197 research outputs found

    Comparative Study of Different Diagnostic Routine Methods for the Identification of Acinetobacter radioresistens

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    Recent publications indicate that A. radioresistens can cause infections in humans, even though it is rarely reported in routine diagnostics. However, the fact that it is infrequently detected may be explained by the misidentification of the species by conventional methods. It is also likely that A. radioresistens is not considered clinically relevant and therefore not consistently included in diagnostic results. To elucidate the medical significance of this probably clinically underestimated bacterial species, we created a well-documented reference strain collection of 21 strains collected in routine diagnostics. For further analysis of A. radioresistens, it is essential to know which methods can be used to achieve a trustworthy identification. We, therefore, compared three methods widely used in routine diagnostics (MALDI-TOF MS, VITEK 2, and sequencing of housekeeping genes) in terms of secure and reliable identification of A. radioresistens. As reference methods, whole genome-based approaches were applied. VITEK 2 led to misidentification for four strains. However, MALDI-TOF MS and sequencing of housekeeping genes led to reliable and robust identifications

    Erratum to : Study of ϒ production in pPb collisions at sNN−−−√= 8.16 TeV

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    jz Vibrational spectroscopic studies and DFT calculations on NaCH₃CO₂(aq) and CH₃COOH(aq)

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    Aqueous solutions of sodium acetate, NaCH₃CO₂, and acetic acid, CH₃COOH, were studied using Raman and infrared spectroscopy. The spectra were recorded over a large concentration range, in the terahertz region and up to 4000 cmˉ¹. In the isotropic Raman spectrum in R-format, a polarized band at 189 cmˉ¹ was assigned to the υ₁Na–O stretch of the hydrated Na⁺-ion and a shoulder at 245 cmˉ¹ to the restricted translation band, υsO–H⋯O* of the hydrated acetate ion, CH₃CO₂ˉ(aq). The CH₃CO₂ˉ(aq) and the hydrated acetic acid, CH₃COOH(aq), possess pseudo Cs symmetry. Geometrical parameters for the species in the gas phase and for CH₃CO₂ˉ(aq) and CH₃COOH(aq) are reported. Characteristic bands for CH₃CO2ˉ(aq) and CH₃COOH(aq) were assigned under the guidance of the DFT vibrational frequency calculations and discussed in detail. In aqueous NaCH₃CO₂ solutions, at high concentrations, no contact ion pairs could be detected, but instead solvent separated ion pairs were found. In LiCH₃CO₂(aq), however, contact ion pairs are formed which is indicated by the appearance of a shoulder at 939 cmˉ¹ and the shift of the symmetric stretching mode of the –CO₂ˉ group to higher wavenumbers

    Hydration and ion pair formation in common aqueous La(III) salt solutions: a Raman scattering and DFT study

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    Raman spectra of aqueous lanthanum perchlorate, triflate (trifluorosulfonate), chloride and nitrate solutions were measured over a broad concentration (0.121–3.050 mol Lˉ¹) range at room temperature (23 °C). A very weak mode at 343 cmˉ¹ with a full width at half height at 49 cmˉ¹ in the isotropic spectrum suggests that the nona-aqua La(III) ion is thermodynamically stable in dilute perchlorate solutions (∼0.2 mol Lˉ¹) while in concentrated perchlorate solutions outer-sphere ion pairs and contact ion pairs are formed. The La³⁺ nona-hydrate was also detected in a 1.2 mol Lˉ¹ La(CF₃SO₃)₃(aq). In lanthanum chloride solutions chloro-complex formation was detected over the measured concentration range from 0.5–3.050 mol Lˉ¹. The chloro-complexes in LaCl₃(aq) are fairly weak and disappear with dilution. At a concentration <0.1 mol Lˉ¹ almost all complexes disappeared. In LaCl₃ solutions, with additional HCl, a series of chloro-complexes of the type [La(OH₂)₉₋nCln]⁺³⁻ⁿ (n = 1–3) were formed. The La(NO₃)₃(aq) spectra were compared with a spectrum of a 0.409 mol Lˉ¹ NaNO₃(aq) and it was concluded that in La(NO₃)₃(aq) over the concentration range from 0.121–1.844 mol Lˉ¹, nitrato-complexes, [La(OH₂)₉₋n-(NO₃)n]⁺³⁻ⁿ (n = 1, 2) were formed. These nitrato-complexes are quite weak and disappear with dilution <0.01 mol Lˉ¹. DFT geometry optimizations and frequency calculations are reported for a lanthanumnona-hydrate with a polarizable dielectric continuum in order to take the solvent into account. The bond distances and angles for the cluster geometry of [La(OH₂)₉]³⁺ with the polarizable dielectric continuum are in good agreement with data from recent structural experimental measurements and high quality simulations. The DFT frequency of the La–O stretching mode at 328.2 cmˉ¹, is only slightly smaller than the experimental one

    Whole-genome sequencing of a large collection of Myroides odoratimimus and Myroides odoratus isolates and antimicrobial susceptibility studies

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    The genus Myroides comprises several species of Gram-negative, non-motile, and non-fermenting bacteria, which have been regarded as non-pathogenic for decades. Multiple recent reports, however, underscore the pathogenic potential that Myroides sp. possesses for humans. These bacteria seem to be resistant to a wide range of antibiotics (including ß-lactams and aminoglycosides). Therefore, treatment options are limited. Knowledge of antimicrobial resistance, however, is based on only one meaningful comprehensive study and on data published from case reports. This lack of data motivated us to test 59 strains from our Myroides collection (43 M. odoratimimus and 16 M. odoratus) for resistance against 20 commonly used antibiotics. We also performed molecular analyses to reveal whether our bacteria harbor the genus-specific M. odoratimimus metallo-ß-lactamase (MUS-1) or the M. odoratus metallo ß-lactamase (TUS-1), and other ß-lactamases, which may provide an explanation for the extended antimicrobial resistance

    Erratum to : Study of ϒ production in pPb collisions at sNN−−−√= 8.16 TeV

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    Identification of six new susceptibility loci for invasive epithelial ovarian cancer.

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    First report on the isolation of Aureimonas altamirensis from a patient with peritonitis

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    The isolation of Aureimonas altamirensis (a rare opportunistic pathogen with a yet unresolved pathogenicity) from the ascites fluid of a patient with bacterial peritonitis is reported. The strain was first identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and the result was confirmed using 16S rDNA sequencing. An antimicrobial susceptibility profile was determined according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines published in 2013, revealing sensitivity to all antibiotics tested. The patient was treated effectively with levofloxacin
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