15 research outputs found

    Antifungal susceptibilities, varieties, and electrophoretic karyotypes of clinical isolates of Cryptococcus neoformans from Brazil, Chile, and Venezuela

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    One hundred clinical isolates of Cryptococcus neoformans from human immunodeficiency virus (HIV)-infected and non-HIV-infected patients from Brazil, Chile, and Venezuela were separated according to varieties and tested for antifungal susceptibility. A high susceptibility to antifungal agents was observed among all the isolates. The electrophoretic karyotyping of 51 strains revealed good discrimination among Cryptococcus neoformans var. neoformans strains.3962348235

    Euclid preparation: LIX. Angular power spectra from discrete observations

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    In this paper we present the framework for measuring angular power spectra in the Euclid mission. The observables in galaxy surveys, such as galaxy clustering and cosmic shear, are not continuous fields, but discrete sets of data, obtained only at the positions of galaxies. We show how to compute the angular power spectra of such discrete data sets, without treating observations as maps of an underlying continuous field that is overlaid with a noise component. This formalism allows us to compute the exact theoretical expectations for our measured spectra, under a number of assumptions that we track explicitly. In particular, we obtain exact expressions for the additive biases (‘shot noise’) in angular galaxy clustering and cosmic shear. For efficient practical computations, we introduce a spin-weighted spherical convolution with a well-defined convolution theorem, which allows us to apply exact theoretical predictions to finite-resolution maps, including HEALPix. When validating our methodology, we find that our measurements are biased by less than 1% of their statistical uncertainty in simulations of Euclid’s first data release

    <em>Euclid </em>preparation LXXIII. Spatially resolved stellar populations of local galaxies with <em>Euclid</em>: A proof of concept using synthetic images with the TNG50 simulation

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    \ua9 The Authors 2025.The European Space Agency’s Euclid mission will observe approximately 14 000 deg2 of the extragalactic sky and deliver high-quality imaging of a large number of galaxies. The depth and high spatial resolution of the data will enable a detailed analysis of the stellar population properties of local galaxies through spatially resolved spectral energy distribution (SED) fitting. In this study, we test our pipeline for spatially resolved SED fitting using synthetic images of Euclid, LSST, and GALEX generated from the TNG50 simulation using the SKIRT 3D radiative transfer code. Our pipeline uses functionalities in piXedfit for processing the simulated data cubes and carrying out SED fitting. We apply our pipeline to 25 simulated galaxies at z ∼ 0 to recover their resolved stellar population properties. For each galaxy, we produce three types of data cubes: GALEX + LSST + Euclid, LSST + Euclid, and Euclid-only. We performed the SED fitting tests with two stellar population synthesis (SPS) models in a Bayesian framework. Because the age, metallicity (Z), and dust attenuation estimates are biased when applying only classical formulations of flat priors (even with the combined GALEX + LSST + Euclid data), we examined the effects of additional physically motivated priors in the forms of mass-age and mass-metallicity relations, constructed using a combination of empirical and simulated data. Stellar-mass surface densities can be recovered well using any of the three data cubes, regardless of the SPS model and prior variations. The new priors then significantly improve the measurements of mass-weighted age and Z compared to results obtained without priors, but they may play an excessive role compared to the data in determining the outcome when no ultraviolet (UV) data is available. Compared to varying the spectral extent of the data cube or including and discarding the additional priors, replacing one SPS model family with the other has little effect on the results. The spatially resolved SED fitting method is powerful for mapping the stellar population properties of many galaxies with the current abundance of high-quality imaging data. Our study re-emphasizes the gain added by including multi-wavelength data from ancillary surveys and the roles of priors in Bayesian SED fitting. With the Euclid data alone, we will be able to generate complete and deep stellar mass maps of galaxies in the local Universe (z . 0.1), exploiting the telescope’s wide field, near-infrared sensitivity, and high spatial resolution

    Molecular epidemiology of systemic infection caused by Enterobacter cloacae in a high-risk neonatal intensive care unit

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    OBJECTIVE: To investigate the molecular epidemiology of systemic nosocomial infections caused by Enterobacter cloacae. SETTING: Neonatal intensive care unit (NICU) of a tertiary-care university hospital. PATIENTS: Forty-two high-risk neonates with systemic infections caused by E. cloacae. METHODS: From 1995 to 1997, the variables associated with death in these patients were evaluated. The molecular epidemiology of the strains responsible for the systemic infections, and 14 unrelated strains, was studied using plasmid analysis and pulsed-field gel electrophoresis (PFGE). RESULTS: The overall mortality rate for infection caused by E. cloacae was 34%, whereas the crude mortality rate during the study period was 8.12% (P < .001). Gestational age (preterm neonates) and birth weight (small for gestational age) were not associated with a higher risk of death. Insertion of a venous catheter by dissection of a peripheral vein was the only invasive procedure related to death (P = .016) in this study, A molecular analysis showed that three outbreaks, each occurring in a different year, were caused by strains with distinctive DNA profiles. Only one outbreak was identified by the infection control service, in the NICU. Plasmid analysis and PFGE showed similar ability to discriminate control strains from the E. cloacae strains isolated from the neonates. CONCLUSIONS: Systemic infections caused by E. cloacae in our NICU were associated with a high mortality rate and occurred as small, unrecognized outbreaks. These results may not be generalizable because the data were from a single center.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.24749049

    The internal transcribed spacers and 5.8S rRNA gene show extensive diversity among isolates of the Cryptococcus neoformans species complex

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    Sequences of the internal transcribed spacer (ITS) region including the 5.8S rRNA gene delineated seven genotypes within the three varieties of Cryptococcus neoformans via specific combinations of eight nucleotide differences located at positions 10, 11, 15, 19, 108 (ITS1), 221 (5.8S), 298 and 346 (ITS2). The ITS types correlated to polymerase chain reaction fingerprint/random amplification of polymorphic DNA (RAPD) molecular types: with ITS type 1 (ATACTAGC) = C neoformans var. grubii, molecular types VNI+VNII and the serotype A allele of the AD hybrid, VNIIIA; ITS type 2 (ATATAGGC) = the serotype D allele of the AD hybrid, VNIIIB, and C neoformans var. neoformans, VNIV; and ITS type 3 (GCGCTGGC) and ITS type 7 (ACGCTGGC) = VGI = RAPID type 111, ITS type 4 (ACACTGAC) = VGII = RAPD type II, ITS type 5: (ACACTGGG) = VGIII = RAPD type 1, ITS type 6 (ACACTGGC) = VGIV = RAPD type IV, all corresponding to C. neoformans var. gattii. Cloned sequences from serotype AD revealed that the hybrid serotype is diploid at the ITS1-5.8S-ITS2 locus carrying the ITS type I (ATACTAGC) and the ITS type 2 (ATATAGGC) alleles. ITS sequencing is a useful technique for genotyping the three C. neoformans varieties and for subtyping within C neoformans var. gattii. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.44176337738

    First isolation of Candida dubliniensis in Rio grande do sul, Brazil

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    Candida dubliniensis is a newly recognized species closely phylogenetically related to Candida albicans and is commonly associated with oral candidiasis in human immunodeficiency virus-positive patients. In this paper we report the isolation of three strains of C. dubliniensis, from AIDS patients, in the state of Rio Grande do Sul (Brazil). The phenotypic identification was based on germ tube emission, abundant production of chlamydospores, assimilation of sucrose but not of xylose and the inability to grow at 42 degreesC. Randomly amplified polymorphic DNA (RAPD) analysis and genomic DNA sequencing confirmed the distinct genetic nature C. dubliniensis. Topics related to the epidemiology, isolation, phenotypical and genotypical identification of C, dubliniensis are also discussed. (C) 2001 Elsevier Science Inc. All rights reserved.39316516

    Bacterial Meningitis In The Elderly: An 8-year Review Of Cases In A University Hospital.

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    The clinical and laboratory characteristics of bacterial meningitis in subjects over 59 years-old were evaluated to establish variables related to prognosis. All patients with clinical and laboratory findings of acute meningitis were included. Sixty-four episodes in 64 patients were registered. S. pneumoniae was responsible for 19 cases (27.5%); L. monocytogenes - 3; S. aureus - 1; S. bovis - 1; S. agalactie - 1 and Corynebacterium jeikeium 1. Gram negative bacilli caused seven cases; two cases were due to N. meningitidis and one to H. influenzae. In 50% of the cases no microorganisms were isolated. The main symptom was fever (67.8%). Headache and neck rigidity were absent in about one-half of the cases and the predominant symptoms were psychomotor agitation, stupor or coma. The presence of concomitant diseases, such as diabetes mellitus (26.6%) and pneumonia (17.2%), were common. The mortality was high (51.5%). This poor prognosis was related to L.monocytogenes (100%), Gram negatives rods (83%) andS.pneumoniae (58%). The univariate analysis showed that absence of headache (p=0.002), presence of coma (p=0.04), pneumonia (p=0.01) and immunocompromised status (p=0.01) were associated with risk of death. The type of the microorganisms isolated in the elderly patients with meningitis were often unusual ones. The clinical symptoms were minimal and in many cases, the only clinical presentation was change in mental status. Poor prognosis was observed in spite of intensive care. A high index of suspicion for meningitis while caring for elderly with changes in mental status must be maintained to avoid delays in initiating appropriate therapy.3111-11

    Trichosporon species infection in bone marrow transplanted patients

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    Trichosporon species are emerging as opportunistic agents that cause systemic diseases in immunocompromised patients. Patients undergoing bone marrow transplant are submitted to intense and prolonged periods of neutropenia and consequently to several risk factors to fungal infections as the use of broad spectrum antibiotics and invsive devices. Two cases of fungal infecitons caused by Trichosporon asahii var, asahii and T. inkin in patients with bone marrow transplant are described T. asahii var, asahii was responsible for fungemia and the identification of this microorganism was later performed. T. inkin caused vascular accesses infection and was recovered from an implanted Hickman-Broviac catheter. Both patients were under oral fluconazole prophylaxis. The patient with systemic infection died despite the therapy with amphotericin B and the patient with catheter-related infection recovered from the fungal infection after catheter removal. Difficulties in the identification of this microorganism lead to delays in treatment and post-mortem diagnosis. (C) 2001 Elsevier Science Inc. All rights reserved.39316116

    Pichia anomala outbreak in a nursery: exogenous source?

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    Background. Pichia anomala is a rare cause of fungemia. From February to April, 1998, eight cases of fungemia occurred in the intensive care and high risk units of the Nursery. There were four infants with P. anomala infection, one of whom also had Candida parapsilosis infection, two cases with C. parapsilosis infection and two with Candida albicans infection. Objective. To determine factors associated with fungemia in the intensive care and high risk units of the Nursery, especially P. anomala. Methods. A cohort study with 59 newborns. Results. Factors associated with fungemia were: central venous catheter (CVC) (P = 0.0006); total parenteral nutrition (TPN) (P = 0.0005); lipid emulsion (P = 0.002); previous antimicrobial use (P = 0.002); and other invasive procedures (P = 0.002). Factors associated with P. anomala fungemia were: CVC (P = 0.004); TPN (P = 0.018); previous antibiotic use (P = 0.037); and other invasive procedures (P = 0.037). Evaluation of the units demonstrated that there were several technical problems involving administration of TPN that was manipulated in the Nursery without precautions. Changes in TPN formulation and education as to adequate technique were implemented. During follow-up (1998 to 1999) only two fungemias occurred that were caused by C. albicans. Cultures of hands of personnel were negative for P. anomala. Electrophoretic karyotyping of P. anomala showed three profiles. Conclusions. Factors associated with fungemia were catheter use, invasive procedures and total parenteral nutrition, suggesting that the acquisition of P. anomala was exogenous.20984384
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