Metabolomics to unveil and understand phenotypic diversity between pathogen populations

Visceral leishmaniasis is caused by a parasite called Leishmania donovani, which every year infects about half a million people and claims several thousand lives. Existing treatments are now becoming less effective due to the emergence of drug resistance. Improving our understanding of the mechanisms used by the parasite to adapt to drugs and achieve resistance is crucial for developing future treatment strategies. Unfortunately, the biological mechanism whereby Leishmania acquires drug resistance is poorly understood. Recent years have brought new technologies with the potential to increase greatly our understanding of drug resistance mechanisms. The latest mass spectrometry techniques allow the metabolome of parasites to be studied rapidly and in great detail. We have applied this approach to determine the metabolome of drug-sensitive and drug-resistant parasites isolated from patients with leishmaniasis. The data show that there are wholesale differences between the isolates and that the membrane composition has been drastically modified in drug-resistant parasites compared with drug-sensitive parasites. Our findings demonstrate that untargeted metabolomics has great potential to identify major metabolic differences between closely related parasite strains and thus should find many applications in distinguishing parasite phenotypes of clinical relevance

Metabolic Variation during Development in Culture of Leishmania donovani Promastigotes

The genome sequencing of several Leishmania species has provided immense amounts of data and allowed the prediction of the metabolic pathways potentially operating. Subsequent genetic and proteomic studies have identified stage-specific proteins and putative virulence factors but many aspects of the metabolic adaptations of Leishmania remain to be elucidated. In this study, we have used an untargeted metabolomics approach to analyze changes in the metabolite profile as promastigotes of L. donovani develop during in vitro cultures from logarithmic to stationary phase. The results show that the metabolomes of promastigotes on days 3–6 of culture differ significantly from each other, consistent with there being distinct developmental changes. Most notable were the structural changes in glycerophospholipids and increase in the abundance of sphingolipids and glycerolipids as cells progress from logarithmic to stationary phase

Evaluation du lavage des dispositifs médicaux réutilisables dans le service de stérilisation du centre hôspitalier d'Argenteuil

La stérilisation est un processus qui comporte plusieurs étapes dont le lavage. Cette étape est essentielle car elle conditionne le résultat de la stérilisation. La diversité des instruments fait du lavage une étape complexe. Ce travail a pour objectif d évaluer le maximum de facteurs humains et techniques influençant la qualité du lavage. Un audit de pratiques associé à un contrôle des équipements a été réalisé. Lors de l audit de pratiques, de multiples non-conformités ont été mises en exergue. Le contrôle des équipements a révélé un dysfonctionnement majeur d un laveur-désinfecteur : les volumes de détergent prélevés étaient non répétitifs et pouvaient être inférieurs de 25% au volume théorique. Ce travail a permis la mise en place d actions correctives. Il s inscrit dans la démarche d assurance qualité du service de stérilisation du Centre Hospitalier d Argenteuil (CHA). Il a permis d évaluer ce qui est réellement fait et complète le suivi des non-conformités.CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF

Evaluation de la traçabilité des dispositifs médicaux implantables au Centre Hospitalier d'Argenteuil (influence sur le contrat de bon usage)

CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF