-15

    We describe an outbreak of Shiga toxin-producing Escherichia coli O26:H11 infection in 20 patients (median age, 2 years). The source of the infection was an organic fermented beef sausage. The source was discovered by using credit card information to obtain and compare customer transaction records from the computer systems of supermarkets.

  1. Rapid latex particle agglutination test for Escherichia coli strains of porcine origin producing heat-labile enterotoxin.

    PubMed Central

    Finkelstein, R A; Yang, Z S; Moseley, S L; Moon, H W

    1983-01-01

    A latex particle agglutination test previously shown to be suitable for the rapid identification of Escherichia coli strains of human origin producing heat-labile enterotoxin (R. A. Finkelstein and Z. Yang, J. Clin. Microbiol. 18:23-28) is equally applicable to strains of porcine origin. PMID:6361056

  2. Isolation and characterization of bacteriophages as potential agents against Shiga toxin – producing Escherichia coli (STEC) strains

    USDA-ARS?s Scientific Manuscript database

    Shiga – toxin producing Escherichia coli (STEC) is a significant group of foodborne pathogens that can cause mild diarrhea to serious human illnesses. The gastrointestinal tracts of cattle and other ruminants are the primary reservoirs of STEC strains and may co-harbor bacteriophages as part of its ...

  3. Biotinylation of environmentally isolated Shiga toxin-producing Escherichia coli (STEC) – specific bacteriophages for biosensor and biocontrol applications

    USDA-ARS?s Scientific Manuscript database

    Like common bacteriophages, Shiga toxin-producing Escherichia coli (STEC) bacteriophages are viruses that recognize and bind to specific bacterial host (STEC) for propagation. They co-exist with STEC hosts, which cause epidemic food and waterborne illnesses, but may act as host populations limiting ...

  4. Draft Genome Sequence of Five Shiga Toxin-Producing Escherichia coli Strains Isolated from Wild Deer in Japan

    PubMed Central

    Ikeda, Tetsuya; Yamamoto, Shiori; Kabeya, Hidenori; Sugiyama, Hiromu; Takai, Shinji

    2017-01-01

    ABSTRACT Shiga toxin-producing Escherichia coli (STEC) is one of the major foodborne pathogens. Having observed the wide distribution of this pathogen in wild deer, we report here the draft genome sequence of five STEC strains isolated from wild deer (Cervus nippon yesoensis) in Hokkaido, Japan. PMID:28254967

  5. Prevalence and characteristics of Shiga toxin-producing Escherichia coli in finishing pigs: implications on public health

    USDA-ARS?s Scientific Manuscript database

    Shiga toxin-producing Escherichia coli (STEC) are important food-borne pathogens, which can cause serious illnesses, including hemorrhagic colitis and hemolytic uremic syndrome. To examine if pigs are potential animal reservoirs for human STEC infections, we conducted a longitudinal cohort study in ...

  6. Classification of non-O157 shiga toxin-producing escherichia coli(STEC) serotypes with hyperspectral microscope imaging

    USDA-ARS?s Scientific Manuscript database

    Non-O157 Shiga toxin-producing Escherichia coli (STEC) strains such as O26, O45, O103, O111, O121 and O145 are recognized as serious outbreak to cause human illness due to their toxicity. A conventional microbiological method for cell counting is laborious and needs long time for the results. Since ...

  7. Molecular characterization of shiga toxin-producing E. coli (STEC) from finishing swine in a longitudinal study

    USDA-ARS?s Scientific Manuscript database

    Shiga toxin-producing E. coli (STEC) infections are a critical public health concern because they can cause severe clinical outcomes, such as hemolytic uremic syndrome, in humans. Determining the presence or absence of virulence genes is essential in assessing the potential pathogenicity of STEC str...

  8. Effect of curli expression and hydrophobicity of E. coli O157:H7 on attachment to fresh produce surfaces

    USDA-ARS?s Scientific Manuscript database

    Aim: To investigate the effect of curli expression on cell hydrophobicity, biofilm formation, and attachment to cut and intact fresh produce surfaces. Methods and Results: Five E. coli O157:H7 strains were evaluated for curli expression, hydrophobicity, biofilm formation, and attachment of E. co...

  9. Genome Sequences of 64 Non-O157:H7 Shiga Toxin-Producing Escherichia coli Strains

    PubMed Central

    Toro, Magaly; Cao, Guojie; Rump, Lydia; Nagaraja, T. G.; Meng, Jianghong

    2015-01-01

    Shiga toxin-producing Escherichia coli (STEC) strains are human pathogens. Although >400 non-O157 serotypes have been involved in human disease, whole-genome sequencing information is missing for many serotypes. We sequenced 64 STEC strains comprising 38 serotypes, isolated from clinical sources, animals, and environmental samples, to improve the phylogenetic understanding of these important foodborne pathogens. PMID:26430026

  10. Genotypic Characterization of Shiga Toxin-Producing Escherichia coli (STEC) Strains Recovered from Farm Animal Feces in Mexico

    USDA-ARS?s Scientific Manuscript database

    Technical Abstract and Interpretive Summary: Provide electronically in Word. Sixty-three strains of Shiga toxin-producing Escherichia coli (STEC) were recovered from farm animal feces in distinct regions in the Culiacan Valley, an important agricultural region in Mexico for horticultural crops that...

  11. Inactivation of a diverse set of shiga toxin-producing Escherichia coli in ground beef by high pressure processing

    USDA-ARS?s Scientific Manuscript database

    Shiga Toxin-Producing Escherichia coli (STEC) are frequently implicated in foodborne illness outbreaks and recalls of ground beef. In this study we determined the High Pressure Processing (HPP) D-10 value (the processing conditions needed to reduce the microbial population by 1 log) of 39 individua...

  12. Virulence gene profiles of shiga toxin-producing Escherichia coli isolated from fecal samples of finishing swine

    USDA-ARS?s Scientific Manuscript database

    Shiga toxin-producing Escherichia coli (STEC) are important pathogens responsible for food-borne outbreaks and serious illness including hemorrhagic colitis and hemolytic uremic syndrome. Certain STEC serogroups may cause edema disease in swine; and similar to cattle, swine have been shown to be a ...

  13. Shiga toxin-producing Escherichia coli in meat: a preliminary simulation study on detection capabilities for three sampling methods

    USDA-ARS?s Scientific Manuscript database

    The objective of this simulation study is to determine which sampling method (Cozzini core sampler, core drill shaving, and N-60 surface excision) will better detect Shiga Toxin-producing Escherichia coli (STEC) at varying levels of contamination when present in the meat. 1000 simulated experiments...

  14. Simultaneous direct detection of Shiga-toxin producing Escherichia coli (STEC) strains by gold nanoparticle optical sensing

    USDA-ARS?s Scientific Manuscript database

    Shiga-toxin producing Escherichia coli (STEC) strains (“Big Six” – O26, O45, O103, O111, O121, O145, and O157) represent significant groups of pathogens responsible for foodborne diseases. The objective of this study was to develop a colorimetric optical sensing assay that can simultaneously detect ...

  15. Current and near-market intervention strategies for reducing Shiga Toxin-producing Escherichia coli (STEC) shedding in cattle

    USDA-ARS?s Scientific Manuscript database

    Cattle can naturally contain foodborne pathogenic bacteria such as Shiga Toxin-Producing E. coli (STEC). These foodborne pathogenic bacteria are a threat to public health through contamination of foods and water supplies. In order to reduce human exposures and resultant illnesses, research has foc...

  16. Shiga Toxin-producing Escherichia coli (STEC) ecology in cattle and management based options for reducing fecal shedding

    USDA-ARS?s Scientific Manuscript database

    Cattle can be naturally colonized with foodborne pathogenic bacteria such as Shiga Toxin-Producing E. coli (STEC) in their gastrointestinal tract. While these foodborne pathogens are a threat to food safety, they also cause human illnesses via cross contamination of other foods and the water supply...

  17. Characterization of Shiga toxin-producing Escherichia coli associated with two multi-state foodborne outbreaks in 2006

    USDA-ARS?s Scientific Manuscript database

    In the fall of 2006 two multi-state outbreaks of E. coli serotype O157:H7 infection occurred that involved contaminated spinach and contaminated lettuce. In this study, we compare 7 Shiga toxin-producing isolates associated with those two outbreaks to a collection of food, environmental, and animal ...

  18. Virulence Factors and Phenotypical Traits of Verotoxin-Producing Escherichia coli Strains Isolated from Asymptomatic Human Carriers

    PubMed Central

    Stephan, R.; Untermann, F.

    1999-01-01

    Fourteen verotoxin-producing Escherichia coli strains isolated from stool samples of 14 different asymptomatic human carriers were further characterized. A variety of serotypes was found, but none of the strains belonged to serogroup O157. Only one isolate carried most of the virulence genes that are associated with increased pathogenicity. PMID:10203524

  19. Shiga toxin-producing E. coli (STEC) in swine: prevalence over the finishing period and characterization of the STEC isolates

    USDA-ARS?s Scientific Manuscript database

    This descriptive longitudinal study was conducted to investigate the fecal shedding of Shiga toxin-producing E. coli (STEC) in finishing swine and to characterize the swine STEC isolates that were recovered. Three cohorts of finishing swine (n=50/cohort; total 150 pigs) were included in the longitu...

  20. The Functional Quality of Soluble Recombinant Polypeptides Produced in Escherichia coli Is Defined by a Wide Conformational Spectrum▿

    PubMed Central

    Martínez-Alonso, Mónica; González-Montalbán, Nuria; García-Fruitós, Elena; Villaverde, Antonio

    2008-01-01

    We have observed that a soluble recombinant green fluorescent protein produced in Escherichia coli occurs in a wide conformational spectrum. This results in differently fluorescent protein fractions in which morphologically diverse soluble aggregates abound. Therefore, the functional quality of soluble versions of aggregation-prone recombinant proteins is defined statistically rather than by the prevalence of a canonical native structure. PMID:18836021

  1. Rapid O serogroup identification of the six clinically relevant Shiga toxin-producing Escherichia coli by antibody microarray

    USDA-ARS?s Scientific Manuscript database

    Antibody array was developed for the detection of the top six non-O157 Shiga toxin-producing Escherichia coli O serogroups. Sensitivity of the array was 10**5 CFU, and the limit of detection of serogroups in ground beef was 1-10 CFU following 12 h of enrichment. The array utilized a minimal amount...

  2. Distribution and detection of Shiga toxin-producing Escherichia coli (STEC) during an industrial grinding process of beef trim

    USDA-ARS?s Scientific Manuscript database

    During the grinding and packaging processes, it is important to understand how Shiga toxin-producing Escherichia coli (STEC) would be distributed and how well it could be detected in beef trim. This study is important because it shows what would happen if contaminated meat is allowed into a commerc...

  3. Biofilm formation of non-O157 Shiga toxin-producing Escherichia coli (STEC) on equipment surfaces

    USDA-ARS?s Scientific Manuscript database

    Introduction: Shiga toxin-producing Escherichia coli (STEC) serotype O157:H7 has been the most commonly recognized STEC serotype responsible for foodborne outbreaks in the US. Numerous outbreaks associated with non-O157 serotypes have also been reported due to consumption of contaminated food. The ...

  4. Multidrug-Resistant and Extended Spectrum Beta-Lactamase-Producing Escherichia coli in Dutch Surface Water and Wastewater

    PubMed Central

    Blaak, Hetty; Lynch, Gretta; Italiaander, Ronald; Hamidjaja, Raditijo A.; Schets, Franciska M.; de Roda Husman, Ana Maria

    2015-01-01

    Objective The goal of the current study was to gain insight into the prevalence and concentrations of antimicrobial resistant (AMR) Escherichia coli in Dutch surface water, and to explore the role of wastewater as AMR contamination source. Methods The prevalence of AMR E. coli was determined in 113 surface water samples obtained from 30 different water bodies, and in 33 wastewater samples obtained at five health care institutions (HCIs), seven municipal wastewater treatment plants (mWWTPs), and an airport WWTP. Overall, 846 surface water and 313 wastewater E. coli isolates were analysed with respect to susceptibility to eight antimicrobials (representing seven different classes): ampicillin, cefotaxime, tetracycline, ciprofloxacin, streptomycin, sulfamethoxazole, trimethoprim, and chloramphenicol. Results Among surface water isolates, 26% were resistant to at least one class of antimicrobials, and 11% were multidrug-resistant (MDR). In wastewater, the proportions of AMR/MDR E. coli were 76%/62% at HCIs, 69%/19% at the airport WWTP, and 37%/27% and 31%/20% in mWWTP influents and effluents, respectively. Median concentrations of MDR E. coli were 2.2×102, 4.0×104, 1.8×107, and 4.1×107 cfu/l in surface water, WWTP effluents, WWTP influents and HCI wastewater, respectively. The different resistance types occurred with similar frequencies among E. coli from surface water and E. coli from municipal wastewater. By contrast, among E. coli from HCI wastewater, resistance to cefotaxime and resistance to ciprofloxacin were significantly overrepresented compared to E. coli from municipal wastewater and surface water. Most cefotaxime-resistant E. coliisolates produced ESBL. In two of the mWWTP, ESBL-producing variants were detected that were identical with respect to phylogenetic group, sequence type, AMR-profile, and ESBL-genotype to variants from HCI wastewater discharged onto the same sewer and sampled on the same day (A1/ST23/CTX-M-1, B23/ST131/CTX-M-15, D2/ST405/CTX

  5. Extended spectrum β-lactamase producing Escherichia coli in broiler breeding roosters: Presence in the reproductive tract and effect on sperm motility.

    PubMed

    Mezhoud, Halima; Boyen, Filip; Touazi, Leg-Hel; Garmyn, An; Moula, Nassim; Smet, Annemieke; Haesbrouck, Freddy; Martel, An; Iguer-Ouada, Mokrane; Touati, Abdelaziz

    2015-08-01

    Extended spectrum β-lactamases (ESBL)-producing Escherichia coli have emerged worldwide in animal husbandry and they were reported from different ecosystems. The purpose of this study was firstly, to investigate the presence of ESBL-producing E. coli in the gastrointestinal (GIT) and reproductive (RT) tracts of broiler breeding roosters, and secondly to study the impact of an ESBL-producing E. coli on artificially infected semen. A total of seventeen ESBL-producing E. coli strains were isolated from the gastrointestinal and reproductive tracts of nine broiler breeding roosters. All isolates were identified to the species level by API 20E system and MALDI-TOF, serotyped, and genetically characterized for ESBL production. Semen was artificially infected with E. coli ATCC25922 or with an ESBL-producing E. coli strain recovered from the reproductive tract. A computer aided semen analyzer (CASA) was used to compare different spermatozoa motility parameters in each sample. All ESBL-producing E. coli isolates could not be typed with the currently used sera and they were harboring a blaCTX-M gene alone or in combination with a blaTEM gene. The semen quality was notably less affected in samples infected with ESBL-producing E. coli strain compared to the control and sample infected with E. coli ATCC25922. The present study revealed that ESBL-producing E. coli can be isolated from both reproductive and digestive tracts of broiler breeding roosters. Contamination of the reproductive tract with ESBL-producing E. coli could lead to contamination of semen and could be an important factor in the dissemination of ESBL-producing E. coli in poultry. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Risk factors and clinical outcomes of extended spectrum beta-lactamase (ESBL)-producing Escherichia coli septicemia at Srinagarind University Hospital, Thailand.

    PubMed

    Anunnatsiri, Siriluck; Towiwat, Patapong; Chaimanee, Prajuab

    2012-09-01

    Escherichia coli producing extended spectrum beta-lactamase (ESBL) has emerged as a worldwide, public health problem. The aims of this study were to determine the incidence of ESBL-producing E. coli septicemia and evaluate the factors associated with the infection and the clinical outcomes. We reviewed 145 cases of E. coli septicemia among adult patients admitted to Srinagarind University Hospital in northeastern Thailand between 2005 and 2006. The incidence of ESBL-producing E. coli septicemia was 9.9 cases per 10,000 hospital admissions. The factors significantly associated with ESBL-producing E. coli septicemia were: 1) hospital acquisition [odds ratio (OR) 6.46; 95% confidence interval (CI) 2.01-20.79], 2) previous use of a fluoroquinolone, (OR 19.14; 95% CI 5.82-62.96), and 3) use of a central venous catheter (OR, 8.59; 95% CI, 1.11-66.27). Seventy-two hours after receiving empiric treatment, a significantly greater proportion of patients with ESBL-producing E. coli septicemia had a worse clinical outcome than those with non-ESBL producing E. coli septicemia (p = 0.01). The overall mortality rate was significantly higher among the ESBL-producing E. coli septicemia group than the non-ESBL producing E. coli septicemia group (29% vs 11.5%, respectively, p = 0.02). A high APACHE II score, ESBL-producing E. coli septicemia, primary septicemia, and having a non-urinary tract infecting as a source of septicemia were significantly independent factors related to mortality among patients with E. coli septicemia. ESBL-producing E. coli septicemia is an important cause of nosocomial infection and is related to higher mortality risk, especially among those with primary septicemia and secondary septicemia due to a non-urinary tract infection.

  7. Comparison of Escherichia coli Isolates from humans, food, and farm and companion animals for presence of Shiga toxin-producing E. coli virulence markers.

    PubMed

    Murinda, Shelton E; Nguyen, Lien T; Landers, Tippi L; Draughon, F Ann; Mathew, Alan G; Hogan, Joseph S; Smith, K Larry; Hancock, Dale D; Oliver, Stephen P

    2004-01-01

    The objective of this study was to characterize Escherichia coli isolates from dairy cows/feedlots, calves, mastitis, pigs, dogs, parrot, iguana, human disease, and food products for prevalence of Shiga toxin-producing E. coli (STEC) virulence markers. The rationale of the study was that, isolates of the same serotypes that were obtained from different sources and possessed the same marker profiles, could be cross-species transmissible. Multiplex polymerase chain reaction (PCR) was used to detect presence of genes encoding Shiga toxin 1 and 2 (stx1 and stx2), H7 flagella (flicC), enterohemolysin (hly) and intimin (eaeA) in E. coli isolates (n = 400). Shiga toxin-producing isolates were tested for production of Shiga toxins (Stx1 and Stx2 and enterohemolysin. Of the E. coli O157:H7/H- strains, 150 of 164 (mostly human, cattle, and food) isolates were stx+. Sixty-five percent of O157 STEC produced both Stx1 and Stx2; 32% and 0.7% produced Stx2 or Stx1, respectively. Ninety-eight percent of O157 STEC had sequences for genes encoding intimin and enterohemolysin. Five of 20 E. coli O111, 4 of 14 O128 and 4 of 10 O26 were stx+ . Five of 6 stx+ O26 and O111 produced Stx1, however, stx+ O128 were Stx-negative. Acid resistance (93.3%) and tellurite resistance (87.3%) were common attributes of O157 STEC, whereas, non-O157 stx+ strains exhibited 38.5% and 30.8% of the respective resistances. stx-positive isolates were mostly associated with humans and cattle, whereas, all isolates from mastitis (n = 105), and pigs, dogs, parrot and iguanas (n = 48) were stx-negative. Multiplex PCR was an effective tool for characterizing STEC pathogenic profiles and distinguished STEC O157:H7 from other STEC. Isolates from cattle and human disease shared similar toxigenic profiles, whereas isolates from other disease sources had few characteristics in common with the former isolates. These data suggest interspecies transmissibility of certain serotypes, in particular, STEC O157:H7, between

  8. Inactivation of Shiga toxin-producing Escherichia coli O104:H4 using cold atmospheric pressure plasma.

    PubMed

    Baier, Matthias; Janssen, Traute; Wieler, Lothar H; Ehlbeck, Jörg; Knorr, Dietrich; Schlüter, Oliver

    2015-09-01

    From cultivation to the end of the post-harvest chain, heat-sensitive fresh produce is exposed to a variety of sources of pathogenic microorganisms. If contaminated, effective gentle means of sanitation are necessary to reduce bacterial pathogen load below their infective dose. The occurrence of rare or new serotypes raises the question of their tenacity to inactivation processes. In this study the antibacterial efficiency of cold plasma by an atmospheric pressure plasma-jet was examined against the Shiga toxin-producing outbreak strain Escherichia coli O104:H4. Argon was transformed into non-thermal plasma at a power input of 8 W and a gas flow of 5 L min(-1). Basic tests were performed on polysaccharide gel discs, including the more common E. coli O157:H7 and non-pathogenic E. coli DSM 1116. At 5 mm treatment distance and 10(5) cfu cm(-2) initial bacterial count, plasma reduced E. coli O104:H4 after 60 s by 4.6 ± 0.6 log, E. coli O157:H7 after 45 s by 4.5 ± 0.6 log, and E. coli DSM 1116 after 30 s by 4.4 ± 1.1 log. On the surface of corn salad leaves, gentle plasma application at 17 mm reduced 10(4) cfu cm(-2) of E. coli O104:H4 by 3.3 ± 1.1 log after 2 min, whereas E. coli O157:H7 was inactivated by 3.2 ± 1.1 log after 60 s. In conclusion, plasma treatment has the potential to reduce pathogens such as E. coli O104:H4 on the surface of fresh produce. However, a serotype-specific adaptation of the process parameters is required. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  9. Persistence of Escherichia coli O157:H7 in major leafy green producing soils

    USDA-ARS?s Scientific Manuscript database

    Persistence of Escherichia coli O157:H7 in 32 (16 organically managed and 16 conventionally managed) soils from California (CA) and Arizona (AZ) was investigated. Results showed that the longest survival (ttd, time needed to reach detection limit, 100 CFU/g dry soil) of E. coli O157:H7 was observed ...

  10. Development of a faster method for detection of Shiga toxin producing E. coli using Tetrahymena thermophila

    USDA-ARS?s Scientific Manuscript database

    While most STEC outbreaks are caused by E. coli O157, non-O157 STECs are increasingly being implicated. Selective agar for E. coli O157 is commercially available but none detect non-O157 STEC. Currently, regulatory agencies screen for non-O157 STECs by enriching foods overnight, spreading aliquots o...

  11. Development of biphasic medium for detection of Shiga toxin producing E. coli using Tetrahymena thermophila

    USDA-ARS?s Scientific Manuscript database

    E. coli O157 has long been the leading cause of major foodborne STEC outbreaks but recently non-O157 STECs are increasingly implicated. Selective media for E. coli O157 are commercially available but none detect non-O157 STEC. Currently, regulatory agencies screen for non-O157 STECs by enriching foo...

  12. Risk Factors for Shiga Toxin-Producing Escherichia coli-Associated Human Diseases.

    PubMed

    Rivas, Marta; Chinen, Isabel; Miliwebsky, Elizabeth; Masana, Marcelo

    2014-10-01

    We have reviewed the risk factors for the occurrence of Shiga toxin-producing Escherichia coli (STEC)-associated human diseases. The analysis of STEC surveillance data and trends shows differences in frequency and severity of the illnesses across countries, whereas the economic and social costs for the affected families, the community, and the health system are better estimated in developed countries. The occurrence of STEC infections is determined by the interaction of the pathogen, the reservoirs, and the biological, cultural, and behavioral aspects of the host. The main risk factors identified in earlier case-control and population-based studies were dietary behaviors and beef consumption. However, in recent years, other risky exposures have also emerged, like the consumption of raw vegetables and sprouts, working or camping in rural areas, visiting farms, and person-to-person transmission. Epidemiological changes have also been determined by the intensification of cattle production, the increase in centralized food production and distribution, and the growth in the volume of international trade of foods. The main lessons learned from recent large outbreaks are knowledge of virulence determinants of new pathogenic strains, recognition of new vehicles of infection, development of new methodologies for detecting STEC in foods and humans, improvement in food regulations and hygiene guidelines, new therapeutic approaches in the treatment of infected patients, establishment of continuous educational programs for food consumers, and enhanced cooperation and teamwork of regional and international networks.

  13. Improved traceability of Shiga-toxin-producing Escherichia coli using CRISPRs for detection and typing.

    PubMed

    Delannoy, Sabine; Beutin, Lothar; Fach, Patrick

    2016-05-01

    Among strains of Shiga-toxin-producing Escherichia coli (STEC), seven serogroups (O26, O45, O103, O111, O121, O145, and O157) are frequently associated with severe clinical illness in humans. The development of methods for their reliable detection from complex samples such as food has been challenging thus far, and is currently based on the PCR detection of the major virulence genes stx1, stx2, and eae, and O-serogroup-specific genes. However, this approach lacks resolution. Moreover, new STEC serotypes are continuously emerging worldwide. For example, in May 2011, strains belonging to the hitherto rarely detected STEC serotype O104:H4 were identified as causative agents of one of the world's largest outbreak of disease with a high incidence of hemorrhagic colitis and hemolytic uremic syndrome in the infected patients. Discriminant typing of pathogens is crucial for epidemiological surveillance and investigations of outbreaks, and especially for tracking and tracing in case of accidental and deliberate contamination of food and water samples. Clustered regularly interspaced short palindromic repeats (CRISPRs) are composed of short, highly conserved DNA repeats separated by unique sequences of similar length. This distinctive sequence signature of CRISPRs can be used for strain typing in several bacterial species including STEC. This review discusses how CRISPRs have recently been used for STEC identification and typing.

  14. Peri- and Postharvest Factors in the Control of Shiga Toxin-Producing Escherichia coli in Beef.

    PubMed

    Moxley, Rodney A; Acuff, Gary R

    2014-12-01

    Certain Shiga toxin-producing Escherichia coli (STEC) strains are important causes of food-borne disease, with hemorrhagic colitis and, in some cases, hemolytic-uremic syndrome as the clinical manifestations of illness. Six serogroups and one serotype of STEC (O26, O45, O103, O111, O121, O145, and O157:H7) are responsible for the vast majority of cases in the United States. Based on recent data for all food commodities combined, 55.3% and 50.0% of the outbreaks of STEC O157 and non-O157 in the United States, respectively, are attributable to beef as a food source. Consequently, the U.S. Department of Agriculture, Food Safety and Inspection Service declared these organisms as adulterants in raw, nonintact beef. In North America, cattle are a major reservoir of STEC strains, with organisms shed in the feces and contaminated hides of the animals being the main vehicle for spread to carcasses at slaughter. A number of peri- and postharvest interventions targeting STEC have been developed, and significant progress has been made in improving the microbiological quality of beef in the past 20 years as a result. However, continued improvements are needed, and accurate assessment of these interventions, especially for non-O157 STEC, would greatly benefit from improvements in detection methods for these organisms.

  15. Prevalence of verotoxin-producing Escherichia coli (VTEC) 0157 in Swedish dairy herds.

    PubMed Central

    Eriksson, E.; Aspan, A.; Gunnarsson, A.; Vågsholm, I.

    2005-01-01

    A prevalence study of verotoxin-producing Escherichia coli O157 (VTEC O157) was performed in 371 randomly selected dairy herds distributed throughout Sweden. Faecal and manure samples were collected and analysed by immunomagnetic separation and culturing. Data were recorded for each herd regarding herd size, age of sampled animals and whether, in addition to cattle, the farm kept other animals. VTEC O157 was isolated from 33 (8.9%) of the 371 investigated herds. The prevalence was higher (23.3%) in Halland county than in the rest of Sweden (P > 0.01). Halland was also the county in Sweden that during the study period had the highest incidence of human VTEC O157 cases. VTEC O157 was not detected on any farm in northern Sweden. Identified risk factors, in the multivariate analyses, for herds being VTEC O157 positive were herd size, geographical localization, presence of pigs on the farm and median age of sampled animals. PMID:15816162

  16. Shiga toxin-producing Escherichia coli (STEC) O157 outbreak, The Netherlands, September-October 2005.

    PubMed

    Doorduyn, Y; de Jager, C M; van der Zwaluw, W K; Friesema, I H M; Heuvelink, A E; de Boer, E; Wannet, W J B; van Duynhoven, Y T H P

    2006-07-01

    In September 2005, the first national food-related outbreak of Shiga toxin (Stx)-producing Escherichia coli (STEC) O157 was investigated in the Netherlands. A total of 21 laboratory-confirmed cases (including one secondary case), and another 11 probable cases (two primary and nine secondary cases) were reported in patients who became ill between 11 September and 10 October 2005. Preliminary investigation suggested consumption of a raw beef product, steak tartare (in the Netherlands also known as "filet americain"), and contact with other symptomatic persons as possible risk factors. A subsequent case-control study supported the hypothesis that steak tartare was the source of the outbreak (matched odds ratio (OR) 272, 95% confidence interval (CI) 3-23,211). Consumption of ready-to-eat vegetables was also associated with STEC O157 infection (matched OR 24, 95% CI 1.1-528), but was considered a less likely source, as only 40% of the cases were exposed. Samples of steak tartare collected from one chain of supermarkets where it is likely that most patients (67%) bought steak tartare, all tested negative for STEC O157. However, sampling was done three days after the date of symptom onset of the last reported case. Since 88% of the cases became ill within a two week period, point source contamination may explain these negative results. It is concluded that steak tartare was the most likely cause of the first national food-related outbreak of STEC O157 in the Netherlands.

  17. Survival of Shiga toxin-producing Escherichia coli and Stx bacteriophages in moisture enhanced beef.

    PubMed

    Langsrud, Solveig; Heir, Even; Rode, Tone Mari

    2014-07-01

    Moisture enhancement of meat through injection is a technology to improve the sensory properties and the weight of meat. However, the technology may increase the risk of food borne infections. Shiga toxin-producing Escherichia coli (STEC) or bacteriophages carrying cytotoxin genes (Shiga toxin genes, stx), which is normally only present on the surface of intact beef, may be transferred to the inner parts of the muscle during the injection process. Pathogens and bacteriophages surviving the storage period may not be eliminated in the cooking process since many consumers prefer undercooked beef. Measures to increase the microbial food safety of moisture enhanced beef may include sterilization or washing of the outer surface of the meat before injection, avoiding recycling of marinade and addition of antimicrobial agents to the marinade. This paper reviews the literature regarding microbial safety of moisture enhanced beef with special emphasis on STEC and Stx bacteriophages. Also, results from a European Union research project, ProSafeBeef (Food-CT-16 2006-36241) are presented.

  18. Occurrence of verocytotoxin-producing Escherichia coli in dairy and meat processing environments.

    PubMed

    McKee, Rosemary; Madden, Robert H; Gilmour, Arthur

    2003-09-01

    From June 1999 to June 2000, 480 environmental swabs were collected from two abattoirs in Northern Ireland. In addition, from July 1999 to July 2000, 420 samples originating from raw cow's milk were collected from two Northern Ireland dairies. All samples were examined for the presence of verocytotoxin-producing Escherichia coli (VTEC). O157 with the use of selective enrichment in tryptone soya broth (TSB) and double-strength MacConkey broth purple (MBP) followed by immunomagnetic separation and selective plating onto sorbitol MacConkey agar supplemented with cefixime tellurite. Non-O157 VTEC was detected by selective enrichment in TSB-MBP and plating on MacConkey agar. A multiplex polymerase chain reaction assay was also used to detect the presence of the VT1, VT2, and eae genes. Two (0.42%) of the 480 abattoir samples tested positive for VTEC; one isolate carried the VT2 gene only, and the other carried both the VT2 and the eae genes. Nine (2.14%) of the 420 dairy samples tested positive for VTEC; four carried the VT2 gene only, four carried both the VT2 and the eae genes, and one carried both the VT1 and the eae genes. These results indicate that the incidence of VTEC was low in the dairy and meat processing environment samples tested, and this finding may help to explain the low incidence of VTEC reported for the local human population.

  19. Antibiotic resistance and integrons in Shiga toxin-producing Escherichia coli (STEC)

    PubMed Central

    Colello, Rocío; Etcheverría, Analía I.; Conza, Jose A. Di; Gutkind, Gabriel O.; Padola, Nora L.

    2015-01-01

    Shiga toxin-producing Escherichia coli (STEC) cause hemorrhagic colitis (HC) and hemolytic-uremic syndrome in humans (HUS). Cattle are the main reservoir of STEC and transmission to humans occurs through contaminated food and water. Antibiotics are used in pig production systems to combat disease and improve productivity and play a key role in the dissemination of antibiotic resistance genes to the bacteria. Integrons have been identified in resistant bacteria allowing for the acquisition and dissemination of antibiotic resistance genes. STEC strains isolated from humans and animals have developed antibiotic resistance. In our laboratory, 21 non-157 STEC strains isolated from pigs were analyzed to detect class 1 and 2 integrons by PCR. Eight carried integrons, 7 of them harbored intl2. In another study 545 STEC strains were also analyzed for the presence of intl1 and intl2 . Strains carrying intl1 belonged to isolates from environment (n = 1), chicken hamburger (n = 2), dairy calves (n = 4) and pigs (n = 8). Two strains isolated from pigs harbored intl2 and only one intl1 / intl2 , highlighting the presence of intl2 in pigs. The selection for multiresistant strains may contribute to the emergence of antibiotic resistant pathogens and facilitate the spreading of the mobile resistance elements to other bacteria. PMID:26221083

  20. Systemic effects of Subtilase cytotoxin produced by Escherichia coli O113:H21.

    PubMed

    Seyahian, E Abril; Oltra, Gisela; Ochoa, Federico; Melendi, Santiago; Hermes, Ricardo; Paton, James C; Paton, Adrienne W; Lago, Nestor; Castro Parodi, Mauricio; Damiano, Alicia; Ibarra, Cristina; Zotta, Elsa

    2017-03-01

    Subtilase cytotoxin (SubAB) is a member of the AB5 cytotoxin family and is produced by certain strains of Shiga toxigenic Escherichia coli. The toxin is known to be lethal to mice, but the pathological mechanisms that contribute to Uremic Hemolytic Syndrome (HUS) are poorly understood. In this study we show that intraperitoneal injection of a sublethal dose of SubAB in rats triggers a systemic response, with ascitic fluid accumulation, heart hypertrophy and damage to the liver, colon and kidney. SubAB treated rats presented microalbuminuria 20 days post inoculation. At this time we found disruption of the glomerular filtration barrier and alteration of the protein reabsorption mechanisms of the proximal tubule. In the kidney, SubAB also triggered an epithelial to mesenchymal transition (Wuyts et al., 1996). These findings indicate that apart from direct cytotoxic effects on renal tissues, SubAB causes significant damage to the other organs, with potential consequences for HUS pathogenesis.

  1. Antibiotic treatment of verocytotoxin-producing Escherichia coli (VTEC) infection: a systematic review and a proposal.

    PubMed

    Agger, Morten; Scheutz, Flemming; Villumsen, Steen; Mølbak, Kåre; Petersen, Andreas Munk

    2015-09-01

    A consensus has existed on not to treat verocytotoxin-producing Escherichia coli (VTEC)-infected individuals with antibiotics because of possible subsequent increased risk of developing haemolytic uraemic syndrome (HUS). The aim of this systematic review is to clarify the risk associated with antibiotic treatment during acute VTEC infection and in chronic VTEC carrier states. A systematic search in PubMed identified 1 meta-analysis, 10 clinical studies and 22 in vitro/in vivo studies. Four clinical studies found an increased risk of HUS, four studies found no altered risk of HUS and two studies found a protective effect of antibiotics. In vitro and clinical studies suggest that DNA synthesis inhibitors should be avoided, whereas evidence from in vitro studies indicates that certain protein and cell wall synthesis inhibitors reduce the release of toxins from VTEC isolates. Overall, these studies provide a more nuanced view of the diversity of responses by VTEC strains to antibiotics. Based on these data, as well as data from the Danish cohort of registered VTEC infections, we propose that antibiotic treatment with protein and cell wall synthesis inhibitors can be considered when specific criteria regarding patient group, serotype, virulence profile and duration of disease are met. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Shiga toxin-producing Escherichia coli in swine: the public health perspective

    PubMed Central

    Tseng, Marion; Fratamico, Pina M.; Manning, Shannon D.; Funk, Julie A.

    2014-01-01

    Shiga toxin-producing Escherichia coli (STEC) strains are food-borne pathogens that are an important public health concern. STEC infection is associated with severe clinical diseases in human beings, including hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS), which can lead to kidney failure and death. Cattle are the most important STEC reservoir. However, a number of STEC outbreaks and HUS cases have been attributed to pork products. In swine, STEC strains are known to be associated with edema disease. Nevertheless, the relationship between STEC of swine origin and human illness has yet to be determined. This review critically summarizes epidemiologic and biological studies of swine STEC. Several epidemiologic studies conducted in multiple regions of the world have demonstrated that domestic swine can carry and shed STEC. Moreover, animal studies have demonstrated that swine are susceptible to STEC O157:H7 infection and can shed the bacterium for 2 months. A limited number of molecular epidemiologic studies, however, have provided conflicting evidence regarding the relationship between swine STEC and human illness. The role that swine play in STEC transmission to people and the contribution to human disease frequency requires further evaluation. PMID:24397985

  3. Cytotoxic and Apoptotic Effects of Recombinant Subtilase Cytotoxin Variants of Shiga Toxin-Producing Escherichia coli

    PubMed Central

    Funk, J.; Biber, N.; Schneider, M.; Hauser, E.; Enzenmüller, S.; Förtsch, C.

    2015-01-01

    In this study, the cytotoxicity of the recently described subtilase variant SubAB2-2 of Shiga toxin-producing Escherichia coli was determined and compared to the plasmid-encoded SubAB1 and the chromosome-encoded SubAB2-1 variant. The genes for the respective enzymatic active (A) subunits and binding (B) subunits of the subtilase toxins were amplified and cloned. The recombinant toxin subunits were expressed and purified. Their cytotoxicity on Vero cells was measured for the single A and B subunits, as well as for mixtures of both, to analyze whether hybrids with toxic activity can be identified. The results demonstrated that all three SubAB variants are toxic for Vero cells. However, the values for the 50% cytotoxic dose (CD50) differ for the individual variants. Highest cytotoxicity was shown for SubAB1. Moreover, hybrids of subunits from different subtilase toxins can be obtained which cause substantial cytotoxicity to Vero cells after mixing the A and B subunits prior to application to the cells, which is characteristic for binary toxins. Furthermore, higher concentrations of the enzymatic subunit SubA1 exhibited cytotoxic effects in the absence of the respective B1 subunit. A more detailed investigation in the human HeLa cell line revealed that SubA1 alone induced apoptosis, while the B1 subunit alone did not induce cell death. PMID:25824835

  4. DNA-binding domain of human c-Myc produced in escherichia coli

    SciTech Connect

    Dang, C.V.; Buckmire, M.; VanDam, H.; Lee, W.M.F.

    1989-06-01

    The authors have identified the domain of the human c-myc protein (c-Myc) produced in Escherichia coli that is responsible for the ability of the protein to bind sequence-nonspecific DNA. Using analysis of binding of DNA by proteins transferred to nitrocellulose, DNA-cellulose chromatography, and a nitrocellulose filter binding assay, they examined the binding properties of c-Myc peptides generated by cyanogen bromide cleavage, of butane c-,Myc, and of proteins that fuse portions of c-Myc to staphylococcal protein A. The results of these analyses indicated that c-Myc amino acid 265 to 318 were responsible for DNA binding and that other regions of the protein (including a highly conserved basic region and a region containing the leucine zipper motif) were not required. Some mutant c-Mycs that did not bind DNA maintained rat embryo cell-cotransforming activity, which indicated that the c-Myc property of in vitro DNA binding was not essential for this activity. These mutants, however, were unable to transform established rat fibroblasts (Rat-1a cells) that were susceptible to transformation by wild-type c-Myc, although this lack of activity may not have been due to their inability to bind DNA.

  5. Genotypic characterization and biofilm formation of Shiga toxin-producing Escherichia coli.

    PubMed

    Picozzi, Claudia; Antoniani, Davide; Vigentini, Ileana; Foschino, Roberto; Kneifel, Wolfgang

    2017-01-01

    Shiga toxin-producing Escherichia coli (STEC) are recognized as one of the most dangerous foodborne pathogens. The production of Shiga toxins together with intimin protein is among the main virulence factors. However, the ability to form biofilm can protect bacteria against environmental factors (i.e. desiccation, exposure to UV rays, predation, etc.) and sanitization procedures (cleaning, rinsing, chlorination), increasing their survival on food products and in manufacturing plants. Forty-five isolates collected from food and fecal samples were genotyped by pulsed field gel electrophoresis analysis with XbaI restriction enzyme and investigated by searching for toxins (stx1, stx2) and intimin (eae) genes and serogroup (O157, O26, O145, O111, O103 and O104). Afterward, the ability to develop biofilm in microtiter assay and the production of adhesive curli fimbriae and cellulose on agar plates were tested. Our study demonstrated that biofilm formation has a great variability among STEC strains and cannot be related to a specific pulsotype nor even to serogroup or presence of virulence genes. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Antibiotic resistance and integrons in Shiga toxin-producing Escherichia coli (STEC).

    PubMed

    Colello, Rocío; Etcheverría, Analía I; Di Conza, Jose A; Gutkind, Gabriel O; Padola, Nora L

    2015-03-01

    Shiga toxin-producing Escherichia coli (STEC) cause hemorrhagic colitis (HC) and hemolytic-uremic syndrome in humans (HUS). Cattle are the main reservoir of STEC and transmission to humans occurs through contaminated food and water. Antibiotics are used in pig production systems to combat disease and improve productivity and play a key role in the dissemination of antibiotic resistance genes to the bacteria. Integrons have been identified in resistant bacteria allowing for the acquisition and dissemination of antibiotic resistance genes. STEC strains isolated from humans and animals have developed antibiotic resistance. In our laboratory, 21 non-157 STEC strains isolated from pigs were analyzed to detect class 1 and 2 integrons by PCR. Eight carried integrons, 7 of them harbored intl2. In another study 545 STEC strains were also analyzed for the presence of intl1 and intl2 . Strains carrying intl1 belonged to isolates from environment (n = 1), chicken hamburger (n = 2), dairy calves (n = 4) and pigs (n = 8). Two strains isolated from pigs harbored intl2 and only one intl1 / intl2 , highlighting the presence of intl2 in pigs. The selection for multiresistant strains may contribute to the emergence of antibiotic resistant pathogens and facilitate the spreading of the mobile resistance elements to other bacteria.

  7. Classification of Shiga toxin-producing escherichia coli (STEC) serotypes with hyperspectral microscope imagery

    NASA Astrophysics Data System (ADS)

    Park, Bosoon; Windham, William R.; Ladely, Scott R.; Gurram, Prudhvi; Kwon, Heesung; Yoon, Seung-Chul; Lawrence, Kurt C.; Narang, Neelam; Cray, William C.

    2012-05-01

    Non-O157:H7 Shiga toxin-producing Escherichia coli (STEC) strains such as O26, O45, O103, O111, O121 and O145 are recognized as serious outbreak to cause human illness due to their toxicity. A conventional microbiological method for cell counting is laborious and needs long time for the results. Since optical detection method is promising for realtime, in-situ foodborne pathogen detection, acousto-optical tunable filters (AOTF)-based hyperspectral microscopic imaging (HMI) method has been developed for identifying pathogenic bacteria because of its capability to differentiate both spatial and spectral characteristics of each bacterial cell from microcolony samples. Using the AOTF-based HMI method, 89 contiguous spectral images could be acquired within approximately 30 seconds with 250 ms exposure time. From this study, we have successfully developed the protocol for live-cell immobilization on glass slides to acquire quality spectral images from STEC bacterial cells using the modified dry method. Among the contiguous spectral imagery between 450 and 800 nm, the intensity of spectral images at 458, 498, 522, 546, 570, 586, 670 and 690 nm were distinctive for STEC bacteria. With two different classification algorithms, Support Vector Machine (SVM) and Sparse Kernel-based Ensemble Learning (SKEL), a STEC serotype O45 could be classified with 92% detection accuracy.

  8. Comparative Genome Analysis of Extended-Spectrum-β-Lactamase-Producing Escherichia coli Sequence Type 131 Strains from Nepal and Japan

    PubMed Central

    Miyoshi-Akiyama, Tohru; Sherchan, Jatan Bahadur; Doi, Yohei; Nagamatsu, Maki; Sherchand, Jeevan B.; Tandukar, Sarmila; Ohmagari, Norio; Kirikae, Teruo; Ohara, Hiroshi

    2016-01-01

    ABSTRACT The global spread of extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli (ESBL-E. coli) has largely been driven by the pandemic sequence type 131 (ST131). This study aimed to determine the molecular epidemiology of their spread in two Asian countries with contrasting prevalence. We conducted whole-genome sequencing (WGS) of ESBL-E. coli ST131 strains collected prospectively from Nepal and Japan, two countries in Asia with a high and low prevalence of ESBL-E. coli, respectively. We also systematically compared these genomes with those reported from other regions using publicly available WGS data for E. coli ST131 strains. Further, we conducted phylogenetic analysis of these isolates and all genome sequence data for ST131 strains to determine sequence diversity. One hundred five unique ESBL-E. coli isolates from Nepal (February 2013 to July 2013) and 76 isolates from Japan (October 2013 to September 2014) were included. Of these isolates, 54 (51%) isolates from Nepal and 11 (14%) isolates from Japan were identified as ST131 by WGS. Phylogenetic analysis based on WGS suggested that the majority of ESBL-E. coli ST131 isolates from Nepal clustered together, whereas those from Japan were more diverse. Half of the ESBL-E. coli ST131 isolates from Japan belonged to virotype C, whereas half of the isolates from Nepal belonged to a virotype other than virotype A, B, C, D, or E (A/B/C/D/E). The dominant sublineage of E. coli ST131 was H30Rx, which was most prominent in ESBL-E. coli ST131 isolates from Nepal. Our results revealed distinct phylogenetic characteristics of ESBL-E. coli ST131 spread in the two geographical areas of Asia, indicating the involvement of multiple factors in its local spread in each region. IMPORTANCE The global spread of ESBL-E. coli has been driven in large part by pandemic sequence type 131 (ST131). A recent study suggested that, within E. coli ST131, certain sublineages have disseminated worldwide with little association

  9. Occurrence of generic E. coli, E. coli O157:H7 and Salmonella spp. in water and sediment from leafy green produce farms and streams on the Central California coast

    USDA-ARS?s Scientific Manuscript database

    Irrigation with water of poor microbiological quality can elevate levels of bacteria on produce. This study aimed to identify climate and management covariates associated with generic E. coli in irrigation water on leafy green produce farms and to measure the prevalence of E. coli O157:H7 and Salmon...

  10. Faecal shedding of CTX-M-producing Escherichia coli in horses receiving broad-spectrum antimicrobial prophylaxis after hospital admission.

    PubMed

    Damborg, Peter; Marskar, Peter; Baptiste, Keith E; Guardabassi, Luca

    2012-01-27

    The objective of this longitudinal study was to investigate the occurrence and genetic background of faecal Escherichia coli resistant to cefotaxime (CTX) in horses receiving broad-spectrum antimicrobial prophylaxis after admission to a veterinary teaching hospital. The ten horses enrolled in the study were treated with cefquinome either alone (n=4) or in combination with metronidazole (n=3) or other antimicrobial agents (n=3). CTX-resistant coliforms in faeces collected before, during and after treatment were quantified on selective MacConkey agar supplemented with CTX, and a colony isolated randomly from each positive sample was characterized by pulsed-field gel electrophoresis, and by PCR detection and sequencing of bla(TEM), bla(SHV), bla(CTX-M) and bla(CMY). All horses were negative for CTX-resistant coliforms at admission but became positive within the first three days of treatment. The average faecal densities of CTX-resistant coliforms increased significantly following antimicrobial prophylaxis (P<0.001). Genetic characterization of 29 faecal isolates revealed that this effect was due to proliferation of E. coli producing either CTX-M-1 (n=28) or CTX-M-14 (n=1). Five CTX-M-1 isolates produced additional β-lactamases (TEM-1, CMY-34 and the novel variant CMY-53). Shedding of CTX-M-producing E. coli appeared intermittent in four horses and persisted two weeks after antimicrobial treatments in five of six patients tested after discharge from hospital. Nosocomial transmission was suggested by finding five identical CTX-M-1-producing E. coli pulsotypes in multiple horses. The originality of the study lies in the unanticipated high frequency and genetic diversity of CTX-M-producing E. coli observed in the faecal flora of hospitalized patients receiving broad-spectrum antimicrobial prophylaxis.

  11. Risk factors for extended spectrum β-lactamase-producing Escherichia coli versus susceptible E. coli in surgical site infections among cancer patients in Mexico.

    PubMed

    Montes, Claudia V; Vilar-Compte, Diana; Velazquez, Consuelo; Golzarri, Maria Fernanda; Cornejo-Juarez, Patricia; Larson, Elaine L

    2014-10-01

    Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli are of increasing concern as a cause of healthcare-associated infections. Using a matched case-control design, demographics, antibiotic use, and relevant surgical data were obtained for 173 cases (ESBL E. coli surgical site infections, [SSI]) and 173 controls (antibiotic-susceptible E. coli SSI) in an oncology hospital in Mexico City. Conditional logistic regression modeling was used to calculate odds ratios (OR). The mean age of patients was 53.6 years, 214 (62%) were female. Demographics and comorbidities were similar between groups. Although antibiotic prophylaxis was common among both cases and controls (84% and 89%), more than one-half of cases (53%) were given prophylaxis outside the recommended window or were exposed for more than 24 h in comparison to 29% of controls. Patients who received untimely (OR=3.13, 95% confidence interval [CI] 1.5-6.4) and discontinued inappropriately (OR 6.38, 95% CI=2.5-16.2) prophylaxis were more likely to develop an ESBL SSI. In addition, patients with an organ/space infection compared with superficial had a higher rate of a resistant infection (OR 4.2, 95% CI 1.3-13.9). Among patients not given timely or appropriately discontinued prophylaxis, post-operative cephalosporin use (OR 3.3, 95% CI 1.4-7.7) was associated with ESBL E. coli SSIs. The appropriate timing and duration of perioperative antimicrobial prophylaxis were associated with lower risk of ESBL E. coli in SSIs. Even though compliance to antimicrobial prophylaxis guidelines is of the utmost importance, reduced exposure to cephalosporins may also potentially decrease the risk of ESBL SSI.

  12. A decisive period in cefoxitin prophylaxis of experimental synergistic wound infection produced by Bacteroides fragilis and Escherichia coli.

    PubMed

    Shapiro, M; Sacks, T

    1982-08-01

    In an experimental model of synergistic infection produced by Escherichia coli and Bacteroides fragilis, a single injection of cefoxitin 1 h before inoculation of the bacteria was able to prevent both death and local wound infection (P less than 0.05). When cefoxitin was administered 1 h after the bacterial inoculum, death of the animals, but not the wound infection, was prevented (P greater than 0.1). Cefazolin, active against the E. coli only, could prevent death, but had no significant effect (P greater than 0.1) on the prevention of wound sepsis.

  13. Clinical isolates of uropathogenic Escherichia coli ST131 producing NDM-7 metallo-β-lactamase in China.

    PubMed

    Wang, Lian-Hui; Liu, Pan-Pan; Wei, Dan-Dan; Liu, Yang; Wan, La-Gen; Xiang, Tian-Xin; Zhang, Yu-Juan

    2016-07-01

    Here we report five cases of NDM-7-producing Escherichia coli from patients with bacteriuria in a teaching hospital in mainland China. Two isolates belonged to sequence type 131 (ST131), simultaneously carrying blaCTX-M-15, blaSHV-11, blaTEM-1 and qnrS1. The blaNDM-7 gene was located on a conjugative IncX3-type plasmid bearing blaTEM-1 and qnrS1. These findings indicate the spread of NDM-7 metallo-β-lactamase in a highly resistant and virulent E. coli sequence type in China.

  14. Contribution of Urease to Colonization by Shiga Toxin-Producing Escherichia coli

    PubMed Central

    Steyert, Susan R.

    2012-01-01

    Shiga toxin-producing Escherichia coli (STEC) is a food-borne pathogen with a low infectious dose that colonizes the colon in humans and can cause severe clinical manifestations such as hemolytic-uremic syndrome. The urease enzyme, encoded in the STEC chromosome, has been demonstrated to act as a virulence factor in other bacterial pathogens. The NH3 produced as urease hydrolyzes urea can aid in buffering bacteria in acidic environments as well as provide an easily assimilated source of nitrogen that bacteria can use to gain a metabolic advantage over intact microflora. Here, we explore the role of urease in STEC pathogenicity. The STEC urease enzyme exhibited maximum activity near neutral pH and during the stationary-growth phase. Experiments altering growth conditions performed with three phylogenetically distinct urease-positive strains demonstrated that the STEC ure gene cluster is inducible by neither urea nor pH but does respond to nitrogen availability. Quantitative reverse transcription-PCR (qRT-PCR) data indicate that nitrogen inhibits the transcriptional response. The deletion of the ure gene locus was constructed in STEC strain 88-0643, and the ure mutant was used with the wild-type strain in competition experiments in mouse models to examine the contribution of urease. The wild-type strain was twice as likely to survive passage through the acidic stomach and demonstrated an enhanced ability to colonize the intestinal tract compared to the ure mutant strain. These in vivo experiments reveal that, although the benefit STEC gains from urease expression is modest and not absolutely required for colonization, urease can contribute to the pathogenicity of STEC. PMID:22665380

  15. Contribution of urease to colonization by Shiga toxin-producing Escherichia coli.

    PubMed

    Steyert, Susan R; Kaper, James B

    2012-08-01

    Shiga toxin-producing Escherichia coli (STEC) is a food-borne pathogen with a low infectious dose that colonizes the colon in humans and can cause severe clinical manifestations such as hemolytic-uremic syndrome. The urease enzyme, encoded in the STEC chromosome, has been demonstrated to act as a virulence factor in other bacterial pathogens. The NH(3) produced as urease hydrolyzes urea can aid in buffering bacteria in acidic environments as well as provide an easily assimilated source of nitrogen that bacteria can use to gain a metabolic advantage over intact microflora. Here, we explore the role of urease in STEC pathogenicity. The STEC urease enzyme exhibited maximum activity near neutral pH and during the stationary-growth phase. Experiments altering growth conditions performed with three phylogenetically distinct urease-positive strains demonstrated that the STEC ure gene cluster is inducible by neither urea nor pH but does respond to nitrogen availability. Quantitative reverse transcription-PCR (qRT-PCR) data indicate that nitrogen inhibits the transcriptional response. The deletion of the ure gene locus was constructed in STEC strain 88-0643, and the ure mutant was used with the wild-type strain in competition experiments in mouse models to examine the contribution of urease. The wild-type strain was twice as likely to survive passage through the acidic stomach and demonstrated an enhanced ability to colonize the intestinal tract compared to the ure mutant strain. These in vivo experiments reveal that, although the benefit STEC gains from urease expression is modest and not absolutely required for colonization, urease can contribute to the pathogenicity of STEC.

  16. Detection and Characterization of Verocytotoxin-Producing Escherichia coli by Automated 5′ Nuclease PCR Assay

    PubMed Central

    Nielsen, Eva Møller; Andersen, Marianne Thorup

    2003-01-01

    In recent years increased attention has been focused on infections caused by isolates of verocytotoxin-producing Escherichia coli (VTEC) serotypes other than O157. These non-O157 VTEC isolates are commonly present in food and food production animals. Easy detection, isolation, and characterization of non-O157 VTEC isolates are essential for improving our knowledge of these organisms. In the present study, we detected VTEC isolates in bovine fecal samples by a duplex 5′ nuclease PCR assay (real-time PCR) that targets vtx1 and vtx2. VTEC isolates were obtained by colony replication by use of hydrophobic-grid membrane filters and DNA probe hybridization. Furthermore, we have developed 5′ nuclease PCR assays for the detection of virulence factors typically present in VTEC isolates, including subtypes of three genes of the locus of enterocyte effacement (LEE) pathogenicity island. The 22 assays included assays for the detection of verocytotoxin genes (vtx1, vtx2), pO157-associated genes (ehxA, katP, espP, and etpD), a recently identified adhesin (saa), intimin (eae, all variants), seven subtypes of eae, four subtypes of tir, and three subtypes of espD. A number of reference strains (VTEC and enteropathogenic E. coli strains) and VTEC strains isolated from calves were tested to validate the PCR assays. The expected virulence profiles were detected for all reference strains. In addition, new information on the subtypes of LEE genes was obtained. For reference strains as well as bovine isolates, a consistent relationship between subtypes of the LEE genes was found, so that a total of seven different combinations of these were recognized (corresponding to the seven subtypes of eae). Isolates with 15 different serogroup-virulence profiles were isolated from 16 calves. Among these, 53% harbored LEE and 73% harbored factors carried by the large virulence plasmid. One LEE-negative isolate had the gene for the adhesin Saa. The most common virulence profile among the bovine

  17. Indistinguishable NDM-producing Escherichia coli isolated from recreational waters, sewage, and a clinical specimen in Ireland, 2016 to 2017.

    PubMed

    Mahon, Bláthnaid M; Brehony, Carina; McGrath, Elaine; Killeen, James; Cormican, Martin; Hickey, Paul; Keane, Shane; Hanahoe, Belinda; Dolan, Ann; Morris, Dearbháile

    2017-04-13

    In this study, New Delhi metallo-beta-lactamase (NDM)-producing Enterobacteriaceae were identified in Irish recreational waters and sewage. Indistinguishable NDM-producing Escherichia coli by pulsed-field gel electrophoresis were isolated from sewage, a fresh water stream and a human source. NDM-producing Klebsiella pneumoniae isolated from sewage and seawater in the same area were closely related to each other and to a human isolate. This raises concerns regarding the potential for sewage discharges to contribute to the spread of carbapenemase-producing Enterobacteriaceae. This article is copyright of The Authors, 2017.

  18. Sequential necrotizing fasciitis caused by the monomicrobial pathogens Streptococcus equisimilis and extended-spectrum beta-lactamase-producing Escherichia coli.

    PubMed

    Endo, Akiko; Matsuoka, Ryosuke; Mizuno, Yasushi; Doi, Asako; Nishioka, Hiroaki

    2016-08-01

    Necrotizing fasciitis is a rapidly progressing bacterial infection of the superficial fascia and subcutaneous tissue that is associated with a high mortality rate and is caused by a single species of bacteria or polymicrobial organisms. Escherichia coli is rarely isolated from patients with monomicrobial disease. Further, there are few reports of extended-spectrum beta-lactamase (ESBL)-producing E. coli associated with necrotizing fasciitis. We report here our treatment of an 85-year-old man who was admitted because of necrotizing fasciitis of his right thigh. Streptococcus equisimilis was detected as a monomicrobial pathogen, and the infection was cured by amputation of the patient's right leg and the administration of antibiotics. However, 5 days after discontinuing antibiotic therapy, he developed necrotizing fasciitis on his right upper limb and died. ESBL-producing E. coli was the only bacterial species isolated from blood and skin cultures. This case demonstrates that ESBL-producing E. coli can cause monomicrobial necrotizing fasciitis, particularly during hospitalization and that a different bacterial species can cause disease shortly after a previous episode.

  19. The occurrence of ESBL-producing Escherichia coli carrying aminoglycoside resistance genes in urinary tract infections in Saudi Arabia.

    PubMed

    Alyamani, Essam J; Khiyami, Anamil M; Booq, Rayan Y; Majrashi, Majed A; Bahwerth, Fayez S; Rechkina, Elena

    2017-01-06

    The infection and prevalence of extended-spectrum β-lactamases (ESBLs) is a worldwide problem, and the presence of ESBLs varies between countries. In this study, we investigated the occurrence of plasmid-mediated ESBL/AmpC/carbapenemase/aminoglycoside resistance gene expression in Escherichia coli using phenotypic and genotypic techniques. A total of 58 E. coli isolates were collected from hospitals in the city of Makkah and screened for the production of ESBL/AmpC/carbapenemase/aminoglycoside resistance genes. All samples were subjected to phenotypic and genotypic analyses. The antibiotic susceptibility of the E. coli isolates was determined using the Vitek-2 system and the minimum inhibitory concentration (MIC) assay. Antimicrobial agents tested using the Vitek 2 system and MIC assay included the expanded-spectrum (or third-generation) cephalosporins (e.g., cefoxitin, cefepime, aztreonam, cefotaxime, ceftriaxone, and ceftazidime) and carbapenems (meropenem and imipenem). Reported positive isolates were investigated using genotyping technology (oligonucleotide microarray-based assay and PCR). The genotyping investigation was focused on ESBL variants and the AmpC, carbapenemase and aminoglycoside resistance genes. E. coli was phylogenetically grouped, and the clonality of the isolates was studied using multilocus sequence typing (MLST). Our E. coli isolates exhibited different levels of resistance to ESBL drugs, including ampicillin (96.61%), cefoxitin (15.25%), ciprofloxacin (79.66%), cefepime (75.58%), aztreonam (89.83%), cefotaxime (76.27%), ceftazidime (81.36%), meropenem (0%) and imipenem (0%). Furthermore, the distribution of ESBL-producing E. coli was consistent with the data obtained using an oligonucleotide microarray-based assay and PCR genotyping against genes associated with β-lactam resistance. ST131 was the dominant sequence type lineage of the isolates and was the most uropathogenic E. coli lineage. The E. coli isolates also carried aminoglycoside

  20. Characterization of extended spectrum β-lactamase-producing Escherichia coli in community-acquired urinary tract infections in Tunisia.

    PubMed

    Hammami, Samia; Saidani, Mabrouka; Ferjeni, Sana; Aissa, Ines; Slim, Amin; Boutiba-Ben Boubaker, Ilhem

    2013-06-01

    This study was conducted to investigate the molecular epidemiology of extended spectrum β-lactamase (ESBL)-producing Escherichia coli in community-acquired (urinary tract) infections (CA-UTI) in Tunisia. Between January 2007 and December 2009, 15 E. coli isolates were collected at the laboratory of microbiology of Charles Nicolle Hospital of Tunis. Microbial identification was done with conventional methods. Antibiotic susceptibility was determined by disk diffusion method and ESBL detection was done with double-disk synergy test. ESBL typing was performed by polymerase chain reaction (PCR) and sequencing. Phylogenetic groups, virulence factors, and sequence type (ST)131 were determined by PCR. Genetic relatedness between strains was examined by pulsed-field gel electrophoresis (PFGE) after restriction with XbaI. The prevalence of ESBL-producing E. coli in CA-UTI was 0.046%. The majority of isolates were multidrug resistant. ESBL types were CTX-M-15 (n=13) and SHV-12 (n=2). The most common phylogenetic group was B2 (n=11) and virulence score was greater than or equal to 9 in nine strains. PFGE revealed 12 clusters. The majority of isolates (n=14) belonged to ST131 clone and 11 of them were CTX-M producers. In conclusion, this is the first detailed documentation of CA-ESBLs producing E. coli in Tunisia. Of particular concern is the emergence in our community of the highly diffusing CTX-M-15-B2-ST131 E. coli clone, which requires strengthening surveillance measures to countervail this emergent public health problem.

  1. Outbreak of verocytotoxin-producing E. coli O145 and O26 infections associated with the consumption of ice cream produced at a farm, Belgium, 2007.

    PubMed

    De Schrijver, K; Buvens, G; Possé, B; Van den Branden, D; Oosterlynck, O; De Zutter, L; Eilers, K; Piérard, D; Dierick, K; Van Damme-Lombaerts, R; Lauwers, C; Jacobs, R

    2008-02-14

    In October 2007, an outbreak of verocytotoxin-producing Escherichia coli (VTEC) O145 and E. coli O26 occurred among consumers of ice cream produced and sold in September 2007 at a farm in the province of Antwerp (Belgium). The ice cream was consumed at two birthday parties and also eaten at the farm. Five children, aged between two and 11 years, developed haemolytic uraemic syndrome (HUS), and seven other co-exposed persons contracted severe diarrhoea. In three of the five HUS cases VTEC O145 infections were laboratory confirmed, one in association with VTEC O26. Identical isolates of E. coli O145 and O26 were detected with PCR and PFGE in faecal samples of patients and in ice cream leftovers from one of the birthday parties, in faecal samples taken from calves, and in samples of soiled straw from the farm at which the ice cream was produced. Ice cream was made from pasteurised milk and most likely contaminated by one of food handlers.

  2. Clonal relatedness of Shiga-like toxin-producing Escherichia coli O101 strains of human and porcine origin.

    PubMed Central

    Franke, S; Harmsen, D; Caprioli, A; Pierard, D; Wieler, L H; Karch, H

    1995-01-01

    Shiga-like toxin (SLT)-producing Escherichia coli (SLTEC) O101 has recently been associated with hemorrhagic colitis and hemolytic-uremic syndrome in humans. In this study, SLTEC O101 strains from humans and pigs were characterized for clonal relatedness by nucleotide sequence analysis of their slt genes, DNA finger-printing of genomic DNA, and determination of virulence factors. The slt genes of five E. coli O101 strains were cloned and sequenced. For all strains, the deduced amino acid sequences of the B subunits were identical to those of the SLT-IIe present in the classical SLTEC O139 strains that cause edema disease in pigs. The A subunit revealed more than 99% homology to that of SLT-IIe. DNA fingerprinting revealed a high degree of genetic relatedness between the human and porcine O101 isolates. None of the O101 strains investigated had virulence factors frequently found in porcine (F107 fimbriae or heat-stable or heat-labile enterotoxins) or human SLTEC strains (eaeA or enterohemorrhagic E. coli hemolysin). The absence of virulence factors typical of SLT-I- and SLT-II-producing E. Coli together with the presence of SLT-IIe, a toxin previously seen only in porcine E. coli, suggests a new pathogenic mechanism for E. coli O101 infection of humans. For diagnostic purposes, we recommend the use of PCR primers and DNA probes complementary to slt-IIe to correctly identify such strains and to further evaluate their role in human diseases. PMID:8586696

  3. Clonal relatedness of Shiga-like toxin-producing Escherichia coli O101 strains of human and porcine origin.

    PubMed

    Franke, S; Harmsen, D; Caprioli, A; Pierard, D; Wieler, L H; Karch, H

    1995-12-01

    Shiga-like toxin (SLT)-producing Escherichia coli (SLTEC) O101 has recently been associated with hemorrhagic colitis and hemolytic-uremic syndrome in humans. In this study, SLTEC O101 strains from humans and pigs were characterized for clonal relatedness by nucleotide sequence analysis of their slt genes, DNA finger-printing of genomic DNA, and determination of virulence factors. The slt genes of five E. coli O101 strains were cloned and sequenced. For all strains, the deduced amino acid sequences of the B subunits were identical to those of the SLT-IIe present in the classical SLTEC O139 strains that cause edema disease in pigs. The A subunit revealed more than 99% homology to that of SLT-IIe. DNA fingerprinting revealed a high degree of genetic relatedness between the human and porcine O101 isolates. None of the O101 strains investigated had virulence factors frequently found in porcine (F107 fimbriae or heat-stable or heat-labile enterotoxins) or human SLTEC strains (eaeA or enterohemorrhagic E. coli hemolysin). The absence of virulence factors typical of SLT-I- and SLT-II-producing E. Coli together with the presence of SLT-IIe, a toxin previously seen only in porcine E. coli, suggests a new pathogenic mechanism for E. coli O101 infection of humans. For diagnostic purposes, we recommend the use of PCR primers and DNA probes complementary to slt-IIe to correctly identify such strains and to further evaluate their role in human diseases.

  4. Escherichia coli common pilus (ECP) targets arabinosyl residues in plant cell walls to mediate adhesion to fresh produce plants.

    PubMed

    Rossez, Yannick; Holmes, Ashleigh; Lodberg-Pedersen, Henriette; Birse, Louise; Marshall, Jacqueline; Willats, William G T; Toth, Ian K; Holden, Nicola J

    2014-12-05

    Outbreaks of verotoxigenic Escherichia coli are often associated with fresh produce. However, the molecular basis to adherence is unknown beyond ionic lipid-flagellum interactions in plant cell membranes. We demonstrate that arabinans present in different constituents of plant cell walls are targeted for adherence by E. coli common pilus (ECP; or meningitis-associated and temperature-regulated (Mat) fimbriae) for E. coli serotypes O157:H7 and O18:K1:H7. l-Arabinose is a common constituent of plant cell wall that is rarely found in other organisms, whereas ECP is widespread in E. coli and other environmental enteric species. ECP bound to oligosaccharides of at least arabinotriose or longer in a glycan array, plant cell wall pectic polysaccharides, and plant glycoproteins. Recognition overlapped with the antibody LM13, which binds arabinanase-sensitive pectic epitopes, and showed a preferential affinity for (1→5)-α-linked l-arabinosyl residues and longer chains of arabinan as demonstrated with the use of arabinan-degrading enzymes. Functional adherence in planta was mediated by the adhesin EcpD in combination with the structural subunit, EcpA, and expression was demonstrated with an ecpR-GFP fusion and ECP antibodies. Spinach was found to be enriched for ECP/LM13 targets compared with lettuce. Specific recognition of arabinosyl residues may help explain the persistence of E. coli in the wider environment and association of verotoxigenic E. coli with some fresh produce plants by exploitation of a glycan found only in plant, not animal, cells.

  5. HlyF Produced by Extraintestinal Pathogenic Escherichia coli Is a Virulence Factor That Regulates Outer Membrane Vesicle Biogenesis.

    PubMed

    Murase, Kazunori; Martin, Patricia; Porcheron, Gaëlle; Houle, Sébastien; Helloin, Emmanuelle; Pénary, Marie; Nougayrède, Jean-Philippe; Dozois, Charles M; Hayashi, Tetsuya; Oswald, Eric

    2016-03-01

    Escherichia coli can cause extraintestinal infections in humans and animals. The hlyF gene is epidemiologically associated with virulent strains of avian pathogenic E. coli and human neonatal meningitis-associated E. coli. We demonstrated that culture supernatants of E. coli expressing HlyF induced autophagy in eukaryotic cells. This phenotype coincided with an enhanced production of outer membrane vesicles (OMVs) by bacteria expressing HlyF. The HlyF protein displays a predicted catalytic domain of the short-chain dehydrogenase/reductase superfamily. This conserved domain was involved the ability of HlyF to promote the production of OMVs. The increased production of OMVs was associated with the release of toxins. hlyF was shown to be expressed during extraintestinal infection and to play a role in the virulence of extraintestinal pathogenic E. coli in a chicken model of colibacillosis. This is the first evidence that pathogenic bacteria produce a virulence factor directly involved in the production of OMVs.

  6. Molecular characterization of extended-spectrum β-lactamase-producing Escherichia coli and Klebsiella spp. isolates in Mongolia.

    PubMed

    Kao, Cheng-Yen; Udval, Uuganbayar; Huang, Yi-Ting; Wu, Hsiu-Mei; Huang, Ay-Huey; Bolormaa, Enkhbaatar; Yan, Jing-Jou; Urangoo, Zorig; Batbaatar, Gunchin; Khosbayar, Tulgaa; Wu, Jiunn-Jong

    2016-10-01

    The aim of this study was to determine the molecular characteristics of β-lactamase genes in extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae isolates from Mongolia. Fifty-six ESBL-producing Enterobacteriaceae isolates were collected, of which 46 were Escherichia coli, seven were Klebsiella pneumoniae, and three were K. oxytoca. Minimum inhibitory concentrations for selected antibiotics were tested using the agar dilution method, and the β-lactamase genes were determined using polymerase chain reaction combined with sequencing. Pulsed-field gel electrophoresis (PFGE) was used for genotyping all isolates, and phylogenetic grouping was performed on ESBL-producing E. coli isolates. Conjugation tests combined with plasmid digestion assays were used to determine whether there was a horizontal spread in Mongolia. Among the 56 ESBL-producing isolates, 43 isolates (76.8%) were resistant to fluoroquinolones, but all isolates were susceptible to carbapenems and amikacin. The polymerase chain reaction sequencing results showed that the dominant CTX-M genotype was CTX-M-15 (19/46, 41.3%) in the ESBL-producing E. coli isolates. By contrast, CTX-M-14 and CTX-M-3 were the major genotypes found in Klebsiella spp. Phylogenetic analysis revealed that 21 ESBL-producing E. coli isolates belonged to group D (21/46, 45.6%), followed by group A (13/46, 28.3%), group B2 (11/46, 23.9%), and group B1 (1/46, 2.2%). Only four E. coli isolates (4/46, 8.7%) belonged to the ST131 clone. PFGE showed that the ESBL-producing Enterobacteriaceae were genetically unrelated. The conjugation assay showed that two plasmids harboring CTX-M-15 in E. coli isolates were genetic unrelated, whereas seven plasmids harboring CTX-M-14 (5/7 and 2/7) and four plasmids harboring CTX-M-55 (4/4) showed genetic relatedness, indicating the dissemination of resistance plasmids in this area. Copyright © 2015. Published by Elsevier B.V.

  7. Current status of extended spectrum β-lactamase-producing Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis in Okinawa prefecture, Japan.

    PubMed

    Nakama, Rika; Shingaki, Aoi; Miyazato, Hiroko; Higa, Rikako; Nagamoto, Chota; Hamamoto, Kouta; Ueda, Shuhei; Hachiman, Teruyuki; Touma, Yuki; Miyagi, Kazufumi; Kawahara, Ryuji; Toyosato, Takehiko; Hirai, Itaru

    2016-05-01

    Enterobacteriaceae producing extended spectrum β-lactamase (ESBL) are distributed worldwide. In this study, 114 ESBL-producing Enterobacteriaceae were isolated by analyzing 1672 clinical isolates of Enterobacteriaceae collected from an Okinawa prefectural hospital in Japan between June 2013 and July 2014. The overall prevalence of ESBL-producing Enterobacteriaceae was 6.8%; the prevalence of different bacterial species among the ESBL-producing isolates was as follows: 11.5% Escherichia coli (90 of 783 isolates), 6.2% Klebsiella pneumoniae (19 of 307 isolates), and 11.1% Proteus mirabilis (5 of 45 isolates). The ESBL types blaCTX-M-1, -3, -15, -2, -14, -27, and mutants of blaSHV-1 were detected. Among them, blaCTX-M-15 (33.3%), blaCTX-M-14 (27.8%) and blaCTX-M-27 (33.3%) were dominant in the E. coli isolates, whereas a blaSHV mutant which possessed four mutations (Tyr7Phe, Leu35Gln, Gly238Ser and Glu240Lys) in the amino acid sequence of SHV-1 dominated in the K. pneumoniae isolates (11 of 19, 57.9%). The pandemic E. coli ST131 clone was found to constitute 3.3% of the overall examined isolates and 62.2% of the ESBL-producing E. coli isolates. Our results suggest that the genetic combination of blaCTX-M, and blaSHV and antibiotics-resistant profile were different from that in other regions such as other areas of Japan, Asia, Europe, and North America, especially in the ESBL-producing K. pneumoniae isolates and in the E. coli B2-O25b-ST131 isolates possessing blaCTX-M-15 (40.7% of the E. coli B2-O25b-ST131 isolates). Taken together, our results indicate that the ESBL-producing Enterobacteriaceae in Okinawa, Japan, might be of a unique nature.

  8. Screening and identification of genetic loci involved in producing more/denser inclusion bodies in Escherichia coli

    PubMed Central

    2013-01-01

    Background Many proteins and peptides have been used in therapeutic or industrial applications. They are often produced in microbial production hosts by fermentation. Robust protein production in the hosts and efficient downstream purification are two critical factors that could significantly reduce cost for microbial protein production by fermentation. Producing proteins/peptides as inclusion bodies in the hosts has the potential to achieve both high titers in fermentation and cost-effective downstream purification. Manipulation of the host cells such as overexpression/deletion of certain genes could lead to producing more and/or denser inclusion bodies. However, there are limited screening methods to help to identify beneficial genetic changes rendering more protein production and/or denser inclusion bodies. Results We report development and optimization of a simple density gradient method that can be used for distinguishing and sorting E. coli cells with different buoyant densities. We demonstrate utilization of the method to screen genetic libraries to identify a) expression of glyQS loci on plasmid that increased expression of a peptide of interest as well as the buoyant density of inclusion body producing E. coli cells; and b) deletion of a host gltA gene that increased the buoyant density of the inclusion body produced in the E. coli cells. Conclusion A novel density gradient sorting method was developed to screen genetic libraries. Beneficial host genetic changes could be exploited to improve recombinant protein expression as well as downstream protein purification. PMID:23638724

  9. Prevalence of ESBL producing Escherichia Coli and Klebsiella species with their co-resistance pattern to antimicrobials.

    PubMed

    Biswas, T; Das, M; Mondal, R; Raj, H J; Mondal, S

    2013-04-01

    Extended spectrum β-lactamase producing bacteria are potential emerging pathogens and continue to be a major challenge in clinical setup worldwide. In the present study an attempt was made to study the prevalence of extended spectrum β-lactamase producing Escherichia coli and Klebsiella species from clinical isolates in a rural tertiary care hospital in West Bengal, India with their antimicrobial susceptibility as well as co-resistance pattern to different antimicrobials. A total of 179 Escherichia coli and 62 Klebsiella isolates recovered from various clinical samples of urine, pus, aural swabs and respiratory secretions (including sputum) for a period of six months were subjected to routine antimicrobial susceptibility testing and also tested for extended spectrum β-lactamase production as per NCCLS recommendations. Extended spectrum β-lactamase was detected in 32.40% of Escherichia coli and 40.32% of Klebsiella species isolates. Urine, pus and respiratory samples were common source of extended spectrum β-lactamase producers and resistance rate of these organisms to third generation cephalosporins were more than 30 to 40%. Co-resistance pattern of these extended spectrum β-lactamase producers to other commonly used antimicrobials were also statistically significant (p≤0.05). From the study it is concluded that indiscriminate use of third generation cephalosporins may be responsible for the selection of extended spectrum β-lactamase producing multidrug resistant strains in hospital setup and amikacin is a reliable drug against them.

  10. Screening and identification of genetic loci involved in producing more/denser inclusion bodies in Escherichia coli.

    PubMed

    Pandey, Neeraj; Sachan, Annapurna; Chen, Qi; Ruebling-Jass, Kristin; Bhalla, Ritu; Panguluri, Kiran Kumar; Rouviere, Pierre E; Cheng, Qiong

    2013-05-02

    Many proteins and peptides have been used in therapeutic or industrial applications. They are often produced in microbial production hosts by fermentation. Robust protein production in the hosts and efficient downstream purification are two critical factors that could significantly reduce cost for microbial protein production by fermentation. Producing proteins/peptides as inclusion bodies in the hosts has the potential to achieve both high titers in fermentation and cost-effective downstream purification. Manipulation of the host cells such as overexpression/deletion of certain genes could lead to producing more and/or denser inclusion bodies. However, there are limited screening methods to help to identify beneficial genetic changes rendering more protein production and/or denser inclusion bodies. We report development and optimization of a simple density gradient method that can be used for distinguishing and sorting E. coli cells with different buoyant densities. We demonstrate utilization of the method to screen genetic libraries to identify a) expression of glyQS loci on plasmid that increased expression of a peptide of interest as well as the buoyant density of inclusion body producing E. coli cells; and b) deletion of a host gltA gene that increased the buoyant density of the inclusion body produced in the E. coli cells. A novel density gradient sorting method was developed to screen genetic libraries. Beneficial host genetic changes could be exploited to improve recombinant protein expression as well as downstream protein purification.

  11. Effect of Ceftriaxone on the Outcome of Murine Pyelonephritis Caused by Extended-Spectrum-β-Lactamase-Producing Escherichia coli

    PubMed Central

    Tratselas, A.; Simitsopoulou, M.; Giannakopoulou, A.; Dori, I.; Saoulidis, S.; Kollios, K.; Papaioannidou, P.; Pournaras, S.

    2014-01-01

    Urinary tract infections (UTIs) due to extended-spectrum-β-lactamase (ESBL)-producing Enterobacteriaceae in children are becoming more frequent, and they are commonly treated initially with a second- or third-generation cephalosporin. We developed a murine model of ascending UTI caused by ESBL-producing Escherichia coli. Using this model, we investigated the renal bacterial burden, interleukin-6 (IL-6) expression, and histopathological alterations caused by ESBL- and non-ESBL-producing bacteria after 1, 2, or 6 days with or without ceftriaxone therapy. The renal bacterial burden, IL-6 concentration, and histological inflammatory lesions were not significantly different between mice infected with ESBL- and non-ESBL-producing bacteria without treatment at any of the time points examined. Following ceftriaxone administration, the bacterial burden was eliminated in the kidneys of mice infected with ESBL- and non-ESBL-producing bacteria on the 6th postinfection day. The histological analysis demonstrated that among mice treated with ceftriaxone, those infected with ESBL-producing bacteria had more profound renal alterations than those infected with non-ESBL-producing bacteria on the 6th day (P < 0.001). In comparison, microbiological outcomes did not differ significantly between mice infected with ESBL- and non-ESBL-producing bacteria at any of the time points examined. The effectiveness of ceftriaxone in mice with UTIs due to ESBL-producing E. coli may have therapeutic implications; it is, however, hampered by limited activity on the histopathological lesions, a finding that needs further investigation. PMID:25224003

  12. O-antigen and virulence profiling of Shiga toxin-producing Escherichia coli by a rapid and cost-effective DNA microarray colorimetric method

    USDA-ARS?s Scientific Manuscript database

    Shiga toxin-producing Escherichia coli (STEC) is a leading cause of foodborne illness worldwide. To evaluate better methods to rapidly detect and genotype Shiga toxin-producing Escherichia coli strains, the present study evaluated the use of the ampliPHOX colorimetric detection technology, based on ...

  13. First characterization of CTX-M-15-producing Escherichia coli ST131 and ST405 clones causing community-onset infections in South America.

    PubMed

    Ruiz, Sory J; Montealegre, Maria Camila; Ruiz-Garbajosa, Patricia; Correa, Adriana; Briceño, David F; Martinez, Ernesto; Rosso, Fernando; Muñoz, Martin; Quinn, John P; Cantón, Rafael; Villegas, Maria Virginia

    2011-05-01

    CTX-M-15-producing Escherichia coli has emerged worldwide as an important pathogen associated with community-onset infections, but in South America reports are scarce. We document the presence of CTX-M-15-producing E. coli of the international ST131 and ST405 clones in Colombia and present the first molecular characterization of these isolates in South America.

  14. Presence of ESBL/AmpC -Producing Escherichia coli in the Broiler Production Pyramid: A Descriptive Study

    PubMed Central

    Dierikx, Cindy M.; van der Goot, Jeanet A.; Smith, Hilde E.; Kant, Arie; Mevius, Dik J.

    2013-01-01

    Broilers and broiler meat products are highly contaminated with extended spectrum beta-lactamase (ESBL) or plasmid-mediated AmpC beta-lactamase producing Escherichia coli and are considered to be a source for human infections. Both horizontal and vertical transmission might play a role in the presence of these strains in broilers. As not much is known about the presence of these strains in the whole production pyramid, the epidemiology of ESBL/AmpC-producing E. coli in the Dutch broiler production pyramid was examined. Cloacal swabs of Grandparent stock (GPS) birds (one−/two-days (breed A and B), 18 and 31 weeks old (breed A)), one-day old Parent stock birds (breed A and B) and broiler chickens of increasing age (breed A) were selectively cultured to detect ESBL/AmpC-producing isolates. ESBL/AmpC-producing isolates were found at all levels in the broiler production pyramid in both broiler breeds examined. Prevalence was already relatively high at the top of the broiler production pyramid. At broiler farms ESBL/AmpC producing E. coli were still present in the environment of the poultry house after cleaning and disinfection. Feed samples taken in the poultry house also became contaminated with ESBL/AmpC producing E. coli after one or more production weeks. The prevalence of ESBL/AmpC-positive birds at broiler farms increased within the first week from 0–24% to 96–100% independent of the use of antibiotics and stayed 100% until slaughter. In GPS breed A, prevalence at 2 days, 18 weeks and 31 weeks stayed below 50% except when beta-lactam antibiotics were administered. In that case prevalence increased to 100%. Interventions minimizing ESBL/AmpC contamination in broilers should focus on preventing horizontal and vertical spread, especially in relation to broiler production farms. PMID:24244401

  15. Presence of ESBL/AmpC-producing Escherichia coli in the broiler production pyramid: a descriptive study.

    PubMed

    Dierikx, Cindy M; van der Goot, Jeanet A; Smith, Hilde E; Kant, Arie; Mevius, Dik J

    2013-01-01

    Broilers and broiler meat products are highly contaminated with extended spectrum beta-lactamase (ESBL) or plasmid-mediated AmpC beta-lactamase producing Escherichia coli and are considered to be a source for human infections. Both horizontal and vertical transmission might play a role in the presence of these strains in broilers. As not much is known about the presence of these strains in the whole production pyramid, the epidemiology of ESBL/AmpC-producing E. coli in the Dutch broiler production pyramid was examined. Cloacal swabs of Grandparent stock (GPS) birds (one-/two-days (breed A and B), 18 and 31 weeks old (breed A)), one-day old Parent stock birds (breed A and B) and broiler chickens of increasing age (breed A) were selectively cultured to detect ESBL/AmpC-producing isolates. ESBL/AmpC-producing isolates were found at all levels in the broiler production pyramid in both broiler breeds examined. Prevalence was already relatively high at the top of the broiler production pyramid. At broiler farms ESBL/AmpC producing E. coli were still present in the environment of the poultry house after cleaning and disinfection. Feed samples taken in the poultry house also became contaminated with ESBL/AmpC producing E. coli after one or more production weeks. The prevalence of ESBL/AmpC-positive birds at broiler farms increased within the first week from 0-24% to 96-100% independent of the use of antibiotics and stayed 100% until slaughter. In GPS breed A, prevalence at 2 days, 18 weeks and 31 weeks stayed below 50% except when beta-lactam antibiotics were administered. In that case prevalence increased to 100%. Interventions minimizing ESBL/AmpC contamination in broilers should focus on preventing horizontal and vertical spread, especially in relation to broiler production farms.

  16. Biodiesel production from different algal oil using immobilized pure lipase and tailor made rPichia pastoris with Cal A and Cal B genes.

    PubMed

    Bharathiraja, B; Ranjith Kumar, R; PraveenKumar, R; Chakravarthy, M; Yogendran, D; Jayamuthunagai, J

    2016-08-01

    In this investigation, oil extraction was performed in marine macroalgae Gracilaria edulis, Enteromorpha compressa and Ulva lactuca. The algal biomass was characterized by Scanning Electron Microscopy and Fourier Transform-Infra Red Spectroscopy. Six different pre-treatment methods were carried out to evaluate the best method for maximum oil extraction. Optimization of extraction parameters were performed and high oil yield was obtained at temperature 55°C, time 150min, particle size 0.10mm, solvent-to-solid ratio 6:1 and agitation rate 500rpm. After optimization, 9.5%, 12.18% and 10.50 (g/g) of oil extraction yield was achieved from the respective algal biomass. The rate constant for extraction was obtained as first order kinetics, by differential method. Stable intracellular Cal A and Cal B lipase producing recombinant Pichia pastoris was constructed and used as biocatalyst for biodiesel production. Comparative analysis of lipase activity and biodiesel yield was made with immobilized Candida antarctica lipase. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Phage biocontrol of enteropathogenic and shiga toxin-producing Escherichia coli in meat products

    PubMed Central

    Tomat, David; Migliore, Leonel; Aquili, Virginia; Quiberoni, Andrea; Balagué, Claudia

    2013-01-01

    Ten bacteriophages were isolated from faeces and their lytic effects assayed on 103 pathogenic and non-pathogenic Enterobacteriaceae. Two phages (DT1 and DT6) were selected based on their host ranges, and their lytic effects on pathogenic E. coli strains inoculated on pieces of beef were determined. We evaluated the reductions of viable cells of Escherichia coli O157:H7 and non-O157 Shiga toxigenic E. coli strains on meat after exposure to DT6 at 5 and 24°C for 3, 6, and 24 h and the effect of both phages against an enteropathogenic E. coli strain. Significant viable cell reductions, compared to controls without phages, at both temperatures were observed, with the greatest decrease taking place within the first hours of the assays. Reductions were also influenced by phage concentration, being the highest concentrations, 1.7 × 1010 plaque forming units per milliliter (PFU/mL) for DT1 and 1.4 × 1010 PFU/mL for DT6, the most effective. When enteropathogenic E. coli and Shiga toxigenic E. coli (O157:H7) strains were tested, we obtained viable cell reductions of 0.67 log (p = 0.01) and 0.77 log (p = 0.01) after 3 h incubation and 0.80 log (p = 0.01) and 1.15 log (p = 0.001) after 6 h. In contrast, all nonpathogenic E. coli strains as well as other enterobacteria tested were resistant. In addition, phage cocktail was evaluated on two strains and further reductions were observed. However, E. coli bacteriophage insensitive mutants (BIMs) emerged in meat assays. BIMs isolated from meat along with those isolated by using the secondary culture method were tested to evaluate resistance phenotype stability and reversion. They presented low emergence frequencies (6.5 × 10−7–1.8 × 10−6) and variable stability and reversion. Results indicate that isolated phages were stable on storage, negative for all the virulence factors assayed, presented lytic activity for different E. coli virotypes and could be useful in reducing Shiga toxigenic E. coli and enteropathogenic E

  18. Presence of Multidrug-Resistant Shiga Toxin-Producing Escherichia coli, Enteropathogenic E. coli and Enterotoxigenic E. coli, on Raw Nopalitos (Opuntia ficus-indica L.) and in Nopalitos Salads from Local Retail Markets in Mexico.

    PubMed

    Gómez-Aldapa, Carlos A; Cerna-Cortes, Jorge F; Rangel-Vargas, Esmeralda; Torres-Vitela, Mdel Refugio; Villarruel-López, Angelica; Gutiérrez-Alcántara, Eduardo J; Castro-Rosas, Javier

    2016-05-01

    The presence of multidrug-resistant pathogenic bacteria in food is a significant public health concern. Diarrheagenic Escherichia coli pathotypes (DEPs) are foodborne bacteria. In Mexico, DEPs have been associated with diarrheal illness. There is no information about the presence of multidrug-resistant DEPs on fresh vegetables and in cooked vegetable salads in Mexico. "Nopalitos" (Opuntia ficus-indica L.) is a Cactacea extensively used as a fresh green vegetable throughout Mexico. The presence of generic E. coli and multidrug-resistant DEPs on raw whole and cut nopalitos and in nopalitos salad samples was determined. One hundred raw whole nopalitos (without prickles) samples, 100 raw nopalitos cut into small square samples, and 100 cooked nopalitos salad samples were collected from markets. Generic E. coli was determined using the most probable number procedures. DEPs were identified using two multiplex polymerase chain reaction procedures. Susceptibility to 16 antibiotics was tested for the isolated DEP strains by standard test. Of the 100 whole nopalitos samples, 100 cut nopalitos samples, and 100 nopalitos salad samples, generic E. coli and DEPs were identified, respectively, in 80% and 10%, 74% and 10%, and 64% and 8%. Eighty-two DEP strains were isolated from positive nopalitos samples. The identified DEPs included Shiga toxin-producing E. coli (STEC), enteropathogenic E. coli (EPEC), and enterotoxigenic E. coli (ETEC). All isolated strains exhibited resistance to at least six antibiotics. To the best of our knowledge, this is the first report of the presence of multidrug-resistant and antibiotic resistance profiles of STEC, ETEC, and EPEC on raw nopalitos and in nopalitos salads in Mexico.

  19. ESBL-producing Escherichia coli isolated from children with acute diarrhea - antimicrobial susceptibility, adherence patterns and phylogenetic background.

    PubMed

    Franiczek, Roman; Sobieszczańska, Beata; Turniak, Michał; Kasprzykowska, Urszula; Krzyzanowska, Barbara; Jermakow, Katarzyna; Mokracka-Latajka, Grazyna

    2012-01-01

    Escherichia coli remains the principal bacterial pathogen in childhood diarrhea and constitutes an important public health problem, especially in developing countries. Diarrheagenic E. coli strains often display resistance to beta-lactams due to the production of extended-spectrum beta-lactamases (ESBLs). A total of thirty ESBL-producing E. coli strains colonizing the gastrointestinal tracts of children with acute diarrhea were studied in order to determine their antimicrobial susceptibility, adherence patterns to the HEp-2 cell line and phylogenetic background. ESBL production was detected by the double disk synergy test (DDST). The minimal inhibitory concentrations (MICs) of antibacterial drugs were determined by an agar dilution technique on Mueller-Hinton agar. The presence of bla(TEM), bla(SHV) and bla(CTX-M) determinants in the strains studied was ascertained by polymerase chain reaction (PCR). The strains displayed the resistance pattern typical of ESBL producers. The majority of them (23 out of 30) were found to produce CTX-M-type ESBLs conferring a high level of resistance to oxyimino-beta-lactams, especially to cefotaxime and ceftriaxone. In many cases, the strains exhibited resistance to non-beta-lactam antimicrobials, such as gentamicin, amikacin, co-trimoxazole and tetracycline. On the other hand, these strains were uniformly susceptible to carbapenems, to oxyimino-beta-lactams combined with clavulanic acid and to tigecycline. The E. coli strains were distributed among the four main phylogenetic groups: A, B1, B2 and D. The in vitro adhesion assay revealed that all but two of the strains adhered to the HEp-2 epithelial cell line. Aggregative and diffuse adherence patterns were found to be the most prevalent. CTX-M-type enzymes were the most prevalent ESBLs among the strains studied. As many as 40% of the diarrheagenic E. coli isolates were found to belong to phylogenetic group D, which usually comprises E. coli strains associated with extra intestinal

  20. Wild Ungulates as Disseminators of Shiga Toxin-Producing Escherichia coli in Urban Areas

    PubMed Central

    Franklin, Alan B.; VerCauteren, Kurt C.; Maguire, Hugh; Cichon, Mary K.; Fischer, Justin W.; Lavelle, Michael J.; Powell, Amber; Root, J. Jeffrey; Scallan, Elaine

    2013-01-01

    Background In 2008, children playing on a soccer field in Colorado were sickened with a strain of Shiga toxin-producing Escherichia coli (STEC) O157:H7, which was ultimately linked to feces from wild Rocky Mountain elk. We addressed whether wild cervids were a potential source of STEC infections in humans and whether STEC was ubiquitous throughout wild cervid populations in Colorado. Methodology/Principal Findings We collected 483 fecal samples from Rocky Mountain elk and mule deer in urban and non-urban areas. Samples testing positive for STEC were higher in urban (11.0%) than non-urban (1.6%) areas. Elk fecal samples in urban areas had a much higher probability of containing STEC, which increased in both urban and non-urban areas as maximum daily temperature increased. Of the STEC-positive samples, 25% contained stx1 strains, 34.3% contained stx2, and 13% contained both stx1 and stx2. Additionally, eaeA genes were detected in 54.1% of the positive samples. Serotypes O103, and O146 were found in elk and deer feces, which also have the potential to cause human illness. Conclusions/Significance The high incidence of stx2 strains combined with eaeA and E-hyl genes that we found in wild cervid feces is associated with severe human disease, such as hemolytic uremic syndrome. This is of concern because there is a very close physical interface between elk and humans in urban areas that we sampled. In addition, we found a strong relationship between ambient temperature and incidence of STEC in elk feces, suggesting a higher incidence of STEC in elk feces in public areas on warmer days, which in turn may increase the likelihood that people will come in contact with infected feces. These concerns also have implications to other urban areas where high densities of coexisting wild cervids and humans interact on a regular basis. PMID:24349083

  1. Inactivation of Shiga toxin-producing Escherichia coli in lean ground beef by gamma irradiation.

    PubMed

    Sommers, Christopher; Rajkowski, Kathleen T; Scullen, O Joseph; Cassidy, Jennifer; Fratamico, Pina; Sheen, Shiowshuh

    2015-08-01

    In this study the radiation resistance of 40 Shiga Toxin-Producing Escherichia coli (STEC) isolates which contained various combinations of the shiga toxin 1 (stx1), shiga toxin 2 (stx2), intimin (eae), and hemolysin (ehx) genes were determined. The STEC were suspended in lean ground beef and irradiated at 4 °C. D10 values, the radiation dose needed to reduce 1 log (90%) of a microorganism, ranged from 0.16 to 0.48 kGy, with a mean of 0.31 kGy for the 40 isolates. Isolates associated with illness outbreaks had a mean D10 of 0.27 kGy, while non-outbreak isolates had a mean D10 of 0.36 kGy (p < 0.05). The presence or absence of stx1, stx2, or both stx1 and 2 had no affect on D10 (p > 0.05). The presence (0.30 kGy) or absence (0.35 kGy) of ehx had no affect on D10 (p > 0.05). However, the mean D10 of isolates lacking eae (0.37 kGy) were significantly higher than those containing eae (0.27 kGy) (p < 0.05). There was no difference in D10 for isolates lacking eae regardless of whether or not they were associated with a foodborne illness outbreak (p > 0.05). It may be possible to use some of the STEC isolates which lacked eae, ehx, or both (D10 > 0.30) as avirulent surrogates in food irradiation research. The data presented in this study provides risk assessors data for metagenomic analysis as well as food and radiation processors with valuable information to control of STEC in meat. Published by Elsevier Ltd.

  2. Edema disease as a model for systemic disease induced by Shiga toxin-producing E. coli.

    PubMed

    Cornick, N A; Matise, I; Samuel, J E; Bosworth, B T; Moon, H W

    1999-01-01

    Edema disease (ED) is a naturally occurring disease of weaned pigs caused by host adapted strains of E. coli that produce Shiga toxin (STEC). We determined the temporal and quantitative relationships between intestinal colonization by STEC, levels of Shiga toxin (Stx2e) in the gut, in the blood, and clinical manifestations of ED. Bacterial colonization (10(8) CFU/cm ileum) was highest 4 days post inoculation (pi) in animals that did not develop clinical disease and 6 days pi in animals with clinical signs of ED. The mean time for the development of clinical signs of ED was 6 days pi (range 4-10). Average peak titers of Stx2e in the ileum were 1:16,384 in asymptomatic animals and 1:32,768 in clinical animals. Titers of Stx2e in the feces reflected the toxin titers in the ileum but were lower. Intestinal titers of Stx2e and the density of bacterial colonization were predictive of clinical ED for a group of animals but not for individuals. Approximately 50% of the pigs that had Stx2e titers of > or = 1:4096 and a bacterial density of > or = 10(6) CFU/cm in their ileum, had clinical ED. Pigs that had intestinal Stx2e titers < 1:4096 were asymptomatic. Stx2e was detected in the red cell fraction of blood from some of the pigs with clinical ED and in some that were asymptomatic. Stx2e was not detected in the serum of any animals. ED may be a useful model for predicting the temporal and quantitative relationships between bacterial colonization, Stx levels in the gut and blood and systemic disease for STEC in other species.

  3. Detection, Characterization, and Typing of Shiga Toxin-Producing Escherichia coli.

    PubMed

    Parsons, Brendon D; Zelyas, Nathan; Berenger, Byron M; Chui, Linda

    2016-01-01

    Shiga toxin-producing Escherichia coli (STEC) are responsible for gastrointestinal diseases reported in numerous outbreaks around the world. Given the public health importance of STEC, effective detection, characterization and typing is critical to any medical laboratory system. While non-O157 serotypes account for the majority of STEC infections, frontline microbiology laboratories may only screen for STEC using O157-specific agar-based methods. As a result, non-O157 STEC infections are significantly under-reported. This review discusses recent advances on the detection, characterization and typing of STEC with emphasis on work performed at the Alberta Provincial Laboratory for Public Health (ProvLab). Candidates for the detection of all STEC serotypes include chromogenic agars, enzyme immunoassays (EIA) and quantitative real time polymerase chain reaction (qPCR). Culture methods allow further characterization of isolates, whereas qPCR provides the greatest sensitivity and specificity, followed by EIA. The virulence gene profiles using PCR arrays and stx gene subtypes can subsequently be determined. Different non-O157 serotypes exhibit markedly different virulence gene profiles and a greater prevalence of stx1 than stx2 subtypes compared to O157:H7 isolates. Finally, recent innovations in whole genome sequencing (WGS) have allowed it to emerge as a candidate for the characterization and typing of STEC in diagnostic surveillance isolates. Methods of whole genome analysis such as single nucleotide polymorphisms and k-mer analysis are concordant with epidemiological data and standard typing methods, such as pulsed-field gel electrophoresis and multiple-locus variable number tandem repeat analysis while offering additional strain differentiation. Together these findings highlight improved strategies for STEC detection using currently available systems and the development of novel approaches for future surveillance.

  4. Detection, Characterization, and Typing of Shiga Toxin-Producing Escherichia coli

    PubMed Central

    Parsons, Brendon D.; Zelyas, Nathan; Berenger, Byron M.; Chui, Linda

    2016-01-01

    Shiga toxin-producing Escherichia coli (STEC) are responsible for gastrointestinal diseases reported in numerous outbreaks around the world. Given the public health importance of STEC, effective detection, characterization and typing is critical to any medical laboratory system. While non-O157 serotypes account for the majority of STEC infections, frontline microbiology laboratories may only screen for STEC using O157-specific agar-based methods. As a result, non-O157 STEC infections are significantly under-reported. This review discusses recent advances on the detection, characterization and typing of STEC with emphasis on work performed at the Alberta Provincial Laboratory for Public Health (ProvLab). Candidates for the detection of all STEC serotypes include chromogenic agars, enzyme immunoassays (EIA) and quantitative real time polymerase chain reaction (qPCR). Culture methods allow further characterization of isolates, whereas qPCR provides the greatest sensitivity and specificity, followed by EIA. The virulence gene profiles using PCR arrays and stx gene subtypes can subsequently be determined. Different non-O157 serotypes exhibit markedly different virulence gene profiles and a greater prevalence of stx1 than stx2 subtypes compared to O157:H7 isolates. Finally, recent innovations in whole genome sequencing (WGS) have allowed it to emerge as a candidate for the characterization and typing of STEC in diagnostic surveillance isolates. Methods of whole genome analysis such as single nucleotide polymorphisms and k-mer analysis are concordant with epidemiological data and standard typing methods, such as pulsed-field gel electrophoresis and multiple-locus variable number tandem repeat analysis while offering additional strain differentiation. Together these findings highlight improved strategies for STEC detection using currently available systems and the development of novel approaches for future surveillance. PMID:27148176

  5. Role of climate in the spread of shiga toxin-producing Escherichia coli infection among children

    NASA Astrophysics Data System (ADS)

    Acquaotta, Fiorella; Ardissino, Gianluigi; Fratianni, Simona; Perrone, Michela

    2017-04-01

    Haemolytic-uraemic syndrome (HUS) is a rare disease mainly affecting children that develops as a complication of shiga toxin-producing Escherichia coli (STEC) infection. It is characterised by acute kidney injury, platelet consumption and mechanical destruction of red blood cells (haemolysis). In order to test the working hypothesis that the spread of the infection is influenced by specific climatic conditions, we analysed all of the identified cases of infection occurring between June 2010 and December 2013 in four provinces of Lombardy, Italy (Milano, Monza Brianza, Varese and Brescia), in which a STEC surveillance system has been developed as part of a preventive programme. In the selected provinces, we recorded in few days a great number of cases and clusters which are unrelated for spatially distant or for the disease are caused by different STEC serotypes. In order to investigate a common factor that favoured the onset of infection, we have analysed in detail the weather conditions of the areas. The daily series of temperature, rain and relative humidity were studied to show the common climate peculiarities whilst the correlation coefficient and the principal component analysis (PCA) were used to point out the meteorological variable, maximum temperature, as the principal climate element in the onset of the infection. The use of distributed lag non-linear models (DLNM) and the climate indices characterising heat waves (HWs) has allowed to identify the weather conditions associated with STEC infection. The study highlighted a close temporal correlation between STEC infection in children and the number, duration and frequency of heat waves. In particular, if the maximum temperature is greater than 90th percentile, days classified as very hot, for 3 or more consecutive days, the risk of infection is increasing.

  6. Whole-Genome Sequencing for National Surveillance of Shiga Toxin–Producing Escherichia coli O157

    PubMed Central

    Dallman, Timothy J.; Byrne, Lisa; Ashton, Philip M.; Cowley, Lauren A.; Perry, Neil T.; Adak, Goutam; Petrovska, Liljana; Ellis, Richard J.; Elson, Richard; Underwood, Anthony; Green, Jonathan; Hanage, William P.; Jenkins, Claire; Grant, Kathie; Wain, John

    2015-01-01

    Background. National surveillance of gastrointestinal pathogens, such as Shiga toxin–producing Escherichia coli O157 (STEC O157), is key to rapidly identifying linked cases in the distributed food network to facilitate public health interventions. In this study, we used whole-genome sequencing (WGS) as a tool to inform national surveillance of STEC O157 in terms of identifying linked cases and clusters and guiding epidemiological investigation. Methods. We retrospectively analyzed 334 isolates randomly sampled from 1002 strains of STEC O157 received by the Gastrointestinal Bacteria Reference Unit at Public Health England, Colindale, in 2012. The genetic distance between each isolate, as estimated by WGS, was calculated and phylogenetic methods were used to place strains in an evolutionary context. Results. Estimates of linked clusters representing STEC O157 outbreaks in England and Wales increased by 2-fold when WGS was used instead of traditional typing techniques. The previously unidentified clusters were often widely geographically distributed and small in size. Phylogenetic analysis facilitated identification of temporally distinct cases sharing common exposures and delineating those that shared epidemiological and temporal links. Comparison with multi locus variable number tandem repeat analysis (MLVA) showed that although MLVA is as sensitive as WGS, WGS provides a more timely resolution to outbreak clustering. Conclusions. WGS has come of age as a molecular typing tool to inform national surveillance of STEC O157; it can be used in real time to provide the highest strain-level resolution for outbreak investigation. WGS allows linked cases to be identified with unprecedented specificity and sensitivity that will facilitate targeted and appropriate public health investigations. PMID:25888672

  7. Preparation of soluble isotopically labeled human growth hormone produced in Escherichia coli.

    PubMed

    Lee, Jin-Hee; Jeong, Ji-Seon; Kim, Sook-Kyung; Song, Jimyeong; Lee, Ji Youn; Baek, Soyun; Choi, Jun-Hyuk

    2016-11-01

    Isotopically labeled proteins have been used as internal standards for mass spectrometry (MS)-based absolute protein quantification. Although this approach can provide highly accurate analyses of proteins of interest within a complex mixture, one of the major limitations of this method is the difficulty in preparing uniformly labeled standards. Human growth hormone (hGH) is one of the most important hormones that circulate throughout the body, and its measurement is primarily of interest in the diagnosis and treatment of growth disorders. In order to provide a useful internal standard for MS-based hGH measurement, we describe an efficient strategy to produce a potentially valuable, stable isotope-labeled hGH with high purity and yield. The strategy involves the following steps: solubilization of hGH under labeling conditions, detection of stable isotope incorporation, large-scale purification, analysis of the labeled protein, and assessment of the labeling efficiency. We show that the yield of soluble hGH under selective isotopic labeling conditions can be greatly increased by optimizing protein expression and extraction. Our efficient method for generating isotopically labeled hGH does not influence the structural integrity of hGH. Finally, we assessed the efficiency of stable isotope labeling at the intact protein level, and the result was further verified by amino acid analysis. These results clearly indicate that our labeling approach allows an almost complete incorporation of (13)C6(15)N4-arginine into the hGH expressed in E.coli without detectable isotope scrambling.

  8. Carriage and Fecal Counts of Cefotaxime M-Producing Escherichia coli in Pigs: a Longitudinal Study

    PubMed Central

    Damborg, Peter; Andreasen, Margit; Nielsen, Søren Saxmose; Guardabassi, Luca

    2013-01-01

    Current knowledge on extended-spectrum beta-lactamases (ESBLs) in animals is based largely on cross-sectional studies and qualitative data. The aim of this longitudinal study was to elucidate carriage proportions and fecal counts of ESBL-producing Escherichia coli in pigs during the production cycle. At each of three ESBL-positive single-sited farrow-to-finisher pig farms (farms A, B, and C) included in the study, individual fecal samples were taken from 17 to 20 sows 1 week before farrowing and from 2 piglets of each sow's litter four times from birth to slaughter (as piglets, weaners, and finishers). Cefotaxime (CTX)-resistant coliforms in feces were counted on MacConkey agar containing 2 μg/ml CTX and characterized for the presence of ESBL-encoding genes by PCR and sequencing. CTX-M-positive pigs were detected in all age groups at farms A (blaCTX-M-9 group, compatible with blaCTX-M-14/17) and B (blaCTX-M-1 group, compatible with blaCTX-M-1/61), whereas only three weaners were positive at farm C (blaCTX-M-1 group, compatible with blaCTX-M-1/61). A significant decrease in carriage was detected during the production cycle, with on average 50% carriage immediately after birth, 58% just before weaning, 29% during weaning, and 12% during finishing. The observed reduction in numbers of CTX-M-positive pigs was accompanied by a significant reduction in mean fecal counts of CTX-resistant coliforms from ∼107 CFU/g in piglets to ∼103 CFU/g in finishers (P < 0.001). These findings provide novel information about the epidemiology of ESBLs at the farm level and have important implications for assessments of risks of meat contamination during slaughter. PMID:23160131

  9. Carriage and fecal counts of cefotaxime M-producing Escherichia coli in pigs: a longitudinal study.

    PubMed

    Hansen, Katrine Hartung; Damborg, Peter; Andreasen, Margit; Nielsen, Søren Saxmose; Guardabassi, Luca

    2013-02-01

    Current knowledge on extended-spectrum beta-lactamases (ESBLs) in animals is based largely on cross-sectional studies and qualitative data. The aim of this longitudinal study was to elucidate carriage proportions and fecal counts of ESBL-producing Escherichia coli in pigs during the production cycle. At each of three ESBL-positive single-sited farrow-to-finisher pig farms (farms A, B, and C) included in the study, individual fecal samples were taken from 17 to 20 sows 1 week before farrowing and from 2 piglets of each sow's litter four times from birth to slaughter (as piglets, weaners, and finishers). Cefotaxime (CTX)-resistant coliforms in feces were counted on MacConkey agar containing 2 μg/ml CTX and characterized for the presence of ESBL-encoding genes by PCR and sequencing. CTX-M-positive pigs were detected in all age groups at farms A (bla(CTX-M-9) group, compatible with bla(CTX-M-14/17)) and B (bla(CTX-M-1) group, compatible with bla(CTX-M-1/61)), whereas only three weaners were positive at farm C (bla(CTX-M-1) group, compatible with bla(CTX-M-1/61)). A significant decrease in carriage was detected during the production cycle, with on average 50% carriage immediately after birth, 58% just before weaning, 29% during weaning, and 12% during finishing. The observed reduction in numbers of CTX-M-positive pigs was accompanied by a significant reduction in mean fecal counts of CTX-resistant coliforms from ~10(7) CFU/g in piglets to ~10(3) CFU/g in finishers (P < 0.001). These findings provide novel information about the epidemiology of ESBLs at the farm level and have important implications for assessments of risks of meat contamination during slaughter.

  10. Detection and characterization of Shiga toxin-producing Escherichia coli in captive non-domestic mammals.

    PubMed

    Leotta, Gerardo A; Deza, Natalia; Origlia, Javier; Toma, Claudia; Chinen, Isabel; Miliwebsky, Elizabeth; Iyoda, Sunao; Sosa-Estani, Sergio; Rivas, Marta

    2006-11-26

    Shiga toxin producing-Escherichia coli (STEC) is an important emerging pathogen, and ruminants are recognized as their main natural reservoir. The aim of this work was to establish the frequency of STEC in non-domestic mammals of the Zoo and Botanical Garden of La Plata City, Argentina, and to pheno-genotypically characterize STEC isolates. By polymerase chain reaction (PCR), Shiga toxin (stx) gene sequences were detected in 50.8% of 65 fecal samples. Twenty-five STEC strains were isolated from 38.5% of the Zoo's animals. Ten species of order Cetartiodactyla and one species of order Rodentia were recognized as new STEC carriers. STEC strains belonged to 7 different serotypes including new serotypes O12:H25 and O13:H6. Serotype O146:H28, previously associated with human infections, represented 24% of STEC isolates. The most frequent Shiga toxin identified were type 1c and type 2c. Nineteen strains were positive for iha gene, 8 strains were positive for ehxA gene. Moreover, all strains were positive for lpfAO113 and negative for rfbO157, eae, saa, lpfAO157/OI-141, lpfAO157/OI-154, efa1, and toxB genes. Results obtained by XbaI-pulsed-field gel electrophoresis (XbaI-PFGE) confirmed the transmission of STEC strains among different animal species and suborders. In addition, we observed a potential association between STEC-harboring animal and factors such as belonging to order Cetartiodactyla, living in a pit, and belonging to a non-autochthonous species. This is the first work developed with zoological mammals and STEC in Argentina.

  11. Shiga toxin-producing Escherichia coli in beef retail markets from Argentina.

    PubMed

    Brusa, Victoria; Aliverti, Virginia; Aliverti, Florencia; Ortega, Emanuel E; de la Torre, Julian H; Linares, Luciano H; Sanz, Marcelo E; Etcheverría, Analía I; Padola, Nora L; Galli, Lucía; Peral García, Pilar; Copes, Julio; Leotta, Gerardo A

    2012-01-01

    Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens that cause mild or serious diseases and can lead to people death. This study reports the prevalence and characteristics of STEC O157 and non-O157 in commercial ground beef and environmental samples, including meat table, knife, meat mincing machine, and manipulator hands (n = 450) obtained from 90 retail markets over a nine-month period. The STEC isolates were serotyped and virulence genes as stx (Shiga toxin), rfb(O157)] (O157 lipopolysaccharide), fliC(H7) (H7 flagellin), eae (intimin), ehxA (enterohemolysin) and saa (STEC autoagglutinating adhesin), were determined. STEC O157 were identified in 23 (25.5%) beef samples and 16 (4.4%) environmental samples, while STEC non-O157 were present in 47 (52.2%) and 182 (50.5%), respectively. Among 54 strains isolated, 17 were STEC O157:H7 and 37 were STEC non-O157. The prevalent genotype for O157 was stx(2)/eae/ehxA/fliC(H7) (83.4%), and for STEC non-O157 the most frequent ones were stx(1)/stx(2)/saa/ehxA (29.7%); stx(2) (29.7%); and stx(2)/saa/ehxA (27%). None of the STEC non-O157 strains were eae-positive. Besides O157:H7, other 20 different serotypes were identified, being O8:H19, O178:H19, and O174:H28 the prevalent. Strains belonging to the same serotype could be isolated from different sources of the same retail market. Also, the same serotype could be detected in different stores. In conclusion, screening techniques are increasingly sensitive, but the isolation of STEC non-O157 is still a challenge. Moreover, with the results obtained from the present work, although more studies are needed, cross-contamination between meat and the environment could be suspected.

  12. Shiga toxin-producing Escherichia coli in beef retail markets from Argentina

    PubMed Central

    Brusa, Victoria; Aliverti, Virginia; Aliverti, Florencia; Ortega, Emanuel E.; de la Torre, Julian H.; Linares, Luciano H.; Sanz, Marcelo E.; Etcheverría, Analía I.; Padola, Nora L.; Galli, Lucía; Peral García, Pilar; Copes, Julio; Leotta, Gerardo A.

    2013-01-01

    Shiga toxin-producing Escherichia coli (STEC) are foodborne pathogens that cause mild or serious diseases and can lead to people death. This study reports the prevalence and characteristics of STEC O157 and non-O157 in commercial ground beef and environmental samples, including meat table, knife, meat mincing machine, and manipulator hands (n = 450) obtained from 90 retail markets over a nine-month period. The STEC isolates were serotyped and virulence genes as stx (Shiga toxin), rfbO157] (O157 lipopolysaccharide), fliCH7 (H7 flagellin), eae (intimin), ehxA (enterohemolysin) and saa (STEC autoagglutinating adhesin), were determined. STEC O157 were identified in 23 (25.5%) beef samples and 16 (4.4%) environmental samples, while STEC non-O157 were present in 47 (52.2%) and 182 (50.5%), respectively. Among 54 strains isolated, 17 were STEC O157:H7 and 37 were STEC non-O157. The prevalent genotype for O157 was stx2/eae/ehxA/fliCH7 (83.4%), and for STEC non-O157 the most frequent ones were stx1/stx2/saa/ehxA (29.7%); stx2 (29.7%); and stx2/saa/ehxA (27%). None of the STEC non-O157 strains were eae-positive. Besides O157:H7, other 20 different serotypes were identified, being O8:H19, O178:H19, and O174:H28 the prevalent. Strains belonging to the same serotype could be isolated from different sources of the same retail market. Also, the same serotype could be detected in different stores. In conclusion, screening techniques are increasingly sensitive, but the isolation of STEC non-O157 is still a challenge. Moreover, with the results obtained from the present work, although more studies are needed, cross-contamination between meat and the environment could be suspected. PMID:23346554

  13. Isolation, genotyping and antimicrobial resistance of Shiga toxin-producing Escherichia coli.

    PubMed

    Amézquita-López, Bianca A; Soto-Beltrán, Marcela; Lee, Bertram G; Yambao, Jaszemyn C; Quiñones, Beatriz

    2017-07-18

    Shiga toxin-producing Escherichia coli (STEC) is an enteric pathogen linked to outbreaks of human gastroenteritis with diverse clinical spectra. In this review, we have examined the currently methodologies and molecular characterization techniques for assessing the phenotypic, genotypic and functional characteristics of STEC O157 and non-O157. In particular, traditional culture and isolation methods, including selective enrichment and differential plating, have enabled the effective recovery of STEC. Following recovery, immunological serotyping of somatic surface antigens (O-antigens) and flagellum (H-antigens) are employed for the classification of the STEC isolates. Molecular genotyping methods, including multiple-locus variable-number tandem repeat analysis, arrays, and whole genome sequencing, can discriminate the isolate virulence profile beyond the serotype level. Virulence profiling is focused on the identification of chromosomal and plasmid genes coding for adhesins, cytotoxins, effectors, and hemolysins to better assess the pathogenic potential of the recovered STEC isolates. Important animal reservoirs are cattle and other small domestic ruminants. STEC can also be recovered from other carriers, such as mammals, birds, fish, amphibians, shellfish and insects. Finally, antimicrobial resistance in STEC is a matter of growing concern, supporting the need to monitor the use of these agents by private, public and agricultural sectors. Certain antimicrobials can induce Shiga toxin production and thus promote the onset of severe disease symptoms in humans. Together, this information will provide a better understanding of risks associated with STEC and will aid in the development of efficient and targeted intervention strategies. Copyright © 2017. Published by Elsevier B.V.

  14. Characterization and Molecular Subtyping of Shiga Toxin-Producing Escherichia coli Strains in Butcher Shops.

    PubMed

    Brusa, Victoria; Costa, Magdalena; Londero, Alejandra; Leotta, Gerardo A; Galli, Lucía

    2017-05-01

    Shiga toxin-producing Escherichia coli (STEC) are important emerging foodborne human pathogens. Ruminants are the main animal reservoir of STEC currently known, and meat can become contaminated at different stages of the production chain. The aim of this work was to subtype and establish the epidemiological relatedness of non-O157 STEC strains isolated from ground beef and the environment in butcher shops before (evaluation stage, 2010-2011 period) and after (verification stage, 2013) implementing improvement actions. Sixty-eight non-O157 STEC strains were tested for eae, saa, ehxA, iha, efa1, toxB, subAB, cdt-V, astA, aggR, and aaiC genes, and stx1 and stx2 variants were determined. Pulsed-field gel electrophoresis (PFGE) was carried out with XbaI and XmaJI. From the 68 strains, 92.6%, 75.0%, 58.8%, 53.5%, 10.3%, 7.3%, and 4.4% were positive for iha, ehxA, subAB, saa, cdt-V, astA, and eae, respectively. All strains were aggR/aaiC-negative. PFGE showed that 19 strains grouped in 9 clusters and 41 showed unique XbaI patterns. During the evaluation stage (2010-2011), we identified clonal strains in different samples, circulating clones in different butcher shops, and more than one different strain in the same butcher shop. The bovine origin of meat and its manufacturing process could not ensure the total absence of all non-O157 STEC serotypes in this foodstuff. Most strains isolated during the evaluation (2010-2011) and verification (2013) stages did not exhibit a genotypic profile associated with human disease. It is necessary to conduct periodic reviews of the new epidemiological information and verify that the analyses of non-O157 STEC in food are appropriate to identify strains affecting the population.

  15. Comparative Exposure Assessment of ESBL-Producing Escherichia coli through Meat Consumption

    PubMed Central

    Pielaat, Annemarie; Smid, Joost H.; van Duijkeren, Engeline; Vennemann, Francy B. C.; Wijnands, Lucas M.; Chardon, Jurgen E.

    2017-01-01

    The presence of extended-spectrum β-lactamase (ESBL) and plasmidic AmpC (pAmpC) producing Escherichia coli (EEC) in food animals, especially broilers, has become a major public health concern. The aim of the present study was to quantify the EEC exposure of humans in The Netherlands through the consumption of meat from different food animals. Calculations were done with a simplified Quantitative Microbiological Risk Assessment (QMRA) model. The model took the effect of pre-retail processing, storage at the consumers home and preparation in the kitchen (cross-contamination and heating) on EEC numbers on/in the raw meat products into account. The contribution of beef products (78%) to the total EEC exposure of the Dutch population through the consumption of meat was much higher than for chicken (18%), pork (4.5%), veal (0.1%) and lamb (0%). After slaughter, chicken meat accounted for 97% of total EEC load on meat, but chicken meat experienced a relatively large effect of heating during food preparation. Exposure via consumption of filet americain (a minced beef product consumed raw) was predicted to be highest (61% of total EEC exposure), followed by chicken fillet (13%). It was estimated that only 18% of EEC exposure occurred via cross-contamination during preparation in the kitchen, which was the only route by which EEC survived for surface-contaminated products. Sensitivity analysis showed that model output is not sensitive for most parameters. However, EEC concentration on meat other than chicken meat was an important data gap. In conclusion, the model assessed that consumption of beef products led to a higher exposure to EEC than chicken products, although the prevalence of EEC on raw chicken meat was much higher than on beef. The (relative) risk of this exposure for public health is yet unknown given the lack of a modelling framework and of exposure studies for other potential transmission routes. PMID:28056081

  16. Role of climate in the spread of shiga toxin-producing Escherichia coli infection among children

    NASA Astrophysics Data System (ADS)

    Acquaotta, Fiorella; Ardissino, Gianluigi; Fratianni, Simona; Perrone, Michela

    2017-09-01

    Haemolytic-uraemic syndrome (HUS) is a rare disease mainly affecting children that develops as a complication of shiga toxin-producing Escherichia coli (STEC) infection. It is characterised by acute kidney injury, platelet consumption and mechanical destruction of red blood cells (haemolysis). In order to test the working hypothesis that the spread of the infection is influenced by specific climatic conditions, we analysed all of the identified cases of infection occurring between June 2010 and December 2013 in four provinces of Lombardy, Italy (Milano, Monza Brianza, Varese and Brescia), in which a STEC surveillance system has been developed as part of a preventive programme. In the selected provinces, we recorded in few days a great number of cases and clusters which are unrelated for spatially distant or for the disease are caused by different STEC serotypes. In order to investigate a common factor that favoured the onset of infection, we have analysed in detail the weather conditions of the areas. The daily series of temperature, rain and relative humidity were studied to show the common climate peculiarities whilst the correlation coefficient and the principal component analysis (PCA) were used to point out the meteorological variable, maximum temperature, as the principal climate element in the onset of the infection. The use of distributed lag non-linear models (DLNM) and the climate indices characterising heat waves (HWs) has allowed to identify the weather conditions associated with STEC infection. The study highlighted a close temporal correlation between STEC infection in children and the number, duration and frequency of heat waves. In particular, if the maximum temperature is greater than 90th percentile, days classified as very hot, for 3 or more consecutive days, the risk of infection is increasing.

  17. [Surveillance of antimicrobial susceptibility of Escherichia coli producing urinary tract infections in Galicia (Spain)].

    PubMed

    Treviño, Mercedes; Losada, Isabel; Fernández-Pérez, Begoña; Coira, Amparo; Peña-Rodríguez, Maria F; Hervada, Xurxo

    2016-04-01

    Escherichia coli is the microorganism responsible for most of the community-acquired urinary tract infections (UTI). Our purpose was to determine the susceptibility of E. coli associated with UTI in Galicia and consider the most appropriate antibiotics for empirical treatment. Retrospective study during the period 2011- 2012 of the isolation of E. coli in urine samples from almost all the Galician population. Demographic variables, minimum inhibitory concentration, and reading data were collected: amoxicillin-clavulanate, cefotaxime, gentamicin, amikacin, ciprofloxacin, cotrimoxazole, nitrofurantoin and fosfomycin. The identification and susceptibility studies were mainly conducted by automated systems. The interpretation of the results was performed according to CLSI criteria. During the study period 55,046 E. coli were isolated in UTI. The percentages of resistance were: cotrimoxazole, 30%; ciprofloxacin, 33%; amoxicillin-clavulanate, 23% and 10% for 3rd generation cephalosporins. Fosfomycin and nitrofurantoin showed the highest activity with more than 96% of susceptibility in our study. The linear trend of resistance regarding age was statistically significant (p <0.0001) as it was regarding males (p <0.00001) for all antibiotics. In Galicia, the most active antibiotics against E. coli associated with UTI are fosfomycin and nitrofurantoin so they should be considered as empirical treatment of choice by the community-acquired UTI not complicated by E. coli.

  18. Extended-spectrum-β-lactamase- and AmpC-β-lactamase-producing Escherichia coli in Dutch broilers and broiler farmers.

    PubMed

    Dierikx, Cindy; van der Goot, Jeanet; Fabri, Teun; van Essen-Zandbergen, Alieda; Smith, Hilde; Mevius, Dik

    2013-01-01

    The aim of this study was to establish the prevalence of extended-spectrum β-lactamase (ESBL)- and AmpC β-lactamase-producing Escherichia coli at Dutch broiler farms and in farmers and to compare ESBL/AmpC-producing isolates from farmers and their animals. Twenty-five to 41 cloacal swabs collected from broilers at each of 26 farms and 18 faecal samples from 18 broiler farmers were analysed for determination of the presence of ESBL/AmpC-producing E. coli. ESBL/AmpC genes were characterized by microarray, PCR and sequencing. Plasmids were characterized by transformation and PCR-based replicon typing. Subtyping of plasmids was done by plasmid multilocus sequence typing or restriction fragment length polymorphism. E. coli genotypes were determined by multilocus sequence typing. Birds from all farms were positive for ESBL/AmpC-producing E. coli, and on 22/26 farms the within-farm prevalence was ≥ 80%. Six of 18 farmers carried isolates containing ESBL/AmpC genes bla(CTX-M-1), bla(CMY-2) and/or bla(SHV-12), which were also present in the samples from their animals. In five of these isolates, the genes were located on identical plasmid families [IncI1 (n = 3), IncK (n = 1) or IncN (n = 1)], and in isolates from two farmers the genes were carried on identical plasmid subtypes (IncI1 ST12 and IncN ST1, where ST stands for sequence type) as in the isolates from their animals. This study shows a high prevalence of birds carrying ESBL/AmpC-producing E. coli at Dutch broiler farms and a high prevalence of ESBL/AmpC-producing E. coli in farmers. This is undesirable due to the risk this poses to human health. Future research should focus on identification of the source of these isolates in the broiler production chain to make interventions resulting in reduction of these isolates possible.

  19. Prevalence and characterization of extended-spectrum beta-lactamase (ESBL)- and CMY-2-producing Escherichia coli isolates from healthy food-producing animals in Tunisia.

    PubMed

    Ben Sallem, Rym; Ben Slama, Karim; Sáenz, Yolanda; Rojo-Bezares, Beatriz; Estepa, Vanesa; Jouini, Ahlem; Gharsa, Haythem; Klibi, Naouel; Boudabous, Abdellatif; Torres, Carmen

    2012-12-01

    The prevalence of extended-spectrum beta-lactamase (ESBL)- and plasmidic AmpC-beta-lactamase (pAmpC-BL)-producing Escherichia coli isolates has been studied in food-producing animals at the farm level in Tunisia, and recovered isolates were characterized for the presence of other resistance genes and integrons. Eighty fecal samples of food-producing animals (23 sheep, 22 chickens, 22 cattle, six horses, five rabbits, and two dromedaries) were obtained from 35 different farms in Tunisia in 2011. Samples were inoculated onto MacConkey agar plates supplemented with cefotaxime (2 mg/L) for cefotaxime-resistant (CTX(R)) E. coli recovery. CTX(R) E. coli isolates were detected in 11 out of 80 samples (13.8%), and one isolate per sample was further characterized (10 from chickens and one from a dromedary). The 11 CTX(R) isolates were distributed into phylogroups: B1 (five isolates), A (two isolates), D (three isolates), and B2 (one isolate). The following beta-lactamase genes were detected: bla(CTX-M-1) (seven isolates), bla(CTX-M-1)+bla(TEM-135) (one isolate), bla(CTX-M-1)+bla(TEM-1b) (one isolate), and bla(CMY-2) (two isolates). All ESBL- and pAmpC-BL-producing E. coli strains showed unrelated pulsed-field gel electrophoresis patterns. Seven isolates contained class 1 integrons with four gene cassette arrangements: dfrA17-aadA5 (three isolates), dfrA1-aadA1 (two isolates), dfrA15-aadA1 (one isolate), and aadA1 (one isolate). All isolates showed tetracycline resistance and contained the tet(A) +/- tet(B) genes. Virulence genes detected were as follows (number of isolates in parentheses): fimA (10); aer (eight); papC (two); and papGIII, hly, cnf, and bfp (none). Chicken farms constitute a reservoir of ESBL- and pAmpC-BL-producing E. coli isolates of the CTX-M-1 and CMY-2 types that potentially could be transmitted to humans via the food chain or by direct contact.

  20. Escherichia coli can produce recombinant chitinase in the soil to control the pathogenesis by Fusarium oxysporum without colonization.

    PubMed

    Chung, Soohee; Kim, Sang-Dal

    2007-03-01

    Fusarium wilt of cucumbers was effectively controlled by Escherichia coli expressing an endochitinase gene (chiA), and the rate was as effective (60.0%) as the wildtype strain S. proteamaculans 3095 (55.0%) where the gene was cloned. However, live cells of soil inoculated E. coli host harboring the chiA gene did not proliferate but declined 100-fold from 108 CFU during the first week and showed less than 10 cells after day 14, suggesting that E. coli was able to express and produce the chitinase enzyme to the soil even as the population was gradually decreasing. Because the majority of the strains was alive for only a short period of time and the Fusarium-affected seedlings showed symptoms of wilting within 7-10 days, it seems that the pathogen control was decided early after the introduction of the biocontrol agent, eliminating the survival of the antagonist. These results indicated that soil inoculated E. coli could sufficiently express and produce the recombinant protein to control the pathogen, and root or soil colonization of the antagonist might not be a significant factor in determining the efficacy of biological control.

  1. Conventional curing practices reduce generic Escherichia coli and Salmonella spp. on dry bulb onions produced with contaminated irrigation water.

    PubMed

    Emch, Alexander W; Waite-Cusic, Joy G

    2016-02-01

    Food Safety Modernization Act (FSMA) has emphasized microbial risks associated with irrigation water. Treasure Valley (eastern Oregon/western Idaho) has the highest yield of dry bulb onions in the country; however, their irrigation water is often non-compliant with current industry and proposed federal standards for fresh produce. Conventional curing practices may provide a mechanism to mitigate irrigation water quality to comply with FSMA regulations. Dry bulb onions were grown in Owyhee silt loam and Semiahmoo muck soils in greenhouses and irrigated with water containing a cocktail of rifampicin-resistant generic Escherichia coli and Salmonella spp. (4.80 log CFU/ml). To mimic conventional practices, mature onions remained undisturbed in soil without irrigation for 12 days prior to being lifted and cured for 16 additional days. Surviving generic E. coli and Salmonella spp. were selectively enumerated on using standard plating (Hektoen Enteric Agar with rifampicin; HE + rif) or most probable number (lactose broth with rifampicin; HE + rif) methods. Generic E. coli and Salmonella spp. on onions decreased 0.19-0.26 log CFU/g·d during the initial 12 days of finishing. At lifting, generic E. coli and Salmonella spp. had been reduced to <1 CFU/g and persisted through the end of curing. This study demonstrates conventional curing practices as an effective mitigation strategy for dry bulb onions produced with water of poor microbiological quality.

  2. Emergence of Escherichia coli encoding Shiga toxin 2f in human Shiga toxin-producing E. coli (STEC) infections in the Netherlands, January 2008 to December 2011.

    PubMed

    Friesema, I; van der Zwaluw, K; Schuurman, T; Kooistra-Smid, M; Franz, E; van Duynhoven, Y; van Pelt, W

    2014-05-01

    The Shiga toxins of Shiga toxin-producing Escherichia coli (STEC) can be divided into Shiga toxin 1 (Stx1) and Shiga toxin 2 (Stx2) with several sub-variants. Variant Stx2f is one of the latest described, but has been rarely associated with symptomatic human infections. In the enhanced STEC surveillance in the Netherlands, 198 STEC O157 cases and 351 STEC non-O157 cases, including 87 stx2f STEC isolates, were reported between 2008 and 2011. Most stx2f strains belonged to the serogroups O63:H6 (n=47, 54%), O113:H6 (n=12, 14%) and O125:H6 (n=12, 14%). Of the 87 stx2f isolates, 84 (97%) harboured the E. coli attaching and effacing (eae) gene, but not the enterohaemorrhagic E. coli haemolysin (hly) gene. stx2f STEC infections show milder symptoms and a less severe clinical course than STEC O157 infections. Almost all infections with stx2f (n=83, 95%) occurred between June and December, compared to 170/198 (86%) of STEC O157 and 173/264 (66%) of other STEC non-O157. stx2f STEC infections in the Netherlands are more common than anticipated, and form a distinct group within STEC with regard to virulence genes and the relatively mild disease.

  3. Presence of non-O157 Shiga toxin-producing Escherichia coli, enterotoxigenic E. coli, enteropathogenic E. coli and Salmonella in fresh beetroot (Beta vulgaris L.) juice from public markets in Mexico.

    PubMed

    Gómez-Aldapa, Carlos A; Rangel-Vargas, Esmeralda; Bautista-De León, Haydee; Castro-Rosas, Javier

    2014-10-01

    Unpasteurized juice has been associated with foodborne illness outbreaks for many years. Beetroot is a vegetable grown all over the world in temperate areas. In Mexico beetroot is consumed cooked in salads or raw as fresh unpasteurized juices. No data about the microbiological quality or safety of unpasteurized beetroot juices are available. Indicator bacteria, diarrheagenic Escherichia coli pathotypes (DEP) and Salmonella frequencies were determined for fresh unpasteurized beetroot juice from restaurants. One hundred unpasteurized beetroot juice samples were collected from public markets in Pachuca, Mexico. Frequencies in these samples were 100%, 75%, 53%, 9% and 4% of positive samples, for coliform bacteria, fecal coliforms, E. coli, DEP and Salmonella, respectively. Identified DEP included enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC) and non-O157 Shiga toxin-producing E. coli (STEC). Identified Salmonella serotypes included Typhimurium and Enteritidis. This is the first report of microbiological quality and atypical EPEC, ETEC, non-O157 STEC and Salmonella isolation from fresh raw beetroot juice in Mexico. Fresh raw beetroot juice from markets is very probably an important factor contributing to the endemicity of atypical EPEC, ETEC, non-O157 STEC and Salmonella-related gastroenteritis in Mexico. © 2014 Society of Chemical Industry.

  4. O157:H7 and O104:H4 Vero/Shiga toxin-producing Escherichia coli outbreaks: respective role of cattle and humans

    PubMed Central

    2012-01-01

    An enteroaggregative Verotoxin (Vtx)-producing Escherichia coli strain of serotype O104:H4 has recently been associated with an outbreak of haemolytic-uremic syndrome and bloody diarrhoea in humans mainly in Germany, but also in 14 other European countries, USA and Canada. This O104:H4 E. coli strain has often been described as an enterohaemorrhagic E. coli (EHEC), i.e. a Vtx-producing E. coli with attaching and effacing properties. Although both EHEC and the German O104:H4 E. coli strains indeed produce Vtx, they nevertheless differ in several other virulence traits, as well as in epidemiological characteristics. For instance, the primary sources and vehicles of typical EHEC infections in humans are ruminants, whereas no animal reservoir has been identified for enteroaggregative E. coli (EAggEC). The present article is introduced by a brief overview of the main characteristics of Vtx-producing E. coli and EAggEC. Thereafter, the O104:H4 E. coli outbreak is compared to typical EHEC outbreaks and the virulence factors and host specificity of EHEC and EAggEC are discussed. Finally, a renewed nomenclature of Vtx-producing E. coli is proposed to avoid more confusion in communication during future outbreaks and to replace the acronym EHEC that only refers to a clinical condition. PMID:22330148

  5. Antibiotic Susceptibilities and Genetic Characteristics of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Isolates from Stools of Pediatric Diarrhea Patients in Surabaya, Indonesia.

    PubMed

    Bagus Wasito, Eddy; Shigemura, Katsumi; Osawa, Kayo; Fardah, Alpha; Kanaida, Akiho; Raharjo, Dadik; Kuntaman, K; Hadi, Usman; Harijono, Sugeng; Marto Sudarmo, Subijanto; Nakamura, Tatsuya; Shibayama, Keigo; Fujisawa, Masato; Shirakawa, Toshiro

    2017-07-24

    The purpose of this study was to investigate extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli isolates from pediatric (aged 0 to 3 years) diarrhea patients in Surabaya, Indonesia, where this kind of survey is rare; our study included assessment of their antibiotic susceptibilities, as well as ESBL typing, multilocus sequence typing (MLST), and diarrheagenic E. coli (DEC)-typing. ESBL-producing E. coli were detected in 18.8% of all the samples. Many ESBL-producing E. coli had significantly lower susceptibility to gentamicin (p < 0.0001) and the quinolones nalidixic acid (p=0.004) and ciprofloxacin (p < 0.0001) than non-producers. In ESBL-producing E. coli, 84.0% of strains expressed CTX-M-15 alone or in combination with other ESBL types. MLST revealed that 24.0% of ESBL-producers had sequence type 617, all of which expressed the CTX-M-15 gene; we also detected expression of 3 DEC-related genes: 2 enteroaggregative E. coli genes and 1 enteropathogenic E. coli gene. In conclusion, CTX-M-15-type ESBL-producing E. coli ST617 appear to have spread to Indonesia.

  6. Unacceptably High Error Rates in Vitek 2 Testing of Cefepime Susceptibility in Extended-Spectrum-β-Lactamase-Producing Escherichia coli

    PubMed Central

    Rhodes, Nathaniel J.; Richardson, Chad L.; Heraty, Ryan; Liu, Jiajun; Malczynski, Michael; Qi, Chao

    2014-01-01

    While a lack of concordance is known between gold standard MIC determinations and Vitek 2, the magnitude of the discrepancy and its impact on treatment decisions for extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli are not. Clinical isolates of ESBL-producing E. coli were collected from blood, tissue, and body fluid samples from January 2003 to July 2009. Resistance genotypes were identified by PCR. Primary analyses evaluated the discordance between Vitek 2 and gold standard methods using cefepime susceptibility breakpoint cutoff values of 8, 4, and 2 μg/ml. The discrepancies in MICs between the methods were classified per convention as very major, major, and minor errors. Sensitivity, specificity, and positive and negative predictive values for susceptibility classifications were calculated. A total of 304 isolates were identified; 59% (179) of the isolates carried blaCTX-M, 47% (143) carried blaTEM, and 4% (12) carried blaSHV. At a breakpoint MIC of 8 μg/ml, Vitek 2 produced a categorical agreement of 66.8% and exhibited very major, major, and minor error rates of 23% (20/87 isolates), 5.1% (8/157 isolates), and 24% (73/304), respectively. The sensitivity, specificity, and positive and negative predictive values for a susceptibility breakpoint of 8 μg/ml were 94.9%, 61.2%, 72.3%, and 91.8%, respectively. The sensitivity, specificity, and positive and negative predictive values for a susceptibility breakpoint of 2 μg/ml were 83.8%, 65.3%, 41%, and 93.3%, respectively. Vitek 2 results in unacceptably high error rates for cefepime compared to those of agar dilution for ESBL-producing E. coli. Clinicians should be wary of making treatment decisions on the basis of Vitek 2 susceptibility results for ESBL-producing E. coli. PMID:24752253

  7. Isolation of Shiga toxin-producing Escherichia coli from fresh produce using STEC heart infusion washed blood agar with mitomycin-C.

    PubMed

    Lin, Andrew; Nguyen, Lam; Clotilde, Laurie M; Kase, Julie A; Son, Insook; Lauzon, Carol R

    2012-11-01

    The ability to detect and isolate Shiga toxin-producing Escherichia coli (STEC) remains a major challenge for food microbiologists. Although methods based on nucleic acids and antibodies have improved detection of STECs in foods, isolation of these bacteria remains arduous. STEC isolation is necessary for matching food, environmental, and clinical isolates during outbreak investigations and for distinguishing between pathogenic and nonpathogenic organisms. STEC heart infusion washed blood agar with mitomycin-C (SHIBAM) is a modification of washed sheep blood agar prepared by adding mitomycin-C and optimizing both the washed blood and base agar to better isolate STECs. Most STEC isolates produce a zone of hemolysis on SHIBAM plates and are easily distinguishable from background microbiota. Here, we present data supporting the use of SHIBAM to isolate STECs from fresh produce. SHIBAM was tested for accuracy in identifying STECs (365 of 410 STEC strains were hemolytic, and 63 of 73 E. coli strains that did not produce Shiga toxin were not hemolytic) and for recovery from artificially inoculated fresh produce (11 of 24 romaine lettuce samples and 6 of 24 tomato samples). STEC recovery with SHIBAM agar was greatly improved when compared with recovery on Levine's eosin-methylene blue agar as a reference method.

  8. Occurrence of CTX-M Producing Escherichia coli in Soils, Cattle, and Farm Environment in France (Burgundy Region)

    PubMed Central

    Hartmann, Alain; Locatelli, Aude; Amoureux, Lucie; Depret, Géraldine; Jolivet, Claudy; Gueneau, Eric; Neuwirth, Catherine

    2012-01-01

    CTX-M [a major type of extended-spectrum beta-lactamase (ESBL)] producing Escherichia coli are increasingly involved in human infections worldwide. The aim of this study was to investigate potential reservoirs for such strains: soils, cattle, and farm environment. The prevalence of blaCTX-M genes was determined directly from soil DNA extracts obtained from 120 sites in Burgundy (France) using real-time PCR. blaCTX-M targets were found in 20% of the DNA extracts tested. Samples of cattle feces (n = 271) were collected from 182 farms in Burgundy. Thirteen ESBL-producing isolates were obtained from 12 farms and further characterized for the presence of bla genes. Of the 13 strains, five and eight strains carried blaTEM-71 genes and blaCTX-M-1 genes respectively. Ten strains of CTX-M-1 producing E. coli were isolated from cultivated and pasture soils as well as from composted manure within two of these farms. The genotypic analysis revealed that environmental and animal strains were clonally related. Our study confirms the occurrence of CTX-M producing E. coli in cattle and reports for the first time the occurrence of such strains in cultivated soils. The environmental competence of such strains has to be determined and might explain their long term survival since CTX-M isolates were recovered from a soil that was last amended with manure 1 year before sampling. PMID:22408639

  9. Isolation of atypical enteropathogenic Escherichia coli and Shiga toxin 1 and 2f-producing Escherichia coli from avian species in India.

    PubMed

    Farooq, S; Hussain, I; Mir, M A; Bhat, M A; Wani, S A

    2009-06-01

    To study the prevalence and characterize atypical enteropathogenic Escherichia coli (EPEC) and Shiga toxin producing E. coli (STEC) in avian species in India. Two hundred and twelve faecal samples collected from 62 chickens, 50 ducks and 100 pigeons were investigated for the presence of stx(1), stx(2), eae and ehxA virulence genes by multiplex PCR. In all, 42 E. coli isolates (25 chicken, 2 duck and 15 pigeon) possessed at least one virulence gene. Out of these, nine (4.24%) isolates were STEC and 33 (15.56%) were EPEC. All isolates from duck and chicken were EPEC while among 15 pigeon isolates nine (60%) were STEC and six (40%) were EPEC. Among the STEC isolates four each carried stx(1) or stx(2) and one possessed both stx(1) and stx(2). Subtype analysis of stx revealed the presence of stx(2f) in four STEC isolates. None of the STEC isolates carried stx(1c), stx(2c), stx(2d) or stx(2e). Isolates carrying stx(2f) demonstrated vero cell toxicity. One each belonged to serogroup O17 and O78, while one was rough and the other untypeable. All EPEC isolates were atypical as they lacked bfpA. This appears to be the first report of detection of stx(2f) from India. The study established the presence of stx(1) and stx(2f) containing E. coli in pigeons and atypical EPEC in poultry in India. Pigeons might serve as vectors for transmission of STEC to environment and humans. Taking into account the close contact between fanciers and pigeons, these findings warrant a more critical appraisal of these zoonotic pathogens in pigeons and humans.

  10. Molecular Characterization of Enterotoxin-Producing Escherichia coli Collected in 2011-2012, Russia.

    PubMed

    Kartsev, Nikolay N; Fursova, Nadezhda K; Pachkunov, Dmitry M; Bannov, Vasiliy A; Eruslanov, Boris V; Svetoch, Edward A; Dyatlov, Ivan A

    2015-01-01

    Enterotoxin-producing Escherichia coli (ETEC) are one of the main causative agents of diarrhea in children especially in developing countries and travel diarrhoea in adults. Pathogenic properties of ETEC associated with their ability to produce a heat-stable (ST) and/or heat-labile (LT) enterotoxins, as well as adhesins providing bacterial adhesion to intestinal epithelial cells. This study presents the molecular characterization of the ETEC isolates collected from the Central and Far-Eastern regions of Russia in 2011-2012. It was shown that all ETEC under study (n=18) had the heat-labile enterotoxin-coding operon elt, and had no the genes of the heat-stable enterotoxin operon est. DNA sequencing revealed two types of nucleotide exchanges in the eltB gene coding subunit B of LT in isolates collected from Cherepovets city (Central region, Russia) and Vladivostok city (Far-East region, Russia). Only one ETEC strain carried genes cfaA, cfaB, cfaC and cfaD coding adhesion factor CFA/I. Expression of LT in four ETEC isolates in the agglutination reaction was detected using a latex test-system. The isolates were assigned to serogroups O142 (n = 6), О6 (n = 4), О25 (n = 5), О26 (n = 2), and O115 (n = 1). Genotyping showed that they belonged to an earlier described sequence-type ST4 (n = 3) as well as to 11 novel sequence-types ST1043, ST1312, ST3697, ST3707, ST3708, ST3709, ST3710, ST3755, ST3756, ST3757 and ST4509. The ETEC isolates displayed different levels of antimicrobial resistance. Eight isolates were resistant to only one drug, three isolates-to two drugs, one isolate-to three drugs, two isolates-to four antibacterials, and only one isolate to each of the five, six and ten antibacterials simultaneously. Genetic determinants of the resistance to beta-lactams and other classes of antibacterials on the ETEC genomes were identified. There are blaTEM (n = 10), blaCTX-M-15 (n = 1), class 1 integron (n = 3) carrying resistance cassettes to aminoglycosides and

  11. Molecular Characterization of Enterotoxin-Producing Escherichia coli Collected in 2011–2012, Russia

    PubMed Central

    Kartsev, Nikolay N.; Fursova, Nadezhda K.; Pachkunov, Dmitry M.; Bannov, Vasiliy A.; Eruslanov, Boris V.; Svetoch, Edward A.; Dyatlov, Ivan A.

    2015-01-01

    Enterotoxin-producing Escherichia coli (ETEC) are one of the main causative agents of diarrhea in children especially in developing countries and travel diarrhoea in adults. Pathogenic properties of ETEC associated with their ability to produce a heat-stable (ST) and/or heat-labile (LT) enterotoxins, as well as adhesins providing bacterial adhesion to intestinal epithelial cells. This study presents the molecular characterization of the ETEC isolates collected from the Central and Far-Eastern regions of Russia in 2011–2012. It was shown that all ETEC under study (n=18) had the heat-labile enterotoxin-coding operon elt, and had no the genes of the heat-stable enterotoxin operon est. DNA sequencing revealed two types of nucleotide exchanges in the eltB gene coding subunit B of LT in isolates collected from Cherepovets city (Central region, Russia) and Vladivostok city (Far-East region, Russia). Only one ETEC strain carried genes cfaA, cfaB, cfaC and cfaD coding adhesion factor CFA/I. Expression of LT in four ETEC isolates in the agglutination reaction was detected using a latex test-system. The isolates were assigned to serogroups O142 (n = 6), О6 (n = 4), О25 (n = 5), О26 (n = 2), and O115 (n = 1). Genotyping showed that they belonged to an earlier described sequence-type ST4 (n = 3) as well as to 11 novel sequence-types ST1043, ST1312, ST3697, ST3707, ST3708, ST3709, ST3710, ST3755, ST3756, ST3757 and ST4509. The ETEC isolates displayed different levels of antimicrobial resistance. Eight isolates were resistant to only one drug, three isolates—to two drugs, one isolate—to three drugs, two isolates—to four antibacterials, and only one isolate to each of the five, six and ten antibacterials simultaneously. Genetic determinants of the resistance to beta-lactams and other classes of antibacterials on the ETEC genomes were identified. There are blaTEM (n = 10), blaCTX-M-15 (n = 1), class 1 integron (n = 3) carrying resistance cassettes to aminoglycosides and

  12. Houseflies (Musca domestica) as Vectors for Extended-Spectrum β-Lactamase-Producing Escherichia coli on Spanish Broiler Farms

    PubMed Central

    Solà-Ginés, Marc; González-López, Juan José; Cameron-Veas, Karla; Piedra-Carrasco, Nuria; Cerdà-Cuéllar, Marta

    2015-01-01

    Flies may act as potential vectors for the spread of resistant bacteria to different environments. This study was intended to evaluate the presence of Escherichia coli strains resistant to cephalosporins in flies captured in the areas surrounding five broiler farms. Phenotypic and molecular characterization of the resistant population was performed by different methods: MIC determination, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and phylotyping. The presence of extended-spectrum beta-lactamase (ESBL) genes, their plasmid location, and the mobile genetic elements involved in their mobilization were studied. Additionally, the presence of 35 genes associated with virulence was evaluated. Out of 682 flies captured, 42 yielded ESBL-producing E. coli. Of these isolates, 23 contained blaCTX-M-1, 18 contained blaCTX-M-14, and 1 contained blaCTX-M-9. ESBL genes were associated mainly with the presence of the IncI1 and IncFIB replicons. Additionally, all the strains were multiresistant, and five of them also harbored qnrS. Identical PFGE profiles were found for E. coli isolates obtained from flies at different sampling times, indicating a persistence of the same clones in the farm environment over months. According to their virulence genes, 81% of the isolates were considered avian-pathogenic E. coli (APEC) and 29% were considered extraintestinal pathogenic E. coli (ExPEC). The entrance of flies into broiler houses constitutes a considerable risk for colonization of broilers with multidrug-resistant E. coli. ESBLs in flies reflect the contamination status of the farm environment. Additionally, this study demonstrates the potential contribution of flies to the dissemination of virulence and resistance genes into different ecological niches. PMID:25795670

  13. Houseflies (Musca domestica) as Vectors for Extended-Spectrum β-Lactamase-Producing Escherichia coli on Spanish Broiler Farms.

    PubMed

    Solà-Ginés, Marc; González-López, Juan José; Cameron-Veas, Karla; Piedra-Carrasco, Nuria; Cerdà-Cuéllar, Marta; Migura-Garcia, Lourdes

    2015-06-01

    Flies may act as potential vectors for the spread of resistant bacteria to different environments. This study was intended to evaluate the presence of Escherichia coli strains resistant to cephalosporins in flies captured in the areas surrounding five broiler farms. Phenotypic and molecular characterization of the resistant population was performed by different methods: MIC determination, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and phylotyping. The presence of extended-spectrum beta-lactamase (ESBL) genes, their plasmid location, and the mobile genetic elements involved in their mobilization were studied. Additionally, the presence of 35 genes associated with virulence was evaluated. Out of 682 flies captured, 42 yielded ESBL-producing E. coli. Of these isolates, 23 contained bla(CTX-M-1), 18 contained bla(CTX-M-14), and 1 contained bla(CTX-M-9). ESBL genes were associated mainly with the presence of the IncI1 and IncFIB replicons. Additionally, all the strains were multiresistant, and five of them also harbored qnrS. Identical PFGE profiles were found for E. coli isolates obtained from flies at different sampling times, indicating a persistence of the same clones in the farm environment over months. According to their virulence genes, 81% of the isolates were considered avian-pathogenic E. coli (APEC) and 29% were considered extraintestinal pathogenic E. coli (ExPEC). The entrance of flies into broiler houses constitutes a considerable risk for colonization of broilers with multidrug-resistant E. coli. ESBLs in flies reflect the contamination status of the farm environment. Additionally, this study demonstrates the potential contribution of flies to the dissemination of virulence and resistance genes into different ecological niches.

  14. Extended-Spectrum-β-Lactamase-Producing Escherichia coli as a Cause of Pediatric Infections: Report of a Neonatal Intensive Care Unit Outbreak Due to a CTX-M-14-Producing Strain

    PubMed Central

    Oteo, Jesús; Cercenado, Emilia; Fernández-Romero, Sara; Saéz, David; Padilla, Belén; Zamora, Elena; Cuevas, Oscar; Bautista, Verónica

    2012-01-01

    Little information is available about pediatric infections caused by extended-spectrum-β-lactamase (ESBL)-producing Escherichia coli. We characterized an outbreak caused by a CTX-M-14-producing E. coli isolate in a neonatal intensive care unit (NICU) and studied other infections caused by ESBL-producing E. coli in non-NICU pediatric units. All children ≤4 years old who were infected or colonized by ESBL-producing E. coli isolates between January 2009 and September 2010 were included. Molecular epidemiology was studied by phylogroup analysis, pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing. Antibiotic resistance genes were analyzed by PCR and sequencing. Plasmids were studied by PFGE with S1 nuclease digestion and by incompatibility group analysis using a PCR-based replicon-typing scheme. Of the ESBL-producing E. coli isolates colonizing or infecting the 30 newborns, identical PFGE results were observed for 21 (70%) isolates, which were classified as CTX-M-14-producing E. coli of ST23 phylogroup A. blaCTX-M-14a was linked to ISEcp1 and was carried on an ∼80-bp IncK plasmid. A smaller ongoing outbreak due to SHV-12-producing ST131 E. coli was also identified in the same NICU. Fifteen additional infections with ESBL-producing E. coli were identified in non-NICU pediatric units, but none was caused by the CTX-M-14-producing E. coli epidemic clone. Overall, CTX-M-14 (71.1%), CTX-M-15 (13.3%), and SHV-12 (13.3%) were the most important ESBLs causing pediatric infections in this study. Infections of newborns with CTX-M-14-producing E. coli were caused by both clonal and nonclonal isolates. PMID:21986825

  15. Broad and efficient control of major foodborne pathogenic strains of Escherichia coli by mixtures of plant-produced colicins

    PubMed Central

    Schulz, Steve; Stephan, Anett; Hahn, Simone; Bortesi, Luisa; Jarczowski, Franziska; Bettmann, Ulrike; Paschke, Anne-Katrin; Tusé, Daniel; Stahl, Chad H.; Giritch, Anatoli; Gleba, Yuri

    2015-01-01

    Enterohemorrhagic Escherichia coli (EHEC) is one of the leading causes of bacterial enteric infections worldwide, causing ∼100,000 illnesses, 3,000 hospitalizations, and 90 deaths annually in the United States alone. These illnesses have been linked to consumption of contaminated animal products and vegetables. Currently, other than thermal inactivation, there are no effective methods to eliminate pathogenic bacteria in food. Colicins are nonantibiotic antimicrobial proteins, produced by E. coli strains that kill or inhibit the growth of other E. coli strains. Several colicins are highly effective against key EHEC strains. Here we demonstrate very high levels of colicin expression (up to 3 g/kg of fresh biomass) in tobacco and edible plants (spinach and leafy beets) at costs that will allow commercialization. Among the colicins examined, plant-expressed colicin M had the broadest antimicrobial activity against EHEC and complemented the potency of other colicins. A mixture of colicin M and colicin E7 showed very high activity against all major EHEC strains, as defined by the US Department of Agriculture/Food and Drug Administration. Treatments with low (less than 10 mg colicins per L) concentrations reduced the pathogenic bacterial load in broth culture by 2 to over 6 logs depending on the strain. In experiments using meats spiked with E. coli O157:H7, colicins efficiently reduced the population of the pathogen by at least 2 logs. Plant-produced colicins could be effectively used for the broad control of pathogenic E. coli in both plant- and animal-based food products and, in the United States, colicins could be approved using the generally recognized as safe (GRAS) regulatory approval pathway. PMID:26351689

  16. Susceptibility of various oral antibacterial agents against extended spectrum β-lactamase producing Escherichia coli and Klebsiella pneumoniae.

    PubMed

    Nakamura, Tatsuya; Komatsu, Masaru; Yamasaki, Katsutoshi; Fukuda, Saori; Higuchi, Takeshi; Ono, Tamotsu; Nishio, Hisaaki; Sueyoshi, Noriyuki; Kida, Kaneyuki; Satoh, Kaori; Toda, Hirofumi; Toyokawa, Masahiro; Nishi, Isao; Sakamoto, Masako; Akagi, Masahiro; Mizutani, Tetsu; Nakai, Isako; Kofuku, Tomomi; Orita, Tamaki; Zikimoto, Takuya; Natsume, Seiko; Wada, Yasunao

    2014-01-01

    With the increase in extended spectrum β-lactamase (ESBL)-producing bacteria in the community, cases are often seen in which treatment of infectious diseases with oral antimicrobial agents is difficult. Therefore, we measured the antimicrobial activities of 14 currently available oral antimicrobial agents against ESBL-producing Escherichia coli and Klebsiella pneumoniae. Based on the standard of the Clinical and Laboratory Standards Institute (CLSI), E. coli showed high susceptibility rates of 99.4% to faropenem (FRPM). In terms of fluoroquinolones, the susceptibility rate of E. coli to levofloxacin (LVFX) was low at 32.2%, whereas it showed a good susceptibility rate of 93.1% to sitafloxacin (STFX). With respect to other antimicrobial agents, susceptibility rates to fosfomycin (FOM) and colistin (CL) were more than 90% each, whereas rates of the two antimicrobial agents expected as therapeutic agents, minocycline (MINO) and sulfamethoxazole-trimethoprim (ST), were low at 62.4% and 44.3%, respectively. Based on the CLSI standard, K. pneumoniae showed high susceptibility rates to ceftibuten (CETB) (91.89%), LVFX (86.49%), and STFX (94.6%), indicating that K. pneumoniae showed higher rates than those of E. coli, particularly to fluoroquinolones. Comparison of susceptibility rates according to E. coli genotype showed that many antimicrobial agents existed to which the CTX-M-9 group showed high susceptibility rates. However, there were many agents to which the CTX-M-1 group showed low susceptibility rates, particularly to CETB (51.1%) and LVFX (17.0%). Although there was no significant difference by genotype between FRPM, STFX, and FOM, a significant difference was observed between LVFX, MINO, and ST. Antibiotic-resistant bacteria with highly pathogenic strains have spread in the community, appropriate use of oral antimicrobial agents is required. Copyright © 2013 Japanese Society of Chemotherapy and the Japanese Association for Infectious Diseases. Published by

  17. Ventilator-associated pneumonia caused by OXA-48-producing Escherichia coli complicated by ciprofloxacin-associated rhabdomyolysis.

    PubMed

    Grisold, Andrea J; Hoenigl, Martin; Ovcina, Ismar; Valentin, Thomas; Fruhwald, Sonja

    2013-12-01

    We report the emergence of OXA-48 carbapenemase-producing Escherichia coli in Austria causing ventilator-associated pneumonia in a traveler returning from Egypt. Depending on resistance testing, quinolones may remain a therapeutic option for infections caused by these multiple resistant pathogens, as this class of drugs has a favorable safety and tolerability profile when compared to the alternatives. In this patient, however, the clinical course was dramatically complicated by the development of ciprofloxacin-associated rhabdomyolysis.

  18. Molecular characteristics of extended-spectrum β-lactamase-producing Escherichia coli in a university teaching hospital.

    PubMed

    Osawa, Kayo; Shigemura, Katsumi; Shimizu, Rika; Kato, Ayaka; Kusuki, Mari; Jikimoto, Takumi; Nakamura, Tatsuya; Yoshida, Hiroyuki; Arakawa, Soichi; Fujisawa, Masato; Shirakawa, Toshiro

    2015-04-01

    The prevalence of extended-spectrum β-lactamases (ESBLs) has been increasing worldwide. Recently, a pandemic clone of Escherichia coli O25:H4, sequence type 131 (ST131), producing ESBL-type CTX-M-15 has been reported as a major problem. In this study, we investigated the molecular characteristics of 72 ESBL-producing E. coli isolates. We detected the ESBL blaCTX-M gene and nine virulence factor genes (papC, papEF, fimH, hlyA, iutA, sfa, eaeA, bfpA, and aggR) by PCR and DNA sequencing, plasmid replicon typing, phylogenetic grouping, repetitive-sequence-based PCR (rep-PCR), and multilocus sequence typing. All strains were positive for blaCTX-M. Twenty-two (30.6%) strains in CTX-M-1 group included 9 (12.5%) of CTX-M-15, 3 (4.2%) in CTX-M-2 group, and 47 (65.3%) strains in CTX-M-9 group. The CTX-M-15-producing E. coli O25:H4 ST131 was derived from phylogenetic group B2 and rep-PCR pattern d. The most prevalent virulence factor was fimH (72 strains; 100%) and the most common replicon type was the IncF type (65 strains; 90.3%). The CTX-M-9 group was significantly associated with the presence of papC and papEF [OR (95% CI)=9.22 (1.32-64.7), p=0.025] or hlyA [OR (95% CI)=5.57 (1.17-26.4), p=0.031]. In conclusion, we confirmed that CTX-M-15-producing E. coli O25:H4 ST131 has emerged in Japan and found significant virulence factors with CTX-M-9 group.

  19. Characterization of Escherichia coli-Producing Extended-Spectrum β-Lactamase (ESBL) Isolated from Chicken Slaughterhouses in South Korea.

    PubMed

    Lim, Jong-Soo; Choi, Da-Som; Kim, Young-Jo; Chon, Jung-Whan; Kim, Hong-Seok; Park, Hyun-Jung; Moon, Jin-San; Wee, Sung-Hwan; Seo, Kun-Ho

    2015-09-01

    In South Korea, few reports have indicated the occurrence and characteristics of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in food-producing animals, particularly in poultry slaughterhouses. In this study, we investigated the occurrence and antibiotic resistance of ESBL-producing E. coli from whole chicken carcasses (n=156) and fecal samples (n=39) of chickens obtained from 2 slaughterhouses. Each sample enriched in buffered peptone water was cultured on MacConkey agar with 2 mg/L cefotaxime and ESBL agar. ESBL production and antibiotic susceptibility were determined using the Trek Diagnostics system. The ESBL genotypes were determined by polymerase chain reaction (PCR) using the bla(SHV), bla(TEM), and bla(CTX-M) gene sequences. Subtyping using a repetitive sequence-based PCR system (DiversiLab™) and multilocus sequence typing (MLST) were used to assess the interspecific biodiversity of isolates. Sixty-two ESBL-producing E. coli isolates were obtained from 156 samples (39.7%). No bla(SHV) genes were detected in any of the isolates, whereas all contained the bla(TEM) gene. Twenty-five strains (40.3%) harbored the CTX-M group 1 gene. The most prevalent MLST sequence type (ST) was ST 93 (14.5%), followed by ST 117 (9.7%) and ST 2303 (8.1%). This study reveals a high occurrence and β-lactams resistance rate of E. coli in fecal samples and whole chickens collected from slaughterhouses in South Korea.

  20. Pulmonary artery reconstruction with a tailor-made bovine pericardial conduit following sleeve resection of a long segmental pulmonary artery for the treatment of lung cancer: technical details of the dog-ear method for adjusting diameter during vascular anastomosis.

    PubMed

    Shimizu, Kimihiro; Nagashima, Toshiteru; Ohtaki, Yoichi; Takahashi, Toru; Mogi, Akira; Kuwano, Hiroyuki

    2017-05-01

    Sleeve resection of the pulmonary artery (PA) is always required for lung-sparing operations in which half or more of the vessel circumference is infiltrated by the primary tumor or metastatic hilar nodes. Following sleeve resection, conduit reconstruction may be indicated if there is excessive distance between the two vascular stumps, because there is a high degree of tension when repaired by direct anastomosis. We herein present a case of PA reconstruction using a tailor-made bovine pericardial conduit after sleeve resection of PA during lung cancer surgery. The length of resection was longer than 3 cm, and the difference in diameter between the conduit and peripheral PA stump was larger than 0.5 cm. We describe the surgical and oncological merits of a bovine pericardial conduit, and provide details of our reconstruction technique, focusing on adjustment of diameter between the conduit and peripheral PA (dog-ear method).

  1. [Detection of verotoxin-producing E. coli in field isolates from domestic and agricultural animals in Sachsen-Anhalt].

    PubMed

    Gallien, P; Klie, H; Lehmann, S; Protz, D; Helmuth, R; Schäfer, R; Ehrler, M

    1994-10-01

    A report is given on the detection of verotoxin-producing E. coli (VTEC) strains from field isolates of healthy or ill cattle (n = 141), pigs (n = 306), sheep (n = 15), cats (n = 29) and dogs (n = 25) in the region of the new federal land Sachsen-Anhalt. 5% of the strains isolated from cattle, 32% from pigs, 20% from sheep, 4% from dogs and 0% from cats have shown VTEC. The E. coli-strains were checked for the presence of other factors of virulence, too. A good correlation (82%) was found between the colonization factor F107 and SLT 2/2v-containing strains from pigs in the region of Sachsen-Anhalt, too. Enterohemolysin was not found in SLT 2/2v-positive strains. 91% of the VTEC, isolated from pigs, produced alpha-Hemolysin. The correlation of SLT-containing strains and the production of enterohemolysin was confirmed for ruminants, only. Plasmidprofilings of VTEC from pigs showed mainly a 60 MDa or a 68 MDa plasmid or both, too. The occurrence of heat labile (LT) and in some cases of heat stable (ST) toxin was also checked, to differentiate the VTEC-strains from the enterotoxigenic E. coli strains (ETEC). These investigations showed, that VTEC produce SLT almost without exception. Correlations and conclusions on the pathogenicity for humans are discussed.

  2. Detection of extended-spectrum beta-lactamase-producing Escherichia coli isolates in faecal samples of Iberian lynx.

    PubMed

    Gonçalves, A; Igrejas, G; Radhouani, H; Estepa, V; Alcaide, E; Zorrilla, I; Serra, R; Torres, C; Poeta, P

    2012-01-01

    To characterize the diversity of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli isolates recovered within the faecal microbiota of Iberian lynx. The identification of other associated resistance genes and the analysis of clonal relationship were also focused in this study. From 2008 to 2010, 128 faecal samples of Iberian lynx (wild and captive animals) were collected. Eleven tested samples contained cefotaxime-resistant E. coli isolates (all belonging to captive animals) and 10 ESBL-producing isolates were showed. CTX-M-14 and SHV-12 ESBL-types were detected and seven different patterns were identified by pulsed-field gel electrophoresis analysis. The occurrence of unrelated multiresistant E. coli in faecal flora of captive specimens of Iberian lynx, including the presence of ESBLs, resistant genes in integrons and virulence determinants was showed in this study. The results obtained in this study highlight the environmental problem as future reintroductions of Iberian lynx could lead to a spread of resistant bacteria. Additionally, ESBL-producing bacteria can represent a health problem for this endangered species. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

  3. [Case of an elderly patient with community acquired bacterial meningitis due to extended spectrum β lactamase producing Escherichia coli].

    PubMed

    Gon, Yasufumi; Otsubo, Ryoichi; Murase, Syo; Park, Kwiyounn; Nakazawa, Kenichiro; Hara, Hitoshi

    2012-01-01

    Community acquired bacterial meningitis due to extended spectrum β lactamase-producing Escherichia coli is very rare. We report the case of a 72-year-old woman being treated for longstanding diabetes mellitus. She developed lower back pain accompanied by elevated body temperature, and was transported to the emergency unit in our hospital five days later because of impaired consciousness. An abdominal plane CT showed acute pyelonephritis and a brain MRI showed inflammatory exudate in the posterior horn of her bilateral ventricles. A lumbar puncture was performed, and examination of the cerebrospinal fluid revealed a marked elevation in her cell count (polymorphonuclear leukocytes dominant) that we diagnosed as bacterial meningitis. Initially, she was treated with intravenous meropenem, ceftriaxon, and vancomycin. Extended spectrum β lactamase-producing Escherichia coli were then detected in her urinary and blood cultures, and the antibiotics were changed to intravenous meropenem, gentamicin, and intrathecal gentamicin. Her clinical symptoms improved, but her inflammatory reaction was prolonged and we detected spondylitis. She was then treated with levofloxacin, and the inflammatory reaction improved. Extended spectrum β lactamase-producing Escherichia coli should be taken into consideration as a cause of community acquired bacterial meningitis.

  4. Molecular epidemiology of carbapenemase-producing Escherichia coli and the prevalence of ST131 subclone H30 in Shanghai, China.

    PubMed

    Zhang, F; Zhu, D; Xie, L; Guo, X; Ni, Y; Sun, J

    2015-06-01

    The molecular characteristics and epidemiology of carbapenemase-producing Escherichia coli (CPEC) isolates from Shanghai, China, were investigated using 21 imipenem-resistant E. coli isolates obtained from a Shanghai teaching hospital from 2011 to 2014. The presence of bla KPC, bla IMP, bla VIM, bla OXA-48, and bla NDM was assessed by polymerase chain reaction (PCR) amplification and sequencing. CPEC isolates were characterized by the Etest®, multilocus sequence typing (MLST), and pulse-field gel electrophoresis (PFGE). Plasmids carrying resistance genes were analyzed by conjugation experiments, replicon typing, plasmid MLST (pMLST), S1 nuclease PFGE (S1-PFGE), and Southern hybridization. The genetic environment of the resistance genes was determined by PCR and sequencing. Among the 21 E. coli isolates, 16 produced carbapenemases; of these, ten isolates transferred carbapenemase-encoding plasmids to recipient bacteria. Nine of the 16 isolates were clonally related, and their PFGE patterns were designated type A. ST131 was the predominant sequence type (11 isolates, 68.8 %); the H30 subclone comprised 81.8 % of the ST131 strains. In all three isolates, bla IMP-4 was located on 50-kb IncN plasmids. All but two bla KPC-2 genes were carried on IncF plasmids of various sizes. Hence, both clone-spread and horizontal transfer mediated the dissemination of carbapenemase-producing genes in the Shanghai isolates.

  5. A QMRA for the Transmission of ESBL-Producing Escherichia coli and Campylobacter from Poultry Farms to Humans Through Flies.

    PubMed

    Evers, Eric G; Blaak, Hetty; Hamidjaja, Raditijo A; de Jonge, Rob; Schets, Franciska M

    2016-02-01

    The public health significance of transmission of ESBL-producing Escherichia coli and Campylobacter from poultry farms to humans through flies was investigated using a worst-case risk model. Human exposure was modeled by the fraction of contaminated flies, the number of specific bacteria per fly, the number of flies leaving the poultry farm, and the number of positive poultry houses in the Netherlands. Simplified risk calculations for transmission through consumption of chicken fillet were used for comparison, in terms of the number of human exposures, the total human exposure, and, for Campylobacter only, the number of human cases of illness. Comparing estimates of the worst-case risk of transmission through flies with estimates of the real risk of chicken fillet consumption, the number of human exposures to ESBL-producing E. coli was higher for chicken fillet as compared with flies, but the total level of exposure was higher for flies. For Campylobacter, risk values were nearly consistently higher for transmission through flies than for chicken fillet consumption. This indicates that the public health risk of transmission of both ESBL-producing E. coli and Campylobacter to humans through flies might be of importance. It justifies further modeling of transmission through flies for which additional data (fly emigration, human exposure) are required. Similar analyses of other environmental transmission routes from poultry farms are suggested to precede further investigations into flies. © 2016 Society for Risk Analysis.

  6. Evaluation of a novel antimicrobial solution and its potential for control E. coli O157:H7, non-O157:H7 shiga toxin-producing E. coli, Salmononella spp., and Listeria monocytogenes on beef

    USDA-ARS?s Scientific Manuscript database

    The goal of this study was to evaluate the efficacy of a novel antimicrobial solution made with chitosan, lauric arginate ester, and organic acids on Escherichia coli O157:H7, Salmonella spp., Listeria monocytogenes, and non-O157 shiga toxin-producing E. coli cocktails and to test its potential to b...

  7. Verocytotoxin-producing Escherichia coli in chamois (Rupicapra rupicapra) and cattle in Austria.

    PubMed

    Freidl, Gudrun; Stalder, Gabrielle; Kostić, Tanja; Sessitsch, Angela; Beiglböck, Christoph; Walzer, Christian

    2011-07-01

    We assessed the prevalence of verotoxigenic Escherichia coli (VTEC) in chamois (Rupicapra rupicapra) and livestock grazing on a mountain pasture in Austria during June-August 2009. We detected VTEC throughout the sampling period in high numbers in cattle as well as in chamois, leading to the assumption that the degree of contamination of the environment is high. This is the first report of pathogenic E. coli identified in chamois, implicating chamois as a new potential reservoir of these zoonotic pathogens. Because the study area also serves recreational purposes, there is a risk of humans acquiring infection via direct or indirect contact.

  8. Emergence of an NDM-5-producing clinical Escherichia coli isolate in Egypt.

    PubMed

    Soliman, Ahmed M; Khalifa, Hazim O; Ahmed, Ashraf M; Shimamoto, Toshi; Shimamoto, Tadashi

    2016-07-01

    The first occurrence of New Delhi metallo-β-lactamase 5 (NDM-5), carried on an IncI1-Iγ-type plasmid of >93kb in a multidrug-resistant Escherichia coli strain in Kafr El-Sheikh, Egypt, is reported. The strain was isolated from a wound pus swab from a patient diagnosed with a fracture of the right femur. This E. coli strain was found to belong to sequence type (ST) 5018 and also to carry other resistance genes, including blaCTX-M-15, blaCMY-42, blaOXA-1, and aac(6')-Ib-cr.

  9. Antimicrobial Resistance and Molecular Epidemiology of ESBL-Producing Escherichia coli Isolated from Outpatients in Town Hospitals of Shandong Province, China.

    PubMed

    Miao, Zengmin; Li, Song; Wang, Lei; Song, Wengang; Zhou, Yufa

    2017-01-01

    This study aimed to investigate antimicrobial resistance and molecular epidemiology of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) isolated from outpatients in town hospitals of Shandong province, China. Antimicrobial susceptibility of ESBL-producing E. coli was tested using the disk diffusion and resistance genes encoding for β-lactamases (blaTEM, blaCTXM, and blaSHV) were detected by polymerase chain reaction (PCR). Multilocus sequence typing (ST) of ESBL-producing E. coli was analyzed in this study. Our results showed that of 320 E. coli isolates, 201 carried ESBL genes (201/320, 62.8%), and these isolates all carried blaCTX-M genes, the most common being blaCTX-M-14 (116/201, 57.7%), followed by blaCTX-M-55 (47/201, 23.4%) and blaCTX-M-15 (31/201, 15.4%). ESBL-producing E. coli exhibited highly resistant to penicillin derivatives, fluoroquinolones, folate pathway inhibitors, and third-generation cephalosporins, but no carbapenem-resistant isolates were found in this study. Forty-two STs were found among the 201 ESBL-producing E. coli, and the most common ST was ST131 (27/201, 13.4%), followed by ST405 (19/201, 9.5%) and ST69 (15/201, 7.5%). Taken together, a high isolation rate of ESBL-producing E. coli (62.8%) was found among outpatients in town hospitals. blaCTX-M gene was most dominant and was composed of a variety of subtypes. No dominant ST was detected among ESBL-producing E. coli, indicating that these ESBL-producing E. coli isolates derive from different clones.

  10. Antimicrobial Resistance and Molecular Epidemiology of ESBL-Producing Escherichia coli Isolated from Outpatients in Town Hospitals of Shandong Province, China

    PubMed Central

    Miao, Zengmin; Li, Song; Wang, Lei; Song, Wengang; Zhou, Yufa

    2017-01-01

    This study aimed to investigate antimicrobial resistance and molecular epidemiology of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) isolated from outpatients in town hospitals of Shandong province, China. Antimicrobial susceptibility of ESBL-producing E. coli was tested using the disk diffusion and resistance genes encoding for β-lactamases (blaTEM, blaCTXM, and blaSHV) were detected by polymerase chain reaction (PCR). Multilocus sequence typing (ST) of ESBL-producing E. coli was analyzed in this study. Our results showed that of 320 E. coli isolates, 201 carried ESBL genes (201/320, 62.8%), and these isolates all carried blaCTX-M genes, the most common being blaCTX-M-14 (116/201, 57.7%), followed by blaCTX-M-55 (47/201, 23.4%) and blaCTX-M-15 (31/201, 15.4%). ESBL-producing E. coli exhibited highly resistant to penicillin derivatives, fluoroquinolones, folate pathway inhibitors, and third-generation cephalosporins, but no carbapenem-resistant isolates were found in this study. Forty-two STs were found among the 201 ESBL-producing E. coli, and the most common ST was ST131 (27/201, 13.4%), followed by ST405 (19/201, 9.5%) and ST69 (15/201, 7.5%). Taken together, a high isolation rate of ESBL-producing E. coli (62.8%) was found among outpatients in town hospitals. blaCTX-M gene was most dominant and was composed of a variety of subtypes. No dominant ST was detected among ESBL-producing E. coli, indicating that these ESBL-producing E. coli isolates derive from different clones. PMID:28174570

  11. Non-O157 Shiga toxin-producing Escherichia coli in U. S. retail ground beef.

    PubMed

    Liao, Yen-Te; Miller, Markus F; Loneragan, Guy H; Brooks, J Chance; Echeverry, Alejandro; Brashears, Mindy M

    2014-07-01

    Shiga toxin-producing Escherichia coli (STEC) serotype O157:H7 and serogroups O26, O45, O103, O111, O121, and O145 are the leading cause of STEC-associated infections in humans in the United States. In the United States, these organisms are considered adulterants in raw nonintact beef products and in intact beef destined to be made into or used in nonintact raw beef products. The objective of this study was to provide an estimate of the burden of the six serogroups of non-O157 STEC in ground beef obtained from retail stores across the United States. A convenience sample of commercial ground beef products (n = 1,129) were purchased from retail stores in 24 states from October 2011 to May 2012. The samples had various lean/fat proportions, muscle group of origin (chuck, round, sirloin, or not specified), and packaging types. For each ground beef sample, 25 g was inoculated in 225 ml of modified tryptic soy broth, stomached for 1 min, and then incubated at 41°C for 18 ± 2 h. These enrichment cultures were then screened for stx, eae, and O group genes using a commercially available, closed-platform PCR-based method. The potential positive samples were subjected to immunomagnetic separation and plated on modified Rainbow agar. Morphologically typical colonies were subjected to latex agglutination and PCR determination of stx and eae genes. Nine (0.8%) of the ground beef samples were potentially positive for at least one STEC serogroup after PCR screening. The serogroups detected by PCR assay were O26 (four samples), O103 (four samples), O145 (three samples), O45 (two samples), and O121 (one sample). No STEC isolates belonging to these serogroups were recovered from the sample cultures. The current research provides updated surveillance data for non-O157 STEC isolates among commercial ground beef products and information regarding the potential sources of contamination from different parts of beef trims destined for ground beef production.

  12. Epidemiology of Shiga toxin producing Escherichia coli in Australia, 2000-2010

    PubMed Central

    2012-01-01

    Background Shiga toxin-producing Escherichia coli (STEC) are an important cause of gastroenteritis in Australia and worldwide and can also result in serious sequelae such as haemolytic uraemic syndrome (HUS). In this paper we describe the epidemiology of STEC in Australia using the latest available data. Methods National and state notifications data, as well as data on serotypes, hospitalizations, mortality and outbreaks were examined. Results For the 11 year period 2000 to 2010, the overall annual Australian rate of all notified STEC illness was 0.4 cases per 100,000 per year. In total, there were 822 STEC infections notified in Australia over this period, with a low of 1 notification in the Australian Capital Territory (corresponding to a rate of 0.03 cases per 100,000/year) and a high of 413 notifications in South Australia (corresponding to a rate of 2.4 cases per 100,000/year), the state with the most comprehensive surveillance for STEC infection in the country. Nationally, 71.2% (504/708) of STEC infections underwent serotype testing between 2001 and 2009, and of these, 58.0% (225/388) were found to be O157 strains, with O111 (13.7%) and O26 (11.1%) strains also commonly associated with STEC infections. The notification rate for STEC O157 infections Australia wide between 2001-2009 was 0.12 cases per 100,000 per year. Over the same 9 year period there were 11 outbreaks caused by STEC, with these outbreaks generally being small in size and caused by a variety of serogroups. The overall annual rate of notified HUS in Australia between 2000 and 2010 was 0.07 cases per 100,000 per year. Both STEC infections and HUS cases showed a similar seasonal distribution, with a larger proportion of reported cases occurring in the summer months of December to February. Conclusions STEC infections in Australia have remained fairly steady over the past 11 years. Overall, the incidence and burden of disease due to STEC and HUS in Australia appears comparable or lower than

  13. Factors Associated with Shiga Toxin-Producing Escherichia coli Shedding by Dairy and Beef Cattle

    PubMed Central

    Venegas-Vargas, Cristina; Henderson, Scott; Khare, Akanksha; Mosci, Rebekah E.; Lehnert, Jonathan D.; Singh, Pallavi; Ouellette, Lindsey M.; Norby, Bo; Funk, Julie A.; Rust, Steven; Bartlett, Paul C.; Grooms, Daniel

    2016-01-01

    ABSTRACT Shiga toxin-producing Escherichia coli (STEC) is an important foodborne pathogen that can cause hemorrhagic colitis and hemolytic-uremic syndrome. Cattle are the primary reservoir for STEC, and food or water contaminated with cattle feces is the most common source of infections in humans. Consequently, we conducted a cross-sectional study of 1,096 cattle in six dairy herds (n = 718 animals) and five beef herds (n = 378 animals) in the summers of 2011 and 2012 to identify epidemiological factors associated with shedding. Fecal samples were obtained from each animal and cultured for STEC. Multivariate analyses were performed to identify risk factors associated with STEC positivity. The prevalence of STEC was higher in beef cattle (21%) than dairy cattle (13%) (odds ratio [OR], 1.76; 95% confidence interval [CI], 1.25, 2.47), with considerable variation occurring across herds (range, 6% to 54%). Dairy cattle were significantly more likely to shed STEC when the average temperature was >28.9°C 1 to 5 days prior to sampling (OR, 2.5; 95% CI, 1.25, 4.91), during their first lactation (OR, 1.8; 95% CI, 1.1, 2.8), and when they were <30 days in milk (OR, 3.9; 95% CI, 2.1, 7.2). These data suggest that the stress or the negative energy balance associated with lactation may result in increased STEC shedding frequencies in Michigan during the warm summer months. Future prevention strategies aimed at reducing stress during lactation or isolating high-risk animals could be implemented to reduce herd-level shedding levels and avoid transmission of STEC to susceptible animals and people. IMPORTANCE STEC shedding frequencies vary considerably across cattle herds in Michigan, and the shedding frequency of strains belonging to non-O157 serotypes far exceeds the shedding frequency of O157 strains, which is congruent with human infections in the state. Dairy cattle sampled at higher temperatures, in their first lactation, and early in the milk production stage were

  14. An epidemiological and environmental study of Shiga toxin-producing Escherichia coli in India.

    PubMed

    Kumar, Ajay; Taneja, Neelam; Sharma, Meera

    2014-06-01

    Shiga toxin-