Draft genome sequence of [i]Pseudomonas[/i] sp. strain ADP, a bacterial model for studying the degradation of the herbicide atrazine

EAPôle BIOME & IPMWe report here the 7,259,392-bp draft genome of [i]Pseudomonas[/i] sp. strain ADP. This is a bacterial strain that was first isolated in the 1990s from soil for its ability to mineralize the herbicide atrazine. It has extensively been studied as a model to understand the atrazine biodegradation pathway. This genome will be used as a reference and compared to evolved populations obtained by experimental evolution conducted on this strain under atrazine selection pressure. Copyright 2016 Devers-Lamrani et al

Ecotoxicological Impact of the Bioherbicide Leptospermone on the Microbial Community of Two Arable Soils

EA BIOmEInternational audienceThe ecotoxicological impact of leptospermone, a β-triketone bioherbicide, on the bacterial community of two arable soils was investigated. Soil microcosms were exposed to 0× (control), 1× or 10× recommended dose of leptospermone. The β-triketone was moderately adsorbed to both soils (i.e.,: K fa ∼ 1.2 and K −1 oc ∼ 140 mL g). Its dissipation was lower in sterilized than in unsterilized soils suggesting that it was mainly influenced by biotic factors. Within 45 days, leptospermone disappeared almost entirely from one of the two soils (i.e., DT 50 < 10 days), while 25% remained in the other. The composition of the microbial community assessed by qPCR targeting 11 microbial groups was found to be significantly modified in soil microcosms exposed to leptospermone. Pyrosequencing of 16S rRNA gene amplicons showed a shift in the bacterial community structure and a significant impact of leptospermone on the diversity of the soil bacterial community. Changes in the composition, and in the α-and β-diversity of microbial community were transient in the soil able to fully dissipate the leptospermone, but were persistent in the soil where β-triketone remained. To conclude the bacterial community of the two soils was sensitive to leptospermone and its resilience was observed only when leptospermone was fully dissipated

Isolation and characterization of Bradyrhizobium sp. SR1 degrading two β-triketone herbicides

In this study, a bacterial strain able to use sulcotrione,a β-triketone herbicide, as sole source of carbon and energy was isolated from soil samples previously treated with this herbicide. Phylogenetic study based on16S rRNA gene sequence showed that the isolate has 100 % of similarity with several Bradyrhizobium and was accordingly designated as Bradyrhizobium sp. SR1. Plasmid profiling revealed the presence of a large plasmid (>50 kb) in SR1 not cured under nonselective conditions. Its transfer to Escherichia coli by electroporation failed to induce β-triketone degrading capacity,suggesting that degrading genes possibly located on this plasmid cannot be expressed in E. coli or that they are not plasmid borne. The evaluation of the SR1 ability to degrade various synthetic (mesotrione and tembotrione) and natural (leptospermone) triketones showed that this strain was also able to degrademesotrione. Although SR1 was able to entirely dissipate both herbicides, degradation rate of sulcotrione was ten times higher than that of mesotrione, showing a greater affinity of degrading-enzyme system to sulcotrione. Degradation pathway of sulcotrione involved the formation of 2-chloro-4-mesylbenzoic acid (CMBA), previously identified in sulcotrione degradation, and of a new metabolite identified as hydroxy-sulcotrione.Mesotrione degradation pathway leads to the accumulation of-methylsulfonyl-2-nitrobenzoic acid(MNBA) and 2-amino-4 methylsulfonylbenzoic acid(AMBA), two well-known metabolites of this herbicide. Along with the dissipation of β-triketones, one could observe the decrease in 4-hydroxyphenylpyruvate dioxygenase(HPPD) inhibition, indicating that toxicity was due to parent molecules, and not to the formed metabolites. This is the first report of the isolation of bacterial strain able to transform two β-triketones

Challenges, solutions and future directions in the evaluation of service innovations in health care and public health

HeadlineEvaluating service innovations in health care and public health requires flexibility, collaboration and pragmatism; this collection identifies robust, innovative and mixed methods to inform such evaluations.This is the final version of the article. It first appeared from the National Institute for Helath Research via http://dx.doi.org/10.3310/hsdr0416

Lab to Field Assessment of the Ecotoxicological Impact of Chlorpyrifos, Isoproturon, or Tebuconazole on the Diversity and Composition of the Soil Bacterial Community

Pesticides are intentionally applied to agricultural fields for crop protection. They can harm non-target organisms such as soil microorganisms involved in important ecosystem functions with impacts at the global scale. Within the frame of the pesticide registration process, the ecotoxicological impact of pesticides on soil microorganisms is still based on carbon and nitrogen mineralization tests, despite the availability of more extensive approaches analyzing the abundance, activity or diversity of soil microorganisms. In this study, we used a high-density DNA microarray (PhyloChip) and 16S rDNA amplicon next-generation sequencing (NGS) to analyze the impact of the organophosphate insecticide chlorpyrifos (CHL), the phenyl-urea herbicide isoproturon (IPU), or the triazole fungicide tebuconazole (TCZ) on the diversity and composition of the soil bacterial community. To our knowledge, it is the first time that the combination of these approaches are applied to assess the impact of these three pesticides in a lab-to-field experimental design. The PhyloChip analysis revealed that although no significant changes in the composition of the bacterial community were observed in soil microcosms exposed to the pesticides, significant differences in detected operational taxonomic units (OTUs) were observed in the field experiment between pesticide treatments and control for all three tested pesticides after 70 days of exposure. NGS revealed that the bacterial diversity and composition varied over time. This trend was more marked in the microcosm than in the field study. Only slight but significant transient effects of CHL or TCZ were observed in the microcosm and the field study, respectively. IPU was not found to significantly modify the soil bacterial diversity or composition. Our results are in accordance with conclusions of the Environmental Food Safety Authority (EFSA), which concluded that these three pesticides may have a low risk toward soil microorganisms

Optimal pharmacotherapy pathway in adults with diabetic peripheral neuropathic pain: the OPTION-DM RCT

Background: The mainstay of treatment for diabetic peripheral neuropathic pain is pharmacotherapy, but the current National Institute for Health and Care Excellence guideline is not based on robust evidence, as the treatments and their combinations have not been directly compared. Objectives: To determine the most clinically beneficial, cost-effective and tolerated treatment pathway for diabetic peripheral neuropathic pain. Design: A randomised crossover trial with health economic analysis. Setting: Twenty-one secondary care centres in the UK. Participants: Adults with diabetic peripheral neuropathic pain with a 7-day average self-rated pain score of ≥ 4 points (Numeric Rating Scale 0–10). Interventions: Participants were randomised to three commonly used treatment pathways: (1) amitriptyline supplemented with pregabalin, (2) duloxetine supplemented with pregabalin and (3) pregabalin supplemented with amitriptyline. Participants and research teams were blinded to treatment allocation, using overencapsulated capsules and matching placebos. Site pharmacists were unblinded. Outcomes: The primary outcome was the difference in 7-day average 24-hour Numeric Rating Scale score between pathways, measured during the final week of each pathway. Secondary end points included 7-day average daily Numeric Rating Scale pain score at week 6 between monotherapies, quality of life (Short Form questionnaire-36 items), Hospital Anxiety and Depression Scale score, the proportion of patients achieving 30% and 50% pain reduction, Brief Pain Inventory – Modified Short Form items scores, Insomnia Severity Index score, Neuropathic Pain Symptom Inventory score, tolerability (scale 0–10), Patient Global Impression of Change score at week 16 and patients’ preferred treatment pathway at week 50. Adverse events and serious adverse events were recorded. A withintrial cost–utility analysis was carried out to compare treatment pathways using incremental costs per quality-adjusted life-years from an NHS and social care perspective. Results: A total of 140 participants were randomised from 13 UK centres, 130 of whom were included in the analyses. Pain score at week 16 was similar between the arms, with a mean difference of –0.1 points (98.3% confidence interval –0.5 to 0.3 points) for duloxetine supplemented with pregabalin compared with amitriptyline supplemented with pregabalin, a mean difference of –0.1 points (98.3% confidence interval –0.5 to 0.3 points) for pregabalin supplemented with amitriptyline compared with amitriptyline supplemented with pregabalin and a mean difference of 0.0 points (98.3% confidence interval –0.4 to 0.4 points) for pregabalin supplemented with amitriptyline compared with duloxetine supplemented with pregabalin. Results for tolerability, discontinuation and quality of life were similar. The adverse events were predictable for each drug. Combination therapy (weeks 6–16) was associated with a further reduction in Numeric Rating Scale pain score (mean 1.0 points, 98.3% confidence interval 0.6 to 1.3 points) compared with those who remained on monotherapy (mean 0.2 points, 98.3% confidence interval –0.1 to 0.5 points). The pregabalin supplemented with amitriptyline pathway had the fewest monotherapy discontinuations due to treatment-emergent adverse events and was most commonly preferred (most commonly preferred by participants: amitriptyline supplemented with pregabalin, 24%; duloxetine supplemented with pregabalin, 33%; pregabalin supplemented with amitriptyline, 43%; p = 0.26). No single pathway was superior in cost-effectiveness. The incremental gains in quality-adjusted life-years were small for each pathway comparison [amitriptyline supplemented with pregabalin compared with duloxetine supplemented with pregabalin –0.002 (95% confidence interval –0.011 to 0.007) quality-adjusted life-years, amitriptyline supplemented with pregabalin compared with pregabalin supplemented with amitriptyline –0.006 (95% confidence interval –0.002 to 0.014) qualityadjusted life-years and duloxetine supplemented with pregabalin compared with pregabalin supplemented with amitriptyline 0.007 (95% confidence interval 0.0002 to 0.015) quality-adjusted life-years] and incremental costs over 16 weeks were similar [amitriptyline supplemented with pregabalin compared with duloxetine supplemented with pregabalin −£113 (95% confidence interval −£381 to £90), ABSTRACT NIHR Journals Library www.journalslibrary.nihr.ac.uk viii amitriptyline supplemented with pregabalin compared with pregabalin supplemented with amitriptyline £155 (95% confidence interval −£37 to £625) and duloxetine supplemented with pregabalin compared with pregabalin supplemented with amitriptyline £141 (95% confidence interval −£13 to £398)]. Limitations: Although there was no placebo arm, there is strong evidence for the use of each study medication from randomised placebo-controlled trials. The addition of a placebo arm would have increased the duration of this already long and demanding trial and it was not felt to be ethically justifiable. Future work: Future research should explore (1) variations in diabetic peripheral neuropathic pain management at the practice level, (2) how OPTION-DM (Optimal Pathway for TreatIng neurOpathic paiN in Diabetes Mellitus) trial findings can be best implemented, (3) why some patients respond to a particular drug and others do not and (4) what options there are for further treatments for those patients on combination treatment with inadequate pain relief. Conclusions: The three treatment pathways appear to give comparable patient outcomes at similar costs, suggesting that the optimal treatment may depend on patients’ preference in terms of side effects. Trial registration: The trial is registered as ISRCTN17545443 and EudraCT 2016-003146-89. Funding: This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme, and will be published in full in Health Technology Assessment; Vol. 26, No. 39. See the NIHR Journals Library website for further project information

Etude des mécanismes à l'origine de la dispersion des gènes codant les enzymes responsables de la minéralisation de l'atrazine au sein de la microflore des sols

Diplôme : DE

Caractérisation de populations microbiennes tolérantes au chlordécone à partir de sols contaminés des Antilles

National audienc

Etude des mécanismes à l origine de la dispersion des gènes codant les enzymes responsables de la minéralisation de l atrazine au sein de la microflore des sols

L utilisation généralisée de l herbicide atrazine a non seulement conduit à la contamination de l environnement mais également à l adaptation des bactéries du sol à la dégradation de cette molécule. Cette adaptation est due à la récente et intense dispersion des gènes atz/trz responsables de sa minéralisation. L objectif de ce travail était de rechercher les mécanismes impliqués dans la dispersion des gènes atz/trz au sein de la microflore des sols. Des expériences (i) de conjugaison, (ii) d évolution, des analyses (iii) de réarrangements génétiques et (iv) d une collection de souches bactériennes dégradantes ont été réalisées. L ensemble des résultats obtenus suggèrent que les gènes atz/trz sont dispersés au sein de la microflore tellurique par conjugaison plasmidique et que les séquences d insertion IS1071 jouent indirectement un rôle dans cette dispersion. De plus, cela suggère que la voie de minéralisation est en cours d évolution et que les IS1071 joueraient un rôle important dans cette évolution.The wide use of atrazine led to the pollution of environment and to the adaptation of soil bacteria to degrade atrazine. The bacterial adaptation results from a recent and intense dispersal of the atz/trz genes encoding the enzymes responsible for atrazine mineralization. The aim of this study was to elucidate the mechanisms responsible for the dispersion of the atz/trz genes in soil microflora. Experiments of (i) conjugation, (ii) evolution, analysis of (iii) genetic rearrangements and (iv) a collection of atrazine-degrading bacteria were performed. Our results indicated that the dispersion of the atz/trz genes in soil bacteria relies directly on plasmid conjugation and indirectly on genetic rearrangement mediated by the insertion sequence IS1071. Moreover, it suggests that the atrazine mineralization genetic pathway is still in course of evolution and that IS1071 plays an important role in this phenomenon.DIJON-BU Sciences Economie (212312102) / SudocSudocFranceF

Genomics based approach to identify the genes involved in ipu mineralization in sphingomonas sp.sh

Phenylurea herbicide isoproturon, 3-(4-isopropylphenyl)-1,1-dimethylurea (IPU), was found to be rapidly mineralised in aFrench agricultural soil previously exposed to IPU. A bacterial strain able to metabolise IPU was isolated from this soil adapted toIPU mineralization