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Guldbrandsen Bondesen posted an update 13 hours, 57 minutes ago
ulated by the intracellular level of tryptophan, which mimics the allosteric role of glutamine in this feedback loop. The HipBA2 module senses different types of stress conditions by increasing the intracellular level of tryptophan, which in turn breaks the tryptophan-glutamine balance and induces glutamine deprivation. Our results reveal a molecular mechanism that allows disparate environmental challenges to converge on a common pathway that results in a dormant state.Invasive mold infections caused by molds other than Aspergillus spp. or Mucorales are emerging. The reported prevalences of infection due to these rare fungal pathogens vary among geographic regions, driven by differences in climatic conditions, susceptible hosts, and diagnostic capabilities. These rare molds-Fusarium, Lomentospora, and Scedosporium species and others-are difficult to detect and often show intrinsic antifungal resistance. Now, international societies of medical mycology and microbiology have joined forces and created the “Global guideline for the diagnosis and management of rare mould infections an initiative of the European Confederation of Medical Mycology in cooperation with the International Society for Human and Animal Mycology and the American Society for Microbiology” (published in Lancet Infect Dis, https//doi.org/10.1016/S1473-3099(20)30784-2), with the goal of improving the diagnosis, treatment, prevention, and survival of persons with rare mold infections. The guideline provides cutting-edge guidance for the correct utilization and application of established and new diagnostic and therapeutic options.Cargo proteins of the type IX secretion system (T9SS) in human pathogens from the Bacteroidetes phylum invariably possess a conserved C-terminal domain (CTD) that functions as a signal for outer membrane (OM) translocation. learn more In Porphyromonas gingivalis, the CTD of cargos is cleaved off after translocation, and anionic lipopolysaccharide (A-LPS) is attached. This transpeptidase reaction anchors secreted proteins to the OM. PorZ, a cell surface-associated protein, is an essential component of the T9SS whose function was previously unknown. We recently solved the crystal structure of PorZ and found that it consists of two β-propeller moieties, followed by a CTD. In this study, we performed structure-based modeling, suggesting that PorZ is a carbohydrate-binding protein. Indeed, we found that recombinant PorZ specifically binds A-LPS in vitro Binding was blocked by monoclonal antibodies that specifically react with a phosphorylated branched mannan in the anionic polysaccharide (A-PS) component of A-LPS, but not wiocate and anchor secreted virulence effectors to the cell surface. Anchorage is facilitated by sortase, an enzyme that covalently attaches T9SS cargo proteins to a unique anionic lipopolysaccharide (A-LPS) moiety of P. gingivalis Here, we show that the T9SS component PorZ interacts with sortase and specifically binds A-LPS. Binding is mediated by a phosphorylated branched mannan repeat in A-LPS polysaccharide. A-LPS-bound PorZ interacts with sortase with significantly higher affinity, facilitating modification of cargo proteins by the cell surface attachment complex of the T9SS.Soil microorganisms are sensitive to temperature in cold ecosystems, but it remains unclear how microbial responses are modulated by other important climate drivers, such as precipitation changes. Here, we examine the effects of six in situ warming and/or precipitation treatments in alpine grasslands on microbial communities, plants, and soil carbon fluxes. These treatments differentially affected soil carbon fluxes, gross primary production, and microbial communities. Variations of soil CO2 and CH4 fluxes across all sites significantly (r > 0.70, P less then 0.050) correlated with relevant microbial functional abundances but not bacterial or fungal abundances. Given tight linkages between microbial functional traits and ecosystem functionality, we conclude that future soil carbon fluxes in alpine grasslands can be predicted by microbial carbon-degrading capacities.IMPORTANCE The warming pace in the Tibetan Plateau, which is predominantly occupied by grassland ecosystems, has been 0.2°C per decade in recent years, dwarfing the rate of global warming by a factor of 2. Many Earth system models project substantial carbon sequestration in Tibet, which has been observed. Here, we analyzed microbial communities under projected climate changes by 2100. As the soil “carbon pump,” the growth and activity of microorganisms can largely influence soil carbon dynamics. However, microbial gene response to future climate scenarios is still obscure. We showed that the abundances of microbial functional genes, but not microbial taxonomy, were correlated with carbon fluxes and ecosystem multifunctionality. By identifying microbial traits linking to ecosystem functioning, our results can guide the assessment of future soil carbon fluxes in alpine grasslands, a critical step toward mitigating climate changes.Severe infections caused by multidrug-resistant Klebsiella pneumoniae sequence type 258 (ST258) highlight the need for new therapeutics with activity against this pathogen. Bacteriophage (phage) therapy is an alternative treatment approach for multidrug-resistant bacterial infections that has shown efficacy in experimental animal models and promise in clinical case reports. In this study, we assessed microbiologic, histopathologic, and survival outcomes following systemic administration of phage in ST258-infected mice. We found that prompt treatment with two phages, either individually or in combination, rescued mice with K. pneumoniae ST258 bacteremia. Among the three treatment groups, mice that received combination phage therapy demonstrated the greatest increase in survival and the lowest frequency of phage resistance among bacteria recovered from mouse blood and tissue. Our findings support the utility of phage therapy as an approach for refractory ST258 infections and underscore the potential of this treoward optimizing and assessing phage therapy’s potential for the treatment of severe ST258 infection in humans.