511 research outputs found

    Haemophilus ducreyi Cutaneous Ulcer Strains Diverged from Both Class I and Class II Genital Ulcer Strains: Implications for Epidemiological Studies

    Get PDF
    BACKGROUND: Haemophilus ducreyi has emerged as a major cause of cutaneous ulcers (CU) in yaws-endemic regions of the tropics in the South Pacific, South East Asia and Africa. H. ducreyi was once thought only to cause the genital ulcer (GU) disease chancroid; GU strains belong to 2 distinct classes, class I and class II. Using whole-genome sequencing of 4 CU strains from Samoa, 1 from Vanuatu and 1 from Papua New Guinea, we showed that CU strains diverged from the class I strain 35000HP and that one CU strain expressed β-lactamase. Recently, the Center for Disease Control and Prevention released the genomes of 11 additional CU strains from Vanuatu and Ghana; however, the evolutionary relationship of these CU strains to previously-characterized CU and GU strains is unknown. METHODOLOGY/PRINCIPAL FINDINGS: We performed phylogenetic analysis of 17 CU and 10 GU strains. Class I and class II GU strains formed two distinct clades. The class I strains formed two subclades, one containing 35000HP and HD183 and the other containing the remainder of the class I strains. Twelve of the CU strains formed a subclone under the class I 35000HP subclade, while 2 CU strains formed a subclone under the other class I subclade. Unexpectedly, 3 of the CU strains formed a subclone under the class II clade. Phylogenetic analysis of dsrA-hgbA-ncaA sequences yielded a tree similar to that of whole-genome phylogenetic tree. CONCLUSIONS/SIGNIFICANCE: CU strains diverged from multiple lineages within both class I and class II GU strains. Multilocus sequence typing of dsrA-hgbA-ncaA could be reliably used for epidemiological investigation of CU and GU strains. As class II strains grow relatively poorly and are relatively more susceptible to vancomycin than class I strains, these findings have implications for methods to recover CU strains. Comparison of contemporary CU and GU isolates would help clarify the relationship between these entities

    Population Status and Trends of Northern Bobwhite (Colinus virginianus) in Ohio: 1984- 2004

    Get PDF
    Author Institution: Terrestrial Wildlife Ecology Laboratory, School of Environment and Natural Resources, The Ohio State UniversityWe assessed the status and trends of northern bobwhite (Colinus virginianus) populations in Ohio from 1984-2004 (21 years). Bobwhite abundance indices were obtained from surveys conducted on secondary roads. The number of roads surveyed per year ranged from 69 to 209 (with 12 stops each). We used Poisson regression with generalized estimating equations and a Generalized Additive Model to analyze bobwhite population trends. Bobwhite populations in Ohio declined 9.3% / year (95% CI=7.3%-11.2%). Overall, populations declined 76% (95% CI=68-82%) over the 21-year period. We also compared annual trends during the same period among 10 weather regions in the state. At least six weather regions showed declining population trends, but analyses for the remaining four regions were inconclusive. We mapped the distribution and abundance of bobwhites in Ohio using abundance indices from surveys conducted during 1985, 1992, and 2002. These maps revealed that the bobwhite range contracted as populations declined during 1984-2004. The current core area of bobwhite abundance is located in Southwestern Ohio, where 16 counties are open for hunting. However, bobwhite distribution shifted eastward within Southwestern Ohio during 1984-2004. Adjacent counties that are currently closed to hunting lie mostly outside the highest abundance zone. We recommend bobwhite population surveys of high resolution on counties open to hunting, as well as surrounding counties where hunting has recently been closed. However, lower resolution efforts, such as site occupancy surveys, should be conducted outside those areas to detect range expansio

    Anamnese cultural de enfermagem nas famílias migrantes: uma scoping review

    Get PDF
    A prática clínica com famílias migrantes coloca desafios aos profissionais de saúde e particularmente aos enfermeiros na atualidade, como apontam diferentes autores nacionais e internacionais. Na anamnese cultural os profissionais procuram identificar elementos facilitadores da comunicação e da avaliação inicial das famílias, visando a promoção da adesão e da continuidade aos cuidados propostos.info:eu-repo/semantics/acceptedVersio

    Determination of an Interaction Network between an Extracellular Bacterial Pathogen and the Human Host

    Get PDF
    A major gap in understanding infectious diseases is the lack of information about molecular interaction networks between pathogens and the human host. Haemophilus ducreyi causes the genital ulcer disease chancroid in adults and is a leading cause of cutaneous ulcers in children in the tropics. We developed a model in which human volunteers are infected on the upper arm with H. ducreyi until they develop pustules. To define the H. ducreyi and human interactome, we determined bacterial and host transcriptomic and host metabolomic changes in pustules. We found that in vivo H. ducreyi transcripts were distinct from those in the inocula, as were host transcripts in pustule and wounded control sites. Many of the upregulated H. ducreyi genes were found to be involved in ascorbic acid and anaerobic metabolism and inorganic ion/nutrient transport. The top 20 significantly expressed human pathways showed that all were involved in immune responses. We generated a bipartite network for interactions between host and bacterial gene transcription; multiple positively correlated networks contained H. ducreyi genes involved in anaerobic metabolism and host genes involved with the immune response. Metabolomic studies showed that pustule and wounded samples had different metabolite compositions; the top ion pathway involved ascorbate and aldarate metabolism, which correlated with the H. ducreyi transcriptional response and upregulation of host genes involved in ascorbic acid recycling. These data show that an interactome exists between H. ducreyi and the human host and suggest that H. ducreyi exploits the metabolic niche created by the host immune response.IMPORTANCE Dual RNA sequencing (RNA-seq) offers the promise of determining an interactome at a transcriptional level between a bacterium and the host but has yet to be done on any bacterial infection in human tissue. We performed dual RNA-seq and metabolomics analyses on wounded and infected sites following experimental infection of the arm with H. ducreyi Our results suggest that H. ducreyi survives in an abscess by utilizing l-ascorbate as an alternative carbon source, possibly taking advantage of host ascorbic acid recycling, and that H. ducreyi also adapts by upregulating genes involved in anaerobic metabolism and inorganic ion and nutrient transport. To our knowledge, this is the first description of an interaction network between a bacterium and the human host at a site of infection

    Draft Whole-Genome Sequence of Haemophilus ducreyi Strain AUSPNG1, Isolated from a Cutaneous Ulcer of a Child from Papua New Guinea.

    Get PDF
    Haemophilus ducreyi has recently emerged as a leading cause of cutaneous ulcers in the yaws-endemic areas of Papua New Guinea and other South Pacific islands. Here, we report the draft genome sequence of the H. ducreyi strain AUSPNG1, isolated from a cutaneous ulcer of a child from Papua New Guinea

    Characterization and sequence analysis of the lsg (LOS synthesis genes) locus from Haemophilus influenzae type b

    Full text link
    Analysis of the lsg (LOS synthesis genes) cluster in Escherichia coli strain K12 and mutations in the lsg locus in Haemophilus influenzae type b indicated the presence of 3 regions responsible for sequential modifications of E. coli lipopolysaccharide (LPS). Sequencing of the lsg region yielded 7,435 bp that encompassed 7 complete and 1 partial open reading frames (ORFs 1-8). The predicted product of ORF1 had homology to the consensus sequence of cytochrome b proteins (21% identity, 51% similarity) and to other transmembrane proteins. The products of ORF5 and ORF6 share overall 23% identity and 49% similarity with each other. The ORF6 protein had high homology with the product of ORF275 of the E. coli rfb gene cluster (40% identity, 58% similarity), whose function is not known. Multiple sequence alignment of the ORF5 and ORF6 proteins with the RfbB, RfbJ and RfbX proteins revealed conserved motifs over the N-terminal half region of all these proteins. The products of ORF7 and ORF8 are homologous with Azotobacter vinelandii MolA protein (30% identity, 51% similarity) and MolB protein (26% identity, 48% similarity), respectively. The promoter regions of ORF1, 7 and 8 were determined by primer extension analysis and found to be similar to bacterial σ70-dependent promoters. ORF7 and ORF8 are transcribed into diverse orientation. At least 5 of the encoded proteins have been identified using coupled E. coli transcription/translation system and labeling with [35S]-methionine. We conclude that the genetic organization of the lsg biosynthesis pathway involves multiple operons that lead to the assembly of an H. influenzae LOS structure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67077/2/10.1177_096805199400100305.pd

    GNN-Assisted Phase Space Integration with Application to Atomistics

    Full text link
    Overcoming the time scale limitations of atomistics can be achieved by switching from the state-space representation of Molecular Dynamics (MD) to a statistical-mechanics-based representation in phase space, where approximations such as maximum-entropy or Gaussian phase packets (GPP) evolve the atomistic ensemble in a time-coarsened fashion. In practice, this requires the computation of expensive high-dimensional integrals over all of phase space of an atomistic ensemble. This, in turn, is commonly accomplished efficiently by low-order numerical quadrature. We show that numerical quadrature in this context, unfortunately, comes with a set of inherent problems, which corrupt the accuracy of simulations -- especially when dealing with crystal lattices with imperfections. As a remedy, we demonstrate that Graph Neural Networks, trained on Monte-Carlo data, can serve as a replacement for commonly used numerical quadrature rules, overcoming their deficiencies and significantly improving the accuracy. This is showcased by three benchmarks: the thermal expansion of copper, the martensitic phase transition of iron, and the energy of grain boundaries. We illustrate the benefits of the proposed technique over classically used third- and fifth-order Gaussian quadrature, we highlight the impact on time-coarsened atomistic predictions, and we discuss the computational efficiency. The latter is of general importance when performing frequent evaluation of phase space or other high-dimensional integrals, which is why the proposed framework promises applications beyond the scope of atomistics

    Subcutaneous immunotherapy with aeroallergens-evaluation of adherence in real life

    Get PDF
    Introduction. Adherence in allergen immunotherapy is crucial for its efficacy. At least 3 years of treatment are recommended for achieving a long-term modifying effect. Objectives. To assess patient’s adherence and to identify determinant factors for allergen subcutaneous immunotherapy (SCIT) suspension in patients with respiratory allergy. Methods. Retrospective analysis of the medical record of patients submitted to SCIT between January 2013 and December 2016 in our Department. Results. 323 patients were included: 52% female; mean age 30 ± 13 years; average treatment time 19 ± 13 months. 52 patients (16%) stopped SCIT: 54% female; mean age 30 ± 9 years; average treatment time 12 ± 6 months; 67% dropped the treatment during the 1st year, 27% in the 2nd and 6% during the 3rd year of treatment. Adherence rate determined was 77%. The most frequent reasons for withdrawal were due to economic reasons (47.9%), followed by patients’ perception of no clinical improvement (23%) and change to sublingual immunotherapy (11.6%). Conclusions. Adherence rate in our study was 77%. Economic reasons were the main cause of abandonment in the first year, while the perception of non-improvement was the main reason for abandonment in subsequent years. Adequate information on SCIT prescribing and rigorous monitoring of patients during the treatment can improve adherence.info:eu-repo/semantics/publishedVersio

    Haemophilus ducreyi RpoE and CpxRA Appear To Play Distinct yet Complementary Roles in Regulation of Envelope-Related Functions

    Get PDF
    Haemophilus ducreyi causes the sexually transmitted disease chancroid and a chronic limb ulceration syndrome in children. In humans, H. ducreyi is found in an abscess and overcomes a hostile environment to establish infection. To sense and respond to membrane stress, bacteria utilize two-component systems (TCSs) and extracytoplasmic function (ECF) sigma factors. We previously showed that activation of CpxRA, the only intact TCS in H. ducreyi, does not regulate homologues of envelope protein folding factors but does downregulate genes encoding envelope-localized proteins, including many virulence determinants. H. ducreyi also harbors a homologue of RpoE, which is the only ECF sigma factor in the organism. To potentially understand how H. ducreyi responds to membrane stress, here we defined RpoE-dependent genes using transcriptome sequencing (RNA-Seq). We identified 180 RpoE-dependent genes, of which 98% were upregulated; a major set of these genes encodes homologues of envelope maintenance and repair factors. We also identified and validated a putative RpoE promoter consensus sequence, which was enriched in the majority of RpoE-dependent targets. Comparison of RpoE-dependent genes to those controlled by CpxR showed that each transcription factor regulated a distinct set of genes. Given that RpoE activated a large number of genes encoding envelope maintenance and repair factors and that CpxRA represses genes encoding envelope-localized proteins, these data suggest that RpoE and CpxRA appear to play distinct yet complementary roles in regulating envelope homeostasis in H. ducreyi

    A (p)ppGpp-Null Mutant of Haemophilus ducreyi Is Partially Attenuated in Humans Due to Multiple Conflicting Phenotypes

    Get PDF
    (p)ppGpp responds to nutrient limitation through a global change in gene regulation patterns to increase survival. The stringent response has been implicated in the virulence of several pathogenic bacterial species. Haemophilus ducreyi, the causative agent of chancroid, has homologs of both relA and spoT, which primarily synthesize and hydrolyze (p)ppGpp in Escherichia coli. We constructed relA and relA spoT deletion mutants to assess the contribution of (p)ppGpp to H. ducreyi pathogenesis. Both the relA single mutant and the relA spoT double mutant failed to synthesize (p)ppGpp, suggesting that relA is the primary synthetase of (p)ppGpp in H. ducreyi. Compared to the parent strain, the double mutant was partially attenuated for pustule formation in human volunteers. The double mutant had several phenotypes that favored attenuation, including increased sensitivity to oxidative stress. The increased sensitivity to oxidative stress could be complemented in trans. However, the double mutant also exhibited phenotypes that favored virulence. When grown to the mid-log phase, the double mutant was significantly more resistant than its parent to being taken up by human macrophages and exhibited increased transcription of lspB, which is involved in resistance to phagocytosis. Additionally, compared to the parent, the double mutant also exhibited prolonged survival in the stationary phase. In E. coli, overexpression of DksA compensates for the loss of (p)ppGpp; the H. ducreyi double mutant expressed higher transcript levels of dksA than the parent strain. These data suggest that the partial attenuation of the double mutant is likely the net result of multiple conflicting phenotypes
    • …
    corecore