Application of Microarray and Functional-Based Screening Methods for the Detection of Antimicrobial Resistance Genes in the Microbiomes of Healthy Humans

The aim of this study was to screen for the presence of antimicrobial resistance genes within the saliva and faecal microbiomes of healthy adult human volunteers from five European countries. Two non-culture based approaches were employed to obviate potential bias associated with difficult to culture members of the microbiota. In a gene target-based approach, a microarray was employed to screen for the presence of over 70 clinically important resistance genes in the saliva and faecal microbiomes. A total of 14 different resistance genes were detected encoding resistances to six antibiotic classes (aminoglycosides, β-lactams, macrolides, sulphonamides, tetracyclines and trimethoprim). The most commonly detected genes were erm(B), blaTEM, and sul2. In a functional-based approach, DNA prepared from pooled saliva samples was cloned into Escherichia coli and screened for expression of resistance to ampicillin or sulphonamide, two of the most common resistances found by array. The functional ampicillin resistance screen recovered genes encoding components of a predicted AcrRAB efflux pump. In the functional sulphonamide resistance screen, folP genes were recovered encoding mutant dihydropteroate synthase, the target of sulphonamide action. The genes recovered from the functional screens were from the chromosomes of commensal species that are opportunistically pathogenic and capable of exchanging DNA with related pathogenic species. Genes identified by microarray were not recovered in the activity-based screen, indicating that these two methods can be complementary in facilitating the identification of a range of resistance mechanisms present within the human microbiome. It also provides further evidence of the diverse reservoir of resistance mechanisms present in bacterial populations in the human gut and saliva. In future the methods described in this study can be used to monitor changes in the resistome in response to antibiotic therapy

Characterization of Complex Optical Modulation Formats at 100 Gb/s and Beyond by Coherent Optical Sampling

Optical fiber communication systems are migrating toward the use of sophisticated, nonbinary, modulation formats. It is thus important to develop measurement techniques and solutions capable of unambiguously quantifying such signals and associated hardware. Although one can adapt certain techniques developed for wireless signal characterization, significant differences exist between optical and RF wireless implementations of advanced modulation formats. To meet this measurement demand we present a method for characterizing high symbol rate multilevel modulation optical signals with high fidelity, based on coherent optical sampling, as a complement to the standard real-time electrical sampling approach. The technique enables constellation-and waveform monitoring, bit-error rate and error-vector magnitude analysis, which makes it suitable for transmitter characterization

Accessibility and Self Archiving of Conference Articles : A Study on a Selection of Swedish Institutional Repositories

QC 20190308</p

Accessibility and Self Archiving of Conference Articles : A Study on a Selection of Swedish Institutional Repositories

QC 20190308</p

Not only oxidized R-(+)- but also S-(-)-limonene is a common cause of contact allergy in dermatitis patients in Europe

Limonene, one of the most often used fragrance terpenes in any kind of scented products, is prone to air-oxidation. The oxidation products formed have a considerable sensitizing potential. In previous patch test studies on consecutively tested dermatitis patients, oxidized R-limonene has been proven to be a good and frequent indicator of fragrance-related contact allergy. The current study extends these investigations to 6 European clinics of dermatology, where the oxidation mixture of both enantiomers of limonene (R and S) have been tested in 2411 dermatitis patients. Altogether, 63 out of 2411 patients tested (2.6%) reacted to 1 or both the oxidized limonene preparations. Only 2.3% reacted to the oxidized R-limonene and 2.0% to the oxidized S-limonene. In 57% of the cases, simultaneous reactions were observed to both oxidation mixtures. Concomitant reactions to the fragrance mix, colophonium, Myroxylon pereirae, and fragrance-related contact allergy were common in patients reacting to 1 or both the oxidized limonene enantiomers. Our study provides clinical evidence for the importance of oxidation products of limonene in contact allergy. It seems advisable to screen consecutive dermatitis patients with oxidized limonene 3% petrolatum, although this patch test material is not yet commercially available

Forum: What are the limits to health intervention?

Thirteen authors contribute to seven articles which constitute the 'forum' on a variety of issues concerned with and relating to health interventio

International Arctic Research: Analyzing Global Funding Trends. A Pilot Report

<p>This pilot analysis is the result of an exploratory collaboration between the UArctic Science & Research Analytics Task Force and Digital Science's international research teams. The aim was to assess the global funding landscape around Arctic-related research for the decade spanning 2006 to 2015 using the funding data from the Dimensions dataset, which includes information from over 200 funders on more than 2,500,000 projects with funding totalling $1 trillion+ (in US Dollars). </p><p>This project is the first ever attempt to create a comprehensive view of global Arctic research funding using a dataset of such magnitude.</p