Tryptophan metabolism and bacterial commensals prevent fungal dysbiosis in Arabidopsis roots

In nature, roots of healthy plants are colonized by multikingdom microbial communities that include bacteria, fungi, and oomycetes. A key question is how plants control the assembly of these diverse microbes in roots to maintain host–microbe homeostasis and health. Using microbiota reconstitution experiments with a set of immunocompromised Arabidopsis thaliana mutants and a multikingdom synthetic microbial community (SynCom) representative of the natural A. thaliana root microbiota, we observed that microbiota-mediated plant growth promotion was abolished in most of the tested immunocompromised mutants. Notably, more than 40% of between-genotype variation in these microbiota-induced growth differences was explained by fungal but not bacterial or oomycete load in roots. Extensive fungal overgrowth in roots and altered plant growth was evident at both vegetative and reproductive stages for a mutant impaired in the production of tryptophan-derived, specialized metabolites (cyp79b2/b3). Microbiota manipulation experiments with single- and multikingdom microbial SynComs further demonstrated that 1) the presence of fungi in the multikingdom SynCom was the direct cause of the dysbiotic phenotype in the cyp79b2/b3 mutant and 2) bacterial commensals and host tryptophan metabolism are both necessary to control fungal load, thereby promoting A. thaliana growth and survival. Our results indicate that protective activities of bacterial root commensals are as critical as the host tryptophan metabolic pathway in preventing fungal dysbiosis in the A. thaliana root endosphere

MESOTHELIUM PERICARDIQUE PRIMITIF SIMULANT UN KYSTE HYDATIQUE PERICARDIQUE

The mesothelioma of pericardium is a rare tumor. Its clinical presentation is polymorphous and its diagnosis is especially histological. We report a case of 63 years old women who presented, one month before, dyspnea on exertion which evolved to orthopnea, associated to atypical thoracic pain, admitted in intensive care unit for symptoms of compressive effusion. Transthoracic echocardiography was favourable of hydatid cyst of pericardium. A thoracotomy, following cardio-circulatory arrest, showed cystic tumor of pericardium invading the left auricle, mediastinal pleura and the left pulmonary hilum. Histopathologic examination confirmed the diagnosis of mesothelioma of pericardium.Le mésothélium péricardique primitif malin est une tumeur rare. Sa présentation clinique est polymorphe et son diagnostic est surtout histologique. Nous rapportons le cas d’une patiente âgée de 63 ans ayant présenté, un mois auparavant, une dyspnée d’effort ayant évolué vers l’orthopnée et associée à des douleurs thoraciques atypiques, a été admise au service des urgences dans un tableau de pré-tamponnade. L’échocardiographie transthoracique était en faveur d’un kyste hydatique péricardique avec compression des cavités cardiaques droites. Suite à un arrêt cardio-circulatoire, une thoracotomie de sauvetage a montré une masse kystique péricardique envahissant l’oreillette gauche, la plèvre mediastinale et le hile pulmonaire gauches. L’examen anatomopathologique à l’autopsie a objectivé un mésothélium péricardique primitif malin

Barriers to the delivery of diabetes care in the Middle East and South Africa: a survey of 1,082 practising physicians in five countries

SUMMARY Aims: Developing countries face a high and growing burden of type 2 diabetes. We surveyed physicians in a diverse range of countries in the Middle East and Africa (Egypt, Kingdom of Saudi Arabia, United Arab Emirates, South Africa and Lebanon) with regard to their perceptions of barriers to type 2 diabetes care identified as potentially important in the literature and by the authors. Methods: One thousand and eighty-two physicians completed a questionnaire developed by the authors. Results: Most physicians enroled in the study employed guideline-driven care; 80–100% of physicians prescribed metformin (with lifestyle intervention, where there are no contraindications) for newly diagnosed type 2 diabetes, with lifestyle intervention alone used where metformin was not prescribed. Sulfonylureas were prescribed widely, consistent with the poor economic status of many patients. About one quarter of physicians were not undertaking any form of continuing medical education, and relatively low proportions of practices had their own diabetes educators, dieticians or diabetic foot specialists. Physicians identified the deficiencies of their patients (unhealthy lifestyles, lack of education and poor diet) as the most important barriers to optimal diabetes care. Low-treatment compliance was not ranked highly. Access to physicians did not appear to be a problem, as most patients were seen multiple times per year. Conclusions: Physicians in the Middle East and South Africa identified limitations relating to their patients as the main barrier to delivering care for diabetes, without giving high priority to issues relating to processes of care delivery. Further study would be needed to ascertain whether these findings reflect an unduly physician-centred view of their practice. More effective provision of services relating to the prevention of complications and improved lifestyles may be needed. What's known It is known that the success of care for diabetes depends critically on the delivery of optimised care for diabetic patients. Many barriers to the delivery of such care have been identified. Relatively little is known regarding how these barriers influence the delivery of diabetes care in the Middle East and South Africa. What's new Physicians generally followed management guidelines in type 2 diabetes care. Perceived barriers to optimal diabetes care mainly focussed on attributes of patients, rather than process issues in care or aspects of the physicians' practice

A mathematical model for the burden of diabetes and its complications

BACKGROUND: The incidence and prevalence of diabetes are increasing all over the world. Complications of diabetes constitute a burden for the individuals and the whole society. METHODS: In the present paper, ordinary differential equations and numerical approximations are used to monitor the size of populations of diabetes with and without complications. RESULTS: Different scenarios are discussed according to a set of parameters and the dynamical evolution of the population from the stage of diabetes to the stage of diabetes with complications is clearly illustrated. CONCLUSIONS: The model shows how efficient and cost-effective strategies can be obtained by acting on diabetes incidence and/or controlling the evolution to the stage of complications

SAG101 Forms a Ternary Complex with EDS1 and PAD4 and Is Required for Resistance Signaling against Turnip Crinkle Virus

EDS1, PAD4, and SAG101 are common regulators of plant immunity against many pathogens. EDS1 interacts with both PAD4 and SAG101 but direct interaction between PAD4 and SAG101 has not been detected, leading to the suggestion that the EDS1-PAD4 and EDS1-SAG101 complexes are distinct. We show that EDS1, PAD4, and SAG101 are present in a single complex in planta. While this complex is preferentially nuclear localized, it can be redirected to the cytoplasm in the presence of an extranuclear form of EDS1. PAD4 and SAG101 can in turn, regulate the subcellular localization of EDS1. We also show that the Arabidopsis genome encodes two functionally redundant isoforms of EDS1, either of which can form ternary complexes with PAD4 and SAG101. Simultaneous mutations in both EDS1 isoforms are essential to abrogate resistance (R) protein-mediated defense against turnip crinkle virus (TCV) as well as avrRps4 expressing Pseudomonas syringae. Interestingly, unlike its function as a PAD4 substitute in bacterial resistance, SAG101 is required for R-mediated resistance to TCV, thus implicating a role for the ternary complex in this defense response. However, only EDS1 is required for HRT-mediated HR to TCV, while only PAD4 is required for SA-dependent induction of HRT. Together, these results suggest that EDS1, PAD4 and SAG101 also perform independent functions in HRT-mediated resistance

Signatures of antagonistic pleiotropy in a bacterial flagellin epitope

Immune systems respond to “non-self” molecules termed microbe-associated molecular patterns (MAMPs). Microbial genes encoding MAMPs have adaptive functions and are thus evolutionarily conserved. In the presence of a host, these genes are maladaptive and drive antagonistic pleiotropy (AP) because they promote microbe elimination by activating immune responses. The role AP plays in balancing the functionality of MAMP-coding genes against their immunogenicity is unknown. To address this, we focused on an epitope of flagellin that triggers antibacterial immunity in plants. Flagellin is conserved because it enables motility. Here, we decode the immunogenic and motility profiles of this flagellin epitope and determine the spectrum of amino acid mutations that drives AP. We discover two synthetic mutational tracks that undermine the detection activities of a plant flagellin receptor. These tracks generate epitopes with either antagonist or weaker agonist activities. Finally, we find signatures of these tracks layered atop each other in natural Pseudomonads