High-throughput Sequencing Analysis of the Actinobacterial Spatial Diversity in Moonmilk Deposits

Moonmilk are cave carbonate deposits that host a rich microbiome, including antibiotic-producing Actinobacteria, making these speleothems appealing for bioprospecting. Here, we investigated the taxonomic profile of the actinobacterial community of three moonmilk deposits of the cave “Grotte des Collemboles” via high-throughput sequencing of 16S rRNA amplicons. Actinobacteria was the most common phylum after Proteobacteria, ranging from 9% to 23% of the total bacterial population. Next to actinobacterial operational taxonomic units (OTUs) attributed to uncultured organisms at the genus level (~44%), we identified 47 actinobacterial genera with Rhodoccocus (4 OTUs, 17%) and Pseudonocardia (9 OTUs, ~16%) as the most abundant in terms of the absolute number of sequences. Streptomycetes presented the highest diversity (19 OTUs, 3%), with most of the OTUs unlinked to the culturable Streptomyces strains that were previously isolated from the same deposits. Furthermore, 43% of the OTUs were shared between the three studied collection points, while 34% were exclusive to one deposit, indicating that distinct speleothems host their own population, despite their nearby localization. This important spatial diversity suggests that prospecting within different moonmilk deposits should result in the isolation of unique and novel Actinobacteria. These speleothems also host a wide range of non-streptomycetes antibiotic-producing genera, and should therefore be subjected to methodologies for isolating rare Actinobacteria

Vivre chez soi après 65 ans. Atlas des besoins et des acteurs à Bruxelles

Cet atlas est le résultat d’une collaboration entre le Centre de Documentation et de Coordination Sociales et l’Observatoire de la Santé et du Social, soutenue par les trois commissions communautaires bruxelloises. Après un chapitre décrivant la situation socio-sanitaire des Bruxellois âgés, on trouve un inventaire de l’offre de services sociaux et de santé permettant aux plus de 65 ans de vivre le plus longtemps possible à domicile. Le chapitre suivant est consacré à l’analyse de cette offre par rapport aux besoins et des pistes pour l’avenir sont dégagées

Feasibility of setting up generic alert levels for maximum skin dose in fluoroscopically guided procedures

International audiencePurpose The feasibility of setting-up generic, hospital-independent dose alert levels to initiate vigilance on possible skin injuries in interventional procedures was studied for three high-dose procedures (chemoembolization (TACE) of the liver, neuro-embolization (NE) and percutaneous coronary intervention (PCI)) in 9 European countries. Methods Gafchromic® films and thermoluminescent dosimeters (TLD) were used to determine the Maximum Skin Dose (MSD). Correlation of the online dose indicators (fluoroscopy time, kerma- or dose-area product (KAP or DAP) and cumulative air kerma at interventional reference point (Ka,r)) with MSD was evaluated and used to establish the alert levels corresponding to a MSD of 2 Gy and 5 Gy. The uncertainties of alert levels in terms of DAP and Ka,r, and uncertainty of MSD were calculated. Results About 20–30% of all MSD values exceeded 2 Gy while only 2–6% exceeded 5 Gy. The correlations suggest that both DAP and Ka,r can be used as a dose indicator for alert levels (Pearson correlation coefficient p mostly andgt;0.8), while fluoroscopy time is not suitable (p mostly andlt;0.6). Generic alert levels based on DAP (Gy cm2) were suggested for MSD of both 2 Gy and 5 Gy (for 5 Gy TACE 750, PCI 250 and NE 400). The suggested levels are close to the lowest values published in several other studies. The uncertainty of the MSD was estimated to be around 10–15% and of hospital-specific skin dose alert levels about 20–30% (with coverage factor k = 1). Conclusions The generic alert levels are feasible for some cases but should be used with caution, only as the first approximation, while hospital-specific alert levels are preferred as the final approach. © 2018 Associazione Italiana di Fisica Medic

AOB community structure and richness under European beech, sessile oak, Norway spruce and Douglas-fir at three temperate forest sites

Abstract Background and aims The relations between tree species, microbial diversity and activity can alter ecosystem functioning. We investigated ammonia oxidizing bacteria (AOB) community structure and richness, microbial/environmental factors related to AOB diversity and the relationship between AOB diversity and the nitrification process under several tree species. Methods Forest floor (Of, Oh) was sampled under European beech, sessile oak, Norway spruce and Douglas-fir at three sites. AOB community structure was assessed by PCR-DGGE and sequencing. Samples were analyzed for net N mineralization, potential nitrification, basal respiration, microbial biomass, microbial or metabolic quotient, pH, total nitrogen, extractable ammonium, organic matter content and exchangeable cations. Results AOB community structure and tree species effect on AOB diversity were site-specific. AOB richness was not related to nitrification. Factors regulating ammonium availability, i.e. net N mineralization or microbial biomass, were related to AOB community structure. Conclusion Our research shows that, at larger spatial scales, site specific characteristics may be more important than the nature of tree species in determining AOB diversity (richness and community structure). Within sites, tree species influence AOB diversity. The absence of a relation between AOB richness and nitrification points to a possibly role of AOB abundance, phenotypic plasticity or the implication of ammonia oxidizing archaea