Evaluation of 16S rRNA gene PCR sensitivity and specificity for diagnosis of prosthetic joint infection: a prospective multicenter cross-sectional study

There is no standard method for the diagnosis of prosthetic joint infection (PJI). The contribution of 16S rRNA gene PCR sequencing on a routine basis remains to be defined. We performed a prospective multicenter study to assess the contributions of 16S rRNA gene assays in PJI diagnosis. Over a 2-year period, all patients suspected to have PJIs and a few uninfected patients undergoing primary arthroplasty (control group) were included. Five perioperative samples per patient were collected for culture and 16S rRNA gene PCR sequencing and one for histological examination. Three multicenter quality control assays were performed with both DNA extracts and crushed samples. The diagnosis of PJI was based on clinical, bacteriological, and histological criteria, according to Infectious Diseases Society of America guidelines. A molecular diagnosis was modeled on the bacteriological criterion (≥ 1 positive sample for strict pathogens and ≥ 2 for commensal skin flora). Molecular data were analyzed according to the diagnosis of PJI. Between December 2010 and March 2012, 264 suspected cases of PJI and 35 control cases were included. PJI was confirmed in 215/264 suspected cases, 192 (89%) with a bacteriological criterion. The PJIs were monomicrobial (163 cases [85%]; staphylococci, n = 108; streptococci, n = 22; Gram-negative bacilli, n = 16; anaerobes, n = 13; others, n = 4) or polymicrobial (29 cases [15%]). The molecular diagnosis was positive in 151/215 confirmed cases of PJI (143 cases with bacteriological PJI documentation and 8 treated cases without bacteriological documentation) and in 2/49 cases without confirmed PJI (sensitivity, 73.3%; specificity, 95.5%). The 16S rRNA gene PCR assay showed a lack of sensitivity in the diagnosis of PJI on a multicenter routine basis

1977-2017: 40 years of decametric observations of Jupiter and the Sun with the Nancay Decameter Array

International audienceThe Nancay Decameter Array (NDA) routinely observes low frequency (10-100 MHz) radio emissions of Jupiter and the Sun since 4 decades. The NDA observations, acquired with a variety of receivers with increasing performances, were the basis for numerous studies of Jovian and solar radio emissions and now form a unique long-term database spanning >=3 solar cycles and Jovian revolutions. In addition, the NDA historically brought a fruitful support to space-based radio observatories of the heliosphere, to multi-wavelength analyses of solar activity and contributes to the development of space weather services. After having summarized the NDA characteristics, this article presents latest instrumental and database developments, some recent scientific results and perspectives for the next decade

T Cell-Derived IL-17 Mediates Epithelial Changes in the Airway and Drives Pulmonary Neutrophilia

Th17 cells are a proinflammatory subset of effector T cells that have been implicated in the pathogenesis of asthma. Their production of the cytokine IL-17 is known to induce local recruitment of neutrophils, but the direct impact of IL-17 on the lung epithelium is poorly understood. In this study, we describe a novel mouse model of spontaneous IL-17-driven lung inflammation that exhibits many similarities to asthma in humans. We have found that STAT3 hyperactivity in T lymphocytes causes an expansion of Th17 cells, which home preferentially to the lungs. IL-17 secretion then leads to neutrophil infiltration and lung epithelial changes, in turn leading to a chronic inflammatory state with increased mucus production and decreased lung function. We used this model to investigate the effects of IL-17 activity on airway epithelium and identified CXCL5 and MIP-2 as important factors in neutrophil recruitment. The neutralization of IL-17 greatly reduces pulmonary neutrophilia, underscoring a key role for IL-17 in promoting chronic airway inflammation. These findings emphasize the role of IL-17 in mediating neutrophil-driven pulmonary inflammation and highlight a new mouse model that may be used for the development of novel therapies targeting Th17 cells in asthma and other chronic pulmonary diseases

Exploration of the Potential of the Radio-Detection Technique for the Detection of High-Energy Gamma Rays

International audienceThe radio detection of atmospheric particle showers initiated by ultra-high energy cosmic rays is today a proven technique that allows to reconstruct their properties (direction of arrival, energy, nature). Among the precursors of this method, the CODALEMA experiment installed at the Nançay radio-astronomy Observatory has contributed to several major technological innovations relevant for the radio detection technique (autonomous triggering, hybrid reconstruction, very wide frequency bands) and its high-performance antennas are also used on the NenuFAR radio telescope in Nançay. We propose to exploit the unique environment of the Nan\c cay Observatory through the CODALEMA experiment and the NenuFAR radio-telescope to explore the possibilities of radio-detection of atmospheric showers initiated by very high energy photons. The central idea is to phase a large set of antennas (several tens) in the direction of known sources emitting gamma (catalogs H.E.S.S., MAGIC, VERITAS, Fermi-LAT ...) to significantly increase the sensitivity of detection and to use the triggering capabilities on ultra fast transients controlled within the framework of CODALEMA. This would make it possible to observe the sources with a useful cycle close to 100 %. We present here the intended instrumental scheme as well as the expected signal level and some first results obtained on the observation of cosmic ray air showers with NenuFAR