Outcome of Diagnostic Tests Using Samples from Patients with Culture-Proven Human Monocytic Ehrlichiosis: Implications for Surveillance

We describe the concordance among results from various laboratory tests using samples derived from nine culture-proven cases of human monocytic ehrlichiosis (HME) caused by Ehrlichia chaffeensis. A class-specific indirect immunofluorescence assay for immunoglobulin M (IgM) and IgG, using E. chaffeensis antigen, identified 44 and 33% of the isolation-confirmed HME patients on the basis of samples obtained at initial clinical presentation, respectively; detection of morulae in blood smears was similarly insensitive (22% positive). PCR amplifications of ehrlichial DNA targeting the 16S rRNA gene, the variable-length PCR target gene, and the groESL operon were positive for whole blood specimens obtained from all patients at initial presentation. As most case definitions of HME require a serologic response with compatible illness for a categorization of even probable disease, PCR would have been required to confirm the diagnosis of HME in all nine of these patients without the submission of a convalescent-phase serum sample. These data suggest that many, if not most, cases of HME in patients who present early in the course of the disease may be missed and underscore the limitations of serologically based surveillance systems

Strategies to enhance recruitment and consent to intensive care studies: a qualitative study with researchers and patient–public involvement contributors

Objective Clinical trials and studies in intensive care units (ICUs) have complex consent processes and often encounter problems in recruiting patients. By interviewing research team members about the challenges in critical care research, we aimed to identify strategies to enhance recruitment and consent to ICU studies. Methods Semistructured interviews with UK-based researchers (N=17) and patient–public involvement (PPI) contributors (N=8) with experience of ICU studies. Analysis of transcripts of audio-recorded interviews drew on thematic approaches. Results Seven themes were identified. Participants emphasised the need for substitute decision-making processes in critical care studies, yet some researchers reported that research ethics committees (RECs) were reluctant to approve such processes. Researchers spoke about the potential benefits of research without prior consent (RWPC) for studies with narrow recruitment windows but believed RECs would not approve them. Participants indicated that the activity of PPI contributors was limited in critical care studies, though researchers who had involved PPI contributors more extensively were clear that their input when designing consent processes was important. Researchers and PPI contributors pointed to resource and staffing limitations as barriers to patient recruitment. Researchers varied in whether and how they used professional consultees as substitute decision-makers, in whether they approached families by telephone to discuss research and in whether they disclosed details of research participation to bereaved relatives. Conclusion Critical care research could benefit from RECs having expertise in consent processes that are suited to this setting, better staffing at research sites, more extensive PPI and an evidence base on stakeholder perspectives on critical care research processes. Guidance on professional consultee processes, telephoning relatives to discuss research, RWPC and disclosure of research participation to bereaved relatives could help to harmonise practice in these areas and enhance recruitment and consent to critical care studies

A Hedged Monte Carlo Approach to Real Option Pricing

In this work we are concerned with valuing optionalities associated to invest or to delay investment in a project when the available information provided to the manager comes from simulated data of cash flows under historical (or subjective) measure in a possibly incomplete market. Our approach is suitable also to incorporating subjective views from management or market experts and to stochastic investment costs. It is based on the Hedged Monte Carlo strategy proposed by Potters et al (2001) where options are priced simultaneously with the determination of the corresponding hedging. The approach is particularly well-suited to the evaluation of commodity related projects whereby the availability of pricing formulae is very rare, the scenario simulations are usually available only in the historical measure, and the cash flows can be highly nonlinear functions of the prices.Comment: 25 pages, 14 figure

Predominance of Ehrlichia ewingii in Missouri dogs

To investigate the species distribution of Ehrlichia present in Missouri dogs, we tested 78 dogs suspected of having acute ehrlichiosis and 10 healthy dogs. Blood from each dog was screened with a broad-range 16S rRNA gene PCR assay that detects known pathogenic species of Ehrlichia and Anaplasma. The species was determined by using species-specific PCR assays and nucleotide sequencing. Ehrlichia antibody testing was performed by using an indirect immunofluorescence assay with Ehrlichia chaffeensis as the antigenic substrate. The broad-range assay detected Ehrlichia or Anaplasma DNA in 20 (26%) of the symptomatic dogs and 2 (20%) of the asymptomatic dogs. E. ewingii accounted for 20 (91%), and E. chaffeensis accounted for 1 (5%) of the positives. Anaplasma phagocytophilum DNA was detected in one dog, and the sequences of regions of the 16S rRNA gene and the groESL operon amplified from the blood of this dog matched the published sequences of this organism. Antibodies reactive with E. chaffeensis were detected in 14 (67%) of the 21 PCR-positive dogs and in 12 (19%) of the 64 PCR-negative dogs. Combining the results of PCR and serology indicated that 33 (39%) of 85 evaluable dogs had evidence of past or current Ehrlichia infection. We conclude that E. ewingii is the predominant etiologic agent of canine ehrlichiosis in the areas of Missouri included in this survey. E. canis, a widely recognized agent of canine ehrlichiosis, was not detected in any animal. The finding of E. ewingii in asymptomatic dogs suggests that dogs could be a reservoir for this Ehrlichia species

Engineering the Redox Potential over a Wide Range within a New Class of FeS Proteins

Abstract: MitoNEET is a newly discovered mitochondrial protein and a target of the TZD class of antidiabetes drugs. MitoNEET is homodimeric with each protomer binding a [2Fe-2S] center through a rare 3-Cys and 1-His coordination geometry. Both the fold and the coordination of the [2Fe-2S] centers suggest that it could have novel properties compared to other known [2Fe-2S] proteins. We tested the robustness of mitoNEET to mutation and the range over which the redox potential (EM) could be tuned. We found that the protein could tolerate an array of mutations that modified the EM of the [2Fe-2S] center over a range of ∼700 mV, which is the largest EM range engineered in an FeS protein and, importantly, spans the cellular redox range (+200 to-300 mV). These properties make mitoNEET potentially useful for both physiological studies and industrial applications as a stable, water-soluble, redox agent

Simonsenia aveniformis sp nov (Bacillariophyceae), molecular phylogeny and systematics of the genus, and a new type of canal raphe system

The genus Simonsenia is reviewed and S. aveniformis described as new for science by light and electron microscopy. The new species originated from estuarine environments in southern Iberia (Atlantic coast) and was isolated into culture. In LM, Simonsenia resembles Nitzschia, with bridges (fibulae) beneath the raphe, which is marginal. It is only electron microscope (EM) examination that reveals the true structure of the raphe system, which consists of a raphe canal raised on a keel (wing), supported by rib like braces (fenestral bars) and tube-like portulae; between the portulae the keel is perforated by open windows (fenestrae). Based on the presence of portulae and a fenestrated keel, Simonsenia has been proposed to be intermediate between Bacillariaceae and Surirellaceae. However, an rbcL phylogeny revealed that Simonsenia belongs firmly in the Bacillariaceae, with which it shares a similar chloroplast arrangement, rather than in the Surirellaceae. Lack of homology between the surirelloid and simonsenioid keels is reflected in subtle differences in the morphology and ontogeny of the portulae and fenestrae. The diversity of Simonsenia has probably been underestimated, particularly in the marine environment.Polish National Science Centre in Cracow within the Maestro program [N 2012/04/A/ST10/00544]; Sciences and Technologies Foundation-FCT (Portugal) [SFRH/BD/62405/2009]info:eu-repo/semantics/publishedVersio

Transmission of Methicillin‐Resistant Staphylococcus aureus Infection Through Solid Organ Transplantation: Confirmation Via Whole Genome Sequencing

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109324/1/ajt12898.pd

The Eco-Epidemiology of Pacific Coast Tick Fever in California

Rickettsia philipii (type strain “Rickettsia 364D”), the etiologic agent of Pacific Coast tick fever (PCTF), is transmitted to people by the Pacific Coast tick, Dermacentor occidentalis. Following the first confirmed human case of PCTF in 2008, 13 additional human cases have been reported in California, more than half of which were pediatric cases. The most common features of PCTF are the presence of at least one necrotic lesion known as an eschar (100%), fever (85%), and headache (79%); four case-patients required hospitalization and four had multiple eschars. Findings presented here implicate the nymphal or larval stages of D. occidentalis as the primary vectors of R. philipii to people. Peak transmission risk from ticks to people occurs in late summer. Rickettsia philipii DNA was detected in D. occidentalis ticks from 15 of 37 California counties. Similarly, non-pathogenic Rickettsia rhipicephali DNA was detected in D. occidentalis in 29 of 38 counties with an average prevalence of 12.0% in adult ticks. In total, 5,601 ticks tested from 2009 through 2015 yielded an overall R. philipii infection prevalence of 2.1% in adults, 0.9% in nymphs and a minimum infection prevalence of 0.4% in larval pools. Although most human cases of PCTF have been reported from northern California, acarological surveillance suggests that R. philipii may occur throughout the distribution range of D. occidentalis