268 research outputs found

    Cytotoxic clinical isolates of Pseudomonas aeruginosa identified during the Steroids for Corneal Ulcers Trial show elevated resistance to fluoroquinolones.

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    BackgroundTo determine the relationship between type three secretion genotype and fluoroquinolone resistance for P. aeruginosa strains isolated from microbial keratitis during the Steroids for Corneal Ulcers Trial (SCUT) and for two laboratory strains, PA103 and PAO1.MethodsConfirmed P. aeruginosa isolates from the SCUT were divided into exoU(+) or exoU(-). The exoU(+) strains contained the gene encoding ExoU, a powerful phospholipase toxin delivered into host cells by the type three secretion system. Isolates were then assessed for susceptibility to fluoroquinolone, cephalosporin, and aminoglycoside antibiotics using disk diffusion assays. Etest was used to determine the MIC of moxifloxacin and other fluoroquinolones. Laboratory isolates in which the exoU gene was added or deleted were also tested.ResultsA significantly higher proportion of exoU(+) strains were resistant to ciprofloxacin (p = 0.001), gatifloxacin (p = 0.003), and ofloxacin (p = 0.002) compared to exoU(-) isolates. There was no significant difference between exoU(+) or exoU(-) negative isolates with respect to susceptibility to other antibiotics except gentamicin. Infections involving resistant exoU(+) strains trended towards worse clinical outcome. Deletion or acquisition of exoU in laboratory isolates did not affect fluoroquinolone susceptibility.ConclusionsFluoroquinolone susceptibility of P. aeruginosa isolated from the SCUT is consistent with previous studies showing elevated resistance involving exoU encoding (cytotoxic) strains, and suggest worse clinical outcome from infections involving resistant isolates. Determination of exoU expression in clinical isolates of P. aeruginosa may be helpful in directing clinical management of patients with microbial keratitis

    Methods and Processes of Developing the Strengthening the Reporting of Observational Studies in Epidemiology – Veterinary (STROBE-Vet) Statement

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    BACKGROUND Reporting of observational studies in veterinary research presents challenges that often are not addressed in published reporting guidelines. OBJECTIVE To develop an extension of the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement that addresses unique reporting requirements for observational studies in veterinary medicine related to health, production, welfare, and food safety. DESIGN Consensus meeting of experts. SETTING Mississauga, Canada. PARTICIPANTS Seventeen experts from North America, Europe, and Australia. METHODS Experts completed a pre-meeting survey about whether items in the STROBE statement should be modified or added to address unique issues related to observational studies in animal species with health, production, welfare, or food safety outcomes. During the meeting, each STROBE item was discussed to determine whether or not rewording was recommended and whether additions were warranted. Anonymous voting was used to determine consensus. RESULTS Six items required no modifications or additions. Modifications or additions were made to the STROBE items 1 (title and abstract), 3 (objectives), 5 (setting), 6 (participants), 7 (variables), 8 (data sources/measurement), 9 (bias), 10 (study size), 12 (statistical methods), 13 (participants), 14 (descriptive data), 15 (outcome data), 16 (main results), 17 (other analyses), 19 (limitations), and 22 (funding). CONCLUSION The methods and processes used were similar to those used for other extensions of the STROBE statement. The use of this STROBE statement extension should improve reporting of observational studies in veterinary research by recognizing unique features of observational studies involving food-producing and companion animals, products of animal origin, aquaculture, and wildlife

    Microbubble-Based Model Analysis of Liquid Breakdown Initiation by a Submicrosecond Pulse

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    An electrical breakdown model for liquids in response to a submicrosecond(∼100ns) voltage pulse is presented, and quantitative evaluations carried out. It is proposed that breakdown is initiated by field emission at the interface of pre-existing microbubbles. Impact ionization within the microbubble gas then contributes to plasma development, with cathode injection having a delayed and secondary role. Continuous field emission at the streamer tip contributes to filament growth and propagation. This model can adequately explain almost all of the experimentally observed features, including dendritic structures and fluctuations in the prebreakdown current. Two-dimensional, time-dependent simulations have been carried out based on a continuum model for water, though the results are quite general. Monte Carlo simulations provide the relevant transport parameters for our model. Our quantitative predictions match the available data quite well, including the breakdown delay times and observed optical emission

    Procedures for standard evaluation and data management of advanced potato clones. Summary guide to selecting potato clones for drought tolerance under field conditions international cooperators’ guide

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    Drought stress is a multidimensional stress and generally leads to changes in the physiological, morphological, ecological, biochemical, and molecular traits of plants (Farooq et al., 2009). In addition, it can negatively affect the quantity and quality of plant growth and yield (Zlatev and Lidon, 2012). Many plants have developed resistance mechanisms to tolerate drought stress, but these mechanisms are varied and depend on plant species (Hossain et al., 2016). There are several options for drought tolerance mechanisms in plants, including developmental, physiological, morphological, ecological, biochemical, and molecular mechanisms. Typically, the mechanisms involved in plant tolerance to drought follow a general plan: maintaining cell water homeostasis under drought conditions (Hossain et al., 2016). Impact of abiotic stresses on potato production will increase over the next decades, due to climate change and the extension of potato cultivation under drought/heat conditions (Hijmanns, 2003) since potato is extremely susceptible to drought (Monneveux et al., 2013). Plant adaptation to drought involves several different morphological and physiological characteristics; however, no specific traits have been reported since drought responses change according to plant genotype and growth stage. Stem height, number of green leaves and leaf length are considered to be the parameters most sensitive to moderate drought conditions (Deblonde and Ledent, 2001); however, these traits have shown inconsistency in many cases. In the present protocol, a selection of traits is shown as a result of previous experiments and exhaustive data analysis at the International Potato Center

    COVID- 19 pandemic and health care disparities in head and neck cancer: Scanning the horizon

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    The COVID- 19 pandemic has profoundly disrupted head and neck cancer (HNC) care delivery in ways that will likely persist long term. As we scan the horizon, this crisis has the potential to amplify preexisting racial/ethnic disparities for patients with HNC. Potential drivers of disparate HNC survival resulting from the pandemic include (a) differential access to telemedicine, timely diagnosis, and treatment; (b) implicit bias in initiatives to triage, prioritize, and schedule HNC- directed therapy; and (c) the marked changes in employment, health insurance, and dependent care. We present four strategies to mitigate these disparities: (a) collect detailed data on access to care by race/ethnicity, income, education, and community; (b) raise awareness of HNC disparities; (c) engage stakeholders in developing culturally appropriate solutions; and (d) ensure that surgical prioritization protocols minimize risk of racial/ethnic bias. Collectively, these measures address social determinants of health and the moral imperative to provide equitable, high- quality HNC care.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156210/2/hed26345.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156210/1/hed26345_am.pd

    Bathyraja albomaculata, Whitedotted Skate

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    The Whitedotted Skate (Bathryraja albomaculata) is a large (to 150 cm total length) skate that occurs in the Southeast Pacific and Southwest Atlantic Oceans from Coquimbo, Chile south around Cape Horn and north to Uruguay, including the Falkland Islands (Malvinas) and the Burdwood Bank, and is demersal on the inshore continental shelf and upper slope at depths of 55?945 m. It is captured in industrial longline and trawl fisheries, which operate throughout its range. Although discarded dead in some parts of its range, it is utilized for human consumption in others. In the Southeast Pacific, skates targeted in fisheries (Dipturus spp.) have undergone severe population reductions where this species is captured as unmanaged bycatch. In the Southwest Atlantic, there are some general management measures in place for skates but they are not species-specific. This skate is now absent from approximately one-third of its distribution in Argentina due to heavy fishing pressure on skates. Overall, due to the level of exposure to inadequately managed fisheries, noted population reductions in other skates, its lack of refuge at depth, a suspected decline in area of occupancy, and a combination of declines in some areas and stability in others, it is suspected that the Whitedotted Skate has undergone a population reduction of 30-49% over the past three generations (40.5 years). Therefore, the Whitedotted Skate is assessed as Vulnerable A2bd.Fil: Pollom, R.. University Fraser Simon; CanadáFil: Dulvy, N. K.. University Fraser Simon; CanadáFil: Acuña, E.. Universidad Católica del Norte; ChileFil: Bustamante, C.. Universidad de Antofagasta; ChileFil: Cevallos, A.. No especifíca;Fil: Chiaramonte, Gustavo Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia". Estación Hidrobiológica de Puerto Quequén (sede Quequén); ArgentinaFil: Cuevas, J. M.. Wildlife Conservation Society; Estados UnidosFil: Herman, K.. Georgia Aquarium; Estados UnidosFil: Navia, A. F.. No especifíca;Fil: Paesch, L.. Dirección Nacional de Recursos Acuáticos; UruguayFil: Pompert, J.. No especifíca;Fil: Velez Zuazo, X.. Smithsonian Conservation Biology Institute; Estados Unido

    Solar Drinking Water Disinfection (SODIS) to Reduce Childhood Diarrhoea in Rural Bolivia: A Cluster-Randomized, Controlled Trial

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    Daniel Maeusezahl and colleagues conducted a cluster-randomized controlled trial in rural Bolivia of solar drinking water disinfection, and find only moderate compliance with the intervention and no evidence of reduction in diarrhea among children

    In-roads to the spread of antibiotic resistance: regional patterns of microbial transmission in northern coastal Ecuador

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    The evolution of antibiotic resistance (AR) increases treatment cost and probability of failure, threatening human health worldwide. The relative importance of individual antibiotic use, environmental transmission and rates of introduction of resistant bacteria in explaining community AR patterns is poorly understood. Evaluating their relative importance requires studying a region where they vary. The construction of a new road in a previously roadless area of northern coastal Ecuador provides a valuable natural experiment to study how changes in the social and natural environment affect the epidemiology of resistant Escherichia coli. We conducted seven bi-annual 15 day surveys of AR between 2003 and 2008 in 21 villages. Resistance to both ampicillin and sulphamethoxazole was the most frequently observed profile, based on antibiogram tests of seven antibiotics from 2210 samples. The prevalence of enteric bacteria with this resistance pair in the less remote communities was 80 per cent higher than in more remote communities (OR = 1.8 [1.3, 2.3]). This pattern could not be explained with data on individual antibiotic use. We used a transmission model to help explain this observed discrepancy. The model analysis suggests that both transmission and the rate of introduction of resistant bacteria into communities may contribute to the observed regional scale AR patterns, and that village-level antibiotic use rate determines which of these two factors predominate. While usually conceived as a main effect on individual risk, antibiotic use rate is revealed in this analysis as an effect modifier with regard to community-level risk of resistance
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