Recherche de peptides cycliques inhibiteurs de la pompe d’efflux AcrAB-TolC conférant une résistance aux antibiotiques chez Escherichia coli

Les pompes d’efflux sont à l'origine de nombreux phénomènes de résistance aux antibiotiques et sont considérées comme des cibles potentielles d’intérêt en pharmacologie. Notre projet visait à identifier, au sein de collections de peptides cycliques biosynthétisés par Escherichia coli, des inhibiteurs de sa principale pompe d'efflux, AcrAB-TolC, en utilisant une stratégie de sélection originale. Les peptides inhibiteurs d’AcrAB-TolC doivent rendre E. coli hypersensible aux antibiotiques substrats de la pompe. Pour pouvoir les identifier, nous avons utilisé l'oxacilline (un substrat de la pompe) pour lyser sélectivement les bactéries dont la pompe est inactive, récupérer les plasmides encodant les peptides inhibiteurs dans le surnageant et retransformer des nouvelles bactéries. Plusieurs protocoles ont d’abord été mis au point sur un système modèle avant de réaliser la sélection sur les banques de peptides cycliques. Un clone intéressant a pu être sélectionné au sein des collections mais son étude suggère que le peptide agit de manière indirecte sur l’activité de la pompe, peut-être en dissipant la force proton motrice nécessaire à l’activité de la pompe. Par ailleurs, nous avons également séquencé et caractérisé des peptides intrinsèquement bactériolytiques sélectionnés dans le cadre d’un autre projet. Une étude statistique de 65 clones montre que la majorité des peptides à effet bactériolytique sont hydrophobes et agissent sans doute par déstabilisation de la membrane interne. Ce n’est cependant pas le cas de trois peptides présentant les effets bactériolytiques les plus prononcés. Ces derniers pourraient donc agir de manière plus spécifique.(SC - Sciences) -- UCL, 201

Study of genetic mutations and dynamic spread of SARS-CoV-2 pandemic and prediction of its evolution according to the SIR model

In this work, we aim to study that the dynamics behavior for cumulative number of SARS-CoV-2 pandemic can provide information on the overall behavior of the spread over daily time.The cumulative data can be synthesized in an empirical form obtained from a Susceptible-Infected-Recovered (SIR) model previously studied on a Euclidean network. From the study we carried out, we can conclude that the SIR model on the Euclidean network can reproduce data from several countries with a deviation of precision for given parameter values. This gives an insight into the different agents that influence the behavior of SARS-CoV-2 especially during the virus mutation period. We are thus trying to analyze the effect of genetic mutations in different countries, and how a specific mutation can make the virus more contagious.Comment: 13 pages, 3 figure

Study of genetic mutations and dynamic spread of SARS-CoV-2 pandemic and prediction of its evolution according to the SIR model

In this work, we aim to study that the dynamics behavior for cumulative number of SARS-CoV-2 pandemic can provide information on the overall behavior of the spread over daily time.The cumulative data can be synthesized in an empirical form obtained from a Susceptible-Infected-Recovered (SIR) model previously studied on a Euclidean network. From the study we carried out, we can conclude that the SIR model on the Euclidean network can reproduce data from several countries with a deviation of precision for given parameter values. This gives an insight into the different agents that influence the behavior of SARS-CoV-2 especially during the virus mutation period. We are thus trying to analyze the effect of genetic mutations in different countries, and how a specific mutation can make the virus more contagious

Evaluating Palliative Care Needs in Middle Eastern Countries

WOS: 000347152600006PubMed ID: 25302525Background: Cancer incidence in Middle Eastern countries, most categorized as low- and middle-income, is predicted to double in the next 10 years, greater than in any other part of the world. While progress has been made in cancer diagnosis/treatment, much remains to be done to improve palliative care for the majority of patients with cancer who present with advanced disease. Objective: To determine knowledge, beliefs, barriers, and resources regarding palliative care services in Middle Eastern countries and use findings to inform future educational and training activities. Design: Descriptive survey. Setting/Subjects: Fifteen Middle Eastern countries; convenience sample of 776 nurses (44.3%), physicians (38.3%) and psychosocial, academic, and other health care professionals (17.4%) employed in varied settings. Measurements: Palliative care needs assessment. Results: Improved pain management services are key facilitators. Top barriers include lack of designated palliative care beds/services, community awareness, staff training, access to hospice services, and personnel/time. The nonexistence of functioning home-based and hospice services leaves families/providers unable to honor patient wishes. Respondents were least satisfied with discussions around advance directives and wish to learn more about palliative care focusing on communication techniques. Populations requiring special consideration comprise: patients with ethnic diversity, language barriers, and low literacy; pediatric and young adults; and the elderly. Conclusions: The majority of Middle Eastern patients with cancer are treated in outlying regions; the community is pivotal and must be incorporated into future plans for developing palliative care services. Promoting palliative care education and certification for physicians and nurses is crucial; home-based and hospice services must be sustained.MECCFunding was provided by MECC. Ronit Esther, MECC coordinator, is acknowledged for assistance with data collection and manuscript formatting. ONS leaders Barbara Lubejko, RN, MS, Project Manager/Education Team and Nurse Peer Review Leader/Approver Unit and Kate Shaughnessy Hankle, MBA, CVA, Management of International and Leadership Development are acknowledged for their assistance with survey revision and qualitative data analysis