Bacterial isolates from positive paired venous catheter and peripheral blood cultures taken during parenteral nutrition were the same species but different strains: A case report.

OBJECTIVE: The same microbial species isolated from blood simultaneously drawn from a central venous catheter hub and a peripheral vein (paired blood cultures) during parenteral nutrition may be assumed to represent the same strain. This case report provides an example of this assumption being incorrect along with a comparator example of it being correct. This has implications for interpretation of differential time to positivity and differential quantitative blood cultures during investigation of suspected intraluminal intravascular catheter or cannula bloodstream infection. CASE DESCRIPTION: Two patients ages ≥18 y prescribed parenteral nutrition each had positive paired blood cultures that had been taken for suspected catheter bloodstream infection because of temperature spikes ≥38°C. The paired Staphylococcus epidermidis isolates from the first patient and the paired Enterococcus faecium isolates from the second patient were each tested beyond routine clinical care to establish if they could be different strains. The central and peripheral isolates of Staphylococcus epidermidis from the first patient were different strains based on hospital-reported antibiograms, genomic DNA profiles, thermograms, and weaker growth and different sizes of colonies of the central strain compared with the peripheral strain. There were no such differences for the isolates of Enterococcus faecium from the second patient. RESULTS: The central and peripheral isolates of Staphylococcus epidermidis from the first patient were different strains based on hospital-reported antibiograms, genomic DNA profiles, thermograms, and weaker growth and different sizes of colonies of the central strain compared with the peripheral strain. There were no such differences for the isolates of Enterococcus faecium from the second patient. CONCLUSION: This case report indicates consideration should be given to reporting whether bacteria have been identified at either species or strain level if differential time to positivity or differential quantitative blood cultures are used to define catheter or cannula bloodstream infection.

Development and Assessment of a Diagnostic DNA Oligonucleotide Microarray for Detection and Typing of Meningitis-Associated Bacterial Species.

Meningitis is commonly caused by infection with a variety of bacterial or viral pathogens. Acute bacterial meningitis (ABM) can cause severe disease, which can progress rapidly to a critical life-threatening condition. Rapid diagnosis of ABM is critical, as this is most commonly associated with severe sequelae with associated high mortality and morbidity rates compared to viral meningitis, which is less severe and self-limiting. We have designed a microarray for detection and diagnosis of ABM. This has been validated using randomly amplified DNA targets (RADT), comparing buffers with or without formamide, in glass slide format or on the Alere ArrayTubeTM (Alere Technologies GmbH) microarray platform. Pathogen-specific signals were observed using purified bacterial nucleic acids and to a lesser extent using patient cerebral spinal fluid (CSF) samples, with some technical issues observed using RADT and glass slides. Repurposing the array onto the Alere ArrayTubeTM platform and using a targeted amplification system increased specific and reduced nonspecific hybridization signals using both pathogen nucleic and patient CSF DNA targets, better revealing pathogen-specific signals although sensitivity was still reduced in the latter. This diagnostic microarray is useful as a laboratory diagnostic tool for species and strain designation for ABM, rather than for primary diagnosis.

Sap flow variation in selected riparian woodland species in the Okavango Delta, Botswana.

In the tropical Okavango Delta, transpiration by trees is an important process partly responsible for maintaining the basin as a freshwater environment. Quantification of evapotranspiration from terrestrial landforms of the delta, fringed by riparian woodlands, is one of the main contributors to uncertainty in current hydrological modelling. We investigated sap flow of common trees in the distal, mid- and upper delta in July-August 2012, November-December 2012 and February-April 2013 using the compensation heat pulse velocity method. In the distal delta, four Diospyros mespiliformis individuals of different sizes were studied. Four trees of different species were studied in the mid- and upper delta. Sap flow density (SFD; flow per unit cross-sectional area) was used as a common unit to facilitate comparison. Sap flow varied with tree size, species, season and location. It was positively correlated with tree size (r 2 = 0.67). Sap flow variation between seasons and across locations in all the species studied indicated two distinct groups. Group 1 transpired the least during the hottest season, November-December, and Group 2 the most. In Group 1, the highest average SFD was 1.17 l cm-2 day-1 during July-August; in Group 2, it was 1.07 l cm-2 day-1 during November-December. Changes in the hydrology of the delta would negatively affect the riparian woodland.

Dans le delta de l'Okavango, tropical, la transpiration des arbres est un processus important partiellement responsable du fait que ce bassin reste un environnement d'eau douce. La quantification de l'évapotranspiration de la topographie terrestre du delta, bordée de forêts riveraines, est un des principaux contributeurs de l'incertitude dans la modélisation hydrologique actuelle. Nous avons étudié la coulée de sève d'arbres communs dans le delta distal, moyen et supérieur en juillet­août 2012, novembre­décembre 2012 et février­avril 2013 par la méthode de compensation heat pulse velocity. Dans le delta distal, nous avons étudié quatre individus de Diospyros mespiliformis de taille différente. Quatre arbres d'espèces différentes ont été étudiés dans les deltas moyens et supérieur. La densité du flux de sève (DFS), flux par unité de surface de section, a servi d'unité commune pour faciliter la comparaison. Le flux de sève variait avec la taille et l'espèce des arbres, la saison et l'emplacement. Il était positivement lié à la taille des arbres (r² = 0,67). La variation du flux de sève avec les saisons et l'emplacement indiquait deux groupes distincts parmi toutes les espèces étudiées. Le Groupe 1 transpirait le moins pendant la saison la plus chaude, novembre­décembre, et le Groupe 2 transpirait le plus. Dans le Groupe 1, la DSF moyenne la plus haute était de 1,17L/cm²/jour en juillet­août; dans le Groupe 2, elle était de 1,07L/cm²/jour en novembre­décembre. Des changements dans l'hydrologie du delta affecteraient négativement la forêt riveraine.

Evaluating the Functionality and Usability of Two Novel Wheelchair Anti-Rollback Devices for Ramp Ascent in Manual Wheelchair Users With Spinal Cord Injury.

BACKGROUND: Difficulty ascending ramps and inclines with a manual wheelchair adversely affects the everyday mobility and overall quality of life of manual wheelchair users. Currently, various anti-rollback devices are available to assist manual wheelchair users to ascend ramps and inclines. However, these devices have 2 main shortcomings: restriction to backward motion limiting recovery from an overturning wheelchair, which is a safety concern; and difficulty in engaging/disengaging the device while on the ramp. OBJECTIVE: To evaluate the functionality and usability of 2 novel wheelchair anti-rollback devices developed to address these shortcomings (prototypes "Wheel" and "Brake"). DESIGN: Cross-sectional. SETTING: Rehabilitation research facility. PARTICIPANTS: Twelve adult participants with chronic spinal cord injury. METHODS: Participants completed training and tested with both the wheelchair anti-rollback devices on a 7.3-m-long ramp. MAIN OUTCOME MEASUREMENTS: Number of stops, perceived physical exertion, pain, and ease of use of these devices as participants maneuvered their wheelchairs up a 7.3-m ramp were assessed. Participants also evaluated their satisfaction with the usability of both the devices using the Quebec User Evaluation of Satisfaction With Assistive Technology (QUEST 2.0). RESULTS: Both prototypes evaluated overcame the limitations of the existing anti-rollback devices. Nonparametric statistical tests showed that participants rated both prototypes similarly for the overall functional and usability aspects. However, the participants' satisfactory rating were higher for the prototype "Brake" than for the prototype "Wheel" based on a functional aspect (ie, engaging/disengaging easiness), and higher for Wheel than for Brake, based on a usability aspect (prototype size). CONCLUSIONS: The qualitative and quantitative outcomes of this investigation, based on the usability and functional evaluations, provided useful information for the improvement in the design of both anti-rollback devices, which may allow manual wheelchair users to manage ramp ascent more safely and easily. Further evaluations with a different SCI population is recommended. LEVEL OF EVIDENCE: IV.

A questionnaire based assessment of numbers, motivation and medical care of UK patients undergoing liver transplant abroad.

BACKGROUND: Medical tourism, where patients travel abroad intentionally to access medical treatment, is a growing trend. Some of these patients travel to undergo organ transplantation. This study aims to quantify the number of UK patients who undergo liver transplantation abroad, assessing their motivations and management. METHODS: Questionnaires were sent to all seven UK liver transplant units enquiring about liver patients receiving transplant abroad. Included were questions on destination, motivation, and pre and post-transplant care. RESULTS: Responses were received from six of the seven transplant centres (86%). A total of 12 patients were identified as having undergone liver transplantation overseas. The top destinations were India, China and Egypt. Four units responded to questions regarding pre-transplant screening. One unit reported Hepatitis B and C screening not taking place. Four units responded to questions regarding post-transplant antimicrobial therapy. This revealed examples of patients inappropriately not receiving valganciclovir, co-trimoxazole, anti-fungal treatment and Hepatitis B immunoglobulins. CONCLUSIONS: UK patients are undergoing liver transplant abroad, albeit in small numbers. Pre and post-transplant management of these patients is of a lower standard than that provided to those undergoing transplantation in the UK. Information transfer between overseas and UK based transplant teams is poor.

Effect of Biochar on Nutrient Leaching in a Young Apple Orchard.

Nutrient leaching from agricultural soils is a worldwide problem that has been implicated in deleterious impacts on the environment. Application of biochar to soil has been proposed as a means to reduce nutrient leaching and improve fertilizer use efficiency. The potential for biochar to reduce nutrient leaching and increase fertilizer use efficiency was tested by applying 47 Mg ha hardwood biochar before replanting a commercial apple () orchard, in the Huon Valley, Tasmania. Passive wick flux meters were installed at the base of the A1 horizon at a depth of 25 cm to monitor leachate volume and the concentration of nutrients leached below the A1 soil horizon over a 38 mo period. Biochar application significantly increased the concentration of phosphorous in the leachate, while having no significant effect on nitrate or potassium concentration. The volume of leachate collected in the flux meters was significantly higher in the biochar treatment, which resulted in significantly higher amounts of potassium and phosphorous being leaching from the biochar treatment than the control. Biochar application had no significant effect on either the concentration or the flux of nitrate leached from the A1 horizon. Nonetheless, nutrient application was well in excess of tree requirements, such that between 53 to 78% of the applied nitrogen, 5 to 11% of the applied phosphate, and 69 to 112% of the applied potassium were leached below the A1 horizon.

Clostridium difficile in children: a review of existing and recently uncovered evidence.

The clinical significance of the presence of Clostridium difficile in children's faeces remains uncertain using current diagnostic procedures. Clostridium difficile is a relatively common finding in infants with no symptoms of gastrointestinal disease, suggesting it may be an incidental finding and form part of the normal gut micro-flora in this age group. On the other hand, particularly in older children or those with significant co-morbidity, there are examples where C. difficile causes disease and exerts considerable morbidity and even mortality (C. difficile infection, CDI). Between these extremes lie a substantial group of children who have both diarrhoea and C. difficile in their stools but where the nature of the association is not clear: Clostridium difficile associated disease (CDAD). We review the significance of C. difficile in children presenting recently uncovered paediatric data from a large UK epidemiological study that informs some key unanswered questions.

Total soil water content accounts for augmented ABA leaf concentration and stomatal regulation of split-rooted apple trees during heterogeneous soil drying.

A split-rooted containerized system was developed by approach grafting two, 1-year-old apple (Malus×domestica Borkh. cv 'Gala') trees to investigate the effect of soil moisture heterogeneity and total soil moisture content (θ(v)) on tree water relations, gas exchange, and leaf abscisic acid (ABA) concentration [ABA(leaf)]. Four irrigation treatments comprising a 2×2 factorial experiment of irrigation volume and placement were imposed over a 30-day period: control (C) [>100% of crop evapotranspiration (ET(c))] applied to both containers; PRD100 (>100% ET(c)) applied to one container only; and two treatments receiving 50% ET(c) applied to either one (PRD50) or both containers (DI50). Irrigation between PRD (partial rootzone drying) root compartments was alternated when θ(v) reached ~35% of field capacity. Maximum daily sap flow of the irrigated roots of PRD100 exceeded that of C roots throughout the experimental period. Pre-dawn water potential (Ψ(pd)) was similar between C and PRD100; however, daily water use and mid-day gas exchange of PRD100 was 30% lower. Slightly higher [ABA(leaf)] was observed in PRD100, but the effect was not significant and could not explain the observed reductions in leaf gas exchange. Both 50% ET(c) treatments had similar, but lower θ(v), Ψ(pd), and gas exchange, and higher [ABA(leaf)] than C and PRD100. Regardless of treatment, the container having the lower θ(v) of a split-rooted system correlated poorly with [ABA(leaf)], but when θ(v) of both containers or θ(v) of the container possessing the higher soil moisture was used, the relationship markedly improved. These results imply that apple canopy gas exchange and [ABA(leaf)] are responsive to the total soil water environment.

Development and evaluation of an ovine antibody-based platform for treatment of Clostridium difficile infection.

Treatment of Clostridium difficile is a major problem as a hospital-associated infection which can cause severe, recurrent diarrhea. The currently available antibiotics are not effective in all cases and alternative treatments are required. In the present study, an ovine antibody-based platform for passive immunotherapy of C. difficile infection is described. Antibodies with high toxin-neutralizing titers were generated against C. difficile toxins A and B and were shown to neutralize three sequence variants of these toxins (toxinotypes) which are prevalent in human C. difficile infection. Passive immunization of hamsters with a mixture of toxin A and B antibodies protected them from a challenge with C. difficile spores in a dose-dependent manner. Antibodies to both toxins A and B were required for protection. The administration of toxin A and B antibodies up to 24 h postchallenge was found to reduce significantly the onset of C. difficile infection compared to nonimmunized controls. Protection from infection was also demonstrated with key disease isolates (ribotypes 027 and 078), which are members of the hypervirulent C. difficile clade. The ribotype 027 and 078 strains also have the capacity to produce an active binary toxin and these data suggest that neutralization of this toxin is unnecessary for the management of infection induced by these strains. In summary, the data suggest that ovine toxin A and B antibodies may be effective in the treatment of C. difficile infection; their potential use for the management of severe, fulminant cases is discussed.

Quantum dot transport in soil, plants, and insects.

Environmental risk assessment of nanomaterials requires information not only on their toxicity to non-target organisms, but also on their potential exposure pathways. Here we report on the transport and fate of quantum dots (QDs) in the total environment: from soils, through their uptake into plants, to their passage through insects following ingestion. Our QDs are nanoparticles with an average particle size of 6.5 nm. Breakthrough curves obtained with CdTe/mercaptopropionic acid QDs applied to columns of top soil from a New Zealand organic apple orchard, a Hastings silt loam, showed there to be preferential flow through the soil's macropores. Yet the effluent recovery of QDs was just 60%, even after several pore volumes, indicating that about 40% of the influent QDs were filtered and retained by the soil column via some unknown exchange/adsorption/sequestration mechanism. Glycine-, mercaptosuccinic acid-, cysteine-, and amine-conjugated CdSe/ZnS QDs were visibly transported to a limited extent in the vasculature of ryegrass (Lolium perenne), onion (Allium cepa) and chrysanthemum (Chrysanthemum sp.) plants when cut stems were placed in aqueous QD solutions. However, they were not seen to be taken up at all by rooted whole plants of ryegrass, onion, or Arabidopsis thaliana placed in these solutions. Leafroller (Lepidoptera: Tortricidae) larvae fed with these QDs for two or four days, showed fluorescence along the entire gut, in their frass (larval feces), and, at a lower intensity, in their haemolymph. Fluorescent QDs were also observed and elevated cadmium levels detected inside the bodies of adult moths that had been fed QDs as larvae. These results suggest that exposure scenarios for QDs in the total environment could be quite complex and variable in each environmental domain.

Quality of malaria information provided on Internet travel operator websites.

BACKGROUND: Over the past 20 years, there has been a steady growth in the number of reported cases of malaria in the UK. With increasing Internet flight sales over recent years, online travel operator websites may be the only place many travellers could conceivably receive pre-travel malaria prevention advice. METHODS: 29 Travel operator websites which allow for online flight purchases to malarious areas from the UK, identified using a Google(®) web search and the website of the International Air Transport Association, were assessed for the existence, accuracy and accessibility of malaria prevention advice available through internal and external website links. RESULTS: Eight (28%) websites provided malaria prevention information on their own pages. Five (17%) websites contained country specific malaria information relevant to the requested destination, including variation of malaria risk within that country and accurate destination specific chemoprophylaxis advice. No malaria information was available, either on internal or external links, on 8 (28%) websites. On average, it took 2.4 additional mouse clicks to access malaria information during the online flight booking process. Six of the 29 websites (21%) allowed for access to information with only 1 click. CONCLUSIONS: Malaria prevention information on online travel operator websites is most often absent or inadequate. Even on websites where such information is of good quality, it can be difficult to access. The travel industry should introduce and enforce guidelines for the malaria information provided by online travel operators.

A new method to quantify the impact of soil carbon management on biophysical soil properties: the example of two apple orchard systems in New Zealand.

A new method to diagnose the environmental sustainability of specific orchard management practices was derived and tested. As a significant factor for soil quality, the soil carbon (C) management in the topsoil of the tree-row of an integrated and organic apple orchard was selected and compared. Soil C management was defined as land management practices that maintain or increase soil C. We analyzed the impact of the soil C management on biological (microbial biomass C, basal respiration, dehydrogenase activity, respiratory quotient) and physical (aggregate stability, amount of plant-available water, conductive mean pore diameter near water saturation) soil properties. Soil in the alley acted as a reference for the managed soil in the tree row. The total and hot-water-extractable C amounts served as a combined proxy for the soil C management. The soil C management accounted for 0 to 81% of the degradation or enhancement of biophysical soil properties in the integrated and organic system. In the integrated system, soil C management led to a loss of C in the top 0.3 m of the tree row within 12 yr, causing a decrease in microbial activities. In the tree row of the organic orchard, C loss occurred in the top 0.1 m, and the decrease in microbial activities was small or not significant. Regarding physical soil properties, the C loss in the integrated system led to a decrease of the aggregate stability, whereas it increased in the organic system. Generally, the impact of soil C management was better correlated with soil microbial than with the physical properties. With respect to environmental soil functions that are sensitive to the decrease in microbial activity or aggregate stability, soil C management was sustainable in the organic system but not in the integrated system.

Mobility of copper, chromium and arsenic from treated timber into grapevines.

The use of chromated copper arsenate (CCA) treated timber posts as support structures in New Zealand vineyards has raised concerns regarding the release of heavy metal(loid)s from the treated timber into the environment. A laboratory experiment was set up to evaluate if post sealing by painting reduces the release rate of CCA metal(loid)s from timber posts. Three posts were painted (Gripset 38, Multi Purpose Bitumen Rubber) on the bottom part, submerged in freshwater, and the concentrations of copper (Cu), chromium (Cr) and arsenic (As) in the water were monitored over a period of 8 months. Three additional, unpainted posts were also used. The CCA contents in the water showed a clear difference between the painted and the unpainted posts, and painting the bottom of the posts reduced the release rate by 50-75%. To monitor the possible mobility of CCA from treated posts into grapevines further, an experiment with four-year-old grapevines planted into sixteen lysimeters was set up in a greenhouse. To half the lysimeters Cu, Cr and As were added to the soil surface at rates of 16, 20, and 12.5 mg/month from 15 November 2005 to 5 May 2006. The other lysimeters acted as a control. Soil solutions were collected at 50, 150 and 300 mm depths using suction cups after seven application of the CCA solution. The results showed that all the elements moved to a depth of 50 mm. Grape fruit, leaves and rachis were analysed for CCA metal(loid)s, but did not show any differences between the CCA-treated and control lysimeters. This indicated either that these metals were not taken up by grapevines or that their translocation from roots to the upper part of the vine was negligible. Further monitoring of CCA metal(loid)s in various parts of the grapevines, including roots, needs to be undertaken.

Clinical decision rules for secondary trauma triage: predictors of emergency operative management.

STUDY OBJECTIVE: Most injured patients taken by ambulance to hospital emergency departments do not require emergency surgery, yet most US trauma centers require a surgeon to be present on their arrival. If a clinical decision rule could be developed to accurately identify which injured patients require emergency operative intervention, then such "secondary triage" criteria could permit a trauma center to more efficiently use their surgeons' time. METHODS: We analyzed 7.5 years of data (8,289 consecutive trauma activations) in our prospectively maintained Level I trauma center registry. We used classification and regression tree analyses to generate clinical decision rules using standard out-of-hospital variables to identify emergency operative intervention (within 1 hour) by a general surgeon (for adults) or a pediatric surgeon (if < or =14 years). RESULTS: Emergency operative intervention occurred in 3.0% of adults and 0.35% of children. For adults, summoning a surgeon for any one of 3 criteria (penetrating mechanism, systolic blood pressure <96 mm Hg, pulse rate >104 beats/min) could reduce surgeon calls by 51.2% while failing to identify emergency operative intervention in only 0.08% (rule sensitivity 97.2% and specificity 48.6%). For children, no rule at all (ie, never automatically summoning a surgeon) would fail to identify emergency operative intervention in only 0.35% of patients, and use of a single criterion (penetrating mechanism) would reduce surgeon calls by 96.2% while failing to identify emergency operative intervention in only 0.09% (rule sensitivity 75.0% and specificity 96.5%). CONCLUSION: We have derived simple decision rules for trauma centers that, if validated, could substantially reduce the need for routine surgeon presence on trauma patient arrival. These rules demonstrate low false-negative rates.

Leaching of copper, chromium and arsenic from treated vineyard posts in Marlborough, New Zealand.

There have been conflicting reports as to the extent that copper-chromium-arsenic (CCA) treatments leach from timber. In New Zealand, vineyards utilise CCA-treated posts at a rate of 579 posts per hectare. This represents a potential CCA burden on the soil of 12, 21, and 17 kg/ha, respectively, for the three elements. Given a replacement rate of 4% per year, the use of CCA-treated posts may result in an accumulation of these elements in the soil, possibly leading to groundwater contamination. We undertook a general survey to determine the extent of CCA leaching from treated vineyard posts. Treated Pinus radiata posts were sampled at six sites around the Marlborough region of New Zealand to represent a range of post ages and soil types. For each post, above- and belowground wood samples were taken. As well, the soil adjacent to the post was sampled at a 50 mm horizontal and 100 mm vertical distances from the post. The belowground wood samples of the posts had significantly lower CCA concentrations than the aboveground portions, which were not significantly different from new posts. This indicates leaching. Soils surrounding the posts had significantly higher CCA concentrations than control soils. Higher CCA concentrations were measured under the posts than laterally. Some 25% of the samples exceeded 100 mg/kg As, the Australian National Environment Protection Council (ANEPC) guideline level for As in agricultural soil, and 10% exceeded 100 mg/kg Cr, the ANEPC limit for chromium. At one site, we found a significant positive correlation between post age and CCA-leaching. The CCA issue could be eliminated by using alternative posts, such as steel, concrete, or untreated woods such as Eucalyptus or beech. Alternatively, CCA-treated posts could, for example, be lacquered or otherwise protected, to reduce the rate of CCA leaching.