Multiresistant-MRSA tricuspid valve infective endocarditis with ancient osteomyelitis locus

BACKGROUND: Methicillin-resistant S. aureus (MRSA) with low susceptibility to glycopeptides is uncommon. CASE PRESENTATION: The case of a 50-year-old non-drug addict patient presenting with tricuspid valve infective endocarditis (IE) by MRSA resistant to vancomycin and linezolid is presented. There was response only to quinupristin/dalfopristin. He had a motorcycling accident four years before undergoing right above-the-knee amputation and orthopaedic fixation of the left limb. There were multiple episodes of left MRSA-osteomyelitis controlled after surgery and vancomycin therapy. MRSA isolated from the blood at the time of IE presented with the same profile than the isolated four years earlier. Sequential treatment with teicoplanin-cotrimoxazole and Linezolid associated to vancomycin – rifampicin – cotrimoxazole had no improvement. Infection was controlled after 28 days of therapy with quinupristin/dalfopristin. CONCLUSION: The literature presents only a few cases of MRSA IE not susceptible to glycopeptides in not drug addicted patients. This case shows the comparison of a highly-resistant MRSA after previous S. aureus osteomyelitis treated with glycopeptides. This is the first description of successful treatment of resistant-MRSA IE of the tricuspid valve complicated by multiple pulmonary septic infarction with quinupristin/dalfopristi

Mapping polyclonal antibody responses to bacterial infection using next generation phage display

Mapping polyclonal antibody responses to infectious diseases to identify individual epitopes has the potential to underpin the development of novel serological assays and vaccines. Here, phage-peptide library panning coupled with screening using next generation sequencing was used to map antibody responses to bacterial infections. In the first instance, pigs experimentally infected with Salmonella enterica serovar Typhimurium was investigated. IgG samples from twelve infected pigs were probed in parallel and phage binding compared to that with equivalent IgG from pre-infected animals. Seventy- seven peptide mimotopes were enriched specifically against sera from multiple infected animals. Twenty-seven of these peptides were tested in ELISA and twenty-two were highly discriminatory for sera taken from pigs post-infection (P < 0.05) indicating that these peptides are mimicking epitopes from the bacteria. In order to further test this methodology, it was applied to differentiate antibody responses in poultry to infections with distinct serovars of Salmonella enterica. Twenty-seven peptides were identified as being enriched specifically against IgY from multiple animals infected with S. Enteritidis compared to those infected with S. Hadar. Nine of fifteen peptides tested in ELISA were highly discriminatory for IgY following S. Enteritidis infection (p < 0.05) compared to infections with S. Hadar or S. Typhimurium

Next-generation sequencing of vertebrate experimental organisms

Next-generation sequencing technologies are revolutionizing biology by allowing for genome-wide transcription factor binding-site profiling, transcriptome sequencing, and more recently, whole-genome resequencing. While it is currently not possible to generate complete de novo assemblies of higher-vertebrate genomes using next-generation sequencing, improvements in sequence read lengths and throughput, coupled with new assembly algorithms for large data sets, will soon make this a reality. These developments will in turn spawn a revolution in how genomic data are used to understand genetics and how model organisms are used for disease gene discovery. This review provides an overview of the current next-generation sequencing platforms and the newest computational tools for the analysis of next-generation sequencing data. We also describe how next-generation sequencing may be applied in the context of vertebrate model organism genetics

Transcriptome Analysis of H2O2-Treated Wheat Seedlings Reveals a H2O2-Responsive Fatty Acid Desaturase Gene Participating in Powdery Mildew Resistance

Hydrogen peroxide (H2O2) plays important roles in plant biotic and abiotic stress responses. However, the effect of H2O2 stress on the bread wheat transcriptome is still lacking. To investigate the cellular and metabolic responses triggered by H2O2, we performed an mRNA tag analysis of wheat seedlings under 10 mM H2O2 treatment for 6 hour in one powdery mildew (PM) resistant (PmA) and two susceptible (Cha and Han) lines. In total, 6,156, 6,875 and 3,276 transcripts were found to be differentially expressed in PmA, Han and Cha respectively. Among them, 260 genes exhibited consistent expression patterns in all three wheat lines and may represent a subset of basal H2O2 responsive genes that were associated with cell defense, signal transduction, photosynthesis, carbohydrate metabolism, lipid metabolism, redox homeostasis, and transport. Among genes specific to PmA, ‘transport’ activity was significantly enriched in Gene Ontology analysis. MapMan classification showed that, while both up- and down- regulations were observed for auxin, abscisic acid, and brassinolides signaling genes, the jasmonic acid and ethylene signaling pathway genes were all up-regulated, suggesting H2O2-enhanced JA/Et functions in PmA. To further study whether any of these genes were involved in wheat PM response, 19 H2O2-responsive putative defense related genes were assayed in wheat seedlings infected with Blumeria graminis f. sp. tritici (Bgt). Eight of these genes were found to be co-regulated by H2O2 and Bgt, among which a fatty acid desaturase gene TaFAD was then confirmed by virus induced gene silencing (VIGS) to be required for the PM resistance. Together, our data presents the first global picture of the wheat transcriptome under H2O2 stress and uncovers potential links between H2O2 and Bgt responses, hence providing important candidate genes for the PM resistance in wheat

Barriers to Non-Viral Vector-Mediated Gene Delivery in the Nervous System

Efficient methods for cell line transfection are well described, but, for primary neurons, a high-yield method different from those relying on viral vectors is lacking. Viral transfection has several drawbacks, such as the complexity of vector preparation, safety concerns, and the generation of immune and inflammatory responses when used in vivo. However, one of the main problems for the use of non-viral gene vectors for neuronal transfection is their low efficiency when compared with viral vectors. Transgene expression, or siRNA delivery mediated by non-viral vectors, is the result of multiple processes related to cellular membrane crossing, intracellular traffic, and/or nuclear delivery of the genetic material cargo. This review will deal with the barriers that different nanoparticles (cationic lipids, polyethyleneimine, dendrimers and carbon nanotubes) must overcome to efficiently deliver their cargo to central nervous system cells, including internalization into the neurons, interaction with intracellular organelles such as lysosomes, and transport across the nuclear membrane of the neuron in the case of DNA transfection. Furthermore, when used in vivo, the nanoparticles should efficiently cross the blood-brain barrier to reach the target cells in the brain

An atlas of over 90.000 conserved noncoding sequences provides insight into crucifer regulatory regions

Despite the central importance of noncoding DNA to gene regulation and evolution, understanding of the extent of selection on plant noncoding DNA remains limited compared to that of other organisms. Here we report sequencing of genomes from three Brassicaceae species (Leavenworthia alabamica, Sisymbrium irio and Aethionema arabicum) and their joint analysis with six previously sequenced crucifer genomes. Conservation across orthologous bases suggests that at least 17% of the Arabidopsis thaliana genome is under selection, with nearly one-quarter of the sequence under selection lying outside of coding regions. Much of this sequence can be localized to approximately 90,000 conserved noncoding sequences (CNSs) that show evidence of transcriptional and post-transcriptional regulation. Population genomics analyses of two crucifer species, A. thaliana and Capsella grandiflora, confirm that most of the identified CNSs are evolving under medium to strong purifying selection. Overall, these CNSs highlight both similarities and several key differences between the regulatory DNA of plants and other species

Income Trends of Residential PV Adopters: An analysis of household-level income estimates

The residential photovoltaic (PV) market has expanded rapidly over the past decade, but questions exist about how equitably that growth has occurred across income groups. Prior studies have investigated this question but are often limited by narrow geographic study regions, now-dated analysis timeframes, or coarse estimates of PV-adopter incomes. At the same time, a spate of new programs and initiatives, as well as innovations in business models and product design, have emerged in recent years with the aim of making solar more accessible and affordable to broader segments of the population. Yet, many of those efforts are proceeding without robust underlying information about the income characteristics of recent residential PV adopters. This work aims to establish basic factual information about income trends among U.S. residential solar adopters, with some emphasis on low- and moderate-income (LMI) households. The analysis is unique in its relatively extensive coverage of the U.S. solar market, relying on Berkeley Lab’s Tracking the Sun dataset, which contains project-level data for the vast majority of all residential PV systems in the country (a subset of which are ultimately included in the analysis sample). This analysis is also unique in its use of household-level income estimates that provide a more-precise characterization of PV-adopter incomes than in most prior studies

Accurate quantification of dystrophin mRNA and exon skipping levels in Duchenne Muscular Dystrophy

Antisense oligonucleotide (AON)-mediated exon skipping aimed at restoring the reading frame is a promising therapeutic approach for Duchenne muscular dystrophy that is currently tested in clinical trials. Numerous AONs have been tested in (patient-derived) cultured muscle cells and the mdx mouse model. The main outcome to measure AON efficiency is usually the exon-skipping percentage, though different groups use different methods to assess these percentages. Here, we compare a series of techniques to quantify exon skipping levels in AON-treated mdx mouse muscle. We compared densitometry of RT-PCR products on ethidium bromide-stained agarose gels, primary and nested RT-PCR followed by bioanalyzer analysis and melting curve analysis. The digital array system (Fluidigm) allows absolute quantification of skipped vs non-skipped transcripts and was used as a reference. Digital array results show that 1 ng of mdx gastrocnemius muscle-derived mRNA contains approximately 1100 dystrophin transcripts and that 665 transcripts are sufficient to determine exon-skipping levels. Quantification using bioanalyzer or densitometric analysis of primary PCR products resulted in values close to those obtained with digital array. The use of the same technique allows comparison between different groups working on exon skipping in the mdx mouse model