Évaluation en bactériologie médicale (intérêt de la modélisation pour revisiter les pratiques)

La connaissance des performances des tests de diagnostic médical est un élément essentiel classiquement obtenu par des études d'observation. Lorsque celles-ci sont de réalisation difficile ou impossible, les méthodes de modélisation et de simulation, reposant sur une approche théorique et probabiliste, s'avèrent des outils intéressants. L'approche quantitative permet de considérer l'optimisation d'une stratégie diagnostique. Les performances du diagnostic des bactériémies par hémoculture ont été évaluées en tenant compte de l'influence de l'ensemble des paramètres pré analytiques et de leur variabilité. L'aspect méthodologique permettant l'évaluation des qualités minimales exigibles des systèmes d'antibiogramme a été analysée. L'influence de la prévalence des souches sensibles, intermédiaires et résistantes sur la valeur prédictive d'un résultat d'antibiogramme a été évaluée. Les résultats sont discutés au regard des pratiques actuellesLYON1-BU.Sciences (692662101) / SudocSudocFranceF

Gut Health in the era of the Human Gut Microbiota : from metaphor to biovalue

International audienceThe human intestinal ecosystem, previously called the gut microflora is now known as the Human Gut Microbiota (HGM). Microbiome research has emphasized the potential role of this ecosystem in human homeostasis, offering unexpected opportunities in therapeutics, far beyond digestive diseases. It has also highlighted ethical, social and commercial concerns related to the gut microbiota. As diet factors are accepted to be the major regulator of the gut microbiota, the modulation of its composition, either by antibiotics or by food intake, should be regarded as a fascinating tool for improving the human health. Scientists, the food industry, consumers and policymakers alike are involved in this new field of nutrition. Defining how knowledge about the HGM is being translated into public perception has never been addressed before. This raises the question of metaphors associated with the HGM, and how they could be used to improve public understanding, and to influence individual decision-making on healthcare policy. This article suggests that a meeting of stakeholders from the social sciences, basic research and the food industry, taking an epistemological approach to the HGM, is needed to foster close, innovative partnerships that will help shape public perception and enable novel behavioural interventions that would benefit public health

Species-driven interpretation guidelines in case of a single-sampling strategy for blood culture

International audienc

Combined Genotypic, Phylogenetic, and Epidemiologic Analyses of Mycobacterium tuberculosis Genetic Diversity in the Rhône Alpes Region, France.

The present work relates to identification and a deep molecular characterization of circulating Mycobacterium tuberculosis complex (MTBC) strains in the Rhône-Alpes region, France from 2000 to 2010. It aimed to provide with a first snapshot of MTBC genetic diversity in conjunction with bacterial drug resistance, type of disease and available demographic and epidemiologic characteristics over an eleven-year period, in the south-east of France.Mycobacterium tuberculosis complex (MTBC) strains isolated in the Rhône-Alpes region, France (n = 2257, 1 isolate per patient) between 2000 and 2010 were analyzed by spoligotyping. MIRU-VNTR typing was applied on n = 1698 strains (with full results available for 974 strains). The data obtained were compared with the SITVIT2 database, followed by detailed genotyping, phylogenetic, and epidemiologic analyses in correlation with anonymized data on available demographic, and epidemiologic characteristics, and location of disease (pulmonary or extrapulmonary TB).The most predominant spoligotyping clusters were SIT53/T1 (n = 346, 15.3%) > SIT50/H3 (n = 166, 7.35%) > SIT42/LAM9 (n = 125, 5.5%) > SIT1/Beijing (n = 72, 3.2%) > SIT47/H1 (n = 71, 3.1%). Evolutionary-recent strains belonging to the Principal Genetic Group (PGG) 2/3, or Euro-American lineages (T, LAM, Haarlem, X, S) were predominant and represented 1768 or 78.33% of all isolates. For strains having drug resistance information (n = 1119), any drug resistance accounted for 14.83% cases vs. 1.52% for multidrug resistance (MDR); and was significantly more associated with age group 21-40 years (p-value<0.001). Extra-pulmonary TB was more common among female patients while pulmonary TB predominated among men (p-value<0.001; OR = 2.16 95%CI [1.69; 2.77]). Also, BOV and CAS lineages were significantly well represented in patients affected by extra-pulmonary TB (p-value<0.001). The origin was known for 927/2257 patients: 376 (40.6%) being French-born vs. 551 (59.4%) Foreign-born. French patients were significantly older (mean age: 58.42 yrs 95%CI [56.04; 60.80]) than Foreign-born patients (mean age: 42.38 yrs. 95%CI [40.75; 44.0]).The study underlined the importance of imported TB cases on the genetic diversity and epidemiologic characteristics of circulating MTBC strains in Rhône-Alpes region, France over a large time-period. It helps better understand intricate relationships between certain lineages and geographic origin of the patients, and pinpoints genotypic and phylogenetic specificities of prevailing MTBC strains. Lastly, it also demonstrated a slow decline in isolation of M. africanum lineage in this region between 2000 and 2010

Description of <i>M</i>. <i>tuberculosis</i> complex biodiversity for patients with known geographical origin (n = 927).

<p>Description of <i>M</i>. <i>tuberculosis</i> complex biodiversity for patients with known geographical origin (n = 927).</p

Number of patients considering their subregion of origin per groups of year (A); and per year of study (from 2000–2010) (B).

<p>Note that although 927 patients were known to be foreign-born (as shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153580#pone.0153580.t002" target="_blank">Table 2</a>), the exact geographical origin allowing to classify them in a specific UN subregion lacked for 7 of 927 foreign-born patients.</p

Multivariate analysis using PGG1 vs. PGG2/3 as the dependent variables.

<p>Multivariate analysis using PGG1 vs. PGG2/3 as the dependent variables.</p