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  • Oncolytic Viral Therapies Offer One-Two Punch to Fight Glioblastoma
    09/18/2018
  • What Your Laboratory Can Do Regarding the VITEK 2 AST Card Recall
    09/17/2018
  • How to Prioritize Projects in a Corporate Company
    09/12/2018
  • Where Did Zika Go (and Will it Come Back)?
    09/10/2018
  • A Bacterial Compound May Fight an Important Crop Fungus
    09/07/2018
  • Microbial Minutes: E. coli in chicken, HPV vaccine and disease, and microbial life origins
    09/04/2018
  • Combination Antibiotic Testing: When Two Drugs are Better than One (or Two)
    09/01/2018
  • Does the Microbiome Program Mental Health in Infancy?
    08/31/2018
  • Microbiology Resource of the Month: ZetaHunter
    08/29/2018
  • Managing Your Time in the Lab: 4 Ways to Have Structured Days
    08/29/2018

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  • Thursday, 20 September 2018

    The pathogenic spirochete Borrelia burgdorferi senses and responds to diverse environmental challenges, including changes in nutrient availability, throughout its enzootic cycle in Ixodes spp. ticks and vertebrate hosts. This study examined the role of DnaK suppressor protein (DksA) in the transcriptional response of B. burgdorferi to starvation. Wild-type and dksA mutant B. burgdorferi strains were subjected to starvation by shifting mid-logarithmic phase cultures grown in BSK II medium to serum-free RPMI medium for 6 h under microaerobic conditions (5% CO2, 3% O2). Microarray analyses of wild-type B. burgdorferi revealed that genes encoding flagellar components, ribosomal proteins, and DNA replication machinery...

  • Thursday, 20 September 2018

    Bacterial serine/threonine kinases are increasingly sought after as drug targets for new antibiotics. PknB, an essential kinase in Mycobacteria tuberculosis, is intensely targeted, and many inhibitors are in the developmental pipeline. These inhibitors typically are derived from screens of known kinase inhibitors and most share similar chemical properties as their parent compounds were all designed for optimal pharmacokinetic properties in the human body. Here, we investigate the reactivity and toxicity of a proposed PknB inhibitor, YH-8, which does not follow traditional drug design rules. We found that the compound is highly reactive with thiolating agents and has appreciable toxicity in...

  • Thursday, 20 September 2018

    In this study, a strain of SAR11 subgroup IIIa (termed HIMB114) isolated from the tropical Pacific Ocean was grown in seawater-based batch and continuous culture in order to quantify cellular features and metabolism relevant to SAR11 ecology. We report the first direct measurements of cellular elemental quotas for nitrogen (N) and phosphorus (P) for SAR11: 1.4 +/- 0.9 fg N and 0.44 +/- 0.01 fg P, respectively, that were consistent with the small size of HIMB114 cells (average volume of 0.09 {micro}m3). However, the mean carbon (C) cellular quota of 50 +/- 47 fg C was anomalously high, but variable....

  • Thursday, 20 September 2018

    Chemerin, a chemoattractant protein, is involved in endothelial dysfunction and vascular inflammation in pathological conditions. In a recent study, we observed the upregulation of chemerin in endothelial cells following in vitro treatment with T. pallidum. Here, we investigated the role of chemerin in endothelial cells dysfunction induced by the T. pallidum predicted membrane protein Tp0965. Following stimulation of human umbilical vein endothelial cells (HUVECs) with Tp0965, chemerin and its ChemR23 receptor were up-regulated, companied with elevated expression of TLR2. Furthermore, chemerin from HUVECs activated endothelial cells via chemerin/ChemR23 signaling in an autocrine/paracrine manner, characterized by upregulated expression of ICAM-1, E-selectin...

  • Thursday, 20 September 2018

    Candida albicans is known for its ability to form biofilms communities of microorganisms embedded in an extracellular matrix developing on different surfaces. Biofilms are highly tolerant to antifungal therapy. This phenomenon has been partially explained by the appearance of so-called persister cells, phenotypic variants of wild-type cells, capable of surviving very high concentrations of antimicrobial agents. Persister cells in C. albicans were found exceptionally in biofilms while none were detected in planktonic cultures of this fungus. Yet, this topic remains controversial as others could not observe persister cells in biofilms formed by the C. albicans SC5314 laboratory strain. Due to...

  • Thursday, 20 September 2018

    Diagnostic testing for Zika virus (ZIKV) or dengue virus (DENV) infection can be accomplished by a nucleic acid detection method; however, a negative result does not exclude infection due to the low virus titer during infection depending on the timing of sample collection. Therefore, a ZIKV- or DENV-specific serological assay is essential for the accurate diagnosis of patients and to prevent potential severe health outcomes. A retrospective study design with dual approaches of collecting human serum samples for testing was developed. All serum samples were extensively evaluated by using both non-infectious virus-like particles (VLPs) and soluble non-structural protein 1 (NS1)...

  • Thursday, 20 September 2018

    Mature bacterial biofilms have elaborate three-dimensional architectures that endow these structures with their durability and resistance to environmental perturbations. We used agent-based modeling to explore whether local cellular interactions were sufficient to give rise to global structural features of biofilms. Specifically, we asked whether chemorepulsion from a self-produced quorum-sensing molecule, autoinducer-2 (AI-2), was sufficient to recapitulate biofilm growth and cellular organization observed for biofilms of the human pathogen Helicobacter pylori. To carry out this modeling, we modified an existing platform, Individual-based Dynamics of Microbial Communities Simulator (iDynoMiCS), to incorporate three-dimensional chemotaxis, planktonic cells that could join or leave the biofilm...

  • Thursday, 20 September 2018

    Cell-cell and cell-substrate adhesion is critical for many functions in life. In eukaryotes, I-domains mediate functions as divergent as tissue traversal by malaria-causing Plasmodium parasites as well as cell adhesion and migration by human leucocytes. The I-domain containing protein TRAP is important for Plasmodium sporozoite motility and invasion. Here we show that the I-domain of TRAP is required to mediate adhesional properties which can be partially preserved when the native I-domain is replaced by I-domains from human integrins or from an apicomplexan parasite that does not infect insects. By putting in vivo data and structural features in perspective we conclude...

  • Wednesday, 19 September 2018

    Abstract Background The highly variable tprK gene of Treponema pallidum has been acknowledged to be the cause of persistent infection. Previous studies mainly focused on the heterogeneity in tprK in propagated strains using a clone-based Sanger approach. Few studies have investigated tprK directly from clinical samples using deep sequencing. Methods/Principal findings We conducted a comprehensive analysis of 14 primary syphilis clinical isolates of T. pallidum via next-generation sequencing to gain better insight into the profile of tprK in primary syphilis patients. Our results based on primary syphilis clinical samples showed that there was a mixture of distinct sequences within each...

  • Tuesday, 18 September 2018

    We describe the characterization of the gastrointestinal tract (gut) and oral microbiota (bacteria) in 32 urban Pakistani adults representing seven major geographies and six ethnicities in the country. Study participants were between ages 18 and 40, had body mass index between 18 and 25 Kg/m2, and were early-career students or professionals belonging to 25 major cities of the country. These individuals donated a total of 61 samples (32 gut and 29 oral) that were subjected to 16S ribosomal RNA (rRNA) gene sequencing. Microbiome composition of Pakistani individuals was compared against the uBiome database of selected individuals who self-reported to be...

  • Tuesday, 18 September 2018

    The microbial ecosystem of the meromictic Lake Cadagno (Ticino, Swiss Alps) has been studied intensively to understand metabolic functions driven by the highly abundant anoxygenic phototrophic sulfur bacteria of the families Chromatiaceae and Chlorobiaceae. It was found that the sequenced isolate "Thiodictyon syntrophicum" nov. sp. str. Cad16T, belonging to the Chromatiaceae, may fix 26% of all bulk inorganic carbon in the chemocline at day and night. With this study, we elucidated the mode of dark carbon fixation of str. Cad16T with a combination of long-term monitoring of key physicochemical parameters with CTD, 14C-incorporation experiments and quantitative proteomics of in situ...

  • Tuesday, 18 September 2018

    Plasmodium falciparum, the causative agent of human malaria, is an apicomplexan parasite with a complex, multi-host life cycle. Sixty percent of transcripts from its extreme AT-rich (81%) genome possess coding polyadenosine (polyA) runs, distinguishing the parasite from its hosts and other sequenced organisms. Recent studies indicate that transcripts with polyA runs encoding poly-lysine are hot spots for ribosome stalling and frameshifting, eliciting mRNA surveillance pathways and attenuating protein synthesis in the majority of prokaryotic and eukaryotic organisms. Here, we show that the P. falciparum translational machinery is paradigm-breaking. Using bioinformatic and biochemical approaches, we demonstrate that both endogenous genes and...

  • Tuesday, 18 September 2018

    Pathogenic bacteria in medical environments can lead to treatment complications and hospital acquired infections (HAIs), and current cleaning protocols do not address hard-to-access areas or that may be beyond line-of-sight treatment such as with ultraviolet radiation. Here, we tested the efficacy of Sanisport ozone as a means to treat hospital equipment and surfaces for killing bacteria. We observed a rapid killing of medically-relevant and environmental bacteria (Escherichia coli, Enterococcus faecalis, Bacillus subtlis, and Deinococcus radiodurans) across four surfaces (blankets, catheter, remotes, and syringes) within 30 minutes, and up to a 99% reduction in viable bacteria at the end of 2-hour...

  • Tuesday, 18 September 2018

    Worldwide outbreaks of enterovirus D68 (EV-D68) in 2014 and 2016 have caused widespread serious respiratory and neurological disease. To investigate diversity, spread, and evolution of EV-D68 we performed near full-length deep sequencing in 54 samples obtained in Sweden during the 2014 and 2016 outbreaks. In most samples, intrapatient variability was low and dominated by rare synonymous variants, but three patients showed evidence of dual infections with distinct EV-D68 variants from the same sub-clade. Interpatient evolution showed a very strong temporal signal, with an evolutionary rate of 0.0038{+/-}0.0001 substitutions per site and year. Phylogenetic trees reconstructed from the sequences suggest that...

  • Tuesday, 18 September 2018

    The phosphoprotein pp150 is a structurally, immunogenically, and regulatorily important capsid-associated tegument protein abundant in {beta}-herpesviruses including cytomegaloviruses (CMV), but absent in -herpesviruses and {gamma}-herpesviruses. In human CMV (HCMV), bridging across each triplex and three adjacent major capsid proteins (MCPs) is a group of three pp150 subunits in a "{Delta}"-shaped fortifying configuration, 320 of which encase and stabilize the genome-containing capsid. Because murine CMV (MCMV) has been used as a model for HCMV pathogenesis and therapeutic studies, one might expect that pp150 and the capsid in MCMV and HCMV have similar structures. Here, by cryoEM and sub-particle reconstructions, we have...

  • Tuesday, 18 September 2018

    Polysaccharide utilisation loci (PUL) are regions within bacterial genomes that encode all the necessary machinery for the cleavage of particular carbohydrates. For the Bacteroidetes phylum, prediction of PUL from genomic data alone involves the identification of carbohydrate-active enzymes (CAZymes) co-localised with susCD gene pairs. Here we present the open prediction of PUL in 5414 public Bacteroidetes genomes, and an open-source pipeline to reproduce or extend the results.

  • Monday, 17 September 2018

    Malaria parasites remodel their host erythrocytes to gain nutrients and avoid the immune system. Host erythrocytes are modified by hundreds of effectors proteins exported from the parasites into the host cell. Protein export is mediated by the PTEX translocon comprising five core components of which EXP2 is considered to form the putative pore that spans the vacuole membrane enveloping the parasite within its erythrocyte. To explore the function and importance of EXP2 for parasite survival in the asexual blood stage of Plasmodium falciparum we inducibly knocked down the expression of EXP2. Reduction in EXP2 expression strongly reduced parasite growth proportional...

  • Monday, 17 September 2018

    Lipoate is an essential cofactor for key enzymes of oxidative and one-carbon metabolism. It is covalently attached to E2 subunits of dehydrogenase (DH) complexes and the GcvH subunit of the glycine cleavage system. Bacillus subtilis possess two protein lipoylation pathways: biosynthesis and scavenging. The former requires octanoylation of GcvH, amidotransfer of the octanoate to E2s, and insertion of sulfur atoms. Lipoate scavenging is mediated by a lipoate ligase (LplJ), that catalizes a classical two-step ATP-dependent reaction. Although these pathways were thought to be redundant, a {Delta}lipL mutant, unable to transfer the octanoyl group from GcvH to the E2s during lipoate...

  • Monday, 17 September 2018

    Chronic obstructive pulmonary disease (COPD) is a smoking-related illness affecting 64 million people worldwide. Airway infection drives recurrent exacerbations and lung function decline. Prophylactic antibiotics may prevent exacerbations but their use is a significant cause of population antimicrobial resistance. We characterised the sputum microbiome by 16S rRNA gene analysis using 138 samples collected during a randomised controlled trial of prophylactic antibiotics in 71 patients with stable COPD. On comparing the profile of the microbiome obtained by sequencing to the isolates grown from samples using standard culture, there were similarities overall, although with a much narrower spectrum of genera on culture...

  • Monday, 17 September 2018

    Commensal microorganisms present at mucosal surfaces play a vital role in protecting the host organism from bacterial infection. There are multiple factors that contribute to selecting for the microbiome, key of which are host genetics. Flavobacterium psychrophillum, the causative agent of Bacterial Cold Water Disease in salmonids, accounts for acute losses in wild and farmed Rainbow Trout (Oncorhynchus mykiss). The U.S. National Center for Cool and Cold Water Aquaculture has used family-based selective breeding to generate a line of rainbow trout with enhanced resistance to F. psychrophilum. The goal of this study is to determine whether selective breeding impacts the...

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