Could Public Restrooms Be an Environment for Bacterial Resistomes?

PMCID: PMC3547874This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

High-throughput discrimination of bacteria isolated from Astacus astacus and A. leptodactylus

Bacterial diseases and pathogens of crayfish are common, widespread, and occasionally causing serious mortalities. In order to take rapid measures for correct treatment of crayfish diseases, the turnover time and accuracy in bacterial identification is an issue. Bacteria isolated from tissues of apparently healthy Astacus astacus and A. leptodactylus were identified by the commercial phenotypic tests (API 20E) and by the matrix assisted laser induced desorption ionization connected to the time of flight mass spectrometry (MALDI-TOF MS). For Gram-negative rods, API 20E resulted in fewer species identifications than MALDI-TOF MS (5.2% versus 52.61%). The most frequently identified genus from A. astacus and A. leptodactylus was Pseudomonas spp.: API 20E (47.82%) and MALDI-TOF MS (52.17%). Both systems identified 60.86% of total isolates identically to the genus. Hafnia alvei was the only isolate for which API 20E and MALDI-TOF MS had a concordant reading to the species. MALDI-TOF MS proved to be a powerful, low-cost, rapid tool in bacterial genus identification. This is the first report of a direct comparison between the two systems for the identification of bacteria in crayfish, and also the first report on using MALDI-TOF MS for discrimination of freshwater crayfish bacterial isolates

Multicenter evaluation of the vitek MS matrix-assisted laser desorption ionization-time of flight mass spectrometry system for identification of gram-positive aerobic bacteria

Matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF) is gaining momentum as a tool for bacterial identification in the clinical microbiology laboratory. Compared with conventional methods, this technology can more readily and conveniently identify a wide range of organisms. Here, we report the findings from a multicenter study to evaluate the Vitek MS v2.0 system (bioMérieux, Inc.) for the identification of aerobic Gram-positive bacteria. A total of 1,146 unique isolates, representing 13 genera and 42 species, were analyzed, and results were compared to those obtained by nucleic acid sequence-based identification as the reference method. For 1,063 of 1,146 isolates (92.8%), the Vitek MS provided a single identification that was accurate to the species level. For an additional 31 isolates (2.7%), multiple possible identifications were provided, all correct at the genus level. Mixed-genus or single-choice incorrect identifications were provided for 18 isolates (1.6%). Although no identification was obtained for 33 isolates (2.9%), there was no specific bacterial species for which the Vitek MS consistently failed to provide identification. In a subset of 463 isolates representing commonly encountered important pathogens, 95% were accurately identified to the species level and there were no misidentifications. Also, in all but one instance, the Vitek MS correctly differentiated Streptococcus pneumoniae from other viridans group streptococci. The findings demonstrate that the Vitek MS system is highly accurate for the identification of Gram-positive aerobic bacteria in the clinical laboratory setting

Reduction of the boron cross-contamination for plasma deposition of p–i–n devices in a single-chamber large area radio-frequency reactor

In this article, a new treatment to reduce boron contamination of the interface between the p- and i- layer is presented. An ammonia flush, performed at 10 Pa for 1 min, after deposition of the p-layer considerably reduces the boron contamination at the p–i interface of amorphous silicon p–i–n solar cells prepared in a single-chamber reactor. This treatment avoids the need to move the substrate out of the reactor during the full deposition process of a solar cell, thereby reducing costs. The measurement of boron contamination depth profile in the i-layer was done by Secondary Ion Mass Spectroscopy and the effectiveness of the treatment was supported by quantum efficiency and I–V measurements of solar cells

Role of i layer deposition parameters on the V0c and FF of an a-Si:H solar cell deposited by PECVD at 27.13 MHz

A study of the i-layer porosity as a function of the deposition parameters by PECVD technique, is presented here. It is demonstrated in particular, that for a fixed deposition rate of 2 Å/s, increasing the plasma power tends to increase the layer density, while increasing the pressure tends to increase the layer porosity. Regarding the cells, no correlation between the layer density and the initial cell performances is observed. On the contrary, the i-layer porosity seems to influence the cell degradation: High porosity of the i-layer leads to high degradation, which gives an easy tool to investigate the layer quality. © 2003 Elsevier B.V. All rights reserved