Whole genome sequencing to investigate the emergence of clonal complex 23 Neisseria meningitidis serogroup Y disease in the United States

In the United States, serogroup Y, ST-23 clonal complex Neisseria meningitidis was responsible for an increase in meningococcal disease incidence during the 1990s. This increase was accompanied by antigenic shift of three outer membrane proteins, with a decrease in the population that predominated in the early 1990s as a different population emerged later in that decade. To understand factors that may have been responsible for the emergence of serogroup Y disease, we used whole genome pyrosequencing to investigate genetic differences between isolates from early and late N. meningitidis populations, obtained from meningococcal disease cases in Maryland in the 1990s. The genomes of isolates from the early and late populations were highly similar, with 1231 of 1776 shared genes exhibiting 100% amino acid identity and an average πN = 0.0033 and average πS = 0.0216. However, differences were found in predicted proteins that affect pilin structure and antigen profile and in predicted proteins involved in iron acquisition and uptake. The observed changes are consistent with acquisition of new alleles through horizontal gene transfer. Changes in antigen profile due to the genetic differences found in this study likely allowed the late population to emerge due to escape from population immunity. These findings may predict which antigenic factors are important in the cyclic epidemiology of meningococcal disease

sodC-Based Real-Time PCR for Detection of Neisseria meningitidis

Real-time PCR (rt-PCR) is a widely used molecular method for detection of Neisseria meningitidis (Nm). Several rt-PCR assays for Nm target the capsule transport gene, ctrA. However, over 16% of meningococcal carriage isolates lack ctrA, rendering this target gene ineffective at identification of this sub-population of meningococcal isolates. The Cu-Zn superoxide dismutase gene, sodC, is found in Nm but not in other Neisseria species. To better identify Nm, regardless of capsule genotype or expression status, a sodC-based TaqMan rt-PCR assay was developed and validated. Standard curves revealed an average lower limit of detection of 73 genomes per reaction at cycle threshold (Ct) value of 35, with 100% average reaction efficiency and an average R2 of 0.9925. 99.7% (624/626) of Nm isolates tested were sodC-positive, with a range of average Ct values from 13.0 to 29.5. The mean sodC Ct value of these Nm isolates was 17.6±2.2 (±SD). Of the 626 Nm tested, 178 were nongroupable (NG) ctrA-negative Nm isolates, and 98.9% (176/178) of these were detected by sodC rt-PCR. The assay was 100% specific, with all 244 non-Nm isolates testing negative. Of 157 clinical specimens tested, sodC detected 25/157 Nm or 4 additional specimens compared to ctrA and 24 more than culture. Among 582 carriage specimens, sodC detected Nm in 1 more than ctrA and in 4 more than culture. This sodC rt-PCR assay is a highly sensitive and specific method for detection of Nm, especially in carriage studies where many meningococcal isolates lack capsule genes

L’épanchement du conte dans la littérature

Pour étudier le phénomène que nous nommons épanchement du conte dans la littérature, nous aurons à questionner le dialogue permanent que la littérature et l’expérience littéraire entretiennent avec le domaine des contes, sur le mode de l’innutrition ou de la réappropriation. Territoire passionnant au regard de la poétique des genres, le conte se prête à tous les jeux de l’hybridation en se mêlant aux autres formes littéraires qu’il transpose, dilue ou incorpore. Outre les réécritures proprement dites, les amalgames de contes, les migrations de personnages, il faut envisager une présence des contes moins flagrante, au détour des phrases, des formules, des clins d’œil qui font écho à l’encyclopédie du lecteur, en somme, les phénomènes intertextuels dans leur diversité. Les contes peuvent être vus comme un vaste réservoir de formes, de formules et d’images qui servent de passe-partout pour franchir les frontières entre les genres littéraires, et de signes de reconnaissance pour instaurer une connivence avec le lecteur. L’épanchement du conte dans la littérature engendre d’infinies combinaisons narratives et textuelles, et ces opérations de métissage concernent les thématiques, les structures, l’écriture, jusqu’à la langue qui, au-delà de la fiction, se trouve elle-même nourrie par les allusions, mentions et références qui l’émaillent d’éclats merveilleux. Certes on pourrait ne voir dans ces incidences que clichés, formules figées à la manière des métaphores lexicalisées, stéréotypes langagiers et culturels, mais les exemples sont si nombreux et témoignent d’une telle mainmise des contes sur la littérature qu’ils méritent toute notre attention. La réflexion se répartit en quatre volets dans lesquels ne sont pas distinguées littérature tout court et littérature de jeunesse. Sont abordés successivement l’emprise singulière des contes sur certains univers d’auteurs, les réécritures des contes de Perrault, le franchissement des frontières génériques, la manière dont les contes sont enseignés

Fully integrated wearable sensor arrays for multiplexed in situ perspiration analysis

Wearable sensor technologies are essential to the realization of personalized medicine through continuously monitoring an individual’s state of health. Sampling human sweat, which is rich in physiological information, could enable non-invasive monitoring. Previously reported sweat-based and other non-invasive biosensors either can only monitor a single analyte at a time or lack on-site signal processing circuitry and sensor calibration mechanisms for accurate analysis of the physiological state. Given the complexity of sweat secretion, simultaneous and multiplexed screening of target biomarkers is critical and requires full system integration to ensure the accuracy of measurements. Here we present a mechanically flexible and fully integrated (that is, no external analysis is needed) sensor array for multiplexed in situ perspiration analysis, which simultaneously and selectively measures sweat metabolites (such as glucose and lactate) and electrolytes (such as sodium and potassium ions), as well as the skin temperature (to calibrate the response of the sensors). Our work bridges the technological gap between signal transduction, conditioning (amplification and filtering), processing and wireless transmission in wearable biosensors by merging plastic-based sensors that interface with the skin with silicon integrated circuits consolidated on a flexible circuit board for complex signal processing. This application could not have been realized using either of these technologies alone owing to their respective inherent limitations. The wearable system is used to measure the detailed sweat profile of human subjects engaged in prolonged indoor and outdoor physical activities, and to make a real-time assessment of the physiological state of the subjects. This platform enables a wide range of personalized diagnostic and physiological monitoring applications