Caractériser la dissémination des bio-agresseurs est un enjeu majeur pour la gestion et la prédiction des maladies en santé des plantes. Face aux limites des approches usuelles en pathologie végétale, une nouvelle vision a été proposée abordant les paradigmes d’histoire de vie des agents phytopathogènes en dehors des limites du système hôte-pathogène. Parmi ces agents phytopathogènes, les études sur P.syringae sont celles qui ont contribuées le plus à ce nouveau courant de pensée et dont on connaît le mieux l’histoire de vie en relation avec ses réservoirs « non hôtes ». L’espèce est détectée dans de nombreux compartiments du cycle de l’eau, des précipitations jusqu’aux rivières et eaux d’irrigation, en passant par les plantes sauvages et le manteau neigeux. L’ensemble de ces observations ont soulevé de nouvelles questions sur la manière dont P. syringae se dissémine au travers de ces environnements et sur les processus impactant sur la dynamique des populations à l’échelle d’un bassin versant. Ces recherches se sont donc intéressées à ses processus dans des précipitations jusqu’aux cours d’eau alpins dans l’optique d’acquérir des données pour la modélisation des flux de P. syringae. Elles ont mis en évidence les populations résidentes de la litière et la survie sa survie dans le sol, processus jamais identifiés à l’histoire de vie de P. syringae. Elles ont également caractérisé (i) les conditions propices à son transport via les précipitations, (ii) le rôle du manteau neigeux comme réservoir et protecteur des populations des prairies alpines et (iii) ont mis en évidence la chimie de l’eau comme indicateur témoin de la dynamique des populations des les rivières. Ces observations suggérant un transport de P. syringae dans le sol, nous l’avons quantifiée à travers des études de terrain et des simulations en laboratoire.Enfin, l’ensemble des données de ces recherches couplées à des outils SIG et des modèles météorologiques et hydrologiques ont permis de proposé un modèle sur les flux de P.syringae des habitats naturels vers les agro-systèmes. / The characterization of the spread of bio-agressors spread is a major issue for themanagement of plant health and the prediction of disease emergence. Given thelimitations of conventional approaches in plant pathology, a new vision has beenproposed addressing paradigms life history of plant pathogens outside the limits of thecrop host-pathogen system. Among the plant pathogens, studies on P. syringae are thosethat have contributed the most to this new way of thought for which life history inrelation to "non host" reservoirs has been highlighted. The species is found in manycompartments of the water cycle, from precipitation to rivers and irrigation water, wildplants and snowpack. All these observations have raised new questions about how P.syringae spreads through these environments and on the processes impactingpopulation dynamics at the scale of a watershed. This research was therefore interestedin these processes with the objective to acquire data for modeling the tranfer of P.syringae through the watershed. They highlighted the resident populations of litter andtheir survival in the soil, processes never identified in association with the life history ofP. syringae. They also revealed (i) the conditions for transport via precipitations, (ii) therole of snowpack as a reservoir and protector of the populations in alpine meadows and(iii) showed that water chemistry can be used as an indicator of the populationdynamics in headwaters. These observations suggested a transport of P. syringae via thesoil that we subsequently characterized through field studies and laboratorysimulations. Finally, all data from this research combined with GIS tools andmeteorological and hydrological models have permitted us to propose a model of theflux of P. syringae of natural habitats to agricultural systems.

Seafood permits the transmission of many bacterial pathogens. In order to reconcile consumer demands with important safety standards, traditional means of regulating microbial spoilage and safety hazards in foods are combined with novel technologies. These include biological antimicrobial systems, such as the use of lactic acid bacteria (LAB) and/or their bacteriocins, such as Carnobacterium maltaromaticum CS526 and its bacteriocin piscicocin CS526. The aims of this study were to investigate the presence of Listeria monocytogenes in temperate seafood, namely fresh and smoked salmon, fresh and smoked haddock, and fresh mussels and oysters. Additionally, there was an aim to recover, characterise and use bacteriocin-like-substance to control Listeria monocytogenes in cold smoked haddock. Vibrio spp., Enterobacteriaceae representatives, total aerobic heterotrophic counts and Listeria monocytogenes were isolated from commercially prepared smoked and fresh Atlantic salmon, smoked and fresh haddock, live mussels and oysters using selective media and tryptone soya agar (TSA). Vibrio spp. occurred in high densities (>106 CFU gˉ1) in mussels and Enterobacteriaceae representatives were recorded at >106 CFU gˉ1 in fresh salmon. Total aerobic heterotrophic counts in fresh salmon, live mussels and oysters reached 107, > 107, and > 106 CFU gˉ1, respectively. Listeria monocytogenes was recorded at 5.0 x 104 CFU gˉ1 in mussels. In total sixty one bacterial isolates were recovered from the seafood examined. The results revealed 19 genera of bacteria, i.e. Acinetobacter, Aerococcus, Aeromonas, Bacillus, Brochothrix, Carnobacterium, Citrobacter, Corynebacterium, Enterobacter, Escherichia coli, Moraxella, Micrococcus, Pseudomonas, Psychrobacter, Serratia, Shewanella, Staphylococcus, Vibrio and Listeria. The prominent characteristics of fish spoilage isolates were demonstrated by the ability of the isolates to reduce trimethylamine oxide (TMAO) to trimethylamine, and to produce H₂S. Sh. baltica OS185, Aeromonas spp. HB-6, Sh. baltica, Sh. putrefaciens, A. hydrophila HX201006-3, A. salmonicida subsp. achromogenes, A. hydrophila, C. freundii, Enterobacter cloacae were strong producers of TMA and H₂S. The spoilage microorganisms were tested for potential pathogenicity. The result revealed that 6/15 of the spoilage microorganisms produced proteolytic, lecithinase, blood (β and α haemolysin) and elastinase activity, respectively, whereas 7/15 of the spoilage microorganisms showed lipolytic activity. Cell free supernatants, ammonium sulphate precipitated supernatants and semi-purified bacteriocin-like substances of Carnobacterium maltaromaticum MMF-32 and KOPRI 25789 producing strains isolated from commercially prepared smoked salmon were investigated for their potential antimicrobial activity against potentially pathogenic and food spoilage microorganisms. Generally, a broad spectrum of activity was revealed against potentially pathogenic and food spoilage microorganisms in vitro. Cold-smoked haddock treated with bacteriocin producing C. maltaromaticum MMF-32, C. piscicola A9b bacˉ phenotype nonbacteriocin producing strain a mutant of C. piscicola A9b bac+, cell free supernatants, ammonium sulphate precipitated supernatants and semi-purified bacteriocin-like substances was challenged with L. monocytogenes ATCC 19114 up to 103 CFU gˉ1, respectively. Samples were stored at 4 °C for 10 days. L. monocytogenes and total bacterial counts were determined along with changes in total volatile base nitrogen (TVBN) and biogenic amines production as well as texture, colour and odour. Although the study on anti-listerial effects of C. maltaromaticum MMF-32 was not successful, this organism did have a positive effect on retention of firmness and sensory perception in cold smoked haddock.

No description available.

Pseudomonas aeruginosa is a Gram-negative, metabolically versatile, opportunistic pathogen that exhibits a multitude of virulence factors, and is extraordinarily resistant to a gamut of clinically significant antibiotics. This ability is in part mediated by two-component systems (TCS) that play a crucial role in regulating virulence mechanisms, metabolism and antibiotic resistance. Our sequence analysis of the P. aeruginosa PAO1 genome revealed the presence of two open reading frames, mifS and mifR, which encodes putative TCS proteins, a histidine sensor kinase MifS and a response regulator MifR, respectively. This two-gene operon was found immediately upstream of the poxAB operon, where poxB encodes a chromosomal ß-lactamase, hinting at the role of MifSR TCS in regulating antibiotic resistance. However, loss of mifSR had no effect on the antibiotic resistance profile when compared to P. aeruginosa parent PAO1 strain. Subsequently, our phenotypic microarray data (BioLOG) and growth profile studies indicated the inability of mifSR mutants to grow in α-ketoglutarate (α-KG), a key tricarboxylic acid (TCA) cycle intermediate, as a sole carbon source. To date, very little is known about the physiology of P. aeruginosa when provided with α-KG as its sole carbon source and the role of MifS and MifR TCS in virulence. Importantly, in the recent years, α-KG has gained notoriety for its newly identified role as a signaling molecule in addition to its conventional role in metabolism. This led us to hypothesize that MifSR TCS is involved in α-KG utilization and virulence in P. aeruginosa. Using mifS, mifR and mifSR clean in-frame deletion strains, our study demonstrates that the MifSR TCS modulates the expression P. aeruginosa kgtP (PA5530) and pcaT (PA0229) genes encoding putative α-KG permeases. In addition, our study shows that the MifSR-regulation of these transporters requires functional sigma factor RpoN (σ54). Loss of mifSR in the presence of α-KG, resulted in differential regulation of P. aeruginosa key virulence determinants including biofilm formation, motility, cell cytoxicity and the production of pyocyanin and pyoverdine. Involvement of multiple regulators and transporters suggests the presence of an intricate circuitry in the transport of α-KG and its importance in P. aeruginosa survival. This is further supported by the α-KG-dependent MifSR regulation of multiple virulence mechanisms. Simultaneous regulation of multiple mechanisms involved in P. aeruginosa pathogenesis suggests a complex mechanism of MifSR action. Understanding the physiological cues and regulation would provide a better stratagem to fight often indomitable P. aeruginosa infections.

Klebsiella pneumoniae is a Gram-negative pathogen associated with numerous infections. Like all Gram-negative bacteria, K. pneumoniae naturally release outer membrane vesicles (OMVs) during all stages of cellular growth. OMVs are composed of the outer membrane components such as lipopolysaccharide (LPS) and outer membrane proteins and contain cytosolic and periplasmic proteins in the lumen. K. pneumoniae is often found to lack an O antigen. The absence of the O antigen has been reported to alter the protein content of the membrane which may further alter the immune response elicited by K. pneumoniae. Therefore the purpose of this study was to analyze the protein content and inflammatory responses of the cellular outer membrane (OM) and the secreted OMVs. A secondary goal of this study was to evaluate any changes to the membrane protein content due to O antigen loss and determine if the loss of the O antigen influences the inflammatory response. This study demonstrated that the cellular OM and OMVs have distinct protein profiles as well as inflammatory responses. OMVs were highly enriched in outer membrane proteins compared to the cellular OM and had a significantly stronger inflammatory response. The protein content of the OM and OMVs were further modified by the absence of the O antigen from the outer membrane. Although there were no significant differences seen in the wild type and O antigen deficient OM inflammatory responses, the loss of the O antigen resulted in OMVs that produced a significantly stronger IL-6 response.

Os mexilhões cultivados no litoral Norte de São Paulo, município de Ubatuba, são comercializados in natura, constituindo risco à população. Com o crescimento da atividade é possível sugerir a implantação de uma unidade de processamento de mexilhões que promova um aumento do tempo de armazenamento, facilitando a comercialização e permitindo a exportação, além de fornecer ao consumidor um produto de melhor qualidade. Os mexilhões foram submetidos ao processamento por cocção, congelamento e armazenamento, sendo então determinados o ponto de congelamento, a velocidade de congelamento a as curvas de congelamento do mexilhão semidesconchado. A qualidade microbiológica e físico-química do produto foi avaliada. O beneficiamento do mexilhão iniciou-se com a cocção por imersão em água à ebulição por 10 minutos. Após a retirada das conchas, os mexilhões foram congelados individualmente IQF (Individually Quick Frozen) a –20ºC e armazenados a -18ºC durante 90 dias. A curva de congelamento do mexilhão apresentou forma geral típica, com o ponto de congelamento situando-se na faixa de zero a –1,5ºC; a velocidade de congelamento variou de 2 cm/h a 3,3 cm/h, conforme a disposição dentro da câmara de congelamento. Os resultados físico-químicos mostraram que não houve diferença significativa no valor nutricional dos mexilhões in natura, processados e armazenados, apresentando os teores médios de 7,4mg/100g de proteínas, 5,8 mg/100g de carboidratos e 1,4 mg/100g de lipídeos. Os valores encontrados para BNVT, TMA e pH no mexilhão in natura foram, 4,3 mg/100g; 2,0 mg/100g e 6,2, respectivamente, estando dentro dos limites estipulados pela legislação de 30mg/100g para BNVT e 4 mg/100g de TMA. Após o processo de cocção e congelamento houve um aumento no valor do pH para 6,9, enquanto o BNVT manteve-se na média. Todas as amostras de mexilhão in natura atenderam aos padrões microbiológicos estabelecidos pela legislação (RDC, nº12 de 02 de janeiro de 2001). Salmonella sp e Vibrio parahaemolyticus não foram isoladas em nenhuma das amostras de mexilhões in natura, cozidos, congelados e armazenados. O tratamento térmico foi efetivo no controle dos coliformes fecais, redução de coliformes totais, Staphylococcus coagulase+ e psicrotróficos. O processo de congelamento reduziu a contagem de coliformes totais e Staphyloocccus coagulase+, mantendo-se inalterados durante o armazenamento a –18ºC por 90 dias. Concluiu-se que o beneficiamento do mexilhão pelo processo combinado de cocção, congelamento e armazenamento assegura a qualidade físico-química e microbiológica do produto, podendo ser adotado como padrão para industrialização. / The mussels cultivated in the coast North of São Paulo, city of Ubatuba, are commercialized in natura, constituting risk to the population. With the growth of the activity it is possible to suggest the implantation of a unit of mussel processing that promotes an increase of the storage time, facilitating the commercialization and allowing the exportation, besides supplying to the consumer a product of better quality. The mussels had been submitted to the processing for cooking, freezing and storage, being then determined the freezing point, the speed of freezing to the curves of freezing of the semidesconchado mussel. The microbiological quality and physicochemical of the product were evaluated. The processing of the mussel was started with the immersion in boiling water per 10 minutes. After the withdrawal of the shells, the mussels had been frozen individually IQF (Individually Quick Frozen) at -20ºC and stored at -18ºC during 90 days. The curve of freezing of the mussel presented typical general form, with the freezing point placing from zero to -1,5ºC; the freezing speed varied from 2 cm.h-1 to 3,3 cm.h-1, as the disposal

No controle da qualidade da água, parâmetros microbiológicos são avaliados e devem estar de acordo com os limites estipulados em portarias e resoluções. Todas as metodologias de monitoramento microbiano demandam o cultivo dos organismos-alvo. Em muitos casos, as cepas isoladas devem ser analisadas por teses fenotípicos para determinação da espécie. Por meio de inóculos de E. coli, demonstrou-se que a variação na técnica de plaqueamento se deve especialmente à falta de consistência entre as diluições. Além disso, para a análise de réplicas, comarando-se as médias de dois métodos de diluição, foi demonstrado que ser utilizado apenas uma série de diluição derivada de um único inóculo. Utilizando-se culturas puras de E. coli, E. faecalis e P. aeruginosa, a recuperação foi similar entre os meios seletivos respectivos (m-Endo, m-EI, m-PA-C) e meio não seletivo (Tripticase Soy Agar). A utilização da técnica de membrana filtrante resultou em contagens significativamente maiores para E.coli e E. faecalis em comparação ao método de spread plate. A microbiota natural presente na água potável (torneira) não influenciou significativamente as contagens de E. coli, E. faecalis e P. aeruginosa em meios seletivos. Entretanto, na água mineral engarrafada inoculada artificialmente com P. aeruginosa, a contagem foi significativamente maior na réplica estéril. Na análise de água marinha, e na réplica não estéril inoculada com E. faecalis, a contagem foi signifivativamente menor e as células de P. aeruginosa produziram colônias atípicas. Analisando-se amostras do meio ambiente (biofilmes de estação de tratamento de água, lodo de esgoto e água de córrego contaminado), 45 colônias típicas isoladas em meios de cultura seletivos foram identificadas por meio do sequenciamento do gene 16S rRNA, testes bioquímicos e MALDI-TOF. Os resultados de sequenciamento do gene 16SrRNA tiveram baixa correlação com a identificação dos organismos por testes bioquímicos (46,6% em nível de gênero e 20% em nível de espécie) e MALDI-TOF (60% em nível de gênero e 48,8% em nível de espécie). Para as cepas identificadas como E. coli e Enterococcus spp., a correlação entre o sequenciamento e MALDI-TOF foi de 75% e 62%, respectivamente. Uma vez que a quantificação de micro-organismo por membrana filtrante depende do micro-organismo em análise e do tipo de água, é necessário que os laboratórios realizem testes de padronização antes de implementar essa metodologia. Os resultados demonstram que os métodos convencionais utilizados não são adequados e suficientes para a análise da qualidade da água e, portanto, novas metodologias devem ser empregadas. Idealmente devem ser utilizadas técnicas baseadas em características fenotípicas, genômica e proteômica cujos resultados são complementares e fornecem uma identificação mais acurada. / All over the world regulatory agencies specify microbiological water quality parameters to guarantee water safety. Conventional microbiological water quality analysis is based on the cultivation of the target organisms. In many analysis protocols, phenotypic assays of isolated strains are mandated for species determination. Reference samples are required for quality assessment and quality control of analytical protocols. Using E. coli as a model organism, it was demonstrated here that the variability of plate counts of reference cultures is caused mainly by the spread of counts in individual serial dilutions. Besides, comparing the means obtained by two dilution approaches, it was demonstrated that in the analysis of replicates it is possible to use only a set of dilutions derived for a unique inoculum. Recovery of pure cultures of E. coli, E. faecalis and P. aeruginosa was similar on selective culture media (m-Endo, m-EI, m-PA-C) and with the non-selective medium (Tripticase Soy Agar). The membrane filter technique yielded significantly higher counts for E.coli and E. faecalis in comparison to spread plate method. The autochthonous microbiota of potable water (tap water) did not influence the counts of E. coli, E. faecalis and P. aeruginosa on selective culture media. However, the sterile replica of mineral water spiked with P. aeruginosa showed higher counts for these bacteria. For marine water analysis, the non-sterile replica spiked with E. faecalis yielded low counts and P. aeruginosa produced an atypical colony. Both, sample-induced variation in target strain recovery and colony appearance on culture plates indicates the requirement for method evaluation tests on particular sample matrices before implementing routine microbiological analysis by culture-based methods in the laboratory. 45 typical colonies obtained from environmental samples in selective culture media (biofilms from activated sludge, drinking water treatment plants and water from creek contaminated with raw sewage) were analyzed by 16S rRNA gene sequencing, biochemical phenotypic assays and MALDI-TOF. Sequencing showed low correlation with phenotypic assays (46,6% at the genus level and 20% at the species level) and MALDI-TOF (60% at the genus level and 48,8% at the species level). On the other hand, the strains identified as E. coli an Enterococcus spp. by 16S rDNA gene sequencing demonstrated a high correlation with MALDI-TOF (75% and 62%, respectively). Since the results showed that conventional methods aren´t suitable and sufficient to assess water quality, new technologies should be employed. Ideally, techniques should be based on phenotypic, genomic and proteomic features since the results are complementary and provide a more accurate identification.

La recherche d’une agriculture durable et respectueuse de l’environnement passe par une réduction de l’usage d’intrants de synthèse. L’agroécologie cherche à utiliser les interactions entre les organismes de l’agroécosystème pour optimiser son fonctionnement, comme la régulation naturelle des bioagresseurs. C’est dans cette optique que s’inscrit ce travail de thèse qui étudie l’effet de la fertilisation des cultures sur les épidémies de pathogènes foliaires fongiques des cultures. De plus, nous étudions l’évolution des pathogènes face à des scénarios de fertilisation. Cela questionne la durabilité des pratiques culturales qui participent à la régulation les épidémies. Pour répondre à ces questions, nous avons adopté une démarche de modélisation qui permet de simuler l’effet de différents scénarios de fertilisation. Le point de départ et l’originalité de notre démarche a été de considérer le système hôte-pathogène comme un système ressource-consommateur et d’y appliquer des concepts de l'écologie évolutive pour répondre à ces questions agronomiques. Dans les deux modèles construits durant cette thèse, la fertilisation influence directement la quantité de ressources disponible pour le pathogène. Nous nous y concentrons sur un trait d'histoire de vie du pathogène, la période de latence (durée séparant l'infection du début de la sporulation), qui correspond à la durée minimale d'un cycle infectieux et qui, conditionne la stratégie d'allocation des ressources du pathogène. La latence détermine en effet la quantité de ressource qui sera allouée à la croissance du mycélium (donc sa taille à maturité) et celle qui sera ensuite allouée à la sporulation (en relation avec sa taille). Les modèles développés permettent d'étudier les réponses épidémiologique et évolutive des pathogènes foliaires fongiques à la fertilisation des cultures, avec comme référence le système Blé d'hiver/Rouille brune. Nous avons considéré différentes échelles dans ce travail : depuis la lésion où le pathogène se nourrit directement sur son hôte, jusqu’à la parcelle où se développent les épidémies et au paysage où les flux de spores entre les parcelles sont source d’extension des épidémies dans l’agroécosystème. Un premier modèle, à l'intersection des modèles épidémiologiques "SEIR" et des modèles de populations structurées, couvre les échelles de la lésion à celles de l’épidémie et de la parcelle. Le second modèle, à l'intersection des modèles SEIR et des modèles spatiaux d'épidémiologie du paysage, couvre les échelles de la parcelle au paysage agricole. Nous étudions les dynamiques épidémiologiques et évolutives, en comparant des concepts de fitness empiriques et d’invasion. Nous montrons que la fertilisation des cultures, en déterminant la dynamique des ressources disponibles pour les pathogènes, impacte fortement les épidémies. Nos modèles prédisent que la latence des pathogènes évolue en réponse à des compromis écologiques variés, d’une part pour optimiser l’allocation des ressources au niveau des feuilles, mais également pour gagner la course face à la croissance du couvert. La fertilisation, en changeant les concentrations de métabolites foliaires et les dynamiques de croissance du couvert, impacte donc épidémies et réponses évolutives de la latence des pathogènes. A l’échelle du paysage, l’introduction de pratiques variées de fertilisation dans un paysage préalablement homogène pourrait permettre de réduire les épidémies. Cependant, notre modèle prédit une durée limitée de cet effet du fait de l’évolution et de la diversification des pathogènes dans un paysage hétérogène. Ce travail ouvre la voie à des travaux sur l’effet et la durabilité des pratiques pour réguler les épidémies dans l’agroécosystème. Enfin, nous montrons par un travail de méta-analyse qu’il existe une relation forte entre type trophique et latence du pathogène, suggérant que les différents types de pathogènes répondront différemment à des scénarios de réduction de fertilisation / The quest for a sustainable agriculture requires a reduction in the use of synthetic inputs. In this perspective, agroecology seeks to use interactions between organisms in the agroecosystem to replace inputs by ecosystem services, such as the natural regulation of pests and diseases. In this context, this thesis studies the effect of crop fertilization on epidemics of crop fungal foliar pathogens. We also take into account the evolution of these pathogens in response to fertilization scenarios. This allows us to study the sustainability of agricultural practices that contribute to the regulation of epidemics. To answer these questions, we adopted a modelling approach that simulates the effect of different fertilization scenarios. The starting point and originality of our approach was to consider the pathosystem as a consumer-resource system and to use concepts of evolutionary ecology to answer the abovementioned agronomic questions. In the two models developed in this thesis, fertilization directly determines the quantity of resources available for the pathogen. We focus on one of the pathogen's life history traits, the latent period (time period between infection and the onset of sporulating lesions), which corresponds to the minimum duration of an infectious cycle and constrains the pathogen's resource allocation strategy. The latent period determines the amount of resource that will be allocated to either growth of mycelium (and therefore to pathogen size at maturity) or to sporulation (proportional to the pathogen’s size). The models we developed make it possible to study the epidemiological and evolutionary responses of fungal foliar pathogens to crop fertilization. We parameterized our models according to our biological knowledge of the wheat-rust pathosystem. Our modelling work encompasses different spatial and temporal scales: from the lesion where the pathogen feeds directly on its host, to the field and the landscape where the spores that flow between fields are the source of epidemics in the agroecosystem. The first model, at the intersection of the "SEIR" epidemiological models and structured population models, covers the scales of a lesion, the crop canopy and the field. The second model, at the intersection of SEIR and spatial landscape epidemiology models, covers the scales of the field and the agricultural landscape. We study epidemiological and evolutionary dynamics of pathogen populations by comparing empirical and invasion fitness concepts. We show that crop fertilization, by determining the dynamics of available resources for pathogens, has a strong impact on foliar fungal epidemics. Our models predict that pathogen latent period evolves in response to various ecological trade-offs; on the one hand to optimize resources allocation at the leaf scale, on the other hand to win the race against canopy growth. By changing the leaf metabolite content and the rate of canopy growth, fertilization therefore impacts both epidemics and evolutionary responses of pathogen latent period. At the landscape scale, the introduction of various fertilization practices in a previously homogeneous landscape could help to partially regulate epidemics. However, our model predicts that the beneficial effects of heterogeneity will vanish due to the evolution and diversification of pathogens in heterogeneous landscapes. This work sets the stage for further work on the effect and sustainability of agricultural practices on the regulation of crop epidemics in agroecosystems. Finally, by performing a meta-analysis, we bring out a strong relation between pathogen trophic type and latent period, suggesting that different trophic types of pathogens will respond differently to decreasing fertilization scenarios

Målsättningen med föreliggande studie är att bidra med kunskap om elevers upplevelser av stödinsatser och delaktighet i grundskolan. Det är sällan som elevernas upplevelser lyfts fram i forskning och syftet med denna studie är därför att belysa hur några elever som inte varit behöriga att söka in på ett nationellt gymnasieprogram, ser på de stödinsatser de fått, eller önskat att de fått, i grundskolan samt deras upplevelse av delaktighet under samma period. Studien bygger på en kvalitativ intervjustudie med semistrukturerade frågor, där fem respondenter bidrar med sina upplevelser. De teoretiska perspektiv som studien utgår ifrån är relationellt- respektive kategoriskt perspektiv, samt salutogent- respektive patogent perspektiv. Resultatet visar på att elevernas upplevelser var övervägande negativa under låg- och mellanstadiet och mer positiva under högstadiet. Detta förklaras framför allt med att de inte kände sig delaktiga, och upplever att stödinsatserna inte var adekvata i förhållande till stödbehovet. Insikterna som framkommit i studien handlar om vikten av att lyssna in varje enskild elevs upplevelse och beakta dessa när det kommer till att utforma och utvärdera stödinsatser. Elevers upplevelser kan ha en stor påverkan på det specialpedagogiska området och bidrar i arbetet med att utveckla lärmiljön i grundskolan för att främja delaktighet. / The aim of this study is to contribute to the understanding about students' experiences of support measures and participation in compulsory school. It is rare that students' experiences are highlighted in research and the purpose of this study is therefore to shed light on how some students who have not been eligible to apply for a Swedish national high school program, look at the support measures they received, or wished they had received, in primary school and their experience of participation during the same period. The study is based on a qualitative interview study with semi-structured questions, where five respondents contribute with their experiences. The theoretical perspectives on which the study is based are relational and categorical perspectives, as well as salutogenic and pathogenic perspectives. The results show that the students' experiences were predominantly negative during elementary school and more positive during middle school. This is mainly explained by the fact that they did not feel participation, nor that the support efforts were adequate in relation to their need for support. The insights that emerged in the study are about the importance of listening to each individual student's experience and taking these into account when it comes to designing and evaluating support measures. Students' experiences can have a major impact on the special education area and contribute to the work of developing the learning environment in compulsory school to promote participation.

Clarireedia spp. (formerly Sclerotinia homoeocarpaF.T. Bennett) is the causal agent dollar spot, the most economically important turfgrass disease impacting golf courses in North America. The most effective strategy for dollar spot control is repeated application of multiple classes of fungicides. However, reliance on chemical application has led to resistance to four classes of fungicides as well as multidrug resistance (MDR). Fungi are known to detoxify xenobiotics, like fungicides, through transcriptional regulation of three detoxification phases: modification, conjugation and secretion. Little is known, however, of the protein-protein interactions that facilitate these pathways. Following next-generation RNA sequencing of Clarireedia spp., a fungus-specific transcription factor, XDR1, was determined to play a role in constitutive and induced overexpression of phases I and III genes of xenobiotic detoxification. Further, a novel activation domain (AD) on XDR1 that does not directly bind with xenobiotics was confirmed to be highly conserved among fungal species. Therefore, we hypothesize that XDR1 must be activated by interacting with other binding partners at this AD in order to regulate downstream xenobiotic detoxification pathways. The main objective of this study is to identify additional proteins/ co-repressors that activate XDR1 in order to gain a better understanding of how transcriptional regulation of xenobiotic detoxification pathways leads to MDR. In order to test the hypothesis, fungicide sensitive strain (HRS10) and fungicide resistant strain (HRI11) were transformed and tagged with xdr1/XDR1 and the 3xFLAG tag. As a result, four fungal transformants were generated and those are HRS10-XDR1-3xFLAG, HRS10-xdr1- 3xFLAG, HRI11-XDR1-3xFLAG, and HRI11-xdr1-3xFLAG. The total protein extractions (whole cell lysates) were subjected to co-immunoprecipitation and the samples were analyzed using LC-MS/MS. According to the set of results, more than 50 proteins were detected with HRS10-XDR1-3xFLAG with and most of these binding partners having functions related to post translational modification, protein turnover, intracellular trafficking, secretion and vascular transport. Going forward, information gained from this experiment could be used to explore how XDR1 interacts with its binding partners to facilitate the transcription of drug metabolizing genes responsible for multidrug resistance. This information could also help identify additional fungicide metabolism pathways in filamentous fungi.