23 research outputs found
A Novel Secretion Pathway of Salmonella enterica Acts as an Antivirulence Modulator during Salmonellosis
Salmonella spp. are Gram-negative enteropathogenic bacteria that infect a variety of vertebrate hosts. Like any other living organism, protein secretion is a fundamental process essential for various aspects of Salmonella biology. Herein we report the identification and characterization of a horizontally acquired, autonomous and previously unreported secretion pathway. In Salmonella enterica serovar Typhimurium, this novel secretion pathway is encoded by STM1669 and STM1668, designated zirT and zirS, respectively. We show that ZirT is localized to the bacterial outer membrane, expected to adopt a compact β-barrel conformation, and functions as a translocator for ZirS. ZirS is an exoprotein, which is secreted into the extracellular environment in a ZirT-dependent manner. The ZirTS secretion pathway was found to share several important features with two-partner secretion (TPS) systems and members of the intimin/invasin family of adhesions. We show that zirTS expression is affected by zinc; and that in vivo, induction of zirT occurs distinctively in Salmonella colonizing the small intestine, but not in systemic sites. Additionally, strong expression of zirT takes place in Salmonella shed in fecal pellets during acute and persistent infections of mice. Inactivation of ZirTS results in a hypervirulence phenotype of Salmonella during oral infection of mice. Cumulatively, these results indicate that the ZirTS pathway plays a unique role as an antivirulence modulator during systemic disease and is involved in fine-tuning a host–pathogen balance during salmonellosis
Microsatellites for the genus Cucurbita and an SSR-based genetic linkage map of Cucurbita pepo L.
Until recently, only a few microsatellites have been available for Cucurbita, thus their development is highly desirable. The Austrian oil-pumpkin variety Gleisdorfer Ölkürbis (C. pepo subsp. pepo) and the C. moschata cultivar Soler (Puerto Rico) were used for SSR development. SSR-enriched partial genomic libraries were established and 2,400 clones were sequenced. Of these 1,058 (44%) contained an SSR at least four repeats long. Primers were designed for 532 SSRs; 500 primer pairs produced fragments of expected size. Of these, 405 (81%) amplified polymorphic fragments in a set of 12 genotypes: three C. moschata, one C. ecuadorensis, and eight C. pepo representing all eight cultivar groups. On an average, C. pepo and C. moschata produced 3.3 alleles per primer pair, showing high inter-species transferability. There were 187 SSR markers detecting polymorphism between the USA oil-pumpkin variety “Lady Godiva” (O5) and the Italian crookneck variety “Bianco Friulano” (CN), which are the parents of our previous F2 mapping population. It has been used to construct the first published C. pepo map, containing mainly RAPD and AFLP markers. Now the updated map comprises 178 SSRs, 244 AFLPs, 230 RAPDs, five SCARs, and two morphological traits (h and B). It contains 20 linkage groups with a map density of 2.9 cM. The observed genome coverage (Co) is 86.8%
An Overview of Three Promising Mechanical, Optical, and Biochemical Engineering Approaches to Improve Selective Photothermolysis of Refractory Port Wine Stains
During the last three decades, several laser systems, ancillary technologies, and treatment modalities have been developed for the treatment of port wine stains (PWSs). However, approximately half of the PWS patient population responds suboptimally to laser treatment. Consequently, novel treatment modalities and therapeutic techniques/strategies are required to improve PWS treatment efficacy. This overview therefore focuses on three distinct experimental approaches for the optimization of PWS laser treatment. The approaches are addressed from the perspective of mechanical engineering (the use of local hypobaric pressure to induce vasodilation in the laser-irradiated dermal microcirculation), optical engineering (laser-speckle imaging of post-treatment flow in laser-treated PWS skin), and biochemical engineering (light- and heat-activatable liposomal drug delivery systems to enhance the extent of post-irradiation vascular occlusion)
EAACI position paper on occupational rhinitis
The present document is the result of a consensus reached by a panel of experts from European and non-European countries on Occupational Rhinitis (OR), a disease of emerging relevance which has received little attention in comparison to occupational asthma. The document covers the main items of OR including epidemiology, diagnosis, management, socio-economic impact, preventive strategies and medicolegal issues. An operational definition and classification of OR tailored on that of occupational asthma, as well as a diagnostic algorithm based on steps allowing for different levels of diagnostic evidence are proposed. The needs for future research are pointed out. Key messages are issued for each item
Inconclusive evidence for allergic rhinitis to predict a prolonged or chronic course of acute rhinosinusitis
Objective To systematically review the evidence on allergic rhinitis as a predictor for a prolonged or chronic course in adult patients with acute rhinosinusitis. Data Sources Pubmed, EMBASE, and the Cochrane library. Review Methods A systematic literature search was performed on March 15, 2013. During screening of title and abstract, 3 authors independently selected studies on allergic rhinitis as a predictor for the course of acute rhinosinusitis in adults. The reported study design was assessed for directness of evidence and risk of bias. We aimed to extract prior and posterior probabilities for a prolonged or chronic course of acute rhinosinusitis. Results Of 13,202 retrieved articles, 2 articles were eligible for study assessment. They provided a high directness of evidence but carried a high risk of bias. The studies showed an incidence of a prolonged and chronic course of, respectively, .19 (95% confidence interval [CI] .16-.23) and .05 (95% CI, .02-.13). In patients with allergic rhinitis, the incidence was .25 (95% CI, .18-.35) and .14 (95% CI, .04-.34), so the added value of allergic rhinitis to predict a prolonged course is 6% and to predict a chronic course 8%. Conclusion and Recommendation While the 2 included studies suggest that allergic rhinitis adds little to the prediction of a prolonged or chronic course in patients with acute rhinosinusitis, they carry a high risk of bias. As the available evidence does not provide grounds for different management of patients with and without allergic rhinitis, namely, according to clinical practice guidelines, both can be managed with expectant observation and symptomatic treatment