32 research outputs found
Haemophilus ducreyi Cutaneous Ulcer Strains Are Nearly Identical to Class I Genital Ulcer Strains
BACKGROUND:
Although cutaneous ulcers (CU) in the tropics is frequently attributed to Treponema pallidum subspecies pertenue, the causative agent of yaws, Haemophilus ducreyi has emerged as a major cause of CU in yaws-endemic regions of the South Pacific islands and Africa. H. ducreyi is generally susceptible to macrolides, but CU strains persist after mass drug administration of azithromycin for yaws or trachoma. H. ducreyi also causes genital ulcers (GU) and was thought to be exclusively transmitted by microabrasions that occur during sex. In human volunteers, the GU strain 35000HP does not infect intact skin; wounds are required to initiate infection. These data led to several questions: Are CU strains a new variant of H. ducreyi or did they evolve from GU strains? Do CU strains contain additional genes that could allow them to infect intact skin? Are CU strains susceptible to azithromycin?
METHODOLOGY/PRINCIPAL FINDINGS:
To address these questions, we performed whole-genome sequencing and antibiotic susceptibility testing of 5 CU strains obtained from Samoa and Vanuatu and 9 archived class I and class II GU strains. Except for single nucleotide polymorphisms, the CU strains were genetically almost identical to the class I strain 35000HP and had no additional genetic content. Phylogenetic analysis showed that class I and class II strains formed two separate clusters and CU strains evolved from class I strains. Class I strains diverged from class II strains ~1.95 million years ago (mya) and CU strains diverged from the class I strain 35000HP ~0.18 mya. CU and GU strains evolved under similar selection pressures. Like 35000HP, the CU strains were highly susceptible to antibiotics, including azithromycin.
CONCLUSIONS/SIGNIFICANCE:
These data suggest that CU strains are derivatives of class I strains that were not recognized until recently. These findings require confirmation by analysis of CU strains from other regions
Microbiomes of Thalassia testudinum throughout the Atlantic Ocean, Caribbean Sea, and Gulf of Mexico are influenced by site and region while maintaining a core microbiome
Plant microbiomes are known to serve several important functions for their host, and it is therefore important to understand their composition as well as the factors that may influence these microbial communities. The microbiome of Thalassia testudinum has only recently been explored, and studies to-date have primarily focused on characterizing the microbiome of plants in a single region. Here, we present the first characterization of the composition of the microbial communities of T. testudinum across a wide geographical range spanning three distinct regions with varying physicochemical conditions. We collected samples of leaves, roots, sediment, and water from six sites throughout the Atlantic Ocean, Caribbean Sea, and the Gulf of Mexico. We then analyzed these samples using 16S rRNA amplicon sequencing. We found that site and region can influence the microbial communities of T. testudinum, while maintaining a plant-associated core microbiome. A comprehensive comparison of available microbial community data from T. testudinum studies determined a core microbiome composed of 14 ASVs that consisted mostly of the family Rhodobacteraceae. The most abundant genera in the microbial communities included organisms with possible plant-beneficial functions, like plant-growth promoting taxa, disease suppressing taxa, and nitrogen fixers
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Hotspots of biogeochemical activity linked to aridity and plant traits across global drylands
14 páginas.- 4 figuras.- 67 referencias.- The online version contains supplementary material available at https://doi.org/10.1038/s41477-024-01670-7Perennial plants create productive and biodiverse hotspots, known as fertile islands, beneath their canopies. These hotspots largely determine the structure and functioning of drylands worldwide. Despite their ubiquity, the factors controlling fertile islands under conditions of contrasting grazing by livestock, the most prevalent land use in drylands, remain virtually unknown. Here we evaluated the relative importance of grazing pressure and herbivore type, climate and plant functional traits on 24 soil physical and chemical attributes that represent proxies of key ecosystem services related to decomposition, soil fertility, and soil and water conservation. To do this, we conducted a standardized global survey of 288 plots at 88 sites in 25 countries worldwide. We show that aridity and plant traits are the major factors associated with the magnitude of plant effects on fertile islands in grazed drylands worldwide. Grazing pressure had little influence on the capacity of plants to support fertile islands. Taller and wider shrubs and grasses supported stronger island effects. Stable and functional soils tended to be linked to species-rich sites with taller plants. Together, our findings dispel the notion that grazing pressure or herbivore type are linked to the formation or intensification of fertile islands in drylands. Rather, our study suggests that changes in aridity, and processes that alter island identity and therefore plant traits, will have marked effects on how perennial plants support and maintain the functioning of drylands in a more arid and grazed world.This research was supported by the European Research Council (ERC grant 647038 (BIODESERT) awarded to F.T.M.) and Generalitat Valenciana (CIDEGENT/2018/041). D.J.E. was supported by the Hermon Slade Foundation (HSF21040). J. Ding was supported by the National Natural Science Foundation of China Project (41991232) and the Fundamental Research Funds for the Central Universities of China. M.D.-B. acknowledges support from TED2021-130908B-C41/AEI/10.13039/501100011033/Unión Europea Next Generation EU/PRTR and the Spanish Ministry of Science and Innovation for the I + D + i project PID2020-115813RA-I00 funded by MCIN/AEI/10.13039/501100011033. O.S. was supported by US National Science Foundation (Grants DEB 1754106, 20-25166), and Y.L.B.-P. by a Marie Sklodowska-Curie Actions Individual Fellowship (MSCA-1018 IF) within the European Program Horizon 2020 (DRYFUN Project 656035). K.G. and N.B. acknowledge support from the German Federal Ministry of Education and Research (BMBF) SPACES projects OPTIMASS (FKZ: 01LL1302A) and ORYCS (FKZ: FKZ01LL1804A). B.B. was supported by the Taylor Family-Asia Foundation Endowed Chair in Ecology and Conservation Biology, and M. Bowker by funding from the School of Forestry, Northern Arizona University. C.B. acknowledges funding from the National Natural Science Foundation of China (41971131). D.B. acknowledges support from the Hungarian Research, Development and Innovation Office (NKFI KKP 144096), and A. Fajardo support from ANID PIA/BASAL FB 210006 and the Millennium Science Initiative Program NCN2021-050. M.F. and H.E. received funding from Ferdowsi University of Mashhad (grant 39843). A.N. and M.K. acknowledge support from FCT (CEECIND/02453/2018/CP1534/CT0001, SFRH/BD/130274/2017, PTDC/ASP-SIL/7743/2020, UIDB/00329/2020), EEA (10/CALL#5), AdaptForGrazing (PRR-C05-i03-I-000035) and LTsER Montado platform (LTER_EU_PT_001) grants. O.V. acknowledges support from the Hungarian Research, Development and Innovation Office (NKFI KKP 144096). L.W. was supported by the US National Science Foundation (EAR 1554894). Y.Z. and X.Z. were supported by the National Natural Science Foundation of China (U2003214). H.S. is supported by a María Zambrano fellowship funded by the Ministry of Universities and European Union-Next Generation plan. The use of any trade, firm or product names does not imply endorsement by any agency, institution or government. Finally, we thank the many people who assisted with field work and the landowners, corporations and national bodies that allowed us access to their land.Peer reviewe
Recommended from our members
Effects of Hypnosis to Facilitate Movement through Stages of Change for Smoking Cessation
On the basis of the transtheoretical model of change, it was hypothesized that hypnosis would facilitate significantly greater movement through the stages of change toward smoking cessation in contrast to an active control condition. Thirty participants were pre-tested for hypnotizability using the Elkins Hypnotizability Scale. Participants readiness for change was assessed using the University of Rhode Island Change Assessment scale. Groups were balanced for hypnotizability, stage of change, number of cigarettes smoked per day, and years spent smoking. The relaxation induction from the Elkins Hypnotizability Scale was used to relax participants and induce hypnosis. Hypnotic suggestions were then matched to participants stage of change and were intended to reduce ambivalence while increasing motivation about smoking cessation. The University of Rhode Island Change Assessment scale was administered immediately following intervention and at a 10-day follow-up. A series of two-factor spilt-plot ANOVA’s showed significant changes within groups in the hypothesized direction at multiple time points, including a decrease in contemplation scores from pre-intervention to 10-days following intervention (p = .002) and an increase in action scores from pre-intervention to post-intervention (p = .00007). Effects of both groups further showed a significant reduction to the amount of cigarettes smoked per day (p = .003)
Cu and Zn isotope fractionation during extreme chemical weathering
Copper and Zn are trace metal micronutrients whose stable isotope systematics are receiving increasing attention as possible paleoenvironmental tracers. However, to realise this potential, their behaviour during chemical weathering must be better constrained. We present coupled Cu and Zn isotope data for a well-characterised Indian laterite weathering profile, which includes a full suite of samples from unaltered greywacke bedrock to indurated lateritic duricrust. This sample set provides an exceptional opportunity to interrogate Cu and Zn isotope compositions during an extreme example of chemical weathering. Despite their occurrence in different host phases within the parent greywacke, Cu and Zn isotopes behave coherently during weathering. We observe preferential loss of heavy isotopes at increasing degrees of alteration, with 0.6‰ total variability in δ66Zn and 0.9‰ in δ65Cu. Given the absence of evidence for CuS or ZnS phases in the parent lithology, we attribute the liberation of heavy isotopes to organic complexation in the aqueous phase and/or incorporation of light isotopes in secondary aluminous Fe-oxides. Strong enrichment of both metals is also associated with a peak in Mn at a previously identified paleo-water table horizon. This dataset confirms that weathering under oxygenated conditions releases isotopically heavy Cu, regardless of the host phase. Meanwhile, Zn isotopes are only fractionated to any significant extent at the most extreme degrees of chemical weathering reached during lateritization. We conclude that the isotopic composition of the weathering-derived input of Zn to rivers should be largely insensitive to climate change on geological timescales
Clinical burden of multi-cause and pneumococcal pneumonia, meningitis, and septicemia in Hungary. Results of a retrospective study (2006–2011)
Pneumococcus, illetve bármely kórokú pneumonia, meningitis és septikaemia miatti hospitalizáció és halálozás Magyarországon. Egy retrospektív értékelés eredménye (2006–2011)Clinical burden of multi-cause and pneumococcal pneumonia, meningitis, and septicemia in Hungary. Results of a retrospective study (2006–2011)
Bevezetés: Kevés adat áll rendelkezésre a konjugált pneumococcusvakcináknak a pneumonia, meningitis és septikaemia előfordulására gyakorolt hatásáról Magyarországon. Célkitűzés: A szerzők retrospektív vizsgálattal kívánták felmérni a 2006–2011 között Magyarországon minden korosztályban előforduló, kórházi kezelést igénylő, bármely kórokú és pneumococcus okozta pneumonia-, meningitis- és septikaemiaeseteket. Módszer: Összesített adatokat gyűjtöttek az Országos Egészségbiztosítási Pénztár adatbázisából előre meghatározott BNO-10-kódok segítségével. Az összehasonlítás χ2-próba segítségével készült a következők alapján: átlagos arány a védőoltás bevezetését megelőzően (2006–2007) versus átlagos arány a védőoltás bevezetését követően (2010–2011). Eredmények: A 0–4 éves korú gyermekeknél a kórházi kezelést igénylő esetek aránya jelentősen csökkent a bármely kórokú tüdőgyulladás és agyhártyagyulladás esetében, de nőtt a septikaemia esetében. A többi korcsoportnál jelentősen növekedett a bármely kórokú pneumonia- és septikaemiaesetek száma. A kórházi halálozás aránya az életkorral emelkedett. A pneumococcusspecifikus kódok korlátozott alkalmazása miatt nem állapítottak meg egyértelmű eredményeket a pneumococcus okozta betegségeket illetően. Következtetések: A bármely kórokú tüdőgyulladás és agyhártyagyulladás csökkenése a 0–4 éves korosztálynál a konjugált pneumococcusvakcinációnak a kórházi kezelés arányára gyakorolt közvetlen hatására utal. Orv. Hetil., 2014, 155(36), 1426–1436.
|
Introduction: Assessment of the impact of pneumococcal conjugate vaccines on the burden of pneumonia, meningitis, and septicemia in Hungary is limited. Aim: The aim of this retrospective study was to quantify rates of hospitalized multi-cause and pneumococcal pneumonia, meningitis, and septicemia in all age groups in Hungary between 2006 and 2011. Method: Aggregate data were obtained from the Hungarian National Healthcare Fund using pre-specified ICD-10 codes. Comparisons included average rates pre-vaccine (2006–2007) versus post-vaccine (2010–2011) using a χ2 test. Results: Hospitalization rates among children aged 0–4 years significantly declined for multi-cause pneumonia and meningitis, but increased for septicemia. There were significant increases in multi-cause pneumonia and septicemia in other age groups. In-hospital mortality rates increased with age. Limited use of pneumococcal-specific codes led to inconclusive findings for pneumococcal diseases. Conclusions: Declines in multi-cause pneumonia and meningitis in children aged 0–4 years suggest direct effects of pneumococcal conjugate vaccination on hospitalization rates. Orv. Hetil., 2014, 155(36), 1426–1436