71 research outputs found

    A bioreactor system to study survival of Salmonella typhimurium in pig gut content

    Get PDF
    The batch culture system included six bioreactors. Three bioreactors containing stomach slurry were maintained at pH 4,5 and 6 respectively. Bioreactors containing small intestine slurry were maintained at pH 5,6 and 7 respectively. The bioreactors were inoculated with 10 ml of viable Salmonella. The bioreactors were maintained for 6 hours. Samples of 10 ml were taken at 0 time and at 1 ,2,4 and 6 hours. The samples were analysed for the presence of Salmonella and SCF A. In the stomach samples Salmonella numbers increased at pH 6 but fell at pH 4. In the small intestine sample Salmonella numbers increased at pH 6 and 7. In terms of SCFA production, in the stomach, with samples at pH 6 there was little change in the amounts of lactate, succinate and formate to that detected at 0 time, however levels of acetate did increase slightly. In the small intestine samples levels of succinate and formate increased slightly up to 4 hours, levels of acetate increased significantly from 0 to 6 hours. In terms of the specific growth rates of the individual strains, both strains grew at pH 6 in the stomach content and to a greater extent in the small intestinal content. A bactericidal effect was observed at pH 4 in the stomach content while neither killing nor growth occurred at pH 5 either in the stomach or the small intestine content. Both strains grew well in the small intestine content at pH 7, showing generation times of up to 24 min

    Competent but complex communication: The phenomena of pheromone-responsive plasmids

    Get PDF
    Enterococci are robust gram-positive bacteria that are found in a variety of surroundings and that cause a significant number of healthcare-associated infections. The genus possesses a high-efficiency pheromone-responsive plasmid (PRP) transfer system for genetic exchange that allows antimicrobial-resistance determinants to spread within bacterial populations. The pCF10 plasmid system is the best characterised, and although other PRP systems are structurally similar, they lack exact functional homologues of pCF10-encoded genes. In this review, we provide an overview of the enterococcal PRP systems, incorporating functional details for the less-well-defined systems. We catalogue the virulence-associated elements of the PRPs that have been identified to date, and we argue that this reinforces the requirement for elucidation of the less studied systems

    The Fate of Foodborne Pathogens in Manure Treated Soil

    Get PDF
    Publication history: Accepted - 22 November 2021; Published online - 10 December 2021.The aim of this review was to provide an update on the complex relationship between manure application, altered pathogen levels and antibiotic resistance. This is necessary to protect health and improve the sustainability of this major farming practice in agricultural systems based on high levels of manure production. It is important to consider soil health in relation to environment and land management practices in the context of the soil microflora and the introduction of pathogens on the health of the soil microbiome. Viable pathogens in manure spread on agricultural land may be distributed by leaching, surface run-off, water source contamination and contaminated crop removal. Thus it is important to understand how multiple pathogens can persist in manures and on soil at farm-scale and how crops produced under these conditions could be a potential transfer route for zoonotic pathogens. The management of pathogen load within livestock manure is a potential mechanism for the reduction and prevention of outbreaks infection with Escherichia coli, Listeria Salmonella, and Campylobacter. The ability of Campylobacter, E. coli, Listeria and Salmonella to combat environmental stress coupled with their survival on food crops and vegetables postharvest emphasizes the need for further study of these pathogens along with the emerging pathogen Providencia given its link to disease in the immunocompromised and its’ high levels of antibiotic resistance. The management of pathogen load within livestock manure has been widely recognized as a potential mechanism for the reduction and prevention of outbreaks infection but any studies undertaken should be considered as region specific due to the variable nature of the factors influencing pathogen content and survival in manures and soil. Mediocre soils that require nutrients could be one template for research on manure inputs and their influence on soil health and on pathogen survival on grassland and in food crops.This work was funded by the Department of Agriculture, Environment and Rural Affairs (DAERA); https://www.daera-ni.gov.uk) as part of the DAERA Postgraduate Studentship Programme and by the DAERA Evidence and Innovation project 18/1/21: Evaluating the impact of a range of organic manures applied to arable land on soil, crop and NI agriculture

    Biofilm regulation in <i>Clostridioides difficile</i>: Novel systems linked to hypervirulence

    Get PDF
    Clostridiodes difficile (C. difficile) was ranked an “urgent threat” by the Centers for Disease Control and Prevention (CDC) in 2019. C. difficile infection (CDI) is the most common healthcare-associated infection (HAI) in the United States of America as well as the leading cause of antibiotic-associated gastrointestinal disease. C. difficile is a gram-positive, rod-shaped, spore-forming, anaerobic bacterium that causes infection of the epithelial lining of the gut. CDI occurs most commonly after disruption of the human gut microflora following the prolonged use of broad-spectrum antibiotics. However, the recurrent nature of this disease has led to the hypothesis that biofilm formation may play a role in its pathogenesis. Biofilms are sessile communities of bacteria protected from extracellular stresses by a matrix of self-produced proteins, polysaccharides, and extracellular DNA. Biofilm regulation in C. difficile is still incompletely understood, and its role in disease recurrence has yet to be fully elucidated. However, many factors have been found to influence biofilm formation in C. difficile, including motility, adhesion, and hydrophobicity of the bacterial cells. Small changes in one of these systems can greatly influence biofilm formation. Therefore, the biofilm regulatory system would need to coordinate all these systems to create optimal biofilm-forming physiology under appropriate environmental conditions. The coordination of these systems is complex and multifactorial, and any analysis must take into consideration the influences of the stress response, quorum sensing (QS), and gene regulation by second messenger molecule cyclic diguanosine monophosphate (c-di-GMP). However, the differences in biofilm-forming ability between C. difficile strains such as 630 and the “hypervirulent” strain, R20291, make it difficult to assign a “one size fits all” mechanism to biofilm regulation in C. difficile. This review seeks to consolidate published data regarding the regulation of C. difficile biofilms in order to identify gaps in knowledge and propose directions for future study

    Synchrony of change in depressive symptoms, health status, and quality of life in persons with clinical depression

    Get PDF
    BACKGROUND: Little is known about longitudinal associations among measures of depression, mental and physical health, and quality of life (QOL). We followed 982 clinically depressed persons to determine which measures changed and whether the change was synchronous with change in depressive symptoms. METHODS: Data were from the Longitudinal Investigation of Depression Outcomes (LIDO). Depressive symptoms, physical and mental health, and quality of life were measured at baseline, 6 weeks, 3 months, and 9 months. Change in the measures was examined over time and for persons with different levels of change in depressive symptoms. RESULTS: On average, all of the measures improved significantly over time, and most were synchronous with change in depressive symptoms. Measures of mental health changed the most, and physical health the least. The measures of change in QOL were intermediate. The 6-week change in QOL could be explained completely by change in depressive symptoms. The instruments varied in sensitivity to changes in depressive symptoms. CONCLUSION: In clinically depressed persons, measures of physical health, mental health, and quality of life showed consistent longitudinal associations with measures of depressive symptoms

    Is Health Related Quality of Life (HRQoL) a valid indicator for health systems evaluation?

    Get PDF
    This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.The purpose of this review is to do a discussion about the use of the HRQoL as a health measure of the populations that enable to analyze its potential use as a measure of development and efficiency of health systems. The principal use of the HRQoL is in health technologies economics evaluation; however this measure can be use in public health when need to know the health state of population. The WHO recognizes its potential use but its necessary to do a discussion about your difficulties for its application and restrictions for its use as a performance indicator for the health systems. The review show the different aspects about the use of HRQoL how a measure of efficiency ot the health system, each aspect identified in the literature is analyzed and discussed, developing the pros and cons of their possible use, especially when it comes as a cardinal measure. The analysis allows recognize that measuring HRQoL in countries could serve as a useful indicator, especially when it seeks to measure the level of health and disease, as do most of the indicators of current use. However, the methodological constraints that do not allow comparability between countries especially when you have large socioeconomic differences have yet to be resolved to allow comparison between different regions.Romero, D.; Vivas Consuelo, DJJ.; Alvis Guzman, NR. (2013). Is Health Related Quality of Life (HRQoL) a valid indicator for health systems evaluation?. SpringerPlus. 2:664-674. doi:10.1186/2193-1801-2-664S6646742Acemoglu D, Johnson S: Disease and development: The effect of life expectancy on economic growth. J Polit Econ 2007, 115(6):925-985. 10.1086/529000Anderson J, Sayles H, Curtis JR, Wolfe F, Michaud K: Converting modified health assessment questionnaire (HAQ), multidimensional HAQ, and HAQII scores into original HAQ scores using models developed with a large cohort of rheumatoid arthritis patients. Arthritis care & research 2010, 62(10):1481-1488. Epub 2010/05/25 10.1002/acr.20265Aristotles : Nicomachean Ethics: Batoche Books Kitchener. 1999. Available from: http://www.efm.bris.ac.uk/het/aristotle/ethics.pdfAugustovski FA, Irazola VE, Velazquez AP, Gibbons L, Craig BM: Argentine valuation of the EQ-5D health states. Value in health 2009, 12(4):587-596. Epub 2009/11/11 10.1111/j.1524-4733.2008.00468.xBernert S, Fernandez A, Haro JM, Konig HH, Alonso J, Vilagut G, et al.: Comparison of different valuation methods for population health status measured by the EQ-5D in three European countries. Value in health 2009, 12(5):750-758. Epub 2009/06/06 10.1111/j.1524-4733.2009.00509.xCervellati M, Sunde U: Life expectancy and economic growth: The role of the demographic transition. Discussion Paper No 2 St. Gallen. Switzerland: Research Center for Ageing, Welfare and Labour Analysis (SCALA); 2009.Cervellati M, Sunde U: Disease and development: The role of life expectancy reconsidered. Econ Lett 2011, 113(3):269-272. 10.1016/j.econlet.2011.08.008Chatters LM: Religion and health: public health research and practice. Annual review of public health 2000, 21: 335-367. Epub 2000/07/08 10.1146/annurev.publhealth.21.1.335Chen B, Mahal A: Measuring the health of the Indian elderly: evidence from National Sample Survey data. Population health metrics 2010, 8: 30. Epub 2010/11/18 10.1186/1478-7954-8-30Cleland JA, Lee AJ, Hall S: Associations of depression and anxiety with gender, age, health-related quality of life and symptoms in primary care COPD patients. Family practice 2007, 24(3):217-223. Epub 2007/05/17 10.1093/fampra/cmm009Cook EL, Harman JS: A comparison of health-related quality of life for individuals with mental health disorders and common chronic medical conditions. Public Health Rep 2008, 123(1):45-51. Epub 2008/03/20Dolan P, Gudex C, Kind P, Williams A: Valuing health states: a comparison of methods. Journal of health economics 1996, 15(2):209-231. Epub 1996/03/08 10.1016/0167-6296(95)00038-0Evans DB, Lauer JA, Tandon A, Murray CJ: Determinants of Health System Performance: Second-Stage Efficiency Analysis. In Health systems performance assessment debates, methods and empiricism. Edited by: Murray CJ, Evans DB. Geneva: World Health Organization; 2003:693-698.Fayers PM, Machin D: Quality of life The assessment, analysis and interpretation of patient-reported outcomes. 2nd edition. John Wiley & Sons Ltda: West Sussex; 2007.Gulis G: Life expectancy as an indicator of environmental health. European Journal of Epidemiolog 2000, 16(2):161-165. 10.1023/A:1007629306606Herdman M, Gudex C, Lloyd A, Janssen M, Kind P, Parkin D, et al.: Development and preliminary testing of the new five-level version of EQ-5D (EQ-5D-5 L). Quality of life research 2011, 20(10):1727-1736. Epub 2011/04/12 10.1007/s11136-011-9903-xHorsman J, Furlong W, Feeny D, Torrance G: The Health Utilities Index (HUI): concepts, measurement properties and applications. Health and quality of life outcomes 2003, 1: 54. Epub 2003/11/14 10.1186/1477-7525-1-54Institute of Medicine, National Academy of Science: Summarizing population health directions for the development and application of population metrics. Washington, D.C: Committee on Summary Measures of Population Health; 1998.Jeremic V, Seke V, Radojicic Z, Jeremic D, Markovic A, Slovic D, et al.: Measuring health of countries: a novel approach. HealthMED 2011, 5(6):1762-1766.Jia H, Moriarty DG, Kanarek N: County-level social environment determinants of health-related quality of life among US adults: a multilevel analysis. Journal of community health 2009, 34(5):430-439. Epub 2009/06/26 10.1007/s10900-009-9173-5Konerding U, Moock J, Kohlmann T: The classification systems of the EQ-5D, the HUI II and the SF-6D: what do they have in common? Quality of life research 2009, 18(9):1249-1261. Epub 2009/09/04 10.1007/s11136-009-9525-8Krabbe PF, Peerenboom L, Langenhoff BS, Ruers TJ: Responsiveness of the generic EQ-5D summary measure compared to the disease-specific EORTC QLQ C-30. Quality of life research 2004, 13(7):1247-1253. Epub 2004/10/12le Hoi V, Chuc NT, Lindholm L: Health-related quality of life, and its determinants, among older people in rural Vietnam. BMC public health 2010, 10: 549. Epub 2010/09/14 10.1186/1471-2458-10-549McDonough CM, Tosteson AN: Measuring preferences for cost-utility analysis: how choice of method may influence decision-making. PharmacoEconomics 2007, 25(2):93-106. Epub 2007/01/26 10.2165/00019053-200725020-00003McHorney CA, Ware JE Jr, Raczek AE: The MOS 36-Item Short-Form Health Survey (SF-36): II Psychometric and clinical tests of validity in measuring physical and mental health constructs. Medical care 1993, 31(3):247-263. Epub 1993/03/01 10.1097/00005650-199303000-00006McHorney CA, Ware JE Jr, Lu JF, SCD : The MOS, 36-item Short-Form Health Survey (SF-36): III. Tests of data quality, scaling assumptions, and reliability across diverse patient groups. Medical care 1994, 32(1):40-66. 10.1097/00005650-199401000-00004Molla M, Madans J, Wagener D, Crimmins E: Summary measures of population health: Report of findings on methodologic and data issues. Hyattsville, MD: National Center for Health Statics; 2003. [cited 2013. Available from: http://www.cdc.gov/nchs/data/misc/pophealth.pdfMolla M, Madans J, Wagener D, Crimmins E: Summary measures of population health: Report of findings on methodologic and data issues. Hyattsville, MD: National Center for Health Statics; 2003.Murray CJ, Frenk J: A framework for assessing the performance of health systems. Bull World Health Organ 2000, 78(6):717-731. Epub 2000/08/05Mykletun A, Stordal E, Dahl AA: Hospital Anxiety and Depression (HAD) scale: factor structure, item analyses and internal consistency in a large population. The British journal of psychiatry 2001, 179: 540-544. Epub 2001/12/04 10.1192/bjp.179.6.540NAUGHTON MJ, Shumaker SA, Anderson RT, Czajkowski SM: Psychological Aspects of Health-Related Quality of Life Measurement: Tests and Scales. In Quality of Life and Pharmaco economics in Clinical Trials. Edited by: Spilker B. New York: Lippincott-Raven; 1996:117-131.Neumann PJ, Jacobson PD, Palmer JA: Measuring the value of public health systems: the disconnect between health economists and public health practitioners. American journal of public health 2008, 98(12):2173-2180. Epub 2008/10/17 10.2105/AJPH.2007.127134OMS: Official records of the world health organization. Geneva: World Health Organization; 1948. Ginebra: Organización Mundial de la Salud; 1948 [cited 2013 Abril]; Available from: http://www.who.int/library/collections/historical/es/index3.html Ginebra: Organización Mundial de la Salud; 1948 [cited 2013 Abril]; Available from:Paternina D, Melguizo E: Calidad de vida en adultos mayores. Revisión sistemática. V encuentro institucional semilleros de investigación. Cartagena, Colombia: Universidad de Cartagena; 2010.PATRICK D, Erickson P: Health Policy, Quality of Life: Health Care Evaluation and Resource Allocation. New York: Oxford University Press; 1993.Pereira CC, Palta M, Mullahy J, Fryback DG: Race and preference-based health-related quality of life measures in the United States. Quality of life research 2011, 20(6):969-978. Epub 2010/12/25 10.1007/s11136-010-9813-3Poole JL, Steen VD: The use of the Health Assessment Questionnaire (HAQ) to determine physical disability in systemic sclerosis. Arthritis care and research 1991, 4(1):27-31. Epub 1991/03/01 10.1002/art.1790040106Prause W, Saletu B, Tribl GG, Rieder A, Rosenberger A, Bolitschek J, et al.: Effects of socio-demographic variables on health-related quality of life determined by the quality of life index–German version. Human psychopharmacology 2005, 20(5):359-365. Epub 2005/06/28 10.1002/hup.699Prieto L, Sacristan JA: Problems and solutions in calculating quality-adjusted life years (QALYs). Health and quality of life outcomes 2003, 1: 80. Epub 2003/12/23 10.1186/1477-7525-1-80Pyne JM, Sieber WJ, David K, Kaplan RM, Hyman Rapaport M, Keith WD: Use of the quality of well-being self-administered version (QWB-SA) in assessing health-related quality of life in depressed patients. Journal of affective disorders 2003, 76(1–3):237-247. Epub 2003/08/29Roset M, Badia X, Mayo NE: Sample size calculations in studies using the EuroQol 5D. Quality of life research 1999, 8(6):539-549. Epub 1999/11/05 10.1023/A:1008973731515Salomon JA, Murray CJ, Ustün TB, Chatterji S: Health state valuations in summary measures of population health. In Health systems performance assessment debates, methods and empiricism. Edited by: Murray CJ, Evans DB. Geneva: World Health Organization; 2003:693-698.Sanders BS: Measuring Community Health Levels. American journal of public health and the nation's health 1964, 54: 1063-1070. Epub 1964/07/01 10.2105/AJPH.54.7.1063Tajvar M, Arab M, Montazeri A: Determinants of health-related quality of life in elderly in Tehran Iran. BMC public health 2008, 8: 323. Epub 2008/09/24 10.1186/1471-2458-8-323Tandon A, Lauer JA, Evans DB, Murray CJ: Health system efficiency: Concepts. In Health systems performance assessment debates, methods and empiricism. Edited by: Murray CJ, Evans DB. Geneva: World Health Organization; 2003:683-692.Thacker SB, Stroup DF, Carande-Kulis V, Marks JS, Roy K, Gerberding JL: Measuring the public's health. Public Health Rep 2006, 121(1):14-22. Epub 2006/01/19Torrance GW: Toward a utility theory foundation for health status index models. Health services research 1976, 11(4):349-369.Vogels T, Verrips GH, Verloove-Vanhorick SP, Fekkes M, Kamphuis RP, Koopman HM, et al.: Measuring health-related quality of life in children: the development of the TACQOL parent form. Quality of life research 1998, 7(5):457-465. Epub 1998/08/06Von Neumann J, Morgenstern O: Theory of games and economic behavior. 3rd edition. New York: Jhon Wiley and Sons; 1967.Wang H, Kindig DA, Mullahy J: Variation in Chinese population health related quality of life: results from a EuroQol study in Beijing, China. Quality of life research 2005, 14(1):119-132. Epub 2005/03/26 10.1007/s11136-004-0612-6Ware JE Jr, Sherbourne CD: The MOS 36-item short-form health survey (SF-36) I. Conceptual framework and item selection. Medical care 1992, 30(6):473-483. Epub 1992/06/11 10.1097/00005650-199206000-00002WHO: WHOQOL: measuring quality of life. 1997. Available from: http://www.who.int/mental_health/media/68.pdfWHO: Health systems performance assessment debates, methods and empiricism. Edited by: Murray CJ, Evans DB. Geneva: World Health Organization; 2003.Wright DR, Wittenberg E, Swan JS, Miksad RA, Prosser LA: Methods for measuring temporary health States for cost-utility analyses. PharmacoEconomics 2009, 27(9):713-723. Epub 2009/09/18 10.2165/11317060-000000000-00000Zarate V, Kind P, Valenzuela P, Vignau A, Olivares-Tirado P, Munoz A: Social valuation of EQ-5D health states: the Chilean case. Value in health 2011, 14(8):1135-1141. Epub 2011/12/14 10.1016/j.jval.2011.09.00

    Accumulation of the antimalarial microtubule inhibitors trifluralin and vinblastine by Plasmodium falciparum

    No full text
    Malaria is a disease in desperate need of new chemotherapeutic approaches. Certain microtubule inhibitors, including vinblastine and taxol, have highly potent activity against malarial parasites and disrupt the normal microtubular structures of intra-erythrocytic parasites at relevant concentrations. While these inhibitors are useful tools, their potential as anti-malarial drugs is limited by their high toxicity to mammalian cells. In contrast, two classes of antimitotic herbicide, namely dinitroanilines (e.g. trifluralin and oryzalin) and phosphorothicamidates (e.g. amiprophosmethyl), exhibit moderate activity against the major human malarial parasite Plasmodium falciparum in culture but very low mammalian cytotoxicity. We examined the dynamics and kinetics of uptake and subcellular compartmentation of [C-14]trifluralin in comparison with [H-3]vinblastine. We wished to determine whether the relatively modest activity of trifluralin was the consequence of poor uptake into parasite cells. Trifluralin accumulated in parasite-infected erythrocytes to similar to 300 times the external concentration and vinblastine at up to similar to 110 times. Accumulation into uninfected erythrocytes was much lower. Uptake of trifluralin was rapid, non-saturable and readily reversed. It appears that the hydrophobic nature of trifluralin leads to accumulation largely in the membranes of the parasite, reducing the levels in the soluble fraction and limiting access to its microtubular target. By contrast, vinblastine accumulated predominantly in the soluble fraction and uptake was saturable and mostly irreversible, consistent with binding predominantly to tubulin. The results indicate that synthesis of more polar trifluralin derivatives may be a promising approach to designing microtubule inhibitors with more potent antimalarial activity. (c) 2008 Elsevier Inc. All rights reserved
    • …
    corecore