6 research outputs found
Laboratory adapted Escherichia coli K-12 becomes a pathogen of Caenorhabditis elegans upon restoration of O antigen biosynthesis
Escherichia coli has been the leading model organism for many decades. It is a fundamental player in modern biology, facilitating the molecular biology revolution of the last century. The acceptance of E.?coli as model organism is predicated primarily on the study of one E. coli lineage; E. coli K-12. However, the antecedents of today's laboratory strains have undergone extensive mutagenesis to create genetically tractable offspring but which resulted in loss of several genetic traits such as O antigen expression. Here we have repaired the wbbL locus, restoring the ability of E. coli K-12 strain MG1655 to express the O antigen. We demonstrate that O antigen production results in drastic alterations of many phenotypes and the density of the O antigen is critical for the observed phenotypes. Importantly, O antigen production enables laboratory strains of E. coli to enter the gut of the Caenorhabditis elegans worm and to kill C. elegans at rates similar to pathogenic bacterial species. We demonstrate C. elegans killing is a feature of other commensal E.?coli. We show killing is associated with bacterial resistance to mechanical shear and persistence in the C. elegans gut. These results suggest C. elegans is not an effective model of human-pathogenic E. coli infectious disease
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ELAIS: final band-merged catalogue (Rowan-Robinson+, 2004)
The catalog represents the final band-merged European Large-Area ISO Survey (ELAIS) Catalogue at 6.7, 15, 90 and 175{mu}m, and the associated data at U, g', r', i', Z, J, H, K and 20cm. Details about the origin of the survey, the observations, data reduction and optical identification are described in the paper. In addition to fluxes in the radio, infrared and optical passbands, spectroscopic redshifts are tabulated, where available. For the N1 and N2 areas, the Isaac Newton Telescope ugriz Wide Field Survey permits photometric redshifts to be estimated for galaxies and quasars.
(2 data files)
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Final analysis of ELAIS 15-m (Vaccari+, 2005)
We present the final analysis of the European Large Area Infrared Space Observatory (ISO) Survey (ELAIS) 15-{mu}m observations, carried out with the ISO Camera (ISOCAM) instrument on board the ISO.
The data-reduction method, known as the Lari Method, is based on a mathematical model of the behaviour of the detector and was specifically designed for the detection of faint sources in ISOCAM/ISO Photopolarimeter (ISOPHOT) data. The method is fully interactive and leads to very reliable and complete source lists.
The resulting catalogue includes 1923 sources detected with signal-to-noise ratio of >5 in the 0.5-100mJy flux range and over an area of 10.85deg2 split into four fields, making it the largest non-serendipitous extragalactic source catalogue obtained to date from the ISO data.
(1 data file)