1,968 research outputs found

    Inability to decarboxylate lysine as a presumptive marker to identify shiga toxin-producing Escherichia coli strains of serogroup 0111

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    Universidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, BrazilInst Adolfo Lutz Registro, Secao Bacteriol, BR-01246902 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, BR-04023062 São Paulo, BrazilWeb of Scienc

    Spatial distribution of B horizon properties in a pine flatwood landscape: New Hanover County, NC

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    The warm humid climate, sandy parent material, needleleaf vegetation, and high water tables of southeastern North Carolina lead to the development of acidic, leached soils known as Spodosols. These soils are defined by a subsurface accumulation of organic matter (Bh horizon). This study tests for relationships between Bh horizons and topography, grain size, depth to water, and surface organic litter in a pine forest on the campus of the University of North Carolina Wilmington. Two study units were established for sampling: one on a higher, hummocky former dune environment and the other on a lower, flatter shoreface environment. A topographic survey was conducted and point samples were collected to measure soil properties in each study unit. Two soil pits in each unit were described in detail and sampled for laboratory analysis. Piezometers were installed near each pit in order to determine depth to the water table. The results show that Bh horizons are closely related to topography. In the upper unit, greater depth to the water table (> 2.3 m) allows for greater leaching and decomposition of organic matter restricting the development of B horizons. In the lower unit, a much shallower water table (0.55-1.5 m) creates an environment that favors precipitation of organic matter and inhibits decomposition. Piezometer data show that in the lower unit, the lower portions of the Bh horizons were saturated about 25% of the time during the study period. In the upper unit, the permanent water table was never observed within the solum. However, in the lower elevations of the upper unit, subsurface clay accumulation in Bt horizons cause episaturation of the overlying soil allowing thin Bh horizons to form. The relationship between surface leaf litter and Bh horizons is not clear. Leaf litter mass is significantly greater in the upper study unit, but the B horizons contain significantly less organic carbon. These results support the concept of southeastern Coastal Plain Spodosols being controlled mainly by parent material and topography. They also show that prior pedogenesis (development of Bt horizons) can be a precursor to development of Bh horizons in drier landscape positions

    Pilomatrixoma Recurring As Giant Form

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    Pilomatrixoma is a benign skin tumor that originates from the hair matrix. It usually appears in children and young adults and is preferably in the head and neck region. It clinically presents as an asymptomatic firm, solitary subcutaneous mass of less than 3 cm. When located in the preauricular area, it is often misdiagnosed as benign or malignant parotids, skin tumors, or sebaceous cysts. Its treatment of choice is surgery, and recurrence is due to incomplete excision. We present a case of a male referred to our hospital with a diagnosis of recurrent pilomatrixoma in its giant form. The lesion was fully excised with no signs of recurrence and no functional impairment.info:eu-repo/semantics/publishedVersio

    Vascular Function Long Term After Kawasaki Disease: Another Piece of the Puzzle?

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    BACKGROUND: Kawasaki disease is an acute systemic vasculitis. Cardiac complications are frequent and include endothelial dysfunction in patients with coronary anomalies. Thus far, endothelial dysfunction in patients with no coronary lesions is poorly understood. Our aim was to access the vascular function in adolescents and young adults long term after Kawasaki disease, but without coronary aneurysms or any other cardiac risk factors. METHODS: We carried out a single-centre prospective study in a Portuguese population. We evaluated two groups of subjects: (1) Kawasaki disease patients over 11 years of age, diagnosed >5 years ago, with no coronary lesions or any other risk factors for cardiovascular disease; (2) control group of individuals without cardiovascular risk factors. Patients and controls were clinically assessed. Endo-PAT and carotid intima-media thickness assessment were performed to determine vascular function. RESULTS: In total, 43 Kawasaki disease patients were assessed and compared with 43 controls. Kawasaki disease patients presented a decreased reactive hyperaemia index compared with controls (1.59±0.45 versus 1.98±0.41; p<0.001). Augmentation index was similar in both groups (-4.5±7 versus -5±9%; p 0.6). The mean carotid intima-media thickness was not significantly increased in the Kawasaki disease group. There were no statistically significant changes with regard to laboratory data. CONCLUSIONS: Children with Kawasaki disease may have long-term sequelae, even when there is no discernible coronary artery involvement in the acute stage of the disease. Further research is needed to assess whether known strategies to improve endothelial function would bring potential benefits to Kawasaki disease patients.info:eu-repo/semantics/publishedVersio

    Perfeccionismo no transtorno obsessivo-compulsivo e nos transtornos alimentares

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    OBJETIVO: Este estudo tem dois objetivos principais. Primeiro, avaliar as dimensões do perfeccionismo no transtorno obsessivo-compulsivo e nos transtornos alimentares em comparação com duas amostras controle: psiquiátrica (depressão/ansiedade) e não clínica. Segundo, avaliar se o perfeccionismo é um traço de personalidade especificamente relacionado com estas diferentes condições clínicas. MÉTODO: 39 pacientes com transtorno obsessivo-compulsivo, 24 com transtornos alimentares, 65 com um diagnóstico de depressão e/ou ansiedade (todos estes pacientes encontravam-se em regime de ambulatório) e 70 controles não clínicos completaram a versão portuguesa da Multidimensional Perfectionism Scale. RESULTADOS: Comparativamente à amostra não clínica, todas as amostras clínicas apresentaram níveis significativamente mais elevados na Multidimensional Perfectionism Scale total, no Perfeccionismo Auto-Orientado e no Perfeccionismo-Socialmente-Prescrito. Não houve diferenças estatisticamente significativas no Perfeccionismo-Auto-Orientado e na Multidimensional Perfectionism Scale total nas três amostras clínicas. No entanto, a amostra com transtornos alimentares apresentou níveis significativamente mais elevados de Perfeccionismo-Socialmente-Prescrito, comparativamente à transtornos alimentares e à amostra psiquiátrica (depressão/ansiedade). CONCLUSÃO: O perfeccionismo revelou estar associado a uma grande variedade de condições psicopatológicas. Contudo, as diferenças encontradas entre a amostra de transtornos alimentares, de transtorno obsessivo-compulsivo e a psiquiátrica no Perfeccionismo-Socialmente-Prescrito necessitam de investigação subsequente no sentido de clarificar a especificidade desta dimensão com os transtornos alimentares

    Escherichia coli phylogenetic group determination and its application in the identification of the major animal source of fecal contamination

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    <p>Abstract</p> <p>Background</p> <p><it>Escherichia coli </it>strains are commonly found in the gut microflora of warm-blooded animals. These strains can be assigned to one of the four main phylogenetic groups, A, B1, B2 and D, which can be divided into seven subgroups (A<sub>0</sub>, A<sub>1</sub>, B1, B2<sub>2</sub>, B2<sub>3</sub>, D<sub>1 </sub>and D<sub>2</sub>), according to the combination of the three genetic markers <it>chuA</it>, <it>yjaA </it>and DNA fragment TspE4.C2. Distinct studies have demonstrated that these phylo-groups differ in the presence of virulence factors, ecological niches and life-history. Therefore, the aim of this work was to analyze the distribution of these <it>E. coli </it>phylo-groups in 94 human strains, 13 chicken strains, 50 cow strains, 16 goat strains, 39 pig strains and 29 sheep strains and to verify the potential of this analysis to investigate the source of fecal contamination.</p> <p>Results</p> <p>The results indicated that the distribution of phylogenetic groups, subgroups and genetic markers is non-random in the hosts analyzed. Strains from group B1 were present in all hosts analyzed but were more prevalent in cow, goat and sheep samples. Subgroup B2<sub>3 </sub>was only found in human samples. The diversity and the similarity indexes have indicated a similarity between the <it>E. coli </it>population structure of human and pig samples and among cow, goat and sheep samples. Correspondence analysis using contingence tables of subgroups, groups and genetic markers frequencies allowed the visualization of the differences among animal samples and the identification of the animal source of an external validation set. The classifier tools Binary logistic regression and Partial least square -- discriminant analysis, using the genetic markers profile of the strains, differentiated the herbivorous from the omnivorous strains, with an average error rate of 17%.</p> <p>Conclusions</p> <p>This is the first work, as far as we are aware, that identifies the major source of fecal contamination of a pool of strains instead of a unique strain. We concluded that the analysis of the <it>E. coli </it>population structure can be useful as a supplementary bacterial source tracking tool.</p

    Invasiveness as a putative additional virulence mechanism of some atypical Enteropathogenic Escherichia coli strains with different uncommon intimin types

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    <p>Abstract</p> <p>Background</p> <p>Enteropathogenic <it>Escherichia coli </it>(EPEC) produce attaching/effacing (A/E) lesions on eukaryotic cells mediated by the outer membrane adhesin intimin. EPEC are sub-grouped into typical (tEPEC) and atypical (aEPEC). We have recently demonstrated that aEPEC strain 1551-2 (serotype O non-typable, non-motile) invades HeLa cells by a process dependent on the expression of intimin sub-type omicron. In this study, we evaluated whether aEPEC strains expressing other intimin sub-types are also invasive using the quantitative gentamicin protection assay. We also evaluated whether aEPEC invade differentiated intestinal T84 cells.</p> <p>Results</p> <p>Five of six strains invaded HeLa and T84 cells in a range of 13.3%–20.9% and 5.8%–17.8%, respectively, of the total cell-associated bacteria. The strains studied were significantly more invasive than prototype tEPEC strain E2348/69 (1.4% and 0.5% in HeLa and T84 cells, respectively). Invasiveness was confirmed by transmission electron microscopy. We also showed that invasion of HeLa cells by aEPEC 1551-2 depended on actin filaments, but not on microtubules. In addition, disruption of tight junctions enhanced its invasion efficiency in T84 cells, suggesting preferential invasion via a non-differentiated surface.</p> <p>Conclusion</p> <p>Some aEPEC strains may invade intestinal cells <it>in vitro </it>with varying efficiencies and independently of the intimin sub-type.</p

    First Emergence of Resistance to Macrolides and Tetracycline Identified in Mannheimia haemolytica and Pasteurella multocida Isolates from Beef Feedlots in Australia

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    Bovine respiratory disease (BRD) causes high morbidity and mortality in beef cattle worldwide. Antimicrobial resistance (AMR) monitoring of BRD pathogens is critical to promote appropriate antimicrobial stewardship in veterinary medicine for optimal treatment and control. Here, the susceptibility of Mannheimia haemolytica and Pasteurella multicoda isolates obtained from BRD clinical cases (deep lung swabs at post-mortem) among feedlots in four Australian states (2014-2019) was determined for 19 antimicrobial agents. The M. haemolytica isolates were pan-susceptible to all tested agents apart from a single macrolide-resistant isolate (1/88; 1.1%) from New South Wales (NSW). Much higher frequencies of P. multocida isolates were resistant to tetracycline (18/140; 12.9%), tilmicosin (19/140; 13.6%), tulathromycin/gamithromycin (17/140; 12.1%), and ampicillin/penicillin (6/140; 4.6%). Five P. multocida isolates (3.6%), all obtained from NSW in 2019, exhibited dual resistance to macrolides and tetracycline, and a further two Queensland isolates from 2019 (1.4%) exhibited a multidrug-resistant phenotype to ampicillin/penicillin, tetracycline, and tilmicosin. Random-amplified polymorphic DNA (RAPD) typing identified a high degree of genetic homogeneity among the M. haemolytica isolates, whereas P. multocida isolates were more heterogeneous. Illumina whole genome sequencing identified the genes msr(E) and mph(E)encoding macrolide resistance, tet(R)-tet(H) or tet(Y) encoding tetracycline resistance, and blaROB-1 encoding ampicillin/penicillin resistance in all isolates exhibiting a corresponding resistant phenotype. The exception was the tilmicosin-resistant, tulathromycin/gamithromycin-susceptible phenotype identified in two Queensland isolates, the genetic basis of which could not be determined. These results confirm the first emergence of AMR in M. haemolytica and P. multocida from BRD cases in Australia, which should be closely monitored

    Self-scheduling of wind-thermal systems using a stochastic MILP approach

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    In this work a stochastic (Stoc) mixed-integer linear programming (MILP) approach for the coordinated trading of a price-taker thermal (Ther) and wind power (WP) producer taking part in a day-ahead market (DAM) electricity market (EMar) is presented. Uncertainty (Uncer) on electricity price (EPr) and WP is considered through established scenarios. Thermal units (TU) are modelled by variable costs, start-up (ST-UP) technical operating constraints and costs, such as: forbidden operating zones, minimum (Min) up/down time limits and ramp up/down limits. The goal is to obtain the optimal bidding strategy (OBS) and the maximization of profit (MPro). The wind-Ther coordinated configuration (CoConf) is modelled and compared with the unCoConf. The CoConf and unCoConf are compared and relevant conclusions are drawn from a case study
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