Direct Testing for KPC-Mediated Carbapenem Resistance from Blood Samples Using a T2 Magnetic Resonance Based Assay.

Molecular-based carbapenem resistance testing in Gram-negative bacterial bloodstream infections (BSIs) is currently limited because of the reliance on positive blood culture (BC) samples. The T2Resistance™ panel may now allow the detection of carbapenemase- and other β-lactamase encoding genes directly from blood samples. We detected carbapenem resistance genes in 11 (84.

Assessment of the effects of novel insecticides on green peach aphid (Myzus persicae) feeding and transmission of Turnip mosaic virus (TuMV).

Background: Laboratory bioassays using treated leaf disks of peach were conducted to determine the efficacy of nine insecticides against the green peach aphid (GPA), Myzus persicae (Sulzer). The effects of these insecticides on aphid feeding behaviors and rates of transmission of Turnip mosaic virus (TuMV) to potted rutabaga plants were also determined.

Results: Median lethal concentration (LC ) values after 48 h feeding varied considerably, ranging from lows of 1.

The T2Bacteria Assay Is a Sensitive and Rapid Detector of Bacteremia That Can Be Initiated in the Emergency Department and Has Potential to Favorably Influence Subsequent Therapy.

Background: Bacteremia causes a major worldwide burden, in terms of financial and productivity costs, as well the morbidity and mortality it can ultimately cause. Proper treatment of bacteremia is a challenge because of the species-dependent response to antibiotics. The T2Bacteria Panel is a U.

Magnetic Resonance-Based Diagnostics for Bleeding Assessment in Neonatal Cardiac Surgery.

Purpose: Infants undergoing a cardiac operation are at high risk for postsurgical bleeding. To date, there are no highly predictive models for postsurgical bleeding in this population. This study's objective was to assess the predictive ability of T2 magnetic resonance (T2MR).

ESKAPE Pathogens in Bloodstream Infections Are Associated With Higher Cost and Mortality but Can Be Predicted Using Diagnoses Upon Admission.

Background: ESKAPE bacteria are thought to be especially resistant to antibiotics, and their resistance and prevalence in bloodstream infections are rising. Large studies are needed to better characterize the clinical impact of these bacteria and to develop algorithms that alert clinicians when patients are at high risk of an ESKAPE infection.

Methods: From a US data set of >1.

T2 Magnetic Resonance to Monitor Hemostasis.

There is a clinical need for pragmatic approaches to measure integrated hemostatic reactions in whole blood rapidly, using small volumes of blood. The authors have applied T2 magnetic resonance (T2MR) to assess coagulation reactions based on partitioning of red blood cells and proteins that occurs during fibrin formation and platelet-mediated clot contraction. T2MR is amenable to measuring clotting times, individual coagulation factors, and platelet function.

T2 Magnetic Resonance Assay-Based Direct Detection of Three Lyme Disease-Related Borrelia Species in Whole-Blood Samples.

In early Lyme disease (LD), serologic testing is insensitive and seroreactivity may reflect active or past infection. In this study, we evaluated a novel assay for the direct detection of three species of spirochetes in whole blood. The T2 magnetic resonance (T2MR) assay platform was used to amplify DNA released from intact spirochetes and to detect amplicon.

Rapid Evaluation of Platelet Function With T2 Magnetic Resonance.

Objectives: The clinical diagnosis of qualitative platelet disorders (QPDs) based on light transmission aggregometry (LTA) requires significant blood volume, time, and expertise, all of which can be barriers to utilization in some populations and settings. Our objective was to develop a more rapid assay of platelet function by measuring platelet-mediated clot contraction in small volumes (35 µL) of whole blood using T2 magnetic resonance (T2MR).

Methods: We established normal ranges for platelet-mediated clot contraction using T2MR, used these ranges to study patients with known platelet dysfunction, and then evaluated agreement between T2MR and LTA with arachidonic acid, adenosine diphosphate, epinephrine, and thrombin receptor activator peptide.

Aphid Transmission of the Ontario Isolate of Plum Pox Virus.

Utilization of timed virus acquisition access probes in studies of plum pox virus (PPV) transmission by aphids demonstrated that endemic species transmitted the virus readily from plum, Prunus domestica (L.) Batsch; peach, P. persica (L.

T2MR and T2Candida: novel technology for the rapid diagnosis of candidemia and invasive candidiasis.

Candidemia and other forms of invasive candidiasis pose a significant diagnostic challenge. In order to provide the best treatment, it is important to accurately detect the fungal infection and identify the species. Historically, diagnosis of Candida infections depended upon three classical laboratory approaches: microbiologic, immunologic, histopathologic; and now includes new methods such as radiographic techniques, molecular, proteomic and biochemical methods.

Diversity and abundance of leafhoppers in Canadian vineyards.

Leafhoppers (Hemiptera: Cicadellidae) are pests of many temperate crops, including grapevines (Vitis species). Uncontrolled populations can induce direct and indirect damage to crops due to feeding that results in significant yield losses and increased mortality in infected vineyards due to virus, bacteria, or phytoplasmas vectored by leafhoppers. The main objective of this work was to determine the diversity of leafhoppers found in vineyards of the three main Canadian production provinces, i.

T2 magnetic resonance: a diagnostic platform for studying integrated hemostasis in whole blood--proof of concept.

Background: Existing approaches for measuring hemostasis parameters require multiple platforms, can take hours to provide results, and generally require 1-25 mL of sample. We developed a diagnostic platform that allows comprehensive assessment of hemostatic parameters on a single instrument and provides results within 15 min using 0.04 mL of blood with minimal sample handling.

Clot contraction: compression of erythrocytes into tightly packed polyhedra and redistribution of platelets and fibrin.

Contraction of blood clots is necessary for hemostasis and wound healing and to restore flow past obstructive thrombi, but little is known about the structure of contracted clots or the role of erythrocytes in contraction. We found that contracted blood clots develop a remarkable structure, with a meshwork of fibrin and platelet aggregates on the exterior of the clot and a close-packed, tessellated array of compressed polyhedral erythrocytes within. The same results were obtained after initiation of clotting with various activators and also with clots from reconstituted human blood and mouse blood.

Insecticide susceptibility of three species of cutworm (Lepidoptera: Noctuidae) pests of grapes.

Climbing cutworms in the genus Abagrotis are economically important pests of grapes in the Okanagan Valley of British Columbia (BC). Grapes are recently introduced into many areas of the region, and the association between crop and pest is new and still evolving. This has led to limited information being available on pest management strategies, including the evaluation of chemical controls compatible with local production practices.

T2 magnetic resonance enables nanoparticle-mediated rapid detection of candidemia in whole blood.

Candida spp. cause both local and disseminated infections in immunocompromised patients. Bloodstream infections of Candida spp.

Relaxivity of gadolinium complexes detected by atomic magnetometry.

Laser atomic magnetometry is a portable and low-cost yet highly sensitive method for low magnetic field detection. In this work, the atomic magnetometer was used in a remote-detection geometry to measure the relaxivity of aqueous gadolinium-diethylenetriamine pentaacetic acid Gd(DTPA) at the Earth's magnetic field (40 μT). The measured relaxivity of 9.

Relationship of insecticide tolerance to esterase enzyme activity in Aphis pomi and Aphis spiraecola (Hemiptera: Aphididae).

Green apple aphid, Aphis pomi De Geer, and Aphis spiraecola Patch (both Hemiptera: Aphididae), are sympatric aphid species that are pests of apples (Malus spp.) and other crops. A.

Temperature response of 129Xe depolarization transfer and its application for ultrasensitive NMR detection.

Trapping xenon in functionalized cryptophane cages makes the sensitivity of hyperpolarized (HP) 129Xe available for specific NMR detection of biomolecules. Here, we study the signal transfer onto a reservoir of unbound HP xenon by gating the residence time of the nuclei in the cage through the temperature-dependant exchange rate. Temperature changes larger than approximately 0.

Influence of mixtures of kaolin particle film and synthetic insecticides on mortality of larval obliquebanded leafrollers (Lepidoptera: Tortricidae) from resistant and susceptible populations.

Experiments were conducted to determine potential interactions between kaolin particle film and three insecticides on neonate larvae of the obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae). Kaolin did not significantly affect the toxicity of azinphosmethyl or indoxacarb to an insecticide-susceptible population when applied simultaneously with either insecticide in a 7-d leaf disk bioassay. Methoxyfenozide was slightly more toxic to the same leafroller population when coapplied with kaolin.

Single-coil, multisample, proton relaxation method for magnetic relaxation switch assays.

Nanoparticle based magnetic relaxation switch (MRSw) biosensors offer the opportunity to develop magnetic resonance based in vitro diagnostics. Critical attributes for point of care in vitro diagnostic products include simple instrumentation and ease of use. To this end, high-resolution biexponential analysis was used to permit measurement and assignment of two samples with a single radio frequency detection coil.

NMR structure of the N-terminal domain of the replication initiator protein DnaA.

DnaA is an essential component in the initiation of bacterial chromosomal replication. DnaA binds to a series of 9 base pair repeats leading to oligomerization, recruitment of the DnaBC helicase, and the assembly of the replication fork machinery. The structure of the N-terminal domain (residues 1-100) of DnaA from Mycoplasma genitalium was determined by NMR spectroscopy.

Flavodoxin hydroquinone reduces Azotobacter vinelandii Fe protein to the all-ferrous redox state with a S = 0 spin state.

Azotobacter vinelandii flavodoxin hydroquinone (FldHQ) is a physiological reductant to nitrogenase supporting catalysis that is twice as energy efficient (ATP/2e- = 2) as dithionite (ATP/2e- = 4). This catalytic efficiency results from reduction of Fe protein from A. vinelandii (Av2) to the all-ferrous oxidation state ([Fe4S4]0), in contrast to dithionite, which only reduces Av2 to the [Fe4S4]1+ state.

Molecular imaging using a targeted magnetic resonance hyperpolarized biosensor.

A magnetic resonance approach is presented that enables high-sensitivity, high-contrast molecular imaging by exploiting xenon biosensors. These sensors link xenon atoms to specific biomolecular targets, coupling the high sensitivity of hyperpolarized nuclei with the specificity of biochemical interactions. We demonstrated spatial resolution of a specific target protein in vitro at micromolar concentration, with a readout scheme that reduces the required acquisition time by >3300-fold relative to direct detection.

Sensitivity enhancement by exchange mediated magnetization transfer of the xenon biosensor signal.

Hyperpolarized xenon associated with ligand derivatized cryptophane-A cages has been developed as a NMR based biosensor. To optimize the detection sensitivity we describe use of xenon exchange between the caged and bulk dissolved xenon as an effective signal amplifier. This approach, somewhat analogous to 'remote detection' described recently, uses the chemical exchange to repeatedly transfer spectroscopic information from caged to bulk xenon, effectively integrating the caged signal.