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To evaluate whole-genome sequencing (WGS) as a molecular typing tool for MRSA outbreak investigation.
Investigation of MRSA colonization/infection in a neonatal intensive care unit (NICU) over 3 years (2014–2017).
Single-center level IV NICU.
NICU infants and healthcare workers (HCWs).
Infants were screened for MRSA using a swab of the anterior nares, axilla, and groin, initially by targeted (ring) screening, and later by universal weekly screening. Clinical cultures were collected as indicated. HCWs were screened once using swabs of the anterior nares. MRSA isolates were typed using WGS with core-genome multilocus sequence typing (cgMLST) analysis and by pulsed-field gel electrophoresis (PFGE). Colonized and infected infants and HCWs were decolonized. Control strategies included reinforcement of hand hygiene, use of contact precautions, cohorting, enhanced environmental cleaning, and remodeling of the NICU.
We identified 64 MRSA-positive infants: 53 (83%) by screening and 11 (17%) by clinical cultures. Of 85 screened HCWs, 5 (6%) were MRSA positive. WGS of MRSA isolates identified 2 large clusters (WGS groups 1 and 2), 1 small cluster (WGS group 3), and 8 unrelated isolates. PFGE failed to distinguish WGS group 2 and 3 isolates. WGS groups 1 and 2 were codistributed over time. HCW MRSA isolates were primarily in WGS group 1. New infant MRSA cases declined after implementation of the control interventions.
We identified 2 contemporaneous MRSA outbreaks alongside sporadic cases in a NICU. WGS was used to determine strain relatedness at a higher resolution than PFGE and was useful in guiding efforts to control MRSA transmission.
To aid in preparation of military medic trainers for a possible new curriculum in teaching junctional tourniquet use, the investigators studied the time to control hemorrhage and blood volume lost in order to provide evidence for ease of use.
Models of junctional tourniquet could perform differentially by blood loss, time to hemostasis, and user preference.
In a laboratory experiment, 30 users controlled simulated hemorrhage from a manikin (Combat Ready Clamp [CRoC] Trainer) with three iterations each of three junctional tourniquets. There were 270 tests which included hemorrhage control (yes/no), time to hemostasis, and blood volume lost. Users also subjectively ranked tourniquet performance. Models included CRoC, Junctional Emergency Treatment Tool (JETT), and SAM Junctional Tourniquet (SJT). Time to hemostasis and total blood loss were log-transformed and analyzed using a mixed model analysis of variance (ANOVA) with the users represented as random effects and the tourniquet model used as the treatment effect. Preference scores were analyzed with ANOVA, and Tukey’s honest significant difference test was used for all post-hoc pairwise comparisons.
All tourniquet uses were 100% effective for hemorrhage control. For blood loss, CRoC and SJT performed best with least blood loss and were significantly better than JETT; in pairwise comparison, CRoC-JETT (P < .0001) and SJT-JETT (P = .0085) were statistically significant in their mean difference, while CRoC-SJT (P = .35) was not. For time to hemostasis in pairwise comparison, the CRoC had a significantly shorter time compared to JETT and SJT (P < .0001, both comparisons); SJT-JETT was also significant (P = .0087). In responding to the directive, “Rank the performance of the models from best to worst,” users did not prefer junctional tourniquet models differently (P > .5, all models).
The CRoC and SJT performed best in having least blood loss, CRoC performed best in having least time to hemostasis, and users did not differ in preference of model. Models of junctional tourniquet performed differentially by blood loss and time to hemostasis.
KraghJFJr, LunatiMP, KharodCU, CunninghamCW, BaileyJA, StockingerZT, CapAP, ChenJ, AdenJK3d, CancioLC. Assessment of Groin Application of Junctional Tourniquets in a Manikin Model. Prehosp Disaster Med. 2016;31(4):358–363.
The intensity ratios of HCO+/HCN and HNC/HCN (1-0) reveal the relative influence of star formation and active galactic nuclei (AGN) or black holes on the circum-nuclear gas of a galaxy, allowing the identification of X-ray dominated regions (XDRs) and Photon-dominated regions (PDRs). It is not always clear in the literature how this intensity ratio calculation has been, or should be performed. This paper discusses ratio calculation methods for interferometric data.
A survey of the Milky Way disk and the Magellanic System at the wavelengths of the 21-cm atomic hydrogen (H i) line and three 18-cm lines of the OH molecule will be carried out with the Australian Square Kilometre Array Pathfinder telescope. The survey will study the distribution of H i emission and absorption with unprecedented angular and velocity resolution, as well as molecular line thermal emission, absorption, and maser lines. The area to be covered includes the Galactic plane (|b| < 10°) at all declinations south of δ = +40°, spanning longitudes 167° through 360°to 79° at b = 0°, plus the entire area of the Magellanic Stream and Clouds, a total of 13 020 deg2. The brightness temperature sensitivity will be very good, typically σT≃ 1 K at resolution 30 arcsec and 1 km s−1. The survey has a wide spectrum of scientific goals, from studies of galaxy evolution to star formation, with particular contributions to understanding stellar wind kinematics, the thermal phases of the interstellar medium, the interaction between gas in the disk and halo, and the dynamical and thermal states of gas at various positions along the Magellanic Stream.
Mandatory reporting of healthcare-associated infections is common, but underreporting by hospitals limits meaningful interpretation.
To validate mandatory intensive care unit (ICU) central line–associated bloodstream infection (CLABSI) reporting by Oregon hospitals.
Blinded comparison of ICU CLABSI determination by hospitals and health department–based external reviewers with group adjudication.
Forty-four Oregon hospitals required by state law to report ICU CLABSIs.
Seventy-six patients with ICU CLABSIs and a systematic sample of 741 other patients with ICU-related bacteremia episodes.
External reviewers examined medical records and determined CLABSI status. All cases with CLABSI determinations discordant from hospital reporting were adjudicated through formal discussion with hospital staff, a process novel to validation of CLABSI reporting.
Hospital representatives and external reviewers agreed on CLABSI status in 782 (96%) of 817 bacteremia episodes (k = 0.77 [95% confidence interval (CI), 0.70-0.84]). Among the 27 episodes identified as CLABSIs by external reviewers but not reported by hospitals, the final status was CLABSI in 16 (59%). The measured sensitivities of hospital ICU CLABSI reporting were 72% (95% CI, 62%-81%) with adjudicated CLABSI determination as the reference standard and 60% (95% CI, 51%-69%) with external review alone as the reference standard (P = .07). Validation increased the statewide ICU CLABSI rate from 1.21 (95% CI, 0.95-1.51) to 1.54 (95% CI, 1.25-1.88) CLABSIs/1,000 central line–days; ICU CLABSI rates increased by more than 1.00 CLABSI/1,000 central line–days in 6 (14%) hospitals.
Validating hospital CLABSI reporting improves accuracy of hospital-based CLABSI surveillance. Discussing discordant findings improves the quality of validation.
This study assessed risk factors for respiratory syncytial virus (RSV) hospitalization and disease severity in Wellington, New Zealand. During the southern hemisphere winter months of 2003–2005, 230 infants aged <24 months hospitalized with bronchiolitis were recruited. RSV was identified in 141 (61%) infants. Comparison with data from all live hospital births from the same region (2003–2005) revealed three independent risk factors for RSV hospitalization: birth between February and July [adjusted risk ratio (aRR) 1·62, 95% confidence interval (CI) 1·15–2·29], gestation <37 weeks (aRR 2·29, 95% CI 1·48–3·56) and Māori ethnicity (aRR 3·64, 95% CI 2·27–5·85) or Pacific ethnicity (aRR 3·60, 95% CI 2·14–6·06). The high risk for Māori and Pacific infants was only partially accounted for by other known risk factors. This work highlights the importance of RSV disease in indigenous and minority populations, and identifies the need for further research to develop public health measures that can reduce health disparities.
Numerous studies have investigated specific pathways that link diabetes and high extracellular glucose exposure to glomerulosclerosis and mesangial cell extracellular matrix production. However, only in the past ten years has a role for glucose transporters in this process been addressed. Many different glucose transporters are expressed in glomeruli; of these, the GLUT1 facilitative glucose transporter is upregulated in the diabetic renal cortex and in response to glomerular hypertension, as well as in cultured mesangial cells exposed to high glucose. Transgenic mouse and cell models have recently been developed to test the role of GLUT1 in the pathogenesis of glomerulosclerosis with and without diabetes. Clinical studies of GLUT1 alleles performed in humans have identified GLUT1 susceptibility alleles for diabetic nephropathy. Studies are also currently under way to assess the potential role of GLUT1 in nondiabetic renal disorders.
We demonstrate a micro-molding method for submicron patterning of a low-index sol-gel nanoporous glass for the purpose of fabricating large-area (∼3”×”) label-free photonic crystal optical biosensors. SEM images show that the sol-gel exhibited minimal shrinkage and good substrate adhesion and depict precise and uniform pattern transfer over the fabricated area within the limits of measurement resolution. A unique characterization approach accurately and quickly revealed porous glass patterned over a large area with geometrical and material properties uniform within 1%. We suggest that this robust method is an excellent approach for photonic crystal sensor fabrication, and may also find applications in integrated optics and electronics.
In order to test the hypothesis that glycogen sparing observed early during exercise following caffeine ingestion was a consequence of tighter metabolic control reflected in faster VO2 kinetics, we examined the effect of caffeine ingestion on oxygen uptake (VO2), carbon dioxide production (VCO2) and expiratory ventilation (VE) kinetics at the onset of both moderate (MOD) and heavy (HVY) intensity exercise. Male subjects (n = 10) were assigned to either a MOD (50 % VO2,max, n = 5) or HVY (80 % VO2,max, n = 5) exercise condition. Constant-load cycle ergometer exercise was performed as a step function from loadless cycling 1 h after ingestion of either dextrose (placebo, PLAC) or caffeine (CAFF; 6 mg (kg body mass)-1). Alveolar gas exchange was measured breath-by-breath. A 2- or 3-component exponential model, fitted through the entire exercise transient, was used to analyse gas exchange and ventilatory data for the determination of total lag time (TLT: the time taken to attain 63 % of the total exponential increase). Caffeine had no effect on TLT for VO2 kinetics at either exercise intensity (MOD: 36 ± 14 s (PLAC) and 41 ± 10 s (CAFF); HVY: 99 ± 30 s (PLAC) and 103 ± 26 (CAFF) (mean ± S.D.)). TLT for VE was increased with caffeine at both exercise intensities (MOD: 50 ± 20 s (PLAC) and 59 ± 21 s (CAFF); HVY: 168 ± 35 s (PLAC) and 203 ± 48 s (CAFF)) and for VCO2 during MOD only (MOD: 47 ± 14 s (PLAC) and 53 ± 17 s (CAFF); HVY: 65 ± 13 s (PLAC) and 69 ± 17 s (CAFF)). Contrary to our hypothesis, the metabolic effects of caffeine did not alter the on-transient VO2 kinetics in moderate or heavy exercise. VCO2 kinetics were slowed by a reduction in CO2 stores reflected in pre-exercise and exercise end-tidal CO2 pressure (PET,CO2) and plasma PCO2 which, we propose, contributed to slowed VE kinetics.
Evidence from the Ross embayment, Antarctica, suggests an abrupt cooling and a concomitant increase in sea-ice cover at about 6000 BP (6 ka). Stable-isotope (δD) concentrations in the Taylor Dome ice core, at the western edge of the Ross embayment, decline rapidly after 6 ka, and continue to decline through the late Holocene. Methanesulfonic acid concentrations at Taylor Dome show opposite trends to δD Sediment cores from the western Ross Sea show a percentage minimum for the sea-ice diatom Fragilariopsis curta between 9 and 6 ka, whenTaylor Dome δD values are highest, followed by an increase through the late Holocene. Radiocarbon dates from raised beach deposits indicate that the retreat of ice shelves in the Ross embayment ceased at about 6 ka, coincident with the environmental changes inferred from the sediment and ice-core records. The similarity in timing suggests an important role for climate in controlling the evolution of ice-shelf margins following the end of the last glaciation.
The small subunit ribosomal RNA (srRNA) gene was amplified from Gyrodactylus salaris using the polymerase chain reaction (PCR), cloned, and the complete gene sequence of 1966 bp determined. The V4 region of the srRNA gene was identified and amplified from single specimens of G. salaris, G. derjavini and G. truttae. Comparison of the V4 sequences from these three species revealed sequence differences from which restriction fragment length polymorphisms (RFLPs) were predicted and an oligonucleotide probe (GsV4) specific to G. salaris designed. Digestion of the amplified V4 region of the srRNA gene with Hae III and either Alw I, BstY I, Dde I or Mbo I provided a means of discriminating between G. salaris, G. derjavini and G. truttae. The GsV4 probe was used to detect the srRNA gene from G. salaris in Southern and dot blots of the amplified V4 region. The nucleotide sequences reported in this paper have been submitted to the EMBL Data Library under accession numbers Z26942 (G. salaris), Z35128 (G. derjavini) and Z35129 (G. truttae).
We review Gas Source Molecular Beam Epitaxy of the GaAs/AlGaAs system. Among the growing number of condensed matter discoveries in materials grown by this approach we describe within resonant tunneling structures. This example serves to demonstrate the high quality quantum well formation and suppressed rate of dopant segregation that occurs during the GSMBE approach. We find a physical basis to quantify the latter growth effects when dopant segregation is viewed in two new ways. First, the broken translational symmetry created by the surface leads to dopant motion (as segregation) that otherwise is not allowed in the crystal interior (as diffusion). Secondly, dopants can dimerize on the crystal surface and this ultimately dictates how the rates of incorporation and segregation proceeds. The manner in which growth creates or destroyes covalent bonds of dopants on semiconductor surfaces thus presents new opportunities to improve dopant control.
Contractile, histochemical and biochemical properties of the triceps surae were compared in 13 aerobically trained male subjects aged 63 to 76 years. Electrical stimulation of the triceps surae was used to determine muscle twitch, tetanic, and fatigue parameters. From these tests, twitch tension (Pt), time to peak tension (TPT), half relaxation time (RT), tetanic tensions at 10(Po10), 20(Po20), and 50(Po50) Hz and a fatigue index (FI) were calculated. Muscle samples from the belly of the lateral head of the gastrocnemius were obtained using the needle biopsy technique. A portion of each sample was tested histochemically for myosin ATPase (pH 4.30, 4.58 and 10.00) and NADH-tetrazolium reductase in order to classify fibre types (ST, FTa, FTb) and to determine fibre areas. The remainder of each sample was analysed for succinic dehydrogenase (SDH) and phosphofructokinase (PFK) enzyme activities. Significant correlations were found between fibre areas (both ST and FT) and Po10/Po50 and FI. No significant relationships were noted between Pt, 1/2RT and MVC and any histochemical parameter. SDH and PFK activities did not correlate significantly with any histochemical or physiological parameter. Regular endurance exercise apparently does not retard the decline in contractile properties seen with the aging process. Substrate related regulatory enzyme activities (PFK) and marker enzyme activities (SDH) from skeletal muscle of the elderly are much lower than activities found in younger subjects, despite regular aerobic exercise.
Solid phase epitaxy was studied in the GexSi1-x/ Si system in the composition range of 4% to 10% Ge. For strained samples regrowth rates decreased with increasing Ge concentrations, with an activation energy of 2.8 and 3.0 eV for the Ge4Si96 and Ge8Si92 alloys respectively. In contrast, the rates of the strain-relaxed samples increased compared with that of pure Si. The minimum yield of fully regrown samples with Ge concentrations lower than 8% recovered to that of the as-deposited samples. However, the minimum yield of a 3500 Å-thick Ge10Si90 alloy increased to 12 % after recrystallization.
We report very small interdiffusion and surface segregation of Si in δ-doped GaAs, A10.3Gao.7As and Quantum Wells grown at 580 C by Gas Source Molecular Beam Epitaxy. Capacitance-Voltage profiles of δ-doped layers are 38 Å wide for growth at 580 C and further, insignificant profile narrowing is observed at 530C and below. Much wider profiles are observed at equivalent substrate temperature for As4 growth. Atomic diffusion of Si in δ-doped Al0.3Ga0.7As is found to have a rate of D0=5× 10−cm2/sec with an activation energy of 1.8 eV.