18 results on '"R, Bonnet"'
Search Results
2. Occurrence of in vivo carbapenem-resistant Campylobacter coli mediated by porA point mutation and overexpression of bla OXA-489 under meropenem treatment.
- Author
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Maurille C, Guérin F, Jehanne Q, Audemard-Verger A, Isnard C, Verdon R, Lehours P, Bonnet R, Giard JC, Le Hello S, and Gravey F
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- 2024
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3. Pirfenidone in patients with progressive fibrotic interstitial lung diseases other than idiopathic pulmonary fibrosis (RELIEF): a double-blind, randomised, placebo-controlled, phase 2b trial.
- Author
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Behr J, Prasse A, Kreuter M, Johow J, Rabe KF, Bonella F, Bonnet R, Grohe C, Held M, Wilkens H, Hammerl P, Koschel D, Blaas S, Wirtz H, Ficker JH, Neumeister W, Schönfeld N, Claussen M, Kneidinger N, Frankenberger M, Hummler S, Kahn N, Tello S, Freise J, Welte T, Neuser P, and Günther A
- Subjects
- Anti-Inflammatory Agents, Non-Steroidal pharmacology, Dose-Response Relationship, Drug, Double-Blind Method, Drug Monitoring methods, Early Termination of Clinical Trials, Female, Humans, Intention to Treat Analysis, Male, Middle Aged, Symptom Assessment statistics & numerical data, Lung Diseases, Interstitial diagnosis, Lung Diseases, Interstitial drug therapy, Lung Diseases, Interstitial physiopathology, Pulmonary Fibrosis diagnosis, Pulmonary Fibrosis drug therapy, Pulmonary Fibrosis physiopathology, Pyridones pharmacology, Respiratory Function Tests methods
- Abstract
Background: Pirfenidone has been shown to slow disease progression in patients with idiopathic pulmonary fibrosis (IPF). However, there are few treatment options for progressive fibrotic interstitial lung diseases (ILDs)) other than IPF. In view of the pathomechanistic and clinical similarities between IPF and other progressive fibrotic ILDs, we aimed to assess the efficacy and safety of pirfenidone in patients with four non-IPF progressive fibrotic ILDs., Methods: We did a multicentre, double-blind, randomised, placebo-controlled, parallel phase 2b trial (RELIEF) in 17 centres with expertise in ILD in Germany. Eligible participants were patients aged 18-80 years with progressive fibrotic ILD due to four diagnoses: collagen or vascular diseases (ie, connective tissue disease-associated ILDs), fibrotic non-specific interstitial pneumonia, chronic hypersensitivity pneumonitis, or asbestos-induced lung fibrosis. Other eligibility criteria included a forced vital capacity (FVC) of 40-90% predicted, a diffusing capacity of the lung for carbon monoxide of 10-90% predicted, and an annual decline of FVC of at least 5% predicted despite conventional therapy, based on at least three measurements within 6-24 months before enrolment. Patients who had received any previous antifibrotic therapy were excluded. We randomly assigned patients (1:1) to either oral pirfenidone (267 mg three times per day in week 1, 534 mg three times per day in week 2, and 801 mg three times per day thereafter) or matched placebo, added to their ongoing medication. Randomisation was done centrally using permuted block randomisation with varying block sizes stratified by the four diagnostic groups. Patients, investigators, statisticians, monitors, and the study coordinator were masked to treatment assignment until database closure. The placebo-controlled study period was 48 weeks (including up-titration). The primary endpoint was absolute change in percentage of predicted FVC (FVC % predicted) from baseline to week 48 in the intention-to-treat population, with imputation of missing data by the smallest sum of squared differences and attribution of deceased patients to the lowest rank in a rank ANCOVA model. Additionally, we did linear mixed-model repeated measures slope analyses of FVC % predicted longitudinal data over the course of the study as a prespecified sensitivity analysis and post-hoc sensitivity analyses of the primary endpoint in the intention-to-treat population using imputation methods of last observation carried forward [LOCF] and a regression-based multiple imputation procedure. Safety was assessed in all patients who received at least one dose of study medication. This trial is registered with EudraCT 2014-000861-32; DRKS00009822 and is no longer recruiting., Findings: Between April 5, 2016, and Oct 4, 2018, we randomly assigned 127 patients to treatment: 64 to pirfenidone, 63 to placebo. After 127 patients had been randomised, the study was prematurely terminated on the basis of an interim analysis for futility triggered by slow recruitment. After 48 weeks and in the overall population of 127 patients, rank ANCOVA with diagnostic group included as a factor showed a significantly lower decline in FVC % predicted in the pirfenidone group compared with placebo (p=0·043); the result was similar when the model was stratified by diagnostic group (p=0·042). A significant treatment effect was also observed when applying the LOCF and multiple imputation methods to analyses of the primary endpoint. The median difference (Hodges-Lehmann estimate) between pirfenidone and placebo groups for the primary endpoint was 1·69 FVC % predicted (95% CI -0·65 to 4·03). In the linear mixed-model repeated measures slope analysis of FVC % predicted, the estimated difference between treatment and placebo groups from baseline to week 48 was 3·53 FVC % predicted (95% CI 0·21 to 6·86) with imputation of deaths as prespecified, or 2·79 FVC % predicted (95% CI 0·03 to 5·54) without imputation. One death (non-respiratory) occurred in the pirfenidone group (2%) and five deaths (three of which were respiratory) occurred in the placebo group (8%). The most frequent serious adverse events in both groups were infections and infestations (five [8%] in the pirfenidone group, ten [16%] in the placebo group); general disorders including disease worsening (two [3%] in the pirfenidone group, seven [11%] in the placebo group); and cardiac disorders (one ([2%] in the pirfenidone group, 5 [8%] in the placebo group). Adverse events (grade 3-4) of nausea (two patients on pirfenidone, two on placebo), dyspnoea (one patient on pirfenidone, one on placebo), and diarrhoea (one patient on pirfenidone) were also observed., Interpretation: In view of the premature study termination, results should be interpreted with care. Nevertheless, our data suggest that in patients with fibrotic ILDs other than IPF who deteriorate despite conventional therapy, adding pirfenidone to existing treatment might attenuate disease progression as measured by decline in FVC., Funding: German Center for Lung Research, Roche Pharma., Competing Interests: Declaration of interests JB reports personal fees from Boehringer Ingelheim, Bristol Myers Squibb, Biogen, Galapagos, Promedior, Roche, and the German Center for Lung Research (DZL). SB reports personal fees and non-financial support from Roche, Bayer, Novartis, and Boehringer Ingelheim; personal fees from Merck Serono; and non-financial support from Teva, Gilead, Lucane Pharma, Actelion, CSL Behring, and Vertex. FB reports personal fees for consultancy, lecturing, and travel support from Boehringer Ingelheim and Roche. MC reports grants from DZL. JHF reports personal fees, grants, and non-financial support from Roche; and personal fees and non-financial support from Boehringer Ingelheim. AG reports grants from DZL, Boehringer Ingelheim, and Roche. MH reports grants from Actelion; honoraria for lectures from Actelion, Bayer Healthcare, Berlin Chemie, Boehringer Ingelheim, GlaxoSmithKline (GSK), Merck Sharp & Dohme (MSD), Novartis, OMT, Pfizer, and Roche; honoraria for advisory boards from Actelion, Bayer, Boehringer Ingelheim, GSK, MSD, and Roche; and honoraria for clinical trials from Actelion, Bayer, GSK, Pfizer, and United Therapeutics. NKn reports personal fees from Roche. DK reports personal fees from Roche; and personal fees and non-financial support from Boehringer Ingelheim. MK reports grants from DZL; and grants and personal fees from Boehringer Ingelheim and Roche. AP reports grants from DZL; grants, personal fees, and non-financial support from Boehringer Ingelheim and AstraZeneca; personal fees and non-financial support from Roche, Pliant, Chiesi Pharmaceuticals, and Nitto Denko; personal fees from Amgen; and non-financial support from Galapagos. KFR reports grants and personal fees from Boehringer Ingelheim and AstraZeneca; and personal fees from Novartis, Sanofi, Regeneron, Roche, and Chiesi Pharmaceuticals. TW reports grants from Roche; and personal fees from Boehringer Ingelheim, Roche, and Novartis. HWil reports personal fees for lectures or consultations from Actelion–Janssen, Bayer, Biotest, Boehringer Ingelheim, GSK, Pfizer, and Roche. HWir reports lecture fees from Roche. All other authors declare no competing interests., (Copyright © 2021 Elsevier Ltd. All rights reserved.)
- Published
- 2021
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4. Emergence of plasmid-mediated colistin resistance (mcr-1) among Enterobacteriaceae strains: Laboratory detection of resistance and measures to control its dissemination.
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Lepelletier D, Bonnet R, Plésiat P, Nicolas-Chanoine MH, Berger-Carbonne A, Chidiac C, and Grandbastien B
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- Bacterial Proteins genetics, Clinical Laboratory Techniques, Enterobacteriaceae Infections epidemiology, Enterobacteriaceae Infections microbiology, Humans, Plasmids genetics, Anti-Bacterial Agents pharmacology, Colistin pharmacology, Communicable Disease Control standards, Drug Resistance, Bacterial genetics, Enterobacteriaceae drug effects, Enterobacteriaceae genetics, Enterobacteriaceae Infections prevention & control
- Abstract
The increasing use of colistin has contributed to the emergence of resistant bacteria and to an increase in the frequency of infections caused by naturally resistant Enterobacteriaceae strains such as Proteus, Providencia, Morganella, and Serratia. In August 2016, the French High Council for Public Health (French acronym HCSP) received a request from the Ministry of Health on the advice of the French National Public Health agency (Santé publique France) with regard to measures that should be taken to tackle the emergence of plasmid-mediated colistin resistance among Enterobacteriaceae strains. French healthcare facilities were asked to take the necessary measures as soon as possible, such as updating the definition of emerging highly resistant bacteria and defining the identification methods so as to take account of the evolving epidemiology of this type of resistance. This article describes the epidemiological context of the discovery of this emergence in France and worldwide, the resistance mechanisms, the microbiological methods of routine laboratory detection and the level of hygiene measures to implement in French facilities., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)
- Published
- 2018
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5. Genetic, biochemical characterization and mutagenesis of the chromosomal class A β-lactamase of Raoultella (formerly Klebsiella) terrigena.
- Author
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Walckenaer E, Delmas J, Leflon-Guibout V, Bonnet R, and Nicolas-Chanoine MH
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- Amino Acid Sequence, Amino Acid Substitution, Anti-Bacterial Agents pharmacology, Bacterial Proteins metabolism, Ceftazidime pharmacology, Chromosomes, Bacterial, Cloning, Molecular, DNA Transposable Elements, Drug Resistance, Multiple, Bacterial genetics, Enterobacteriaceae classification, Enterobacteriaceae genetics, Escherichia coli, Genes, Bacterial, Molecular Sequence Data, Mutagenesis, Site-Directed, Promoter Regions, Genetic, Sequence Alignment, Sequence Homology, Amino Acid, beta-Lactamases classification, beta-Lactamases metabolism, beta-Lactams pharmacology, Bacterial Proteins genetics, Enterobacteriaceae enzymology, beta-Lactam Resistance genetics, beta-Lactamases genetics
- Abstract
Background: Chromosomal class A β-lactamases have been characterized in Raoultella ornithinolytica and Raoultella planticola. The purpose of this study was to characterize that of Raoultella terrigena., Materials and Methods: The blaTER-1 gene of R. terrigena strain ATCC33257(T) was cloned (pACter-1) and sequenced. It was then used to detect the bla gene of strains BM 85 01 095 and SB2796. The hypermutable Escherichia coli strain AB1157 mutS::Tn10 was transformed with pACter-1 and mutants growing on plates containing>2mg/L ceftazidime were studied. Notably, the impact of mutations only observed in the promoter region on β-lactam resistance was assessed by site-directed mutagenesis experiments., Results: R. terrigena strains ATCC33257(T) and BM 85 01 095 had the same bla gene and deduced protein (TER-1) whereas there were 3 substitutions in those of strain SB2796 (TER-2). Class A β-lactamases TER showed 78%, 69.9% and 38.7% identity with PLA or ORN, TEM-1 and KOXY, respectively. Compared with TEM-1, TER-1 and TER-2 showed 2 particular substitutions, Leu75Pro and Glu240Asn demonstrated to be involved in the inherent β-lactam resistance profile of R. terrigena. TER-1 (pI of 7.6) had a high activity against penicillin G and a significantly low one against amoxicillin. Substitution G/T observed in the -35 region of the blaTER gene harbored by strains growing in the presence of≥2mg/L ceftazidime was shown to be responsible for this growth., Conclusion: TER is a new class A β-lactamase belonging to functional group 2b., (Copyright © 2015. Published by Elsevier SAS.)
- Published
- 2015
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6. Four-year epidemiological study of extended-spectrum β-lactamase-producing Enterobacteriaceae in a French teaching hospital.
- Author
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Gibold L, Robin F, Tan RN, Delmas J, and Bonnet R
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- Community-Acquired Infections epidemiology, Community-Acquired Infections microbiology, Drug Resistance, Bacterial, Drug Resistance, Multiple, Bacterial, Enterobacteriaceae classification, Enterobacteriaceae isolation & purification, Enterobacteriaceae Infections epidemiology, Escherichia coli classification, Escherichia coli isolation & purification, Escherichia coli Infections epidemiology, Escherichia coli Infections mortality, Fluoroquinolones pharmacology, Fosfomycin pharmacology, France epidemiology, Furans pharmacology, Hospitals, Teaching, Humans, Microbial Sensitivity Tests, Retrospective Studies, beta-Lactamases genetics, Anti-Bacterial Agents pharmacology, Enterobacteriaceae enzymology, Enterobacteriaceae Infections microbiology, beta-Lactamases metabolism
- Abstract
Since the end of the last century resistance to oxyimino β-lactams has steadily increased in Enterobacteriaceae. In the present work we studied extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae strains isolated in the teaching hospital of Clermont-Ferrand, France, between 2006 and 2009. A total of 1368 ESBL-producing isolates were collected. Most of these isolates (69%) were CTX-M-producing Escherichia coli. During the study, the clinical incidence increased by more than 400%, even in the emergency department, and especially in community-acquired infections, as is the case elsewhere in the world. Most of the ESBL-producing isolates remained susceptible to furans and fosfomycin, but only 50% to fluoroquinolons. In conclusion, ESBL-producing bacteria constantly increased during the study period. Unlike many studies, this increase was associated with the wide dissemination of three different CTX-M enzymes: CTX-M-14, CTX-M-15 and CTX-M-1., (© 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.)
- Published
- 2014
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7. Analysis of structure-function relationships in the colibactin-maturating enzyme ClbP.
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Cougnoux A, Gibold L, Robin F, Dubois D, Pradel N, Darfeuille-Michaud A, Dalmasso G, Delmas J, and Bonnet R
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- Blotting, Western, Escherichia coli genetics, Escherichia coli Proteins genetics, Escherichia coli Proteins isolation & purification, Membrane Proteins chemistry, Membrane Proteins genetics, Membrane Proteins isolation & purification, Membrane Proteins metabolism, Models, Biological, Models, Molecular, Mutagenesis, Site-Directed, Peptide Hydrolases genetics, Peptide Hydrolases isolation & purification, Protein Conformation, Escherichia coli enzymology, Escherichia coli Proteins chemistry, Escherichia coli Proteins metabolism, Peptide Hydrolases chemistry, Peptide Hydrolases metabolism, Peptides metabolism, Polyketides metabolism
- Abstract
pks genomic island of Escherichia coli is involved in the synthesis of the non-ribosomal peptide-type genotoxin colibactin, which has been suggesting as affecting the host immune response and having an impact on cancer development. The pks-encoded enzyme ClbP is an atypical peptidase that contributes to the synthesis of colibactin. In this work, we identified key features of ClbP. Bacterial fractionation and Western-blot analysis revealed the docking of ClbP to the bacterial inner membrane via a C-terminal domain harboring three predicted transmembrane helices. Whereas only one helix was necessary for the location in the inner membrane, the complete sequence of the C-terminal domain was necessary for ClbP bioactivity. In addition, the N-terminal sequence of ClbP allowed the SRP/Sec/YidC- and MreB-dependent translocation of the enzymatic domain in the periplasmic compartment, a feature also essential for ClbP bioactivity. Finally, the comparison of ClbP structure with that of the paralogs FmtA-like and AmpC revealed at an extremity of the catalytic groove a negative electrostatic potential surface characteristic of ClbP. Site-directed mutagenesis experiments identified in this zone two aspartic residues that were important for ClbP bioactivity. Overall, these results suggest a model for precolibactin activation by ClbP and pave a way for the design of inhibitors targeting colibactin production., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
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- 2012
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8. [Hip prosthetic Streptococcus oralis infection].
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Robin F, Palmieri M, Levai JP, Bonnet R, and Hennequin C
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- Aged, 80 and over, Female, Humans, Hip Prosthesis adverse effects, Prosthesis-Related Infections, Streptococcal Infections etiology, Streptococcus oralis
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- 2010
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9. Structural insights into substrate recognition and product expulsion in CTX-M enzymes.
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Delmas J, Leyssene D, Dubois D, Birck C, Vazeille E, Robin F, and Bonnet R
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- Anti-Bacterial Agents chemistry, Anti-Bacterial Agents metabolism, Catalytic Domain, Cefotaxime chemistry, Cefotaxime metabolism, Cephalosporins chemistry, Cephalosporins metabolism, Crystallography, X-Ray, Molecular Dynamics Simulation, Molecular Sequence Data, Molecular Structure, X-Ray Diffraction, beta-Lactamases genetics, Protein Structure, Tertiary, beta-Lactamases chemistry, beta-Lactamases metabolism
- Abstract
beta-Lactamase-mediated resistance to beta-lactam antibiotics poses a major threat to our antibiotic armamentarium. Among beta-lactamases, a significant threat comes from enzymes that hydrolyze extended-spectrum cephalosporins such as cefotaxime. Among the enzymes that exhibit this phenotype, the CTX-M family is found worldwide. These enzymes have a small active site, which makes it difficult to explain how they hydrolyze the bulky extended-spectrum cephalosporins into the binding site. We investigated noncovalent substrate recognition and product release in CTX-M enzymes using steered molecular dynamics simulation and X-ray diffraction. An arginine residue located far from the binding site favors the capture and tracking of substrates during entrance into the catalytic pocket. We show that the accommodation of extended-spectrum cephalosporins by CTX-M enzymes induced subtle changes in the active site and established a high density of electrostatic interactions. Interestingly, the product of the catalytic reaction initiates its own release because of steric hindrances and electrostatic repulsions. This suggests that there exists a general mechanism for product release for all members of the beta-lactamase family and probably for most carboxypeptidases., (Copyright 2010 Elsevier Ltd. All rights reserved.)
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- 2010
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10. [Streptococcus anginosus and Streptococcus gallolyticus subsp. pasteurianus chorioamniotitis].
- Author
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Steux R, Dubois D, Bonnet R, Jacquetin B, and Hennequin C
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- Adult, Amoxicillin therapeutic use, Drug Therapy, Combination, Female, Gentamicins therapeutic use, Humans, Infant, Newborn, Male, Placenta microbiology, Pregnancy, Pregnancy Outcome, Anti-Bacterial Agents therapeutic use, Pregnancy Complications, Infectious diagnosis, Streptococcal Infections diagnosis, Streptococcus isolation & purification, Streptococcus anginosus isolation & purification
- Published
- 2008
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11. Evaluation of the Vitek-2 extended-spectrum beta-lactamase test against non-duplicate strains of Enterobacteriaceae producing a broad diversity of well-characterised beta-lactamases.
- Author
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Robin F, Delmas J, Schweitzer C, and Bonnet R
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- Anti-Bacterial Agents pharmacology, Enterobacteriaceae drug effects, Microbial Sensitivity Tests methods, Microbial Sensitivity Tests standards, Microbial Sensitivity Tests statistics & numerical data, Reproducibility of Results, Sensitivity and Specificity, beta-Lactam Resistance, beta-Lactamases biosynthesis, Bacteriological Techniques methods, Enterobacteriaceae classification, Enterobacteriaceae enzymology, beta-Lactamases analysis
- Abstract
The Vitek-2 extended-spectrum beta-lactamase (ESBL) test was assessed using a collection of 94 ESBL-positive and 71 ESBL-negative non-duplicate isolates of Enterobacteriaceae. These isolates produced a wide diversity of well-characterised beta-lactamases, including 61 different ESBLs, two class A carbapenemases and various species-specific beta-lactamases. ESBL detection was performed using (i) the conventional synergy test as recommended by the Comité de l'Antibiogramme de la Société Française de Microbiologie, (ii) the CLSI phenotypic confirmatory test for ESBLs, and (iii) the Vitek-2 ESBL test. For Escherichia coli and klebsiellae, the sensitivity/specificity values were 97.3%/96.9% for the synergy test, 91.8%/100% for the CLSI phenotypic confirmatory test, and 91.8%/100% for the Vitek-2 ESBL test. For other organisms, the sensitivity/specificity values were 100%/97.4% for the synergy test, 90.5%/100% for the CLSI phenotypic confirmatory test, and 90.5%/100% for the Vitek-2 ESBL test. The Vitek-2 ESBL test seemed to be an efficient method for routine detection of ESBL-producing isolates of Enterobacteriaceae, including isolates producing AmpC-type enzymes.
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- 2008
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12. Structure and dynamics of CTX-M enzymes reveal insights into substrate accommodation by extended-spectrum beta-lactamases.
- Author
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Delmas J, Chen Y, Prati F, Robin F, Shoichet BK, and Bonnet R
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- Amino Acid Substitution, Anti-Bacterial Agents isolation & purification, Binding Sites, Boronic Acids metabolism, Catalysis, Computer Simulation, Crystallography, X-Ray, Escherichia coli genetics, Glycine metabolism, Hydrogen Bonding, Hydrolysis, Models, Chemical, Models, Molecular, Molecular Structure, Plasmids, Protein Binding, Protein Conformation, Protein Structure, Secondary, Protein Structure, Tertiary, Rotation, Substrate Specificity, Water chemistry, beta-Lactamases genetics, beta-Lactamases isolation & purification, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents metabolism, beta-Lactamases chemistry, beta-Lactamases metabolism
- Abstract
Oxyimino-cephalosporin antibiotics, such as ceftazidime, escape the hydrolytic activity of most bacterial beta-lactamases. Their widespread use prompted the emergence of the extended-spectrum beta-lactamases CTX-Ms, which have become highly prevalent. The C7 beta-amino thiazol-oxyimino-amide side chain of ceftazidime has a protective effect against most CTX-M beta-lactamases. However, Asp240Gly CTX-M derivatives demonstrate enhanced hydrolytic activity against this compound. In this work, we present the crystallographic structures of Asp240Gly-harboring enzyme CTX-M-16 in complex with ceftazidime-like glycylboronic acid (resolution 1.80 A) and molecular dynamics simulations of the corresponding acyl-enzyme complex. These experiments revealed breathing motions of CTX-M enzymes and the role of the substitution Asp240Gly in the accommodation of ceftazidime. The substitution Asp240Gly resulted in insertion of the C7 beta side chain of ceftazidime deep in the catalytic pocket and orchestrated motions of the active serine Ser70, the beta 3 strand and the omega loop, which favored the key interactions of the residues 237 and 235 with ceftazidime.
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- 2008
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13. [Should presumptive meningoencephalitis treatment in adults be active against Mycoplasma pneumoniae?].
- Author
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Trouillier S, Dionet E, Bocquier B, Constantin JM, Guelon D, Bonnet R, Romaszko JP, Laurichesse H, Beytout J, and Lesens O
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- Adult, Aged, Anti-Bacterial Agents classification, Female, Humans, Male, Middle Aged, Treatment Outcome, Anti-Bacterial Agents therapeutic use, Meningoencephalitis drug therapy, Mycoplasma pneumoniae drug effects, Pneumonia, Mycoplasma drug therapy
- Abstract
Introduction: Meningoencephalitis is the most common central nervous system complication caused by Mycoplasma pneumoniae. Its frequency is probably underestimated., Objective: The study's aim was to determine the retrospectively incidence of M. pneumoniae meningoencephalitis among other cases of encephalitis diagnosed in infectiology, neurology and ICU at the Clermont-Ferrand University hospital in 2004 and 2005., Design: A case of meningoencephalitis was defined by encephalopathy (altered level of consciousness and/or change in personality), with one or more of the following symptoms: fever, seizure, focal neurological findings, meningitis, electroencephalography or neuroimaging findings consistent with encephalitis. Tumor and hematoma diagnosed by scan were excluded. M. pneumoniae was considered as a possible cause when patients had positive serological test (IgM Elisa) and/or positive PCR results for the CSF., Results: Four (8.3%) patients among 48 cases of encephalitis could have been caused by M. pneumoniae. All except one convulsed initially. Pneumopathy was found in two patients. All received a specific treatment later. Antibiotics seemed to influence evolution in only two patients. These 4 cases appeared during an epidemic between November 2004 and August 2005: 48 hospitalized adults had positive serological test for M. pneumoniae in 2005 and 15 in 2004, whereas the number of tests was the same in 2004 and in 2005., Conclusions: M. pneumoniae should be investigated as a cause of meningoencephalitis if initial tests are negative, if patients have respiratory symptoms and in case of epidemic. Presumptive treatment of meningoencephalitis should include an antibiotic active against M. pneumoniae.
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- 2007
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14. Occurrence of qnrA-positive clinical isolates in French teaching hospitals during 2002-2005.
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Cambau E, Lascols C, Sougakoff W, Bébéar C, Bonnet R, Cavallo JD, Gutmann L, Ploy MC, Jarlier V, Soussy CJ, and Robert J
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- Enterobacteriaceae metabolism, France epidemiology, Humans, Time Factors, Bacterial Proteins genetics, Drug Resistance, Bacterial, Enterobacteriaceae genetics, Enterobacteriaceae Infections epidemiology, Enterobacteriaceae Infections microbiology, Quinolones pharmacology
- Abstract
Bacteria harbouring the novel qnrA plasmid-mediated mechanism of quinolone resistance have been described in different countries, but the frequency of their occurrence has not been investigated. In total, 1,468 clinical isolates of Enterobacteriaceae with quinolone resistance or extended-spectrum beta-lactamase (ESBL) phenotypes were collected from eight teaching hospitals in France during 2002-2005 and screened for qnrA. Overall, 28 isolates (22 Enterobacter cloacae, three Klebsiella pneumoniae, one Citrobacter freundii, one Klebsiella oxytoca and one Proteus mirabilis) were positive for qnrA, representing 1.9% of all isolates, 3.3% of ESBL-producing isolates (22% of the E. cloacae isolates) and 0% of non-ESBL-producing isolates. The prevalence of qnrA among consecutive ESBL-producing isolates in 2004 from the eight hospitals was 2.8% (18/639). Of the qnrA-positive isolates, 100% were intermediately-resistant or resistant to nalidixic acid, and 75% to ciprofloxacin. Twenty-one of the 22 qnrA-positive E. cloacae isolates were obtained from two hospitals in the Paris area, and molecular typing and plasmid content analysis showed clonal relationships for five, three and two isolates, respectively. The qnrA genetic environment was similar to that of the In36 integron. The remaining two isolates had qnrA variants (30 and 29 nucleotide differences, respectively, compared with the original sequence) and an unknown genetic environment. The ESBL gene associated with qnrA was bla(SHV-12) in most of the isolates, but bla(PER-1) and bla(SHV-2a) were found in two isolates. In France, it appears that qnrA-positive isolates are predominantly E. cloacae isolates producing SHV-12, and may be associated with the dissemination of an In36-like integron.
- Published
- 2006
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15. [VCA agar (bioMérieux) for selective isolation of vancomycin-resistant Enterococci (VRE) from fecal specimens].
- Author
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Delmas J, Robin F, Romaszko JP, Baraduc R, Lesens O, Sirot J, and Bonnet R
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- Cross Infection microbiology, Enterococcus classification, Enterococcus drug effects, Enterococcus faecium isolation & purification, Gram-Positive Bacterial Infections transmission, Humans, Sensitivity and Specificity, Enterococcus isolation & purification, Feces microbiology, Vancomycin Resistance
- Abstract
Screening for Vancomycin Resistant Enterococci (VRE) is recommended for preventing nosocomial infections with VRE. The aim of this study was to assess the performance of VCA3 agar (bioMérieux) in VRE isolation from fecal specimens. 220 specimens were cultured on VCA3 agar, which contains vancomycin and in parallel, on CAP agar (Oxoid), which is vancomycin-free. 36 vancomycin resistant enterococci were isolated: 24 isolates of Enterococcus faecium expressed a high-level resistance to vancomycin and 12 isolates of E. gallinarum/casseliflavus exhibited resistance at low-level. The sensitivity of VCA3 appeared greater than that of CAP for VRE isolation: 92% (22/24) vs 79% (19/24) for E. faecium (NS, P>0.05) ; 83% (10/12) vs 50% (6/12) for E. gallinarum/casselliflavus (NS, P>0.05). As expected, initial cultures of multiple gram positive organisms were far more frequent on CAP agar than on VCA3 agar. The isolation rate of vancomycin susceptible gram positive strains was impressively lower on VCA3 medium than on CAP medium. VCA3 agar avoided therefore additional subcultures, useless identification and susceptibility tests. In conclusion, VCA3 medium could be useful for the direct, rapid and selective isolation of VRE from fecal specimens.
- Published
- 2005
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16. Atomic resolution structures of CTX-M beta-lactamases: extended spectrum activities from increased mobility and decreased stability.
- Author
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Chen Y, Delmas J, Sirot J, Shoichet B, and Bonnet R
- Subjects
- Anti-Bacterial Agents chemistry, Aspartic Acid genetics, Aspartic Acid metabolism, Binding Sites, Circular Dichroism, Crystallography, X-Ray, Enzyme Stability, Kinetics, Models, Molecular, Mutation genetics, Protein Denaturation, Protein Folding, Protein Structure, Tertiary, Temperature, Valine genetics, Valine metabolism, beta-Lactamases genetics, beta-Lactamases chemistry, beta-Lactamases metabolism
- Abstract
Extended spectrum beta-lactamases (ESBLs) confer bacterial resistance to third-generation cephalosporins, such as cefotaxime and ceftazidime, increasing hospital mortality rates. Whereas these antibiotics are almost impervious to classic beta-lactamases, such as TEM-1, ESBLs have one to four orders greater activity against them. The origins of this activity have been widely studied for the TEM and SHV-type ESBLs, but have received less attention for the CTX-M beta-lactamases, an emerging family that is now the dominant ESBL in several regions. To understand how CTX-M beta-lactamases achieve their remarkable activity, biophysical and structural studies were undertaken. Using reversible, two-state thermal denaturation, it was found that as these enzymes evolve a broader substrate range, they sacrifice stability. Thus, the mutant enzyme CTX-M-16 is eightfold more active against ceftazidime than the pseudo-wild-type CTX-M-14 but is 1.9 kcal/mol less stable. This is consistent with a "stability-activity tradeoff," similar to that observed in the evolution of other resistance enzymes. To investigate the structural basis of enzyme activity and stability, the structures of four CTX-M enzymes were determined by X-ray crystallography. The structures of CTX-M-14, CTX-M-27, CTX-M-9 and CTX-M-16 were determined to 1.10 Angstroms, 1.20 Angstroms, 0.98 Angstroms and 1.74 Angstroms resolution, respectively. The enzyme active sites resemble those of the narrow-spectrum TEM-1 and SHV-1, and not the enlarged sites typical of ESBL mutants such as TEM-52 and TEM-64. Instead, point substitutions leading to specific interactions may be responsible for the improved activity against ceftazidime and cefotaxime, consistent with observations first made for the related Toho-1 enzyme. The broadened substrate range of CTX-M-16 may result from coupled defects in the enzyme's B3 strand, which lines the active site. Substitutions Val231-->Ala and Asp240-->Gly, which convert CTX-M-14 into CTX-M-16, occur at either end of this strand. These defects appear to increase the mobility of B3 based on anisotropic B-factor analyses at ultrahigh resolution, consistent with stability loss and activity gain. The unusually high resolution of these structures that makes such analyses possible also makes them good templates for inhibitor discovery.
- Published
- 2005
- Full Text
- View/download PDF
17. Proton-beam radiotherapy for early-stage lung cancer.
- Author
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Bush DA, Slater JD, Bonnet R, Cheek GA, Dunbar RD, Moyers M, and Slater JM
- Subjects
- Aged, Aged, 80 and over, Biopsy, Needle, Bronchoscopy, California epidemiology, Carcinoma, Non-Small-Cell Lung diagnostic imaging, Carcinoma, Non-Small-Cell Lung mortality, Carcinoma, Non-Small-Cell Lung pathology, Disease-Free Survival, Female, Follow-Up Studies, Humans, Lung Neoplasms diagnostic imaging, Lung Neoplasms mortality, Lung Neoplasms pathology, Male, Middle Aged, Neoplasm Staging, Prospective Studies, Proton Therapy, Radiotherapy, Computer-Assisted, Survival Rate, Tomography, X-Ray Computed, Treatment Outcome, Carcinoma, Non-Small-Cell Lung radiotherapy, Lung Neoplasms radiotherapy
- Abstract
Study Objective: A prospective study was undertaken to assess the efficacy and toxicity of conformal proton-beam radiotherapy for early-stage, medically inoperable non-small cell lung cancer., Design: Eligible patients had clinical stage I to IIIa non-small cell lung cancer and were not candidates for surgical resection for medical reasons or because of patient refusal. Patients with adequate cardiopulmonary function received 45 Gy to the mediastinum and gross tumor volume with photons with a concurrent proton boost to the gross tumor volume of an additional 28.8 cobalt gray equivalents (CGE). Total tumor dose was 73.8 CGE given over 5 weeks. Patients with poor cardiopulmonary function received proton-beam radiotherapy to the gross tumor volume only, with 51 CGE given in 10 fractions over a 2-week period., Results: Thirty-seven patients were treated in the study from July 1994 to March 1998. Clinical staging of patients was as follows: stage I, 27 patients; stage II, 2 patients; and stage IIIa, 8 patients. Eighteen patients received a combination of protons and x rays, while 19 patients received proton-beam radiation only. Follow-up of evaluable patients ranged from 3 to 45 months, with a median of 14 months. Two patients in the proton and photon arm developed pneumonitis that resolved with oral steroids; otherwise, no significant toxicities were encountered. The actuarial disease-free survival at 2 years for the entire group was 63%; for stage I patients, disease-free survival at 2 years was 86%. Local disease control was 87%., Conclusion: Preliminary results from this study indicate that proton-beam radiotherapy can be used safely in this group of patients. Disease-free survival and local control appear to be good and compare favorably with published reports utilizing conventional photon irradiation.
- Published
- 1999
- Full Text
- View/download PDF
18. Intractable cough associated with the supine body position. Effective therapy with nasal CPAP.
- Author
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Bonnet R, Jörres R, Downey R, Hein H, and Magnussen H
- Subjects
- Adult, Aged, Cough diagnosis, Cough physiopathology, Female, Humans, Male, Middle Aged, Supine Position physiology, Cough etiology, Cough therapy, Positive-Pressure Respiration methods
- Abstract
We describe five patients with severe nocturnal cough and daytime somnolence in whom the coughing attacks are triggered by assuming the supine body position. Quantity and quality of the nocturnal cough were evaluated in the sleep laboratory with and without nasal continuous positive airway pressure (N-CPAP). Air flow characteristics were assessed using flow volume and airway resistance loops. Airway anatomy was evaluated bronchoscopically. In all five patients, the cough had a barking quality. Flow-volume loops showed an expiratory collapse phenomenon in two of the patients. Endoscopically, all five patients had signs of airway collapse. All patients had difficulty falling asleep because of coughing and were awakened by it frequently. Sleep times ranged from 2.5 to 4.5 h per night. With N-CPAP pressures ranging from 5 to 13 cm H2O, all five patients had clinically significant improvement in their symptoms. Their sleep times increased to a range of 5 to 7.5 h per night and the daytime somnolence markedly improved or resolved. All five patients requested a N-CPAP unit for home use. We conclude that a cough that is predominantly associated with or exacerbated by the supine body position may be treated effectively with N-CPAP.
- Published
- 1995
- Full Text
- View/download PDF
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