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Molecular Analysis of Human, Porcine, and Poultry Enterococcus faecium Isolates and Their erm(B) Genes 下载免费PDF全文
E. De Leener A. Martel E. M. De Graef J. Top P. Butaye F. Haesebrouck R. Willems A. Decostere 《Applied microbiology》2005,71(5):2766-2770
Fifty-nine erm(B)-positive Enterococcus faecium strains isolated from pigs, broilers, and humans were typed using multilocus sequence typing (MLST), and the coding sequence of the erm(B) gene was determined. Identical erm(B) gene sequences were detected in genetically unrelated isolates. Furthermore, genetically indistinguishable strains were found to contain different erm(B) alleles. This may suggest that horizontal exchange of the erm(B) gene between animal and human E. faecium strains or the existence of a common reservoir of erm(B) genes might be more important than direct transmission of resistant strains. 相似文献
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Historical Ecology on Sandoy, Faroe Islands: Palaeoenvironmental and Archaeological Perspectives 总被引:1,自引:1,他引:0
Ian T. Lawson Mike J. Church Tom H. McGovern Símun V. Arge James Woollet Kevin J. Edwards Freddy J. Gathorne-Hardy Andrew J. Dugmore Gordon Cook Kerry-Anne Mairs Amanda M. Thomson Guðrún Sveinbjarnardótti 《Human ecology: an interdisciplinary journal》2005,33(5):651-684
We present palaeoenvironmental, geomorphological, archaeological, and place-name data which allow a holistic assessment of
the history of landscape change on Sandoy, Faroe Islands, especially in terms of the changes that occurred in response to
the colonization of the island by humans. In contrast to other situations in the North Atlantic region, there is considerable
continuity in the patterns and processes of landscape evolution across the initial settlement horizon. Many of the characteristic
features of post-settlement North Atlantic landscapes—absence of trees, widespread blanket mires, high rates of soil erosion—were
already in place when the first people arrived. Although human impact on Sandoy appears to have been light, conversely, the
unusual environment forced major alterations of the subsistence economy imported by the colonists. Settlement-era archaeological
records suggest that, from the start, patterns of resource use differed substantially from the regional norm, and these differences
became amplified over time as the Faroese economy created a locally sustainable cultural landscape. 相似文献
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Pyridoxal 5′-phosphate is the active form of vitamin B6 and its deficiency is directly related with several human disorders, which make human pyridoxal kinase (hPLK) an important pharmacologic target. In spite of this, a carefully kinetic characterization of hPLK including the main species that regulates the enzymatic activity is at date missing. Here we analyse the catalytic and regulatory mechanisms of hPLK as a function of a precise determination of the species involved in metal–nucleotide equilibriums and describe new regulatory mechanisms for this enzyme. hPLK activity is supported by several metals, being Zn2+ the most effective, although the magnitude of the effect observed is highly dependent on the relative concentrations of metal and nucleotide used. The true substrate for the reaction catalyzed by hPLK is the metal nucleotide complex, while ATP4? and HATP3? did not affect the activity. The enzyme presents substrate inhibition by both pyridoxal (PL) and ZnATP2?, although the latter behaves as a weakly inhibitor. Our study also established, for the first time, a dual role for free Zn2+; as an activator at low concentrations (19 μM optimal concentration) and as a potent inhibitor with a IC50 of 37 μM. These results highlighted the importance of an accurate estimation of the actual concentration of the species involved in metal–nucleotide equilibriums in order to obtain reliable values for the kinetic parameters, and for determine the true regulators of the PLK activity. They also help to explain the dissimilar kinetic parameters reported in the literature for this enzyme. 相似文献
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Weiguo Zhang Malou Fraiture Dagmar Kolb Birgit L?ffelhardt Yoshitake Desaki Freddy F.G. Boutrot Mahmut T?r Cyril Zipfel Andrea A. Gust Frédéric Brunner 《The Plant cell》2013,25(10):4227-4241
Effective plant defense strategies rely in part on the perception of non-self determinants, so-called microbe-associated molecular patterns (MAMPs), by transmembrane pattern recognition receptors leading to MAMP-triggered immunity. Plant resistance against necrotrophic pathogens with a broad host range is complex and yet not well understood. Particularly, it is unclear if resistance to necrotrophs involves pattern recognition receptors. Here, we partially purified a novel proteinaceous elicitor called SCLEROTINIA CULTURE FILTRATE ELICITOR1 (SCFE1) from the necrotrophic fungal pathogen Sclerotinia sclerotiorum that induces typical MAMP-triggered immune responses in Arabidopsis thaliana. Analysis of natural genetic variation revealed five Arabidopsis accessions (Mt-0, Lov-1, Lov-5, Br-0, and Sq-1) that are fully insensitive to the SCFE1-containing fraction. We used a forward genetics approach and mapped the locus determining SCFE1 sensitivity to RECEPTOR-LIKE PROTEIN30 (RLP30). We also show that SCFE1-triggered immune responses engage a signaling pathway dependent on the regulatory receptor-like kinases BRASSINOSTEROID INSENSITIVE1-ASSOCIATED RECEPTOR KINASE1 (BAK1) and SUPPRESSOR OF BIR1-1/EVERSHED (SOBIR1/EVR). Mutants of RLP30, BAK1, and SOBIR1 are more susceptible to S. sclerotiorum and the related fungus Botrytis cinerea. The presence of an elicitor in S. sclerotiorum evoking MAMP-triggered immune responses and sensed by RLP30/SOBIR1/BAK1 demonstrates the relevance of MAMP-triggered immunity in resistance to necrotrophic fungi. 相似文献
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Freddy Sitas Alison Gibberd Clare Kahn Marianne F. Weber May Chiew Rajah Supramaniam Louiza Velentzis Carolyn Nickson David P. Smith Dianne O’Connell Megan A. Smith Katie Armstrong Xue Qin Yu Karen Canfell Monica Robotin Eleonora Feletto Andrew Penman 《Cancer epidemiology》2013,37(6):780-787
BackgroundAustralia has one of the highest rates of cancer incidence worldwide and, despite improving survival, cancer continues to be a major public health problem. Our aim was to provide simple summary measures of changes in cancer mortality and incidence in Australia so that progress and areas for improvement in cancer control can be identified.MethodsWe used national data on cancer deaths and newly registered cancer cases and compared expected and observed numbers of deaths and cases diagnosed in 2007. The expected numbers were obtained by applying 1987 age–sex specific rates (average of 1986–1988) directly to the 2007 population. The observed numbers of deaths and incident cases were calculated for 2007 (average of 2006–2008). We limited the analyses to people aged less than 75 years.ResultsThere was a 28% fall in cancer mortality (7827 fewer deaths in 2007 vs. 1987) and a 21% increase in new cancer diagnoses (13,012 more diagnosed cases in 2007). The greatest reductions in deaths were for cancers of the lung in males (?2259), bowel (?1797), breast (?773) and stomach (?577). Other notable falls were for cancers of the prostate (?295), cervix (?242) and non-Hodgkin lymphoma (?240). Only small or no changes occurred in mortality for cancers of the lung (female only), pancreas, brain and related, oesophagus and thyroid, with an increase in liver cancer (267). Cancer types that showed the greatest increase in incident cases were cancers of the prostate (10,245), breast (2736), other cancers (1353), melanoma (1138) and thyroid (1107), while falls were seen for cancers of the lung (?1705), bladder (?1110) and unknown primary (?904).ConclusionsThe reduction in mortality indicates that prevention strategies, improvements in cancer treatment, and screening programmes have made significant contributions to cancer control in Australia since 1987. The rise in incidence is partly due to diagnoses being brought forward by technological improvements and increased coverage of screening and early diagnostic testing. 相似文献
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Elhaseen Elamin Ad Masclee Kati Juuti-Uusitalo Sven van IJzendoorn Freddy Troost Harm-Jan Pieters Jan Dekker Daisy Jonkers 《PloS one》2013,8(3)
Background & Aims
Evidence is accumulating that ethanol and its oxidative metabolite, acetaldehyde, can disrupt intestinal epithelial integrity, an important factor contributing to ethanol-induced liver injury. However, ethanol can also be metabolized non-oxidatively generating phosphatidylethanol and fatty acid ethyl esters (FAEEs). This study aims to investigate the effects of FAEEs on barrier function, and to explore the role of oxidative stress as possible mechanism.Methods
Epithelial permeability was assessed by paracellular flux of fluorescein isothiocyanate-conjugated dextran using live cell imaging. Cell integrity was evaluated by lactate dehydrogenase release. Localization and protein levels of ZO-1 and occludin were analyzed by immunofluorescence and cell-based ELISA, respectively. Intracellular oxidative stress and cellular ATP levels were measured by dichlorofluorescein and luciferase driven bioluminescence, respectively.Results
In vitro, ethyl oleate and ethyl palmitate dose dependently increased permeability associated with disruption and decreased ZO-1 and occludin protein levels, respectively, and increased intracellular oxidative stress without compromising cell viability. These effects could partially be attenuated by pretreatment with the antioxidant, resveratrol, pointing to the role of oxidative stress in the FAEEs-induced intestinal barrier dysfunction.Conclusions
These findings show that FAEEs can induce intestinal barrier dysfunction by disrupting the tight junctions, most likely via reactive oxygen species-dependent mechanism. 相似文献9.
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