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The ECHo experiment aims at determining the effective electron neutrino mass by analyzing the endpoint of the 163Ho electron capture spectrum. High energy resolution detectors with a well-tailored detector response are the essential ingredient for the success of the ECHo experiment. Metallic magnetic calorimeter arrays enclosing 163Ho have been chosen for the ECHo experiment. The first MMC array, ECHo-1k, showed excellent performances with an average energy resolution of 5.5 eV FWHM @ 5.9 keV. Based on the results obtained with the ECHo-1k array, optimization studies have paved the way towards a new detector design for the next experimental phase, ECHo-100k. The ECHo-100k chip features an optimized single pixel design to improve the detector performance as well as an upgraded on-chip thermalization layout. The newly fabricated ECHo-100k detectors have been fully characterized at room temperature, at 4 K and at millikelvin temperature. The obtained results show that the ECHo-100k array achieved the expected performance with an average energy resolution of 3.5 eV FWHM @ 5.9 keV, fulfilling the requirements for the ECHo-100k experimental phase. [ABSTRACT FROM AUTHOR]

The determination of the effective electron neutrino mass by analyzing the end point region of the 163 Ho electron capture (EC) spectrum relies on the precise description of the expected 163 Ho events and background events. In the ECHo experiment, arrays of metallic magnetic calorimeters, implanted with 163 Ho, are operated to measure the 163 Ho EC spectrum. In an energy range of 10 eV below Q EC , the maximum available energy for the EC decay of about 2.8 keV, a 163 Ho event rate of the order of 10 - 4 day - 1 pixel - 1 is expected for an activity of 1 Bq of 163 Ho per pixel. This means, a control of the background level in the order of 10 - 5 day - 1 pixel - 1 is extremely important. We discuss the results of a Monte Carlo study based on simulations, which use the GEANT4 framework to understand the impact of natural radioactive isotopes close to the active detector volume in the case of the ECHo-1k set-up, which is used for the first phase of the ECHo experiment. For this, the ECHo-1k set-up was modeled in GEANT4 using the proper geometry and materials, including the information of screening measurements of some materials used in the ECHo-1k set-up and reasonable assumptions. Based on the simulation and on assumptions, we derive the expected background around Q EC and give upper limits of tolerable concentrations of natural radionuclides in the set-up materials. In addition, we compare our results to background spectra acquired in detector pixels with and without implanted 163 Ho. We conclude that typical concentration of radioactive nuclides found in the used materials should not endanger the analysis of the endpoint region of the 163 Ho EC spectrum for an exposure time of half a year. [ABSTRACT FROM AUTHOR]

The performance of BBL CHROMagar Salmonella (Becton Dickinson, France), a new selective chromogenic medium for the isolation and presumptive identification of Salmonella spp., was evaluated. On this medium, which is a modification of CHROMagar Salmonella (CHROMagar Microbiology, France) with enhanced selectivity, the colonies of Salmonella are stained in mauve (rose-violet), while those of other organisms appear in blue-green or are not stained by any of the chromogens of the medium. The medium was evaluated with a total of 176 strains of Salmonella and other organisms, consisting of 18 reference strains and 158 clinical isolates. All Salmonella strains except subspecies IIIa and IIIb strains and Salmonella Gallinarum yielded typical mauve colonies. During the evaluation with 107 known positive and 332 unknown stool specimens in a clinical laboratory, a total of 115 and 105 Salmonella isolates were obtained on BBL CHROMagar Salmonella and Hektoen enteric agar, respectively. From the known positive stool specimens, 92 true positive cultures were obtained on BBL CHROMagar Salmonella and 89 on Hektoen enteric agar, yielding sensitivities of 86 and 83%, respectively. From the unknown stool specimens, a total of 27 Salmonella isolates were obtained, with 23 isolated from BBL CHROMagar Salmonella and 16 from Hektoen enteric agar by direct plating (sensitivity 85 and 59%, specificity 99 and 97%, respectively). Seroagglutination tests could be performed directly from BBL CHROMagar Salmonella. Compared to conventional isolation media, the time needed for confirmatory biochemical and serological tests was shortened by about 1 day when BBL CHROMagar Salmonella was used. On the basis of these results, the medium can be recommended for the primary isolation and presumptive identification of Salmonella spp. from clinical stool specimens. [ABSTRACT FROM AUTHOR]

Copyright of Infection is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The isolation of a Leptotrichia buccalis-like bacterium from the blood of a patient with endocarditis associated with a prosthetic aortic valve is reported. The organism was isolated from different blood cultures. It was similar but not completely identical to Leptotrichia buccalis. The microbiological identification was confirmed independently by three laboratories, including two reference institutions. The case and the characteristics of the microorganism are reported. [ABSTRACT FROM AUTHOR]

A recurrent infection of the left cervical area dorsal to the sternocleidomastoid muscle with actinomycosis in a 6-year-old girl is presented. Several antibiotic regimens failed, and repeated surgical treatments were necessary. The existence of a lateral cervical cyst and subsequent infection with agents of actinomycosis may have been the route of infection in this case. [ABSTRACT FROM AUTHOR]

Copyright of Infection is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Infection is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)