54 research outputs found

    Virulence genes and intimin types of Shiga-toxin-producing Escherichia coli isolated from cattle and beef products in Argentina

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    A total of 153 Shiga-toxin-producing Escherichia coli (STEC) isolates from feces of cattle and beef products (hamburgers and ground beef) in Argentina were characterized in this study. PCR showed that 22 (14%) isolates carried stx1 genes, 113 (74%) possessed stx2 genes and 18 (12%) both stx1 and stx2. Intimin (eae), enterohemolysin (ehxA), and STEC autoagglutinating adhesin (saa) virulence genes were detected in 36 (24%), 70 (46%) and in 34 (22%) of the isolates, respectively. None of 34 saa-positive isolates carried the gene eae, and 31 were ehxA-positive. Fourteen (7 of serotype O26:H11 and 4 of serotype O5:H-) isolates had intimin ÎČ1, 16 isolates possessed intimin Îł1 (11 of serotype O145:Hand 5 of serotype O157:H7), 5 isolates had intimin type Δ1 (4 of serotypes O103:Hand O103:H2), and one isolate O111:H- showed intimin type Ξ/Îł2. Although the 153 STEC isolates belonged to 63 different seropathotypes, only 12 accounted for 58% of isolates. Seropathotype ONT:H- stx2 (18 isolates) was the most common, followed by O171:H2 stx2 (12 isolates), etc. The majority (84%) of STEC isolates belonged to serotypes previously found in human STEC and 56% to serotypes associated with STEC isolated from patients with hemolytic uremic syndrome (HUS). Thus, this study confirms that cattle are a major reservoir of STEC pathogenic for humans. To our knowledge, this is the first study that described the presence of saa gene in STEC of serotypes O20:H19, O39:H49, O74:H28, O79:H19, O116:H21, O120:H19, O141:H7, O141:H8, O174:H21, and ONT:H21. The serotypes O120:H19 and O185:H7 were not previously reported in bovine STEC. [Int Microbiol 2004; 7(4):269-276

    Measurement of forward charged hadron flow harmonics in peripheral PbPb collisions at √sNN = 5.02 TeV with the LHCb detector

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    Flow harmonic coefficients, v n , which are the key to studying the hydrodynamics of the quark-gluon plasma (QGP) created in heavy-ion collisions, have been measured in various collision systems and kinematic regions and using various particle species. The study of flow harmonics in a wide pseudorapidity range is particularly valuable to understand the temperature dependence of the shear viscosity to entropy density ratio of the QGP. This paper presents the first LHCb results of the second- and the third-order flow harmonic coefficients of charged hadrons as a function of transverse momentum in the forward region, corresponding to pseudorapidities between 2.0 and 4.9, using the data collected from PbPb collisions in 2018 at a center-of-mass energy of 5.02 TeV . The coefficients measured using the two-particle angular correlation analysis method are smaller than the central-pseudorapidity measurements at ALICE and ATLAS from the same collision system but share similar features

    Helium identification with LHCb

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    The identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using pp collision data at √(s) = 13 TeV recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5 fb-1. A total of around 105 helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50% with a corresponding background rejection rate of up to O(10^12). These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei

    Curvature-bias corrections using a pseudomass method

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    Momentum measurements for very high momentum charged particles, such as muons from electroweak vector boson decays, are particularly susceptible to charge-dependent curvature biases that arise from misalignments of tracking detectors. Low momentum charged particles used in alignment procedures have limited sensitivity to coherent displacements of such detectors, and therefore are unable to fully constrain these misalignments to the precision necessary for studies of electroweak physics. Additional approaches are therefore required to understand and correct for these effects. In this paper the curvature biases present at the LHCb detector are studied using the pseudomass method in proton-proton collision data recorded at centre of mass energy √(s)=13 TeV during 2016, 2017 and 2018. The biases are determined using Z→Ό + ÎŒ - decays in intervals defined by the data-taking period, magnet polarity and muon direction. Correcting for these biases, which are typically at the 10-4 GeV-1 level, improves the Z→Ό + ÎŒ - mass resolution by roughly 18% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass

    A regulação em saĂșde no Brasil: um breve exame das dĂ©cadas de 1999 a 2008 Health regulation in Brazil: a brief survey of the decade from 1999 to 2008

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    Este artigo discute a experiĂȘncia brasileira de regulação em saĂșde no perĂ­odo de 1999 a 2008. Buscou-se compreender as interfaces do processo de regulação em saĂșde no Brasil, sobretudo com o setor farmacĂȘutico, identificando, historicamente, os atores e contextos referentes a esse processo. A pesquisa baseou-se na revisĂŁo bibliogrĂĄfica e no levantamento das resoluçÔes da diretoria colegiada da AgĂȘncia Nacional de VigilĂąncia SanitĂĄria. Esse levantamento permitiu identificar a concentração dessas resoluçÔes nas subĂĄreas: medicamentos, recursos humanos e alimentos. No tocante Ă  subĂĄrea medicamentos, a concentração se deu em trĂȘs descritores: registro de medicamentos, boas prĂĄticas e substĂąncias sujeitas a controle especial. AlĂ©m de fazer uma sĂ­ntese histĂłrica da evolução da vigilĂąncia sanitĂĄria brasileira, o artigo focalizou os aspectos regulatĂłrios da AgĂȘncia Nacional de VigilĂąncia SanitĂĄria e sua relação com a indĂșstria farmacĂȘutica. Portanto, o texto pautou-se pela pretensĂŁo de dar resposta Ă  seguinte questĂŁo: serĂĄ que a experiĂȘncia de regulação da AgĂȘncia Nacional de VigilĂąncia SanitĂĄria estĂĄ apta a enfrentar o cenĂĄrio adverso gerado pela nova crise mundial, especialmente no que se refere ao setor farmacĂȘutico? A principal conclusĂŁo do trabalho Ă© de que, apesar dos muitos desafios a serem superados pela AgĂȘncia Nacional de VigilĂąncia SanitĂĄria no Brasil contemporĂąneo, a experiĂȘncia de regulação avançou bastante nesta dĂ©cada. Uma conclusĂŁo adicional Ă© que esses avanços constituĂ­ram, para o setor farmacĂȘutico, uma proteção face ao quadro adverso gerado pela crise mundial.<br>This paper discusses the Brazilian experience of health regulation from 1999 to 2008. It aims to understand the interfaces of the regulatory process in health in Brazil, particularly the pharmaceutical industry, seeking to identify, historically, the actors and contexts relating to the proceedings. The research was based on literature review and survey of the resolutions of the Board of the National Health Surveillance Agency. This survey identified the concentration of these resolutions in the following areas: drugs, human resources and food. Regarding drugs, emphasis was placed in three key words: drug registration, practices and substances subject to special control. In addition to a brief history of the evolution of Brazilian health surveillance, this paper focused on the regulatory aspects of the National Health Surveillance Agency and its relationship with the pharmaceutical industry. Therefore, the text was guided by the desire to answer the following question: is the experience of regulation of the National Health Surveillance Agency able to cope with the adverse scenario created by the world crisis, especially with regard to the pharmaceutical industry? The main conclusion of this study is that despite the many challenges to be overcome by the National Sanitary Surveillance Agency in Brazil today, the experience of regulation has made good progress in this decade. A further finding is that these developments were, for the pharmaceutical industry, a protection against the adverse situation created by the global crisis

    Differentiation of pathogenic and non-pathogenic leptospires by means of the polymerase chain reaction

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    A polymerase chain reaction was carried out to detect pathogenic leptospires isolated from animals and humans in Argentina. A double set of primers (G1/G2, B64-I/B64-II), described before, were used to amplify by PCR a DNA fragment from serogroups belonging to Leptospira interrogans but did not allow to detect saprophytic strains isolated from soil and water (L. biflexa). This fact represents an advantage since it makes possible the differentiation of pathogenic from non-pathogenic leptospires in cultures. The sensitivity of this assay has been determined, allowing to detect just only 10 leptospires in the reaction tube. Those sets of primers generated either a 285 bp or 360 bp fragment, depending on the pathogenic strain<br>Diferenciação das leptospiras patogĂȘnicas e nĂŁo patogĂȘnicas por PCR Utilizou-se a reação em cadeia da polimerase (PCR) para identificar leptospiras patogĂȘnicas isoladas, na Argentina, de animais e do homem. Foram usados dois pares de primers (G1/G2; B64-I/B64-II), descritos anteriormente como apropriados para amplificar amostras pertencentes aos diferentes sorogrupos de Leptospira interrogans. AtravĂ©s deste mĂ©todo nĂŁo se detectaram as leptospiras saprĂłfitas (L. biflexa) isolados de ĂĄgua e solo. Este fato representa uma vantagem uma vez que possibilita a diferenciação de leptospiras patogĂȘnicas das nĂŁo patogĂȘnicas em culturas. A sensibilidade da prova foi determinada, verificando-se que ela permitiu detectar 10 leptospiras por tubo de reação. Os tamanhos dos fragmentos amplificados foram de 285 ou 360 pares de bases (bp), dependendo da amostra patogĂȘnica estudad

    Search for the suppressed decays B<sup>+</sup> → K<sup>+</sup>K<sup>+</sup>π<sup>−</sup> and B<sup>+</sup> → π<sup>+</sup>π<sup>+</sup>K<sup>−</sup>

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