Search results for "Bacteria"
showing 10 items of 4919 documents
Prediabetes is associated with the modulation of antigen-specific Th1/Tc1 and Th17/Tc17 responses in latent Mycobacterium tuberculosis infection.
2017
Type 2 diabetes mellitus (DM) is associated with the down modulation of Th1, Th2 and Th17 responses in latent Mycobacterium tuberculosis infection but the role of prediabetes (PDM) in this setting is not well understood. To examine the role of CD4+ and CD8+ T cell cytokines in latent tuberculosis (LTB) with coincident PDM, we studied the baseline, mycobacterial, control antigen and mitogen-stimulated T cell cytokine responses in LTB individuals with (LTB-PDM; n = 20) or without (LTB-NDM; n = 20) concomitant prediabetes. LTB-PDM is characterized by diminished frequencies of mono-and dual-functional CD4+ Th1 and Th17 cells and mono-functional Th2 cells at baseline and/or following mycobacteri…
Gut vascular barrier impairment leads to intestinal bacteria dissemination and colorectal cancer metastasis to liver
2021
Metastasis is facilitated by the formation of a "premetastatic niche," which is fostered by primary tumor-derived factors. Colorectal cancer (CRC) metastasizes mainly to the liver. We show that the premetastatic niche in the liver is induced by bacteria dissemination from primary CRC. We report that tumor-resident bacteria Escherichia coli disrupt the gut vascular barrier (GVB), an anatomical structure controlling bacterial dissemination along the gut-liver axis, depending on the virulence regulator VirF. Upon GVB impairment, bacteria disseminate to the liver, boost the formation of a premetastatic niche, and favor the recruitment of metastatic cells. In training and validation cohorts of C…
Platelet-Derived GARP Induces Peripheral Regulatory T Cells—Potential Impact on T Cell Suppression in Patients with Melanoma-Associated Thrombocytosis
2020
Platelets have been recently described as an important component of the innate and adaptive immunity through their interaction with immune cells. However, information on the platelet&ndash
Plastic and micro-evolutionary responses of a nematode to the host immune environment
2017
9 pages; International audience; Parasitic organisms have to cope with the defences deployed by their hosts and this can be achieved adopting immune evasion strategies or optimal life history traits according to the prevailing pattern of immune-mediated mortality. Parasites often encounter variable immune environments both within and between hosts, promoting the evolution of plastic strategies instead of fixed responses. Here, we explored the plasticity and micro-evolutionary responses of immunomodulatory mechanisms and life history traits to the immune environment provided by the host, using the parasitic nematode Heligmosomoides polygyrus. To test if the parasite responds plastically to t…
Determination of meropenem in endotracheal tubes by in-tube solid phase microextraction coupled to capillary liquid chromatography with diode array d…
2017
Meropenem is a widely used antimicrobial for the treatment of infections associated with the use of invasive medical devices in intensive care unit patients. These treatments are not always effective, in fact, in-vitro studies have demonstrated the difficulty of antimicrobials to penetrate into the biofilm, however in-vivo studies of the effect of these compounds is a trend, mostly because of the complexity of pulmonary samples extracted from ETTs. Therefore, the objective of this study was to evaluate in-tube solid phase microextraction (in-tube SPME) coupled to capillary liquid chromatography (CapLC) with DAD to determine meropenem in Errs in order to estimate the penetration capability i…
Resistance profiles and risk factors of resistant microorganisms in bacteraemia of abdominal origin
2017
Abstract Objective The presence of resistant microorganisms is a major cause of failure in initial empirical antimicrobial therapy. The objectives of this study are to determine the resistance profile of microorganisms that cause bacteraemia of abdominal origin and to identify whether the previous use of antibiotics and the place of acquisition of bacteraemia are risk factors associated with the presence of resistant organisms. Material and methods A clinical, observational, epidemiological, retrospective cohort study was conducted with all the adult patients admitted to a university hospital from 2011 to 2013. Antimicrobial resistance profiles were described and a 95% confidence interval c…
Ceftazidime-Avibactam Combination Therapy Compared to Ceftazidime-Avibactam Monotherapy for the Treatment of Severe Infections Due to Carbapenem-Resi…
2020
Ceftazidime-avibactam (CZA) is a novel beta-lactam beta-lactamase inhibitor combination approved for the treatment of complicated urinary tract infections, complicated intra-abdominal infections, and for hospital-acquired/ventilator-associated pneumonia. The aim of this systematic review (PROSPERO registration number: CRD42019128927) was to evaluate the effectiveness of CZA combination therapy versus CZA monotherapy in the treatment of severe infections. The databases included in the search, until February 12th, 2020, were MEDLINE by PubMed, EMBASE, and The Cochrane Central Register of Controlled Trials. We included both randomized controlled trials (RCTs) and non-randomized studies publish…
C 4 -Dicarboxylate Utilization in Aerobic and Anaerobic Growth
2016
C 4 -dicarboxylates and the C 4 -dicarboxylic amino acid l -aspartate support aerobic and anaerobic growth of Escherichia coli and related bacteria. In aerobic growth, succinate, fumarate, D - and L -malate, L -aspartate, and L -tartrate are metabolized by the citric acid cycle and associated reactions. Because of the interruption of the citric acid cycle under anaerobic conditions, anaerobic metabolism of C 4 -dicarboxylates depends on fumarate reduction to succinate (fumarate respiration). In some related bacteria (e.g., Klebsiella ), utilization of C 4 -dicarboxylates, such as tartrate, is independent of fumarate respiration and uses a Na + -dependent membrane-bound oxaloacetate decarbo…
Specific interaction of IM30/Vipp1 with cyanobacterial and chloroplast membranes results in membrane remodeling and eventually in membrane fusion.
2016
The photosynthetic light reaction takes place within the thylakoid membrane system in cyanobacteria and chloroplasts. Besides its global importance, the biogenesis, maintenance and dynamics of this membrane system are still a mystery. In the last two decades, strong evidence supported the idea that these processes involve IM30, the inner membrane-associated protein of 30kDa, a protein also known as the vesicle-inducing protein in plastids 1 (Vipp1). Even though we just only begin to understand the precise physiological function of this protein, it is clear that interaction of IM30 with membranes is crucial for biogenesis of thylakoid membranes. Here we summarize and discuss forces guiding I…
Staphylococcus aureus α-toxin: small pore, large consequences
2018
Abstract The small β-pore-forming α-toxin, also termed α-hemolysin or Hla is considered to be an important virulence factor of Staphylococcus aureus. Perforation of the plasma membrane (PM) by Hla leads to uncontrolled flux of ions and water. Already a small number of toxin pores seems to be sufficient to induce complex cellular responses, many of which depend on the efflux of potassium. In this article, we discuss the implications of secondary membrane lesions, for example, by endogenous channels, for Hla-mediated toxicity, for calcium-influx and membrane repair. Activation of purinergic receptors has been proposed to be a major contributor to the lytic effects of various pore forming prot…