413 research outputs found

    Bioactive metabolites of Streptomyces misakiensis display broad-spectrum antimicrobial activity against multidrug-resistant bacteria and fungi

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    BackgroundAntimicrobial resistance is a serious threat to public health globally. It is a slower-moving pandemic than COVID-19, so we are fast running out of treatment options.PurposeThus, this study was designed to search for an alternative biomaterial with broad-spectrum activity for the treatment of multidrug-resistant (MDR) bacterial and fungal pathogen-related infections.MethodsWe isolated Streptomyces species from soil samples and identified the most active strains with antimicrobial activity. The culture filtrates of active species were purified, and the bioactive metabolite extracts were identified by thin-layer chromatography (TLC), preparative high-performance liquid chromatography (HPLC), nuclear magnetic resonance (NMR) spectroscopy, and gas chromatography-mass spectrometry (GC-MS). The minimum inhibitory concentrations (MICs) of the bioactive metabolites against MDR bacteria and fungi were determined using the broth microdilution method.ResultsPreliminary screening revealed that Streptomyces misakiensis and S. coeruleorubidus exhibited antimicrobial potential. The MIC50 and MIC90 of S. misakiensis antibacterial bioactive metabolite (ursolic acid methyl ester) and antifungal metabolite (tetradecamethylcycloheptasiloxane) against all tested bacteria and fungi were 0.5 μg/ml and 1 μg/mL, respectively, versus S. coeruleorubidus metabolites: thiocarbamic acid, N,N-dimethyl, S-1,3-diphenyl-2-butenyl ester against bacteria (MIC50: 2 μg/ml and MIC90: 4 μg/mL) and fungi (MIC50: 4 μg/ml and MIC90: 8 μg/mL). Ursolic acid methyl ester was active against ciprofloxacin-resistant strains of Streptococcus pyogenes, S. agalactiae, Escherichia coli, Klebsiella pneumoniae, and Salmonella enterica serovars, colistin-resistant Aeromonas hydrophila and K. pneumoniae, and vancomycin-resistant Staphylococcus aureus. Tetradecamethylcycloheptasiloxane was active against azole- and amphotericin B-resistant Candida albicans, Cryptococcus neoformans, C. gattii, Aspergillus flavus, A. niger, and A. fumigatus. Ursolic acid methyl ester was applied in vivo for treating S. aureus septicemia and K. pneumoniae pneumonia models in mice. In the septicemia model, the ursolic acid methyl ester-treated group had a significant 4.00 and 3.98 log CFU/g decrease (P < 0.05) in liver and spleen tissue compared to the infected, untreated control group. Lung tissue in the pneumonia model showed a 2.20 log CFU/g significant decrease in the ursolic acid methyl ester-treated group in comparison to the control group. The haematological and biochemical markers in the ursolic acid methyl ester-treated group did not change in a statistically significant way. Moreover, no abnormalities were found in the histopathology of the liver, kidneys, lungs, and spleen of ursolic acid methyl ester-treated mice in comparison with the control group. ConclusionS. misakiensis metabolite extracts are broad-spectrum antimicrobial biomaterials that can be further investigated for the potential against MDR pathogen infections. Hence, it opens up new horizons for exploring alternative drugs for current and reemerging diseases

    Search for the lepton-family-number nonconserving decay \mu -> e + \gamma

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    The MEGA experiment, which searched for the muon- and electron-number violating decay \mu -> e + \gamma, is described. The spectrometer system, the calibrations, the data taking procedures, the data analysis, and the sensitivity of the experiment are discussed. The most stringent upper limit on the branching ratio of \mu -> e + \gamma) < 1.2 x 10^{-11} was obtained

    Association of Spermatogenic Failure with the b2/b3 Partial AZFc Deletion

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    Infertility affects around 1 in 10 men and in most cases the cause is unknown. The Y chromosome plays an important role in spermatogenesis and specific deletions of this chromosome, the AZF deletions, are associated with spermatogenic failure. Recently partial AZF deletions have been described but their association with spermatogenic failure is unclear. Here we screened a total of 339 men with idiopathic spermatogenic failure, and 256 normozoospermic ancestry-matched men for chromosome microdeletions including AZFa, AZFb, AZFc, and the AZFc partial deletions (gr/gr, b1/b3 and b2/b3)

    Gender and Educational Differences in Perception of Domestic Violence Against Women Among Libyan Migrants in Manchester.

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    Domestic violence against women (DVAW) is a worldwide phenomenon and refers to any act committed against women that results in physical and psychological harm, and coercion, loss of liberty, and deprivation. There is a dearth of research and information about the extent and prevalence of domestic violence among Libyan communities. The aim of the study was to explore community knowledge of, and attitudes toward, DVAW and to improve our understanding of the factors that influence knowledge, attitudes, and responses, particularly educational and gender differences. Using snowball sampling, we analyzed 20 semistructured interviews with Libyans living in Manchester, United Kingdom. We found gender and education-influenced participants' perception of DVAW. Men in general did not recognize DVAW as a serious social problem; noticeably, they saw it as a personal and family issue. Knowing attitudes toward DVAW is necessary for government and communities' prevention policies as attitudes influence perpetration of DVAW

    Editors’ Introduction: An Overview of the Educational Administration and Leadership Curriculum: Traditions of Islamic Educational Administration and Leadership in Higher Education

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    This chapter provides an overview of several topics relevant to constructing an approach to teaching educational administration and leadership in Muslim countries. First, it places the topic in the context of the changing nature and critiques of the field that argue for a greater internationalisation to both resist some of the negative aspects of globalisation and to represent countries’ traditions in the professional curriculum. Then, it identifies literature that presents the underlying principles and values of Islamic education that guide curriculum and pedagogy and shape its administration and leadership including the Qur’an and Sunnah and the classical educational literature which focuses on aims, values and goals of education as well as character development upon which a ‘good’ society is built. This is followed by a section on the Islamic administration and leadership traditions that are relevant to education, including the values of educational organisations and how they should be administered, identifying literature on the distinctive Islamic traditions of leadership and administrator education and training as it applies to education from the establishment of Islam and early classical scholars and senior administrators in the medieval period who laid a strong foundation for a highly sophisticated preparation and practice of administration in philosophical writings and the Mirrors of Princes writings, and subsequent authors who have built upon it up to the contemporary period. The final section provides an overview of the chapters in this collection

    Public Services Reforms in Neo-Patrimonial Systems: The Commercialization of Healthcare and Education in Saudi Arabia

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    Reforms of public services have been extensively researched in representative democracies, where they have been especially explained by ideological change, political turnover, financial crises and pressures from international organizations. Meanwhile, less attention has been paid to explaining them in countries whose institutions have been characterized as neo-patrimonial systems. This study aims to explain the commercialization of healthcare and education services that took place in Saudi Arabia since the 2000s. The analysis provides some ways to refine and expand existing theoretical accounts of public services reforms in regimes that differ from representative democracies

    Mupirocin-resistant Staphylococcus aureus in Africa: a systematic review and meta-analysis

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    Background Mupirocin is widely used for nasal decolonization of Staphylococcus aureus to prevent subsequent staphylococcal infection in patients and healthcare personnel. However, the prolonged and unrestricted use has led to the emergence of mupirocin-resistant (mupR) S. aureus. The aim of this systematic review was to investigate the prevalence, phenotypic and molecular characteristics, and geographic spread of mupR S. aureus in Africa. Methods We examined five electronic databases (EBSCOhost, Google Scholar, ISI Web of Science, MEDLINE, and Scopus) for relevant English articles on screening for mupR S. aureus from various samples in Africa. In addition, we performed random effects meta-analysis of proportions to determine the pooled prevalence of mupR S. aureus in Africa. The search was conducted until 3 August 2016. Results We identified 43 eligible studies of which 11 (26%) were obtained only through Google Scholar. Most of the eligible studies (28/43; 65%) were conducted in Nigeria (10/43; 23%), Egypt (7/43; 16%), South Africa (6/43; 14%) and Tunisia (5/43; 12%). Overall, screening for mupR S. aureus was described in only 12 of 54 (22%) African countries. The disk diffusion method was the widely used technique (67%; 29/43) for the detection of mupR S. aureus in Africa. The mupA-positive S. aureus isolates were identified in five studies conducted in Egypt (n = 2), South Africa (n = 2), and Nigeria (n = 1). Low-level resistance (LmupR) and high-level resistance (HmupR) were both reported in six human studies from South Africa (n = 3), Egypt (n = 2) and Libya (n = 1). Data on mupR-MRSA was available in 11 studies from five countries, including Egypt, Ghana, Libya, Nigeria and South Africa. The pooled prevalence (based on 11 human studies) of mupR S. aureus in Africa was 14% (95% CI =6.8 to 23.2%). The proportion of mupA-positive S. aureus in Africa ranged between 0.5 and 8%. Furthermore, the frequency of S. aureus isolates that exhibited LmupR, HmupR and mupR-MRSA in Africa were 4 and 47%, 0.5 and 38%, 5 and 50%, respectively. Conclusions The prevalence of mupR S. aureus in Africa (14%) is worrisome and there is a need for data on administration and use of mupirocin. The disk diffusion method which is widely utilized in Africa could be an important method for the screening and identification of mupR S. aureus. Moreover, we advocate for surveillance studies with appropriate guidelines for screening mupR S. aureus in Africa

    The Impact of Entrepreneurship Education in Higher Education: A Systematic Review and Research Agenda

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    Using a teaching model framework, we systematically review empirical evidence on the impact of entrepreneurship education (EE) in higher education on a range of entrepreneurial outcomes, analyzing 159 published articles from 2004 to 2016. The teaching model framework allows us for the first time to start rigorously examining relationships between pedagogical methods and specific outcomes. Reconfirming past reviews and meta-analyses, we find that EE impact research still predominantly focuses on short-term and subjective outcome measures and tends to severely underdescribe the actual pedagogies being tested. Moreover, we use our review to provide an up-to-date and empirically rooted call for less obvious, yet greatly promising, new or underemphasized directions for future research on the impact of university-based entrepreneurship education. This includes, for example, the use of novel impact indicators related to emotion and mind-set, focus on the impact indicators related to the intention-to-behavior transition, and exploring the reasons for some contradictory findings in impact studies including person-, context-, and pedagogical model-specific moderator
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