225 research outputs found

    The Challenge to Interpret Antimicrobial Susceptibility at a Small Community Hospital

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    Abstract Objective: We aimed to determine the prevailing resistance rates at a local community hospital for a select group of gram-positive and gram-negative microorganisms for the period 2008-2012. Methods: Aerobic and facultative anaerobic culture isolates representing blood, urine and wounds specimens from all wards were tested at the Microbiology Laboratory, using the MicroScan AutoScan4, to determine antimicrobial susceptibility at the local community hospital. Results: the findings allude to the prevalence of resistance at the institution for the period under review. Conclusion: Resistance trends are speculative at best without the inclusion of molecular characterization of resistance and consumption data. Pharmacists should play a greater role in the determination of resistance by providing the microbiologist with consumption or utilization data, such as the daily defined dose. The inclusion of the daily defined dose in the estimation of resistance would allow clinicians to determine if selective pressure may have contributed to the prevailing resistance rates

    Methicillin sensitive Staphylococcus aureus producing Panton-Valentine leukocidin toxin in Trinidad & Tobago: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Certain <it>Staphylococcus aureus </it>strains produce Panton-Valentine leukocidin, a toxin that lyses white blood cells causing extensive tissue necrosis and chronic, recurrent or severe infection. This report documents a confirmed case of methicillin-sensitive <it>Staphylococcus aureus </it>strain harboring Panton-Valentine leukocidin genes from Trinidad and Tobago. To the best of our knowledge, this is the first time that such a case has been identified and reported from this country.</p> <p>Case presentation</p> <p>A 13-year-old Trinidadian boy of African descent presented with upper respiratory symptoms and gastroenteritis-like syptoms. About two weeks later he was re-admitted to our hospital complaining of pain and weakness affecting his left leg, where he had received an intramuscular injection of an anti-emetic drug. He deteriorated and developed septic arthritis, necrotizing fasciitis and septic shock with acute respiratory distress syndrome, leading to death within 48 hours of admission despite intensive care treatment. The infection was caused by <it>S. aureus</it>. Bacterial isolates from specimens recovered from our patient before and after his death were analyzed using microarray DNA analysis and <it>spa </it>typing, and the results revealed that the <it>S. aureus </it>isolates belonged to clonal complex 8, were methicillin-susceptible and positive for Panton-Valentine leukocidin. An autopsy revealed multi-organ failure and histological tissue stains of several organs were also performed and showed involvement of his lungs, liver, kidneys and thymus, which showed Hassal's corpuscles.</p> <p>Conclusion</p> <p>Rapid identification of Panton-Valentine leukocidin in methicillin-sensitive <it>S. aureus </it>isolates causing severe infections is necessary so as not to miss their potentially devastating consequences. Early feedback from the clinical laboratories is crucial.</p

    Methicillin sensitive Staphylococcus aureus producing Panton-Valentine leukocidin toxin in Trinidad & Tobago: a case report

    Get PDF
    <p>Abstract</p> <p>Introduction</p> <p>Certain <it>Staphylococcus aureus </it>strains produce Panton-Valentine leukocidin, a toxin that lyses white blood cells causing extensive tissue necrosis and chronic, recurrent or severe infection. This report documents a confirmed case of methicillin-sensitive <it>Staphylococcus aureus </it>strain harboring Panton-Valentine leukocidin genes from Trinidad and Tobago. To the best of our knowledge, this is the first time that such a case has been identified and reported from this country.</p> <p>Case presentation</p> <p>A 13-year-old Trinidadian boy of African descent presented with upper respiratory symptoms and gastroenteritis-like syptoms. About two weeks later he was re-admitted to our hospital complaining of pain and weakness affecting his left leg, where he had received an intramuscular injection of an anti-emetic drug. He deteriorated and developed septic arthritis, necrotizing fasciitis and septic shock with acute respiratory distress syndrome, leading to death within 48 hours of admission despite intensive care treatment. The infection was caused by <it>S. aureus</it>. Bacterial isolates from specimens recovered from our patient before and after his death were analyzed using microarray DNA analysis and <it>spa </it>typing, and the results revealed that the <it>S. aureus </it>isolates belonged to clonal complex 8, were methicillin-susceptible and positive for Panton-Valentine leukocidin. An autopsy revealed multi-organ failure and histological tissue stains of several organs were also performed and showed involvement of his lungs, liver, kidneys and thymus, which showed Hassal's corpuscles.</p> <p>Conclusion</p> <p>Rapid identification of Panton-Valentine leukocidin in methicillin-sensitive <it>S. aureus </it>isolates causing severe infections is necessary so as not to miss their potentially devastating consequences. Early feedback from the clinical laboratories is crucial.</p

    Forensic Technologies in Music Copyright

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    The essay explores some recent controversies in British music copyright through the evolving technologies used to perform or play music in the courtroom. While the conceptual tension between cases has caused doctrinal anxiety about the effect of popular music in copyright, the essay contends that the recent stream of music copyright cases can be considered from a historical perspective, taking into account the tools, materials and experts as they featured in court. In doing so, the essay connects a history of legal expertise to the emergence of new technologies while arguing that legal knowledge about music copyright was, in fact, stabilised in the courtroom

    Dynamics of carbon pools in post-agrogenic sandy soils of southern taiga of Russia

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    <p>Abstract</p> <p>Background</p> <p>Until recently, a lot of arable lands were abandoned in many countries of the world and, especially, in Russia, where about half a million square kilometers of arable lands were abandoned in 1961-2007. The soils at these fallows undergo a process of natural restoration (or self-restoration) that changes the balance of soil organic matter (SOM) supply and mineralization.</p> <p>Results</p> <p>A soil chronosequence study, covering the ecosystems of 3, 20, 55, 100, and 170 years of self-restoration in southern taiga zone, shows that soil organic content of mineral horizons remains relatively stable during the self-restoration. This does not imply, however, that SOM pools remain steady. The C/N ratio of active SOM reached steady state after 55 years, and increased doubly (from 12.5 - 15.6 to 32.2-33.8). As to the C/N ratio of passive SOM, it has been continuously increasing (from 11.8-12.7 to 19.0-22.8) over the 170 years, and did not reach a steady condition.</p> <p>Conclusion</p> <p>The results of the study imply that soil recovery at the abandoned arable sandy lands of taiga is incredibly slow process. Not only soil morphological features of a former ploughing remained detectable but also the balance of soil organic matter input and mineralization remained unsteady after 170 years of self-restoration.</p

    The Characterization of Helicobacter pylori DNA Associated with Ancient Human Remains Recovered from a Canadian Glacier

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    Helicobacter pylori is a gram-negative bacterium that colonizes the stomach of nearly half of the world's population. Genotypic characterization of H. pylori strains involves the analysis of virulence-associated genes, such as vacA, which has multiple alleles. Previous phylogenetic analyses have revealed a connection between modern H. pylori strains and the movement of ancient human populations. In this study, H. pylori DNA was amplified from the stomach tissue of the Kwäday Dän Ts'ìnchi individual. This ancient individual was recovered from the Samuel Glacier in Tatshenshini-Alsek Park, British Columbia, Canada on the traditional territory of the Champagne and Aishihik First Nations and radiocarbon dated to a timeframe of approximately AD 1670 to 1850. This is the first ancient H. pylori strain to be characterized with vacA sequence data. The Tatshenshini H. pylori strain has a potential hybrid vacA m2a/m1d middle (m) region allele and a vacA s2 signal (s) region allele. A vacA s2 allele is more commonly identified with Western strains, and this suggests that European strains were present in northwestern Canada during the ancient individual's time. Phylogenetic analysis indicated that the vacA m1d region of the ancient strain clusters with previously published novel Native American strains that are closely related to Asian strains. This indicates a past connection between the Kwäday Dän Ts'ìnchi individual and the ancestors who arrived in the New World thousands of years ago

    Decadal-scale litter manipulation alters the biochemical and physical character of tropical forest soil carbon

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    © 2018 Elsevier Ltd Climate change and rising atmospheric carbon dioxide (CO2) concentrations are likely to alter tropical forest net primary productivity (NPP), potentially affecting soil C storage. We examined biochemical and physical changes in soil C fractions in a humid tropical forest where experimental litter manipulation changed total soil C stocks. We hypothesized that: (1.) low-density soil organic C (SOC) fractions are more responsive to altered litter inputs than mineral-associated SOC, because they cycle relatively rapidly. (2.) Any accumulation of mineral-associated SOC with litter addition is relatively stable (i.e. low leaching potential). (3.) Certain biomolecules, such as waxes (alkyl) and proteins (N-alkyl), form more stable mineral-associations than other biomolecules in strongly weathered soils. A decade of litter addition and removal affected bulk soil C content in the upper 5 cm by +32% and −31%, respectively. Most notably, C concentration in the mineral-associated SOC fraction was greater in litter addition plots relative to controls by 18% and 28% in the dry and wet seasons, respectively, accounting for the majority of greater bulk soil C stock. Radiocarbon and leaching analyses demonstrated that the greater mineral-associated SOC in litter addition plots consisted of new and relatively stable C, with only 3% of mineral-associated SOC leachable in salt solution. Solid-state13C NMR spectroscopy indicated that waxes (alkyl C) and microbial biomass compounds (O-alkyl and N-alkyl C) in mineral-associated SOC are relatively stable, whereas plant-derived compounds (aromatic and phenolic C) are lost from mineral associations on decadal timescales. We conclude that changes in tropical forest NPP will alter the quantity, biochemistry, and stability of C stored in strongly weathered tropical soils
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