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The aim of this longitudinal multisite randomized controlled trial (RCT) was to evaluate the effectiveness of the EMDR-Integrative Group Treatment Protocol for Ongoing Traumatic Stress (EMDR-IGTP-OTS) in reducing severe posttraumatic stress disorder, depression, and anxiety symptoms in refugee minors living in Valencia, Spain. The study was conducted in 2019 in the city of Valencia, Spain, in six sites for refugees (homes or residences). A total of 184 minors (all males) met the inclusion criteria. Participants’ ages ranged from 13 to 17 years old (M =16.36 years). Participants’ time since the arrival to the sites in Valencia varied from January 2018 to March 2019. Participation was voluntary with the participants and their legal guardian's consent. In this study, intensive EMDR therapy was provided. This intensive format allowed the participants to complete the full course of treatment in a short period. Treatment was provided simultaneously by eighteen licensed EMDR clinicians formally trained in the protocol administration divided into six teams. Each of the treatment group participants received an average of eight hours of treatment, provided during nine group-treatment sessions, three times daily during three consecutive days in a setting inside the six refugee sites. EMDR-IGTP-OTS treatment focused only on the distressing memories related to their life as refugees and did not address any other memories. No adverse effects were reported during treatment or at three-month post-treatment assessment. Data analysis by repeated measures ANOVA showed that the EMDR-IGTP-OTS was effective in reducing PTSD symptoms in the treatment group (F (2, 122) = 43.17p

Spodoptera littoralis, one of the major pests of many important crop plants, is more susceptible to Bacillus thuringiensis aizawai delta-endotoxins than to those of Bacillus thuringiensis kurstaki. Within the framework of the development of efficient bioinsecticides and the prevention against insect resistance, we tested the effect of mixing B. thuringiensis kurstaki delta-endotoxins and Photorhabdus luminescens cells on S. littoralis growth. The obtained results showed that the growth inhibition of this insect was more effective when B. thuringiensis kurstaki spore-crystal mixture and Photorhabdus luminescens cells were used in combination. Furthermore, this synergism is mainly due to the presence of Cry1Ac, which is one of the three delta-endotoxins that form the crystal of B. thuringiensis kurstaki strain BNS3 in addition to Cry1Aa and Cry2Aa. This work shows a possibility to use B. thuringiensis as a delivery means for Photorhabdus bacteria in order to infect the insect hemocoel and to reduce the risk of developing resistance in the target organism.

The eye movement desensitization and reprocessing (EMDR) individual protocol for paraprofessional use in acute trauma situations (EMDR-PROPARA) is part of a project developed at the initiative of Dr. Francine Shapiro. This randomized clinical trial examined the effectiveness of the protocol administered by experienced EMDR therapists. There were 39 traumatized first responders on active duty randomly assigned to receive two 90-min sessions of either EMDR-PROPARA or of supportive counseling. Participants in the EMDR-PROPARA group showed benefits immediately after treatment, with their scores on the Short PTSD Rating Interview (SPRINT) showing further decreases at 3-month follow-up. In comparison, supportive counseling participants experienced a nonsignificant decrease after treatment and an increase in the SPRINT scores at the second follow-up. The significant difference between the two treatments provides preliminary support for EMDR-PROPARA’s effectiveness in reducing severity of posttraumatic symptoms and subjective global improvement. More controlled research is recommended to evaluate further the efficacy of this intervention.

Comparative genomics in the entomopathogenic genera [i]Xenorhabdus[/i] and [i]Photorhabdus[/i]: insight in the XaxAB binary cytolysin-encoding locus. 49. Annual Meeting of the Society for Invertebrate Pathology

Bacteria of the genus Xenorhabdus are symbionts of soil entomopathogenic nematodes of the genus Steinernema. This symbiotic association constitutes an insecticidal complex active against a wide range of insect pests. Within Xenorhabdus bovienii species, the X. bovienii CS03 strain (Xb CS03) is nonvirulent when directly injected into lepidopteran insects, and displays a low virulence when associated with its Steinernema symbiont. The genome of Xb CS03 was sequenced and compared with the genome of a virulent strain, X. bovienii SS-2004 (Xb SS-2004). The genome size and content widely differed between the two strains. Indeed, Xb CS03 had a large genome containing several specific loci involved in the inhibition of competitors, including a few NRPS-PKS loci (nonribosomal peptide synthetases and polyketide synthases) producing antimicrobial molecules. Consistently, Xb CS03 had a greater antimicrobial activity than Xb SS-2004. The Xb CS03 strain contained more pseudogenes than Xb SS-2004. Decay of genes involved in the host invasion and exploitation (toxins, invasins, or extracellular enzymes) was particularly important in Xb CS03. This may provide an explanation for the nonvirulence of the strain when injected into an insect host. We suggest that Xb CS03 and Xb SS-2004 followed divergent evolutionary scenarios to cope with their peculiar life cycle. The fitness strategy of Xb CS03 would involve competitor inhibition, whereas Xb SS-2004 would quickly and efficiently kill the insect host. Hence, Xenorhabdus strains would have widely divergent host exploitation strategies, which impact their genome structure.

There is a complex interplay between the regulation of flagellar motility and the expression of virulence factors in many bacterial pathogens. Here, we review the literature on the direct and indirect roles of flagellar motility in mediating the tripartite interaction between entomopathogenic bacteria (Photorhabdus and Xenorhabdus), their nematode hosts, and their insect targets. First, we describe the swimming and swarming motility of insect pathogenic bacteria and its impact on insect colonization. Then, we describe the coupling between the expression of flagellar and virulence genes and the dynamic of expression of the flagellar regulon during invertebrate infection. We show that the flagellar type 3 secretion system (T3SS) is also an export apparatus for virulence proteins in X. nematophila. Finally, we demonstrate that phenotypic variation, a common property of the bacterial symbionts of nematodes, also alters flagellar motility in Photorhabdus and Xenorhabdus. Finally, the so-called phenotypic heterogeneity phenomenon in the flagellar gene expression network will be also discussed. As the main molecular studies were performed in X. nematophila, future perspectives for the study of the interplay between flagellum and invertebrate interactions in Photorhabdus will be discussed.

Lipid A is a potent endotoxin, and its fatty acids (lauric, myristic, and sometimes palmitic acid) anchors lipopolysaccharide (LPS) into the outer leaflet of the outer membrane of most Gram-negative bacteria. The highly anionic charge of the glucosamine lipid A moiety makes the LPS a powerful attractant for cationic antimicrobial peptides (AMPs). AMPs are major component of innate immunity that kill bacteria by permeabilization of lipid bilayers. Secondary lipid A acylation of Klebsiella pneumoniae, involving the acyltransferase LpxM (formally, msbB or WaaN) that acylates (KDO)2-(lauroyl)-lipid IV-A with myristate during lipid A biosynthesis, has been associated with bacterial resistance to AMPs contributing to virulence in animal models. We investigated here the role of the msbB gene of the entomopathogenic bacterium Photorhabdus luminescens in AMP resistance, by functional complementation of the AMP susceptible K. pneumoniae lpxM mutant with the P. luminescens msbB gene. We showed that msbB (lpxM) gene of P. luminescens is able to enhance polymyxin B, colistin and cecropin A resistance of K. pneumoniae lpxM mutant, compared to the non-complemented mutant. However, we could not obtain any msbB mutant of Photorhabdus by performing allelic exchange experiments based on positive selection of sucrose highly resistant mutants. We thus suggest that msbB-mediated Photorhabdus lipid A acylation is essential for outer membrane low-permeability and that modification of lipid A composition, fluidity and osmosis-resistance have an important role in the ability of Photorhabdus to grow in sucrose at high concentrations.

Resume L’hypothese neurodeveloppementale est aujourd’hui l’un des modeles phares pour expliquer la schizophrenie. Selon ce modele, la schizophrenie est la consequence d’anomalies cerebrales precoces engendrees par l’interaction de facteurs genetiques et de facteurs environnementaux. Les donnees en faveur de ce modele sont nombreuses. Plusieurs etudes retrouvent des anomalies perinatales beaucoup plus nombreuses que chez les sujets controles. Sur le plan clinique, les sujets schizophrenes presentent de multiples deficits cognitifs bien avant l’eclosion de la maladie. Ces anomalies parfois subtiles sont selon le modele neurodeveloppemental l’expression des anomalies precoces du systeme nerveux central. Ces donnees sont concordantes avec les donnees en imagerie cerebrale qui montrent des anomalies precoces mais egalement des changements progressifs du systeme nerveux central. Enfin, les donnees genetiques et histologiques confirment que les genes impliques dans la schizophrenie sont les genes codant les differentes etapes du developpement du systeme nerveux central.

Xenorhabdus nematophila engages in complex interactions with invertebrates, through its symbiosis with soil nematodes and its pathogenicity to a broad range of insect larvae. Among the regulatory proteins of Xenorhabdus involved in host interactions, the sigma factor FliA and the regulator FliZ, expressed from the fliAZ operon, play a key role in mediating the production of exoenzymes, motility and full virulence in insects (Lanois et al., 2008). In this study, we investigated the dynamics of the FliA-dependent flagellin gene fliC and FliZ-dependent haemolysin genes xaxAB during insect infection and nematode association by carrying out real-time expression analysis using an unstable GFP monitoring system. We showed that expression of the FliAZ-dependent genes in infected insects is not restricted to a specific tissue but increases significantly just prior to host death and reaches a maximal level in larvae cadaver. Using an iron availability reporter construct, we also showed that iron starvation conditions inhibit expression of FliAZ-dependent genes in vitro, as well as during the first steps of the infectious process. These findings shed further light on the role of the FliAZ regulon in the Xenorhabdus life cycle and suggest that iron may constitute a signal governing Xenorhabdus adaptation to shifting host environments.

The aim of this randomized controlled trial was to evaluate the effectiveness of the EMDR-Integrative Group Treatment Protocol for Ongoing Traumatic Stress (EMDR-IGTP-OTS) in reducing posttraumatic stress disorder symptoms, depression and anxiety symptoms related to the diagnosis and treatment of cancer. Twenty-three adolescents and young adults (13 male and 10 female) with different types of cancer (breast, leukemia, lymphoma) and PTSD symptoms related to their diagnosis and cancer treatment met the inclusion criteria. Participants age ranged from 13 to 22 years old (M = 16.71 years). Participant’s time since diagnosis varied from 2006 to 2018. Participants in treatment (N=11) and no-treatment control (N=12) groups completed pre, post, and follow up measurements using the Posttraumatic Stress Disorder Checklist for DSM-5 (PCL-5) and the Hospital Anxiety and Depression Scale (HADS). Data analysis by repeated measures ANOVA showed that the EMDR-IGTP-OTS was effective in significantly reducing symptoms of PTSD, anxiety, and depression, with symptoms maintained at 90-day follow-up and with large effect sizes (e.g., d=1.17). A comparison of the treatment and no-treatment control groups showed significantly greater decreases for the treatment group on symptoms of PTSD, anxiety, and depression. This study suggests that EMDR-IGTP-OTS may be an efficient and effective way to address cancer-related PTSD, depressive, and anxious symptoms in adolescents and young adults.

Vibrio splendidus, strain LGP32, is an oyster pathogen associated with the summer mortalities affecting the production of Crassostrea gigas oysters worldwide. Vibrio splendidus LGP32 was shown to resist to up to 10 µM Cg-Def defensin and Cg-BPI bactericidal permeability increasing protein, two antimicrobial peptides/proteins (AMPs) involved in C. gigas immunity. The resistance to both oyster Cg-Def and Cg-BPI and standard AMPs (polymyxin B, protegrin, human BPI) was dependent on the ompU gene. Indeed, upon ompU inactivation, minimal bactericidal concentrations decreased by up to fourfold. AMP resistance was restored upon ectopic expression of ompU. The susceptibility of bacterial membranes to AMP-induced damages was independent of the ompU-mediated AMP resistance. Besides its role in AMP resistance, ompU proved to be essential for the adherence of V. splendidus LGP32 to fibronectin. Interestingly, in vivo, ompU was identified as a major determinant of V. splendidus pathogenicity in oyster experimental infections. Indeed, the V. splendidus-induced oyster mortalities dropped from 56% to 11% upon ompU mutation (Kaplan-Meier survival curves, P < 0.01). Moreover, in co-infection assays, the ompU mutant was out competed by the wild-type strain with competitive indexes in the range of 0.1-0.2. From this study, ompU is required for virulence of V. splendidus. Contributing to AMP resistance, conferring adhesive properties to V. splendidus, and being essential for in vivo fitness, the OmpU porin appears as an essential effector of the C. gigas/V. splendidus interaction.

Reverse Osmosis is the most widely used method for treating municipal solid waste landfill leachates, since it produces a permeate in compliance with reject requirements. However, the efficiency of this process at the industrial scale is limited mainly because of membrane fouling and the high osmotic pressures involved. Although lime precipitation is traditionally used to eliminate the temporary hardness of water by decarbonation, it has also been shown to be highly efficient in removing humic substances which are known to have strong fouling potential towards membranes. Our objective is to study the lime/leachate physico-chemistry, in order to determine the potential of the lime precipitation as pre-treatment for reverse osmosis. The results show that the lime treatment makes it possible (i) to act efficiently on the inorganic fraction of leachates through a decarbonation mechanism which entails massive precipitation of the carbonates under the form of CaCO3, (ii) to eliminate by co-precipitation the high Molecular Weight (MW) organic macromolecules (>50,000 g.mol−1) such as humic acids, and (iii) to generate a stable residue that can be easily stored at a landfill. The reverse osmosis step will be facilitated through significant reduction of the osmotic pressures and prevention of membrane fouling.

Governments in developing countries need effective programmes to advance public policies and improve social welfare. NGOs often have well-tested programmes and research outcomes that are relevant to such needs, yet the scaling up of pilot programmes to national level is difficult to achieve and frequently unsuccessful. This article presents a case of successful scaling up for an adolescent sexual-health and psychosocial-competencies programme in Mexico, through an NGO–government partnership involving IMIFAP, a Mexican NGO. The case illustrates how an NGO can create a successful partnership with government to scale up effective programmes, in ways that meet key needs of the target population while protecting the NGO's core values.

There is a complex interplay between the regulation of flagellar motility and the expression of virulence factors in many bacterial pathogens. We investigated the role of FliZ in the regulation of flagellar and virulence genes in Xenorhabdus nematophila, an insect pathogen. The fliZ gene is the second gene in the fliAZ operon in X. nematophila. In vivo transcription analysis revealed a positive feedback loop of fliAZ transcription in which FliZ activates flhDC, the master operon of flagellar regulon in X. nematophila, leading to an increased transcription of the FlhDC-dependent promoter of fliAZ. We also showed that fliAZ and flhDC mutants lacked motility, had no haemolysin or Tween lipase activity and displayed an attenuated virulence phenotype in insects. Lipase activity is controlled by FliA, whereas haemolysin production and full virulence phenotype have been reported to be FliZ-dependent. Transcriptional analysis revealed that FliZ directly controlled expression of the xhlBA and xaxAB operons, which encode haemolysins from the two-partner secretion system and the binary XaxAB toxin family respectively. We suggest that this regulatory pathway may also occur in other pathogenic enterobacteria with genes encoding members of these two growing families of haemolysins.

A quasi-experimental study is reported with four measurement occasions to evaluate longer-term effects of a life-skills and HIV/AIDS school-based prevention program. Trained teachers administered the program promoting precursors of safer sex behavior to 2064 Mexican high-school students at an age before most were sexually active. The variables included in the study (knowledge about HIV/AIDS prevention, attitudes towards use of condoms, subjective norms, intentions to use condoms and life skills as decision-making skills, partner communication and individual responsibility) have been reported as precursors of protective sexual behavior. The results demonstrate the stability of training effects and a positive impact on these precursors over 1 year of follow-up.

International audience; Comparison of the proteomes of wild-type Photorhabdus luminescens and its hcaR derivative, grown in insect hemolymph, showed that hcaR disruption decreased the production of toxins (tcdA1, mcf and pirAB) and proteins involved in oxidative stress response (SodA, AhpC, Gor). The disruption of hcaR did not affect growth rate in insects, but did delay the virulence of P. luminescens in Bombyx mori and Spodoptera littoralis larvae. This delayed virulence was associated with a lower toxemia rather than delay in bacteremia. The disruption of hcaR also increased bacterial sensitivity to hydrogen peroxide. A sodA mutant and an hcaR mutant had similar phenotypes in terms of sensitivity to hydrogen peroxide, virulence, toxin gene expression, and growth rate in insects. Thus, the two processes affected by hcaR disruption - toxemia and oxidative stress response - appear to be related. Besides, expression of toxin genes tcdA1, mcf, and pirAB was decreased by paraquat challenge. We provide here the first demonstration of the importance of toxemia for P. luminescens virulence. Our results also highlight the power of proteomic analysis for detecting unexpected links between different, concomitant processes in bacteria

A school-based life skills and sexuality education HIV/AIDS program for adolescents was evaluated in Toluca, Mexico, through a quasi-experimental pre–post design with 1,566 cases, divided over a control group and an experimental group. Based on a previously tested path model, 3 levels of variables were included as a guide for the contents of the program: personal variables (self-knowledge, self-efficacy regarding condom use, and decision making), intervening variables (subjective norms about, knowledge about HIV/AIDS, and attitudes toward condoms), and outcome variables (communication on sexuality and intentions to use condoms). Evaluation was conducted following these categories. Significant increases in all of these variables recognized as precursors of safer sex were found in the experimental group.

National audience; Genus Xenorhabdus (Enterobacteriaceae) consists of bacterial symbionts of soil entomopathogenic nematodes belonging to the genus Steinernema. The symbiotic association represents an insecticidal complex against a wide range of insect pests. Xenorhabdus is also considered as an entomopathogenic bacterium since it kills insects when it is directly injected into insect hemolymph. In the genus Xenorhabdus, only mutants defective for global regulators were totally impaired in virulence, suggesting that weapons of virulence are multiple and redundant (1). We initiated a global approach to identify integrated functions involved in bacterial adaptation to insects and to describe evolutionary history of the virulence/host adaptation factors in Xenorhabdus. We conducted a thorough comparative analysis of several Xenorhabdus strains by undergoing a pathology survey of our Xenorhabdus collection and by sequencing genomes of strains of interest in order to carry out comparative genomics. We identified strains that are non virulent by injection into two lepidopteran model insects, Galleria mellonella (sensitive insect), Spodoptera littoralis (resistant insect). We showed that Xenorhabdus genomes present an important flexible genome (40-50% of the whole genome), organized in functional genomic modules that undergo shuffling (2). We then focused our genomic analysis on two Xenorhabdus species. In Xenorhabdus poinarii, all the strains are attenuated in virulence and display genome reduction (3). In Xenorhabdus bovienii, one non-virulent strain display a genomic expansion and pseudogenization of of some virulence gene (4). We proposed several evolutionary scenarios that may explain the non-virulence of these bacterial strains. References : (1) Nielsen-LeRoux et al. (2012). Curr Opin Microbiol 15: 220–231. (2) Ogier J-C, et al. (2010). BMC Genomics 11: 568. (3) Ogier J-C, et al. (2014). Genome Biol Evol 6: 1495–1513. (4) Bisch G, et al. (2014). J Invertebr Pathol. 124: 15–22.

This article reports on the development and administration of a programme in seven rural villages in the Mexican state of Oaxaca to address high rates of cervical cancer. The rationale and strategy are described on which the programme is based. The development and administration of the programme (to 1513 women) is presented, aimed at enabling women to take better care of themselves. Various additional activities that were added in the course of the programme in order to facilitate contextual factors are also described, including community campaigning, programmes with men and the training of health personnel. Effectiveness was evaluated in terms of both process and impact indices, showing high rates of attendance at programme sessions by enrolled women, an increase in knowledge and a substantial increase in the number of preventive diagnostic tests. The final section reflects on both the achievements, and the scope and the limitations of the programme. Copyright © 2005 John Wiley & Sons, Ltd.

Entomopathogenic bacteria of the genus Photorhabdu s harbor a type III secretion system. This system was probably acquired prior to the separation of the species within this genus. Furthermore, the core components of the secretion machinery are highly conserved but the predicted effectors differ between Photorhabdus luminescens and P. asymbiotica , two highly related species with different hosts.

Analysis of the Photorhabdus luminescens genome sequence revealed that the pts region is related to the tail synthesis gene core of the P2 phage. The pts locus encodes a DNA invertase homologue. PCR-RFLP analysis showed the two potential tail fiber regions of the pts locus present DNA inversions. Electron microscopy revealed a phage tail-like particle, related to the R-type family and named R-photorhabdicin, in the culture supernatant of P. luminescens. Mass spectrometry analysis of two sub-units of R-photorhabdicin revealed that they are encoded by the pts locus. The role of this P2-related prophage remnant in the Photorhabdus genome is discussed.

One of the tasks of psychology is to promote positive changes in individual health behavior. Interventions to bring about these changes should be directed at skills knowledge, and beliefs pertinent to specific situations.Maintenance of change is facilitated by a conducive context. A conceptual framework is presented that reflects these concerns A systematic strategy is also outlined that includes needs analysis, development and piloting of programs, as well as advocacy and dissemination for large-scale implementation. A program aimed at enhancing the role of pharmacy sales staff in HIV/AIDS prevention in Mexico is presented to illustrate how the framework and strategy are used.

Utilisation des nématodes en lutte biologique. Les cercles Innovation Qualiméditerranée: INTRANTS ALTERNATIFS : EXTRAITS NATURELS ET MICRO-ORGANISMES

PM1072 - Bistability and antimicrobial peptide resista nce in the entomopathogenic bacteria Photorhabdus. International Union of Microbiological Societies Congresses - IUMS2014

International audience; Because earthworms sustain soil functioning and fertility, there is a need to advance the knowledge of their adaptation potential to chemicals in anthropogenic landscapes. Our hypothesis is that there is acclimation to organic chemicals (pesticides) in earthworms that durably persist under conventional farming in anthropogenic landscapes. The adaptation capability of two populations of earthworms (Aporectodea caliginosa) having a different chemical exposure history, - one originating from 20 years of organic farming (naïve population) and another from 20 years of conventional farming (pre-exposed population) - to cope with soil organic pollutant (Opus®, epoxiconazole a worldwide used fungicide) were investigated. Several complementary metabolic and energetic endpoints were followed, and cast production was assessed as a behavioural biomarker related to earthworms ecological role for the soil. Basal metabolism reflected by respiration rate was increased in both fungicide-exposed worms compared to controls. Glycogen resources were decreased in the same proportion in the two populations but more rapidly for the naïve (7 days) than for the pre-exposed population (28 days). Soluble protein and most amino-acids contents increased in the pre-exposed population only, suggesting a detoxification mechanism. Metabolomic profiles showed a cut-off between fungicide-exposed and control groups in the pre-exposed earthworms only, with an increase in most of the metabolites. Exposure to a low dose of epoxiconazole increased cast production of pre-exposed earthworms, and this resulted in an increase in pesticide disappearance. As far as we know, this is the first study which evidenced there is an acclimation to an agricultural chemical in earthworms derived from conventional farming that also relates to a change in their burrowing behaviour, and for which larger consequences for the soil ecosystem need to be addressed. This original finding is of major interest in the frame of ecosystem resilience to global changes. Whether this physiological adaptation is a general pattern of response against fungicides or other pesticides would need to be confirmed with other molecules and agricultural contexts.

International audience

Bistability and antimicrobial peptide resistance in the entomopathogenic bacteria [i]Photorhabdus[/i]. 5. Journée du Réseau thématique transversal « INTERACTION MICRO-ORGANISMES HOTES (IMH)»

I dette arbejde blev der forsket i om langsigtet residualforurening af landbrugsjord fører til pesticidadaptation hos regnorme. Forskningen sigtede også efter at identificere adaptations-omkostningerne fra individ- til populationsniveau, og konsekvenserne for økosystemet. Pesticiders residualforurening blev vurderet og sammenlignet i; tre konventionelt styrede marker (klassificeret efter evaluering af pesticid-anvendelser som ”højt-”, ”medium-”, og ”lav-input”), en mark styret ud fra økologiske betingelser, og et økologisk permanent græsningsareal, alle havde været styret på denne måde i mere end 20 år. Ved hjælp af en vand-ekstraktionsmetode blev 6,8 og 4 pesticidresiduums udvundet i henholdsvis ”høj-”, ”medium-”, og ”lav-input” markerne, og næsten ingen pesticider blev detekteret i jorden fra den økologiske mark bortset fra lave niveauer af resterende (højst sandsynligt 20 år gammelt) atrazin. Regnorms-populationerne Aporrectodea caliginosa og Allolobophora chlorotica blev fundet i alle fem marker, bortset fra A. chlorotica som ikke var til stede i den økologiske mark. Adaptationsstrategier blev undersøgt ved at sammenligne populationerne af disse regnorme de forskellige marker imellem ifølge flere parametre i felt- og laboratoriebedømmelserne. De målte parametre rangerede fra molekylære- (biotransformation og antioxiderende enzymer), biokemiske- (primære energiressourcer), og metaboliske- (respirationsrate, metabolomics) niveauer, til individuelle- (vægt, længde) og populations-relaterede parametre (puppe og juvenile livskarakterer), og til de mulige konsekvenser for økosystemet med hensyn til bioturbation (regnormes grave-adfærd) og nedgang i koncentrationen af ekstraherbare pesticider. Forbedret afgiftnings- og antioxiderende potentiale blev demonstreret langs gradienten af pesticid forurening i felten. Forbedret afgiftning i den pre-eksponerede population var særdeles tydeliggjort ved eksponeringen til pesticider i laboratoriet sammenliget med den økologiske population. Der blev observeret distinkte energibehov og metabolisk omgruppering populationerne imellem, dette var mere udtalt hos de pre-eksponerede regnorme. Der blev detekteret fysiologiske adaptationer hos de pre-eksponerede dyr, og dette hang sammen med en kompensatorisk øgning i grave-adfærd og nedgang i koncentrationen af ekstraherbare pesticider i jorden. Konsekvenser, på populationsniveau, blev bedømt ud fra de to populationers livskarakterer. Brug af pesticider resulterede i vægtnedgang hos de voksne orme i felten og omfordeling af energiressourcer, formodentlig fra reproduktiv til metabolisk funktion. Dette førte til lavere frugtbarhed og udklæknings-succes og kunne til dels forklare de lavere regnorme-densiteter i den pesticid-påvirkede jord.; This work investigated if long-term residual contamination of agricultural soils leads to adaptation of earthworm populations to pesticides. It also aimed at identifying the costs of adaptation from the individual to the population level, and the consequences for the ecosystem. Residual contamination by pesticides was assessed and compared in three fields under conventional management (classified after evaluation of pesticide applications as ''high-'', ''medium-'', and ''low-''pesticide input), one field under organic agriculture requirements and one organic permanent pasture, all in this type of management for more than 20 years. Using a water extraction method, as indicative of the amount of bioavailable pesticides 6, 8 and 4 residues of pesticides were recovered in the ''high-'', ''medium-'', and ''low-input'' fields, respectively, and almost no pesticides were detected in the soil of the organic field except for low levels of residual (possibly 20 years old) atrazine. The endogeic species Aporrectodea caliginosa and Allolobophora chlorotica were found in common to the five fields, -except A. chlorotica which was absent from the organic field-, and were used as biological models. Adaptation strategies were investigated by comparing the populations of these earthworms between the different fields according to several endpoints in field and laboratory assessments. The endpoints measured ranged from the molecular (biotransformation and anti-oxidant enzymes), biochemical (main energy resources), and metabolic (respiration rate, metabolomics) levels, to individual (weight, length) and population-related parameters (cocoon and juvenile life traits), and to the possible consequences for the ecosystem in terms of bioturbation (earthworm burrowing behaviour) and pesticide disappearance as an crucial ecosystem service. Enhanced detoxification and anti-oxidant potential was demonstrated along the gradient of contamination in the fields, and in particular comparing the response to an experimental pesticide exposure between the pre-exposed, thus possibly adapted earthworms from the ''high-input'' field-, and the naïve population from the organic field. Distinct energetic demands and metabolic rearrangements were observed between the populations, more pronounced in the pre-exposed earthworms. Physiological adaptation was demonstrated in pre-exposed animals, and this was associated with an increase in burrowing behaviour and pesticide disappearance in the soil. Population-level consequences were assessed in life traits of the two populations. The conventional farming including the use of pesticides decreased the weight of adult worms in the field and resulted in reallocation of energy resources, possibly from reproductive to metabolic function. This led to lower fecundity and hatching success and could partly explain lower earthworm densities in pesticide-impacted soils.; Ce travail de thèse a cherché à déterminer si la contamination résiduelle à long terme des sols agricoles par les pesticides induit le développement de mécanismes d’adaptation aux pesticides chez les vers de terre. Il a aussi visé à identifier les coûts potentiels de l’adaptation de l’échelle de l’individu à celle de la population, et les conséquences pour l’écosystème sol. Une contamination résiduelle du sol par les pesticides est mesurée et comparée dans trois champs cultivés en agriculture conventionnelle (classés en fonction de l’historique cultural comme « haut », « moyen » et « bas » niveaux d’intrants), un champ cultivé en agriculture biologique et une prairie permanente biologique, tous dans ce type de management agricole depuis plus de 20 ans. En utilisant une méthode d’extraction des pesticides en milieu aqueux (représentant la fraction « biodisponible » des pesticides), 6, 8 et 4 résidus de pesticides sont détectés dans les champs à « haut », « moyen », et « bas » niveaux d’applications, respectivement, et un seul pesticide dans le sol du champ biologique (un résidu d’atrazine potentiellement vieux de plus de 20 ans). Les deux espèces endogées Allolobophora chlorotica et Aporrectodea caliginosa , communnes dans les sols des 5 champs,- mis à part A. chlorotica qui est absente du champ cultivé en agriculture biologique-, ont servi de modèles biologiques d’étude. Les stratégies d’adaptation aux pesticides sont étudiées en comparant les réponses de ces populations de vers de terre sur le terrain et après des expositions aux pesticides en laboratoire. Les réponses mesurées s’étendent de l’échelle moléculaire (enzymes de biotransformation et du stress oxidatif), biochimique (ressources énergétiques), métabolique (taux de respiration, métabolomique) à l’échelle de l’individu (biomasse, longueur) et de la population (traits de vie des cocons et des juvéniles), et aux possibles conséquences pour l’écosystème sol en termes de bioturbation (creusement et ingestion de sol) et de dissipation des pesticides comme service ecosystémique. Une capacité de détoxification augmentée et un plus grand potentiel anti-oxidant sont observés le long du gradient de contamination du sol et en laboratoire après exposition des vers de terre des champs conventionnel (population « pré-exposée ») et biologique (« naïve) à des pesticides. Des demandes énergétiques et des réarrangements métaboliques différents sont observés dans les deux populations, et sont plus prononcés chez la population pré-exposée. Une adaptation physiologique est démontrée chez les animaux pré-exposés, qui est associée à une ’augmentation de la bioturbation, et en cascade à une dissipation du pesticide dans le sol. Les conséquences au niveau de la population sont étudiées en termes de traits d’histoire de vie des deux populations pré-exposées et naïves. Le management en conventionnel incluant l’utilisation de pesticides semble diminuer le poids des adultes au champ, et implique potentiellement la réallocation des ressources énergétiques, des mécanismes reproductifs vers les processus métaboliques. Ceci aboutit à une diminution de la fécondité et du pourcentage d’éclosion et pourrait être un facteur participant à la diminution des populations de vers de terre dans les champs cultivés avec utilisation de produits phytosanitaires.

We report the genome sequence of Xenorhabdus szentirmaii DSM16338 (4.84 Mb), a symbiont of the entomopathogenic nematode Steinernema rarum . This strain produces antimicrobial activity.

Aspects génomiques et moléculaires de la virulence chez les bactéries pathogènes d’insectes, Xenorhabdus et Photorhabdus. 11. Rencontres Plantes-Bactéries