Versatile Graded-Index Multi-Mode Fiber for High Capacity Single-and Multi-Mode Optical Home Network

International audienceA graded-index multi-mode fiber has been optimized to sustain a single excited mode when coupled with a standard single-mode fiber at 1310/1550nm while offering large effective modal bandwidth at 850nm under VCSEL excitations. Modeling and experimental results are presented

Fibre à gradient d'indice adaptative pour réseau local domestique optique multimode et monomode haut débit

National audienceNous présentons des travaux théoriques et expérimentaux concernant une fibre optique à gradient d'indice optimisée pour supporter une propagation monomode lors d'une injection à partir d'une fibre monomode aux longueurs d'onde 1310/1550 mm tout en offrant une propagation multimode à 850m

Proficiency Program for Real-Time PCR Diagnosis of Bordetella pertussis Infections in French Hospital Laboratories and at the French National Reference Center for Whooping Cough and other Bordetelloses

ABSTRACT With the support of a ministerial program for innovative and expensive technologies, dedicated to the economic evaluation of laboratory diagnosis of pertussis by real-time PCR, external quality assessment for real-time IS 481 PCR was carried out. Coordinated by the National Centre of Reference of Pertussis and other Bordetelloses (NCR), this study aimed to harmonize and to assess the performances of eight participating microbiology hospital laboratories throughout the French territory. Between January 2006 and February 2007, 10 proficiency panels were sent by the NCR (ascending proficiency program), representing a total of 49 samples and including eight panels to analyze and evaluate the global sensitivity and specificity of real-time PCR, one to assess the limit of detection, and one to evaluate nucleic acid extraction methods. As part of the descending proficiency program, extracted DNA from clinical samples was sent by the eight participating laboratories in different panels and analyzed by the NCR. In the ascending proficiency analysis, the sensitivity and specificity of the real-time PCR methods were 92.2% and 94.3%, respectively. The limit of detection of the different methods ranged between 0.1 and 1 fg/μl (0.2 to 2 CFU/μl). The nucleic acid extraction methods showed similar performances. During the descending proficiency analysis, performed with 126 samples, the result of the NCR for 15 samples (11.9%) was discordant with the result obtained by the source laboratory. Despite several initial differences, harmonization was easy and performances were homogeneous. However, the risk of false-positive results remains quite high, and we strongly recommend establishment of uniform quality control procedures performed regularly

Bactériémies à Bacillus cereus en réanimation néonatale à l’AP-HP en 2016

International audienceIntroduction – Nine cases of Bacillus cereus bacteremia occurred in five neonatal resuscitation units (NRU) of the Assistance Publique-Hôpitaux de Paris (AP-HP) between August and December 2016. Method – The survey conducted around these cases included a study of the records to search for a common source, samples of the environment (surfaces, materials, batches of pasteurized milk, parenteral nutrition), a genetic comparison of clinical and environmental strains, a retrospective survey of AP-HP microbiology labo - ratories to estimate the incidence of B. cereus bacteremia in NRUs, and finally an evaluation of the milk circuit, from production to administration. Results – The retrospective survey showed that the incidence of B. cereus bacteremia in NRUs increased from 0.05 to 0.33 per 100 admissions between 2014-2015 and 2016. The only common point to all cases was to have received a lipid emulsion from the same manufacturer, as the majority of newborns in NRUs do. No common source contaminated by B. cereu s was identified. B. cereus was isolated from lots of pasteu - rized breast milk (two lots consumed by 2 cases and some not delivered), and some environmental samples. The comparison of the strains showed a great genotypic diversity. Improvements were implemented after evaluation of the milk circuit. Conclusion – At the end of 2016, an upsurge in the number of cases of B. cereus bacteremia was observed in five neonatal resuscitations units of AP-HP. The implication of a batch contamination of pasteurized milk has not been proven. No common source could be identifiedIntroduction – Neuf cas de bactériémie à Bacillus cereus sont survenus dans cinq réanimations néonatales (RNN) de l’Assistance publique-Hôpitaux de Paris (AP-HP) entre août et décembre 2016. Méthode – L’enquête menée autour de ces cas a inclus une étude des dossiers pour rechercher une source commune, des prélèvements de l’environnement (surfaces, matériels, lots de lait pasteurisé, nutrition paren - térale), une comparaison génétique des souches cliniques et environnementales, une enquête rétrospective auprès des laboratoires de microbiologie de l’AP-HP pour estimer l’incidence des bactériémies à B. cereus en RNN, et enfin une évaluation du circuit du lait, de la production à l’administration. Résultats – L’enquête rétrospective a montré que l’incidence des bactériémies à B. cereus en RNN avait augmenté de 0,05 à 0,33 pour 100 admissions entre 2014-2015 et 2016. Le seul point commun à tous les cas était d’avoir reçu une émulsion lipidique d’un même fabricant, comme la majorité des nouveau-nés en RNN. Aucune source commune contaminée par B. cereus n’a été identifiée. B. cereus a été isolé dans des lots de lait maternel pasteurisé (deux lots consommés par deux des cas et d’autres non délivrés) et quelques prélèvements d’environnement. La comparaison des souches a montré une grande diversité génotypique. Des améliorations ont été mises en place après évaluation du circuit du lait. Conclusion – Fin 2016, une recrudescence du nombre de cas de bactériémies à B. cereus a été constatée dans cinq réanimations néonatales de l’AP-HP. L’implication d’une contamination de lots de lait pasteurisé n’a pas été prouvée. Aucune source commune n’a pu être identifiée

Gene-nutrient interactions in the metabolic syndrome: single nucleotide polymorphisms in ADIPOQ and ADIPOR1 interact with plasma saturated fatty acids to modulate insulin resistance

Background: Progression of the metabolic syndrome (MetS) is determined by genetic and environmental factors. Gene-environment interactions may be important in modulating the susceptibility to the development of MetS traits. Objective: Gene-nutrient interactions were examined in MetS subjects to determine interactions between single nucleotide polymorphisms (SNPs) in the adiponectin gene (ADIPOQ) and its receptors (ADIPOR1 and ADIPOR2) and plasma fatty acid composition and their effects on MetS characteristics. Design: Plasma fatty acid composition, insulin sensitivity, plasma adiponectin and lipid concentrations, and ADIPOQ, ADIPOR1, and ADIPOR2 SNP genotypes were determined in a cross-sectional analysis of 451 subjects with the MetS who participated in the LIPGENE (Diet, Genomics, and the Metabolic Syndrome: an Integrated Nutrition, Agro-food, Social, and Economic Analysis) dietary intervention study and were repeated in 1754 subjects from the LIPGENE-SU.VI.MAX (SUpplementation en VItamines et Mineraux AntioXydants) case-control study (http://www.ucd.ie/lipgene). Results: Single SNP effects were detected in the cohort. Triacylglycerols, nonesterified fatty acids, and waist circumference were significantly different between genotypes for 2 SNPs (rs266729 in ADIPOQ and rs10920533 in ADIPOR1). Minor allele homozygotes for both of these SNPs were identified as having degrees of insulin resistance, as measured by the homeostasis model assessment of insulin resistance, that were highly responsive to differences in plasma saturated fatty acids (SFAs). The SFA-dependent association between ADIPOR1 rs10920533 and insulin resistance was replicated in cases with MetS from a separate independent study, which was an association not present in controls. Conclusions: A reduction in plasma SFAs could be expected to lower insulin resistance in MetS subjects who are minor allele carriers of rs266729 in ADIPOQ and rs10920533 in ADIPOR1. Personalized dietary advice to decrease SFA consumption in these individuals may be recommended as a possible therapeutic measure to improve insulin sensitivity. This trial was registered at clinicaltrials

Decrease of hospital- and community-acquired bloodstream infections due to Streptococcus pneumoniae and Streptococcus pyogenes during the first year of the COVID-19 pandemic: A time-series analysis in Paris region

Members of the Collégiale de Bactériologue – Virologie – Hygiène (CBVH)Guillaume Arlet, Laurence Armand Lefevre, Alexandra Aubry, Laurent Belec, Béatrice Bercot, Stéphane Bonacorsi, Vincent Calvez, Emmanuelle Cambau, Etienne Carbonnelle, Stéphane Chevaliez, Jean-Winoc Decousser, Constance Delaugerre, Diane Descamps, Florence Doucet-Populaire, Jean-Louis Gaillard, Antoine Garbarg-Chenon, Elyanne Gault, Jean-Louis Herrmann, Vincent Jarlier, Jérôme Le Goff, Jean-Christophe Lucet, Jean-Luc Mainardi, Anne-Geneviève Marcellin, Laurence Morand-Joubert, Xavier Nassif, Jean-Michel Pawlotsky, Jérôme Robert, Anne-Marie Roque Afonso, Martin Rottman, Christine Rouzioux, Flore Rozenberg, François Simon, Nicolas Veziris, David Skurnik, Jean-Ralph Zahar, Guilene Barnaud, Typhaine Billard Pomares, Gaëlle Cuzon, Dominique Decré, Alexandra Doloy, Jean-Luc Donay, Laurence Drieux-Rouzet, Isabelle Durand, Agnès Ferroni, Vincent Fihman, Nicolas Fortineau, Camille Gomart, Nathalie Grall, Christelle Guillet Caruba, Françoise Jaureguy, Valérie Lalande, Luce Landraud, Véronique Leflon, Patricia Mariani, Liliana Mihaila, Didier Moissenet, Latifa Noussair, Isabelle Podglajen, Isabelle Poilane, Hélène Poupet, Emilie Rondinaud, Valérie Sivadon Tardy, David Trystram, Charlotte Verdet, Emmanuelle Vigier, Sophie Vimont BillarantInternational audienceThe impact of the COVID-19 pandemic on bloodstream infections (BSIs) due to Streptococcus pneumoniae and Streptococcus pyogenes was assessed in 25 university hospitals of Paris. Monthly BSIs incidence rates that appeared stable in 2018 and 2019, decreased for the 2 pathogens during the 2 COVID-19 lockdown periods of 2020. Containment policies, including social distancing, masking and hand hygiene strengthening in both community and hospital settings are likely to reduce BSIs due to these pathogens

Erratum to 'Predominance of healthcare-associated cases among episodes of community-onset bacteraemia due to extended-spectrum β-lactamase-producing Enterobacteriaceae' [International Journal of Antimicrobial Agents 49/1 67-73]

International audienc