A case of Ureaplasma parvum meningitis in an adult after transphenoidal ablation of craniopharyngioma

We report the case of a Ureaplasma parvum meningitis in an immunocompetent patient, 17 days after surgical ablation of a craniopharyngioma. Presence of U. parvum in the cerebrospinal fluid was assessed by 16S rDNA sequencing and U. parvum specific PCR. This article details a surprising complication in an adult of a transphenoidal surgery for ablation of a craniopharyngioma. This is the first case, to our knowledge, of U. parvum meningitis in an adult patient

Réservoir extra-digestif d’entérobactéries productrices de bêtalactamase à spectre élargi chez des patients non infectés: étude à partir d’une recherche systématique dans les urines et d’autres prélèvements à visée diagnostique

Notre objectif était d’étudier le réservoir extra-digestif d’entérobactéries productrices de β-lactamases à spectre élargi (EBLSE) en les recherchant dans des prélèvements à visée diagnostique (PVD) pour lesquels les colonies bactériennes isolées sur les milieux de cultures utilisés ne sont pas obligatoirement analysées (identification bactérienne et antibiogramme) en routine. Pendant une période de 5 semaines, des identifications et des antibiogrammes ont été réalisés de manière systématique pour les colonies correspondant à des entérobactéries isolées dans certains PVD comme les urines, les prélèvements respiratoires, et un groupe de prélèvements appelé “divers”. Les prélèvements pour lesquels un antibiogramme a été réalisé conformément à la pratique de routine du laboratoire ont été considérés comme infectés. Les prélèvements pour lesquels les entérobactéries ont été recherchées et étudiées suivant le protocole de l’étude ont été considérés comme colonisés. Au cours de l’étude, 2 312 urines, 327 prélèvements respiratoires et 1 887 prélèvements divers ont été envoyés au laboratoire. Parmi les 114 urines colonisées par au moins une entérobactérie, 13 (11,4 %) comportaient une EBLSE, alors que cette proportion était de 5,1 % (35/682) dans les urines infectées (p < 0,01). Parmi les prélèvements respiratoires et divers, 3 EBLSE ont été isolées dans 55 prélèvements colonisés par au moins une entérobactérie. Au total, la recherche systématique d’EBLSE dans les PVD a permis une augmentation de 27,7 % du nombre de patients identifiés comme porteurs de ces bactéries. D’autres études pourraient être utiles pour évaluer l’intérêt de mettre en place une telle stratégie comme alternative au dépistage rectal habituellement pratiqué

Cell surface properties of two differently virulent strains of Acinetobacter baumannii isolated from a patient

The aim of this study was to unravel, by focusing on cell surface properties, the underlying virulence factors contributing to the difference in the pathogenicity observed in two Acinetobacter baumannii strains isolated from the same patient. The two strains were phenotypically different: (i) a mucoid strain (AB-M), highly virulent in a mouse model of pneumonia, and (ii) a nonmucoid strain (AB-NM), moderately virulent in the same model. The study of the cell surface properties included the microbial adhesion to solvents method, the measurement of the electrophoretic mobility of bacteria, the analysis of biofilm formation by calcofluor white staining, the adherence to silicone catheters, and scanning electron microscopy. The AB-NM strain was more hydrophobic, more adherent to silicone catheters, and produced more biofilm than the AB-M strain. Scanning electron microscopy showed bacterial cells with a rough surface and the formation of large cell clusters for AB-NM whereas the AB-M strain had a smooth surfa..., Le but de cette etude était d’étudier, en se focalisant sur les propriétés de surface des bactéries, des caractères potentiellement impliqués dans la différence de pouvoir pathogène de deux souches d’Acinetobacter baumannii isolées chez un même patient. Ces souches étaient phénotypiquement différentes : une souche mucoïde (AB-M) caractérisée par un pouvoir pathogène élevé dans un modèle expérimental murin de pneumopathie, et une souche non mucoïde (AB-NM), plus faiblement pathogène dans le même modèle. L’étude des propriétés de surface a utilisé la méthode d’adhésion des bactéries aux solvants, la mesure de la mobilité électrophorétique des bactéries, l’analyse de la formation de biofilm par marquage au calcofluor, l’adhésion à des cathéters en silicone, et la microscopie électronique à balayage. La souche AB-NM est apparue plus hydrophobe, plus adhérente aux cathéters, et plus productrice de biofilm que la souche AB-M. L’observation en microscopie électronique à balayage a montré des bactéries à surface ..

Extended-spectrum β-lactamase Enterobacteriaceae (ESBLE) in intensive care units: strong correlation with the ESBLE colonization pressure in patients but not same species

Sink drains of six intensive care units (ICUs) were sampled for screening contamination with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBLE). A high prevalence (59.4%) of sink drain contamination was observed. Analysing the data by ICU, the ratio \u27number of ESBLE species isolated in sink drains/total number of sink drains sampled\u27 was highly correlated (Spearman coefficient: 0.87; P = 0.02) with the ratio \u27number of hospitalization days for patients with ESBLE carriage identified within the preceding year/total number of hospitalization days within the preceding year\u27. Concurrently, the distribution of ESBLE species differed significantly between patients and sink drains

The impact of performing bacterial identification (BI) and antimicrobial susceptibility testing (AST) for bronchoalveolar fluid (BAL) cultures 24h a day in a clinical microbiology laboratory

We previously demonstrated the positive impact of performing bacterial identification and antimicrobial susceptibility testing (AST) after day hours (night service [NS]) for certain clinical samples on the treatment of infected patients. Our objective was to evaluate the impact of including positive bronchoalveolar lavage (BAL) cultures in our NS. Two major positive consequences were recorded: initiation of earlier appropriate treatment and earlier change to a reduced-spectrum but still effective regimen. Reductions in delay were defined as the differences between the hours actually spent and hours estimated as though laboratory tests had been performed in the absence of NS. Fifty BALs were included. The NS led to the implementation of earlier appropriate therapy in 10 cases (20%), to earlier de-escalation in 15 cases (30%), and to earlier appropriate therapy and de-escalation in 4 cases (8%). In conclusion, performing bacterial identification and AST for positive BAL after laboratory opening hours could be relevant

Microbial community functioning during plant litter decomposition

International audienceAbstract Microbial life in soil is fueled by dissolved organic matter (DOM) that leaches from the litter layer. It is well known that decomposer communities adapt to the available litter source, but it remains unclear if they functionally compete or synergistically address different litter types. Therefore, we decomposed beech, oak, pine and grass litter from two geologically distinct sites in a lab-scale decomposition experiment. We performed a correlative network analysis on the results of direct infusion HR-MS DOM analysis and cross-validated functional predictions from 16S rRNA gene amplicon sequencing and with DOM and metaproteomic analyses. Here we show that many functions are redundantly distributed within decomposer communities and that their relative expression is rapidly optimized to address litter-specific properties. However, community changes are likely forced by antagonistic mechanisms as we identified several natural antibiotics in DOM. As a consequence, the decomposer community is specializing towards the litter source and the state of decomposition (community divergence) but showing similar litter metabolomes (metabolome convergence). Our multi-omics-based results highlight that DOM not only fuels microbial life, but it additionally holds meta-metabolomic information on the functioning of ecosystems

Investigating the microbial ecology of coastal hotspots of marine nitrogen fixation in the western North Atlantic

Variation in the microbial cycling of nutrients and carbon in the ocean is an emergent property of complex planktonic communities. While recent findings have considerably expanded our understanding of the diversity and distribution of nitrogen (N2) fixing marine diazotrophs, knowledge gaps remain regarding ecological interactions between diazotrophs and other community members. Using quantitative 16S and 18S V4 rDNA amplicon sequencing, we surveyed eukaryotic and prokaryotic microbial communities from samples collected in August 2016 and 2017 across the Western North Atlantic. Leveraging and significantly expanding an earlier published 2015 molecular dataset, we examined microbial community structure and ecological co-occurrence relationships associated with intense hotspots of N2 fixation previously reported at sites off the Southern New England Shelf and Mid-Atlantic Bight. Overall, we observed a negative relationship between eukaryotic diversity and both N2 fixation and net community production (NCP). Maximum N2 fixation rates occurred at sites with high abundances of mixotrophic stramenopiles, notably Chrysophyceae. Network analysis revealed such stramenopiles to be keystone taxa alongside the haptophyte diazotroph host Braarudosphaera bigelowii and chlorophytes. Our findings highlight an intriguing relationship between marine stramenopiles and high N2 fixation coastal sites

The impact of performing bacterial identification and antimicrobial susceptibility testing on bronchoalveolar fluid cultures 24 h a day in a microbiology laboratory

We previously demonstrated the positive impact of performing bacterial identification and antimicrobial susceptibility testing (AST) after day hours (night service [NS]) for certain clinical samples on the treatment of infected patients. Our objective was to evaluate the impact of including positive bronchoalveolar lavage (BAL) cultures in our NS. Two major positive consequences were recorded: initiation of earlier appropriate treatment and earlier change to a reduced-spectrum but still effective regimen. Reductions in delay were defined as the differences between the hours actually spent and hours estimated as though laboratory tests had been performed in the absence of NS. Fifty BALs were included. The NS led to the implementation of earlier appropriate therapy in 10 cases (20%), to earlier de-escalation in 15 cases (30%), and to earlier appropriate therapy and de-escalation in 4 cases (8%). In conclusion, performing bacterial identification and AST for positive BAL after laboratory opening hours could be relevant