A cohort study of bacteremic pneumonia: The importance of antibiotic resistance and appropriate initial therapy?

Bacteremic pneumonia is usually associated with greater mortality. However, risk factors associated with hospital mortality in bacteremic pneumonia are inadequately described. The study was a retrospective cohort study, conducted in Barnes-Jewish Hospital (2008–2015). For purposes of this investigation, antibiotic susceptibility was determined according to ceftriaxone susceptibility, as ceftriaxone represents the antimicrobial agent most frequently recommended for hospitalized patients with community-acquired pneumonia as opposed to nosocomial pneumonia. Two multivariable analyses were planned: the first model included resistance to ceftriaxone as a variable, whereas the second model included the various antibiotic-resistant species (methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, and Enterobacteriaceae). In all, 1031 consecutive patients with bacteremic pneumonia (mortality 37.1%) were included. The most common pathogens associated with infection were S aureus (34.1%; methicillin resistance 54.0%), Enterobacteriaceae (28.0%), P aeruginosa (10.6%), anaerobic bacteria (7.3%), and Streptococcus pneumoniae (5.6%). Compared with ceftriaxone-susceptible pathogens (46.8%), ceftriaxone-resistant pathogens (53.2%) were significantly more likely to receive inappropriate initial antibiotic treatment (IIAT) (27.9% vs 7.1%; P < 0.001) and to die during hospitalization (41.5% vs 32.0%; P = 0.001). The first logistic regression analysis identified IIAT with the greatest odds ratio (OR) for mortality (OR 2.2, 95% confidence interval [CI] 1.5–3.2, P < 0.001). Other independent predictors of mortality included age, mechanical ventilation, immune suppression, prior hospitalization, prior antibiotic administration, septic shock, comorbid conditions, and severity of illness. In the second multivariable analysis that included the antibiotic-resistant species, IIAT was still associated with excess mortality, and P aeruginosa infection was identified as an independent predictor of mortality (OR 1.6, 95% CI 1.1–2.2, P = 0.047), whereas infection with ceftriaxone-resistant Enterobacteriaceae (OR 0.6, 95% CI 0.4–1.0, P = 0.050) was associated with lower mortality. More than one-third of our patients hospitalized with bacteremic pneumonia died. IIAT was identified as the most important risk factor for hospital mortality and the only risk factor amenable to potential intervention. Specific antibiotic-resistant pathogen species were also associated with mortality

Insights into the Evolution of Multicellularity from the Sea Lettuce Genome

We report here the 98.5 Mbp haploid genome (12,924 protein coding genes) of Ulva mutabilis, a ubiquitous and iconic representative of the Ulvophyceae or green seaweeds. Ulva’s rapid and abundant growth makes it a key contributor to coastal biogeochemical cycles; its role in marine sulfur cycles is particularly important because it produces high levels of dimethylsulfoniopropionate (DMSP), the main precursor of volatile dimethyl sulfide (DMS). Rapid growth makes Ulva attractive biomass feedstock but also increasingly a driver of nuisance “green tides.” Ulvophytes are key to understanding the evolution of multicellularity in the green lineage, and Ulva morphogenesis is dependent on bacterial signals, making it an important species with which to study cross-kingdom communication. Our sequenced genome informs these aspects of ulvophyte cell biology, physiology, and ecology. Gene family expansions associated with multicellularity are distinct from those of freshwater algae. Candidate genes, including some that arose following horizontal gene transfer from chromalveolates, are present for the transport and metabolism of DMSP. The Ulva genome offers, therefore, new opportunities to understand coastal and marine ecosystems and the fundamental evolution of the green lineage

Numerical And Experimental Modelling Of Two-dimensional Unsteady Heat Transfer During Inward Solidification Of Square Billets

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The development of air gaps between the solidifying shell and the mould is an inherent phenomenon in both continuous and static casting processes, and is one of the major factors affecting not only the microstructure formation but also the resulting properties and surface quality of castings. The heat flux transients at the casting/mould interface therefore attracted many attempts of mathematical modelling. In this study, an explicitly solved unsteady-state two-dimensional finite difference heat transfer model was used for the solution of the inverse heat conduction problem. The overall heat transfer coefficient between the casting surface and the cooling fluid (h(g)) - which is affected by a series of thermal resistances such as those from water, mould and air gap formed between the metal surface and the inner mould surface - is determined for the inward solidification of a hypoeutectic Al-Fe alloy casting in a water-cooled steel mould. Thermocouples were inserted into the casting with a view to continuously measure temperatures during solidification, which is necessary to furnish thermal information to be compared with simulations, and an automatic search selected the best theoretical-experimental fit from a range of transient heat transfer coefficient profiles. The microstructural cellular spacing was measured in order to permit correlations with the cooling rate ((T)over dot) at different positions from the metal/mould interface to be established. It is shown by numerical heat transfer simulations that the cooling rate decreases from the casting surface, and after reaching a minimum value, starts to increase characterising a reversal trend towards the centre of the casting. It is also shown that the cellular spacing accompanies the trend in the cooling rate. The obtained results - transient (h(g)) profiles and growth laws relating the cellular spacing to () - can contribute to a better understanding of transport phenomena and microstructure evolution of more complex processes involving transient solidification. (C) 2016 Elsevier Ltd. All rights reserved.96454462FAPESP-Sao Paulo Research Foundation, Brazil [2012/08494-0, 2012/16328-2, 2013/23396-7]CNPq (The Brazilian Research Council)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Length Scale Of The Dendritic Microstructure Affecting Tensile Properties Of Al-(ag)-(cu) Alloys

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The dependence of tensile properties on the length scale of the dendritic morphology of Al-Cu, Al-Ag and Al-Ag-Cu alloys is experimentally investigated. These alloys were directionally solidified (DS) under a wide range of cooling rates ((T)over dot), permitting extensive microstructural scales to be examined. Experimental growth laws are proposed relating the primary dendritic arm spacing, lambda(1) to (T)over dot. and tensile properties to lambda(1). It is shown that the most significant effect of the scale of lambda(1) on the tensile properties is that of the ternary alloy, which is attributed to the more homogeneous distribution of the eutectic mixture for smaller lambda(1) and by the combined reinforcement roles of the intermetallics present in the ternary eutectic: Al2Cu and nonequilibrium Ag3Al.303FAPESP [2012/08494-0, 2013/23396-7]CNPq [471581/2012-7, 475480/2012-0]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Influence In The Microstructure And In The Microhardness Regarding The Effects Of Adding 4%ag In The Al-4%cu Unidirectionally Solidified Alloy

Al-Cu alloys are used in several industrial applications, such as automotive and aerospace manufacturing, which demand mechanical strength and toughness performances. The Al-Cu-Ag ternary alloy system has been investigated to obtain a better understanding on ternary eutectic alloys besides its inherent applications. However, studies concerning the effects on microstructure and hardness due to Ag addition on Al-Cu alloys solidified under transient conditions, are not found in literature. In this sense, the main objective of this work consists in investigating the solidification parameters such as growth (V-L) and cooling (T)over dot rate, microstructure and microhardness regarding the effects of adding 4wt% Ag on a Al-4wt% Cu alloy unidirectionally solidified vertically upwards under unsteady-state solidification conditions. Experimental growth laws correlating the primary (lambda(1)) and secondary (lambda(2)) dendritic spacings with growth and cooling rate are proposed for Al-4wt%Cu and Al-4wt%Cu-4wt% Ag alloys. X-Ray Diffraction (XRD) analyses were performed in order to determine the crystalline phases of the compounds present in the alloys microstructure. The diffractogram of the binary alloy showed the presence of theta-Al2Cu, Al-Cu, Al4Cu9 and Al6Fe intermetallics and, for the case of the ternary alloy, the mu-Ag3Al intermetallic was detected. Chemical compositions at the boundary regions of the dendrite as also inside the dendrite were obtained using scanning electron microscope (SEM) connected to an Energy-Dispersive Spectrometer (EDS) system. Several positions along the ingot were analyzed through the X-Ray Fluorescence (XRF) technique permitting the detection of macrosegregation occurrence. It is shown that the microhardness is not influenced by both spacing patterns of the Al-rich matrix. The rho-Ag2Al and mu-Ag3Al intermetallics are responsible for the increase in hardness due to the interaction with ternary dendrite arm spacing and other intermetallics.204992100

Multigenic resistance to Xylella fastidiosa in wild grapes (Vitis sps.) and its implications within a changing climate

Abstract Xylella fastidiosa is a bacterium that infects crops like grapevines, coffee, almonds, citrus and olives. There is little understanding of the genes that contribute to plant resistance, the genomic architecture of resistance, and the potential role of climate in shaping resistance, in part because major crops like grapevines (Vitis vinifera) are not resistant to the bacterium. Here we study a wild grapevine species, V. arizonica, that segregates for resistance. Using genome-wide association, we identify candidate resistance genes. Resistance-associated kmers are shared with a sister species of V. arizonica but not with more distant species, suggesting that resistance evolved more than once. Finally, resistance is climate dependent, because individuals from low ( < 10 °C) temperature locations in the wettest quarter were typically susceptible to infection, likely reflecting a lack of pathogen pressure in colder climates. In fact, climate is as effective a predictor of resistance phenotypes as some genetic markers. We extend our climate observations to additional crops, predicting that increased pathogen pressure is more likely for grapevines and almonds than some other susceptible crops