Salmonella Typhimurium and Multidirectional Communication in the Gut

The mammalian digestive tract is home to trillions of microbes, including bacteria, archaea, protozoa, fungi and viruses. In monogastric mammals the stomach and small intestine harbor diverse bacterial populations but are typically less populated than the colon. The gut bacterial community (microbiota hereafter) varies widely among different host species and individuals within a species. It is influenced by season of the year, age of the host, stress and disease. Ideally, the host and microbiota benefit each other. The host provides nutrients to the microbiota and the microbiota assists the host with digestion and nutrient metabolism. The resident microbiota competes with pathogens for space and nutrients and, through this competition, protects the host in a phenomenon called colonization resistance. The microbiota participates in development of the host immune system, particularly regulation of autoimmunity and mucosal immune response. The microbiota also shapes gut-brain communication and host responses to stress; and, indeed, the microbiota is a newly recognized endocrine organ within mammalian hosts.Salmonella enterica serovar Typhimurium (S. Typhimurium hereafter) is a food-borne pathogen which adapts to and alters the gastrointestinal (GI) environment. In the GI tract, S. Typhimurium competes with the microbiota for nutrients and overcomes colonization resistance to establish infection. To do this, S. Typhimurium uses multiple defense mechanisms to resist environmental stressors, like the acidic pH of the stomach, and virulence mechanisms which allow it to invade the intestinal epithelium and disseminate throughout the host. To coordinate gene expression and disrupt signaling within the microbiota and between host and microbiota, S. Typhimurium employs its own chemical signaling and may regulate host hormone metabolism.This review will discuss the multidirectional interaction between S. Typhimurium, host and microbiota as well as mechanisms that allow S. Typhimurium to succeed in the gut

A educação para o trabalho nos sistemas prisionais paulistas

We discuss, in this article, the materialization of PET developed by FUNAP. It is an empirical research, with bibliographical and documentary analysis, carried out in three units of the penitentiary system located in a municipality of the interior of the State of São Paulo. Systematic observations were made in the institutions and semi-structured interviews with the managers and monitors involved in PET planning and implementation. The analysis showed that the professional training offered is not effective in the prison units due to the reduced hours of classes, the lack of infrastructure for classes, and the reduced number of prisoners attended.Discutimos, en este artículo, la materialización del PET desarrollado por FUNAP. Se trata de una investigación empírica, con análisis bibliográfico y documental, realizada en tres unidades del sistema penitenciário, ubicadas en un municipio del interior del Estado de São Paulo. Se realizaron observaciones sistemáticas en las instituciones y entrevistas semiestructuradas con los gestores y monitores que actúan en la planificación y la implementación del PET. El análisis evidenció que la formación profesional propuesta no se efectúa en las unidades carcelarias debido a circuntancias determinadas, como la reducida carga horaria de los cursos, la ausencia de infraestructura para clases, y el reducido número de detenidos atendidos.Discutimos, neste artigo, a materialização do PET (Programa de Educação para o Trabalho) desenvolvido pela FUNAP. Trata-se de uma pesquisa empírica, com análise bibliográfica e documental, realizada em três unidades do sistema penitenciário, localizadas em um município do interior do Estado de São Paulo. Foram realizadas observações sistemáticas nas instituições e entrevistas semiestruturadas com os gestores e monitores que atuam no planejamento e na implementação do PET. A análise evidenciou que a formação profissional proposta não se efetiva nas unidades carcerárias devido à determinadas circunstâncias, como a reduzida carga horária dos cursos, a ausência de infraestrutura para aulas, e o reduzido número de detentos atendidos

Increasing Public Health Mosquito Surveillance in Hidalgo County, Texas to Monitor Vector and Arboviral Presence

From 2016 to 2018, Hidalgo County observed the emergence of Zika virus (ZIKV) infections along with sporadic cases of Dengue virus (DENV) and West Nile virus (WNV). Due to the emergence of ZIKV and the historical presence of other mosquito-borne illnesses, Hidalgo County obtained funding to enhance mosquito surveillance and educate residents on arboviruses and travel risks. During this time period, Hidalgo County mosquito surveillance efforts increased by 1.275%. This increase resulted in \u3e8000 mosquitoes collected, and 28 mosquito species identified. Aedes aegypti, Ae albopictus and Culex quinquefasciatus made up approximately two-thirds of the mosquitoes collected in 2018 (4122/6171). Spatiotemporal shifts in vector species composition were observed as the collection period progressed. Significantly, temperature variations (p \u3c 0.05) accounted for associated variations in vector abundance, whereas all other climate variables were not significant

High Yield Production Process for Shigella Outer Membrane Particles

Gram-negative bacteria naturally shed particles that consist of outer membrane lipids, outer membrane proteins, and soluble periplasmic components. These particles have been proposed for use as vaccines but the yield has been problematic. We developed a high yielding production process of genetically derived outer membrane particles from the human pathogen Shigella sonnei. Yields of approximately 100 milligrams of membrane-associated proteins per liter of fermentation were obtained from cultures of S. sonnei ΔtolR ΔgalU at optical densities of 30–45 in a 5 L fermenter. Proteomic analysis of the purified particles showed the preparation to primarily contain predicted outer membrane and periplasmic proteins. These were highly immunogenic in mice. The production of these outer membrane particles from high density cultivation of bacteria supports the feasibility of scaling up this approach as an affordable manufacturing process. Furthermore, we demonstrate the feasibility of using this process with other genetic manipulations e.g. abolition of O antigen synthesis and modification of the lipopolysaccharide structure in order to modify the immunogenicity or reactogenicity of the particles. This work provides the basis for a large scale manufacturing process of Generalized Modules of Membrane Antigens (GMMA) for production of vaccines from Gram-negative bacteria

Dynamic Imaging of the Effector Immune Response to Listeria Infection In Vivo

Host defense against the intracellular pathogen Listeria monocytogenes (Lm) requires innate and adaptive immunity. Here, we directly imaged immune cell dynamics at Lm foci established by dendritic cells in the subcapsular red pulp (scDC) using intravital microscopy. Blood borne Lm rapidly associated with scDC. Myelomonocytic cells (MMC) swarmed around non-motile scDC forming foci from which blood flow was excluded. The depletion of scDC after foci were established resulted in a 10-fold reduction in viable Lm, while graded depletion of MMC resulted in 30–1000 fold increase in viable Lm in foci with enhanced blood flow. Effector CD8+ [CD8 superscript +] T cells at sites of infection displayed a two-tiered reduction in motility with antigen independent and antigen dependent components, including stable interactions with infected and non-infected scDC. Thus, swarming MMC contribute to control of Lm prior to development of T cell immunity by direct killing and sequestration from blood flow, while scDC appear to promote Lm survival while preferentially interacting with CD8+ [CD8 superscript +] T cells in effector sites.National Institutes of Health (U.S.) (Grant P01AI-071195

Electrophilic α-oxygenation reaction of β-ketoesters using N-hydroxycarbamates: Control of the ambident reactivity of nitrosoformate intermediates

A copper-catalyzed aminooxylation of β-ketoesters using transient nitrosoformate intermediates is reported. The transformation is highly practical, efficient and highlights the ambident reactivity of nitrosocarbonyl compounds through a rare example of a nitrosocarbonyl aldol reaction. Along with a broad substrate scope, the reaction conditions that help control the regiochemistry are explored and the use of N-carbamate protected hydroxylamine is showcased by subsequent one-pot annulation reactions. © 2013 The Royal Society of Chemistry

Electrophilic α-oxygenation reaction of β-ketoesters using N-hydroxycarbamates: Control of the ambident reactivity of nitrosoformate intermediates

A copper-catalyzed aminooxylation of β-ketoesters using transient nitrosoformate intermediates is reported. The transformation is highly practical, efficient and highlights the ambident reactivity of nitrosocarbonyl compounds through a rare example of a nitrosocarbonyl aldol reaction. Along with a broad substrate scope, the reaction conditions that help control the regiochemistry are explored and the use of N-carbamate protected hydroxylamine is showcased by subsequent one-pot annulation reactions. © 2013 The Royal Society of Chemistry

Optical characterization and confocal fluorescence imaging of mechanochromic acrylate polymers

The development of mechanochromic molecules has opened new pathways for the study of localized stress and failure in polymers. Their application as stress or temperature diagnostics, however, requires suitable measurement techniques capable of detecting the force- and temperature-sensitive chemical species with high spatial resolution. Confocal imaging techniques offer excellent spatial resolution but the energy input during these measurements can itself affect the activation state of the mechanochromic species. Here, we present a systematic study of the effects of laser-based imaging on the activation and fluorescence behavior of mechanochromic spiropyran (SP) integrated into poly(methyl acrylate) (PMA) and poly(methyl methacrylate) matrices using a confocal Raman microspectrometer. Localized stress and temperature activation were studied by means of high-rate compressive loading and dynamic fracture. Laser illumination of SP in PMA revealed a strong excitation wavelength- and power-dependence. Suitable correction functions were established and used to account for the observed laser effects. The presented study demonstrates that confocal imaging using conventional Raman spectrometers is a powerful characterization tool for localized stress analysis in mechanochromic polymers, offering quantifiable information on the activation state with high spatial resolution. However, laser-mechanophore interactions must be well understood and effects of laser excitation and exposure times must be taken into consideration when interpreting the obtained results