Is Penicillin Plus Gentamicin Synergistic Against Sessile Group B Streptococcal Isolates? An In Vivo Study With An Experimental Model Of Foreign-body Infection

The rate of invasive group B Streptococcus (GBS) infections is steadily increasing, particularly in older persons and in adults with diabetes and other comorbidities. This population includes persons with a foreign body (e.g., who have undergone arthroplasty). In a rat tissue cage model, we evaluated the efficacy of adjunctive gentamicin (GEN) administered systemically (5 mg/kg body weight) every 24 h, or locally (12.5 mg/L tissue cage concentration) every 24 or 72 h, in combination with penicillin (PEN) administered systemically (250,000 IU/kg body weight three times per day). The efficacy was evaluated on two different sessile forms of GBS: transition (i.e., in between planktonic and biofilm) and biofilm. After 3 days of treatment, the mean bacterial load reduction of transition-form GBS was greater in all PEN-GEN combination groups than in the PEN monotherapy group (P <= 0.03). The 6-day regimen decreased the bacterial load significantly in comparison to the 3-day regimen, irrespective of growth form and adjunctive GEN (P < 0.01). After 6 days of treatment, the mean reduction in transition-form GBS was greater with PEN plus GEN administered locally every 24 h than with PEN monotherapy (P = 0.03). These results were not confirmed with biofilm GBS. The difference in mean bacterial load reduction between all PEN-GEN and PEN monotherapy groups was <100 CFU/mL. Hence, synergy criteria were not fulfilled. Adjunctive systemic GEN consists of potential side effects and showed poor efficacy in this study. Combining systemic PEN and local GEN has a potential application in the treatment of streptococcal implant-associated infections

Cumulative indoor exposures to Semi-Volatile Organic Compounds (SVOCs) in France: the ECOS project.

International audienceSemivolatile organic compounds (SVOCs) are widely used indoor as plasticizers, flame retardants, or pesticides. They are present in indoor environments both in air (as gas and suspended particles) and settled dust. Thus exposition to possibly harmful agents: (phthalates, polybromodiphenylethers, organophosphorous compounds...) occurs (Mitchell et al. 2007;Wu et al. 2007). Here is presented the framework of the ECOS project, which objective is to assess domestic cumulative exposure to these substances and associated health risks

Randomized Controlled Trial of Parent Therapeutic Education on Antibiotics to Improve Parent Satisfaction and Attitudes in a Pediatric Emergency Department

Objective: To evaluate therapeutic education delivered in a pediatric emergency department to improve parents’ satisfaction and attitudes about judicious antibiotic use. Methods: In an emergency department of a tertiary pediatric hospital, children aged 1 month to 6 years and discharged with an oral antibiotic prescription for an acute respiratory or urinary tract infection were randomized to a patient therapeutic education on antibiotic use (intervention group) or fever control (control group) delivered to the parents (in the presence of the children) by a pharmacist trained in therapeutic education. Education consisted in a 30-minute face-to-face session with four components: educational diagnosis, educational contract, education, and evaluation. The main outcome measure was parent satisfaction about information on antibiotics received at the hospital, as assessed by a telephone interview on day 14. The secondary outcome was attitudes about antibiotic use evaluated on day 14 and at month 6. Results: Of the 300 randomized children, 150 per arm, 259 were evaluated on day 14. Parent satisfaction with information on antibiotics was higher in the intervention group (125/129, 96.9%, versus 108/130, 83.0%; P=0.002, exact Fisher test). Intervention Group parents had higher proportions of correct answers on day 14 to questions on attitudes about judicious antibiotic use than did control-group parents (P=0.017, Mann-Whitney U test). Conclusion: Therapeutic education delivered by a clinical pharmacist in the pediatric emergency department holds promise for improving the use of antibiotics prescribed to pediatric outpatients. Trial Registration ClinicalTrials.gov NCT00948779 http://clinicaltrials.gov/show/NCT0094877

Small microplastics as a main contributor to plastic mass balance in the North Atlantic subtropical gyre

Estimates of cumulative plastic inputs into the oceans are expressed in hundred million tons, whereas the total mass of microplastics afloat at sea is 3 orders of magnitude below this. This large gap is evidence of our ignorance about the fate of plastics, as well as transformations and sinks in the oceans. One of the current challenges consists of identifying and quantifying plastic particles at the microscale, the small microplastics (SMP, 25–1000 μm). The aim of the present study is to investigate SMP concentration in count and in mass at the sea surface in the North Atlantic subtropical gyre during the sea campaign Expedition 7th Continent. After isolation, SMP were characterized by micro-Fourier-transform infrared spectroscopy. Microplastic distribution was modeled by a wind-driven vertical mixing correction model taking into account individual particle properties (dimension, shape and density). We demonstrate that SMP buoyancy is significantly decreased compared to the large microplastics (LMP, 1–5 mm) and consequently more susceptible to vertical transport. The uncorrected LMP concentration in count was between 13 000 and 174 000 pieces km–2, and was between 5 and 170 times more abundant for SMP. With a wind-driven vertical mixing correction, we estimated that SMP were 300 to 70 000 times more abundant than LMP. When discussing this in terms of weight after correction, LMP concentrations were between 50 and 1000 g km–2, and SMP concentrations were between 5 and 14 000 g km–2

Differential Modulation of TNF-α–Induced Apoptosis by Neisseria meningitidis

Infections by Neisseria meningitidis show duality between frequent asymptomatic carriage and occasional life-threatening disease. Bacterial and host factors involved in this balance are not fully understood. Cytopathic effects and cell damage may prelude to pathogenesis of isolates belonging to hyper-invasive lineages. We aimed to analyze cell–bacteria interactions using both pathogenic and carriage meningococcal isolates. Several pathogenic isolates of the ST-11 clonal complex and carriage isolates were used to infect human epithelial cells. Cytopathic effect was determined and apoptosis was scored using several methods (FITC-Annexin V staining followed by FACS analysis, caspase assays and DNA fragmentation). Only pathogenic isolates were able to induce apoptosis in human epithelial cells, mainly by lipooligosaccharide (endotoxin). Bioactive TNF-α is only detected when cells were infected by pathogenic isolates. At the opposite, carriage isolates seem to provoke shedding of the TNF-α receptor I (TNF-RI) from the surface that protect cells from apoptosis by chelating TNF-α. Ability to induce apoptosis and inflammation may represent major traits in the pathogenesis of N. meningitidis. However, our data strongly suggest that carriage isolates of meningococci reduce inflammatory response and apoptosis induction, resulting in the protection of their ecological niche at the human nasopharynx

Rapid protein evolution, organellar reductions, and invasive intronic elements in the marine aerobic parasite dinoflagellate Amoebophrya spp

Background: Dinoflagellates are aquatic protists particularly widespread in the oceans worldwide. Some are responsible for toxic blooms while others live in symbiotic relationships, either as mutualistic symbionts in corals or as parasites infecting other protists and animals. Dinoflagellates harbor atypically large genomes (similar to 3 to 250 Gb), with gene organization and gene expression patterns very different from closely related apicomplexan parasites. Here we sequenced and analyzed the genomes of two early-diverging and co-occurring parasitic dinoflagellate Amoebophrya strains, to shed light on the emergence of such atypical genomic features, dinoflagellate evolution, and host specialization. Results: We sequenced, assembled, and annotated high-quality genomes for two Amoebophrya strains (A25 and A120), using a combination of Illumina paired-end short-read and Oxford Nanopore Technology (ONT) MinION long-read sequencing approaches. We found a small number of transposable elements, along with short introns and intergenic regions, and a limited number of gene families, together contribute to the compactness of the Amoebophrya genomes, a feature potentially linked with parasitism. While the majority of Amoebophrya proteins (63.7% of A25 and 59.3% of A120) had no functional assignment, we found many orthologs shared with Dinophyceae. Our analyses revealed a strong tendency for genes encoded by unidirectional clusters and high levels of synteny conservation between the two genomes despite low interspecific protein sequence similarity, suggesting rapid protein evolution. Most strikingly, we identified a large portion of non-canonical introns, including repeated introns, displaying a broad variability of associated splicing motifs never observed among eukaryotes. Those introner elements appear to have the capacity to spread over their respective genomes in a manner similar to transposable elements. Finally, we confirmed the reduction of organelles observed in Amoebophrya spp., i.e., loss of the plastid, potential loss of a mitochondrial genome and functions. Conclusion: These results expand the range of atypical genome features found in basal dinoflagellates and raise questions regarding speciation and the evolutionary mechanisms at play while parastitism was selected for in this particular unicellular lineage

Rapid protein evolution, organellar reductions, and invasive intronic elements in the marine aerobic parasite dinoflagellate Amoebophrya spp

BACKGROUND : Dinoflagellates are aquatic protists particularly widespread in the oceans worldwide. Some are responsible for toxic blooms while others live in symbiotic relationships, either as mutualistic symbionts in corals or as parasites infecting other protists and animals. Dinoflagellates harbor atypically large genomes (~ 3 to 250 Gb), with gene organization and gene expression patterns very different from closely related apicomplexan parasites. Here we sequenced and analyzed the genomes of two early-diverging and co-occurring parasitic dinoflagellate Amoebophrya strains, to shed light on the emergence of such atypical genomic features, dinoflagellate evolution, and host specialization. RESULTS : We sequenced, assembled, and annotated high-quality genomes for two Amoebophrya strains (A25 and A120), using a combination of Illumina paired-end short-read and Oxford Nanopore Technology (ONT) MinION long-read sequencing approaches. We found a small number of transposable elements, along with short introns and intergenic regions, and a limited number of gene families, together contribute to the compactness of the Amoebophrya genomes, a feature potentially linked with parasitism. While the majority of Amoebophrya proteins (63.7% of A25 and 59.3% of A120) had no functional assignment, we found many orthologs shared with Dinophyceae. Our analyses revealed a strong tendency for genes encoded by unidirectional clusters and high levels of synteny conservation between the two genomes despite low interspecific protein sequence similarity, suggesting rapid protein evolution. Most strikingly, we identified a large portion of non-canonical introns, including repeated introns, displaying a broad variability of associated splicing motifs never observed among eukaryotes. Those introner elements appear to have the capacity to spread over their respective genomes in a manner similar to transposable elements. Finally, we confirmed the reduction of organelles observed in Amoebophrya spp., i.e., loss of the plastid, potential loss of a mitochondrial genome and functions. CONCLUSION : These results expand the range of atypical genome features found in basal dinoflagellates and raise questions regarding speciation and the evolutionary mechanisms at play while parastitism was selected for in this particular unicellular lineage.ADDITIONAL FILE 1: FIGURE S1. Phylogeny of Alveolata. Proteomes from 89 alveolates genomes and transcriptome assemblies from the MMETSP project (https://zenodo.org/record/257026/files/) were used to create orthologous groups using orthofinder v2.2 with the diamond BLAST similarity search. Single ortholog alignments were pruned using PhyloTreePruner v.1.0 (minimum taxa to keep 44 and support value 0.9) and realigned using mafft v7 and filtered with Gblocks v.0.91b (−b5 = a -p = n). Filtered alignments were concatenated using seqCat.pl and a phylogenetic tree was produced under Maximum Likelihood framework using RAxML v8.2.9 with the PROTGAMMALGF model of sequence evolution and 101 bootstraps. Asterics represent support values of 95 and above. A detailed method can be found in Kayal et al. 2018 BMC Evol. Biol. (https://doi.org/10.1186/s12862-018-1142-0). The full tree can be found at http://mmo.sb-roscoff.fr/jbrowseAmoebophrya/. FIGURE S2. SSU rDNA sequence identity (in percentage, relative to A25 and A120 compared to other species). FIGURE S3. Distribution of k-mer in A25 and A120 genomes. FIGURE S4. Classification of repeated elements in 3 Amoebophrya genomes (AT5, A25, and A120) using REPET. The x-axis represents the cumulated number of bases of repeated elements in the genome. FIGURE S5. Conserved motif of the putative splice leader (SL) in A25 and A120. FIGURE S6. Alignments of gene encoding the putative spliced leader (SL) gene in A25 and A120. FIGURE S7. Gene orientation change rate in 3 Amoebophrya genomes. FIGURE S8. Number of orthologs genes shared by selected taxa. FIGURE S9. Boxplot of the dN/dS ratios of orthologous genes between A25 and A120, calculated using the model average method (MA). FIGURE S10. Synteny dot-plot obtained by comparison between Amoebophrya A25 and AT5 genomes. FIGURE S11. Synteny dot-plot obtained by comparison between Amoebophrya A120 and AT5 genomes. FIGURE S12. Intron length distribution. FIGURE S13. GC content distribution. FIGURE S14. Multiple alignments of U2 snRNAs. FIGURE S15. Multiple alignments of U4 snRNAs. FIGURE S16. Multiple alignments of U5 snRNAs. FIGURE S17. Multiple alignments of U6 snRNAs. FIGURE S18. Secondary structure of Amoebophrya snRNA. FIGURE S19. Example of introner elements (IEs) in Amoebophrya. FIGURE S20. Distribution the direct repeats with size ranging between 3 and 8 nucleotides in A25. FIGURE S21. Distribution of the direct repeats with size ranging between 3 and 8 nucleotides in A120. FIGURE S22. Composition of direct repeats in introners elements. The diversity in composition of the three (a, b, c) most abundant of direct repeats in introner elements in A25 (up) and A120 (down). FIGURE S23. Terminal inverted repeat locations around the splicing sites in A25 and A120. The position of inverted repeats according to the location of the splice sites in A25 and A120. Left, the inverted repeats of A120 are located at 1–5 the nucleotides upstream and downstream of the splice sites. Right, the inverted repeats of A25 are located at the 1–6 nucleotides in upstream and downstream of the splice sites. FIGURE S24. The flowchart for the in silico search of introner elements. FIGURE S25. Hierarchical clustering analysis (pairwise similarity and OrthoMCL) of all intron families and of the inverted repeats in A25 and A120. FIGURE S26. Percentage of genes with assigned functions in relation with introns composition. FIGURE S27. Difference in the proportion of IEs-containing-genes compared to their KEGG assignment in A25 and A120. FIGURE S28. Distribution of conserved introns. TABLE S1. RCC number, date and site of isolation of strains considered in this study. TABLE S2. Metrics of Nanopore runs for the two Amoebophrya strains. TABLE S3. Search for pathways involved in plastidial functions that are entirely independent of plastid-encoded gene content. TABLE S4. Number of the different types of introns identified in A25 and A120 genomes. TABLE S5. Search for RNA editing in A25 and A120 introns. TABLE S6. Putative Amoebophrya A25 and A120 snRNP homologs. TABLE S7. Classification into families of non-canonical introns in A25 and A120. TABLE S8. RNAseq read assembly statistics of Amoebophrya A25 and A120 corresponding samples from the different time of infection and to the freeliving stage (dinospore only). TABLE S9. Total number of contigs belonging to samples from different stages of infection and the proportion of them that were aligned against the genomes of both Amoebophrya A25 and A120. ND corresponds to “not determined” when no measurement was done. TABLE S10. Metabolic pathway screened in A25 and A120 proteomes.This research was funded by the ANR (Agence Nationale de la Recherche) Grant ANR-14-CE02-0007 HAPAR, the CEA and the Région Bretagne (RC doctoral grant ARED PARASITE 9450 and EK postdoctoral grant SAD HAPAR 9229), and the CNRS (X-life SEAgOInG).http://www.mdpi.com/journal/biomedicinesam2022BiochemistryGeneticsMicrobiology and Plant Patholog