Lasserre C.,Brest University Hospital Center |
De Martin L.S.,Brest University Hospital Center |
Cuzon G.,University Paris - Sud |
Bogaerts P.,Laboratoire Of Bacteriologie |
And 4 more authors.
Journal of Clinical Microbiology | Year: 2015
The recognition of carbapenemase-producing Enterobacteriaceae (CPE) isolates is a major laboratory challenge, and their inappropriate or delayed detection may have negative impacts on patient management and on the implementation of infection control measures. We describe here a matrix-assisted laser desorption ionization - time of flight (MALDI-TOF)-based method to detect carbapenemase activity in Enterobacteriaceae. After a 20-min incubation of the isolate with 0.5 mg/ml imipenem at 37°C, supernatants were analyzed by MALDI-TOF in order to identify peaks corresponding to imipenem (300 Da) and an imipenem metabolite (254 Da). A total of 223 strains, 77 CPE (OXA-48 variants, KPC, NDM, VIM, IMI, IMP, and NMC-A) and 146 non- CPE (cephalosporinases, extended-spectrum β-lactamases [ESBLs], and porin defects), were tested and used to calculate a ratio of imipenem hydrolysis: mass spectrometry [MS] ratio = metabolite/(imipenem + metabolite). An MS ratio cutoff was statistically determined to classify strains as carbapenemase producers (MS ratio of ≥0.82). We validated this method first by testing 30 of our 223 isolates (15 CPE and 15 non-CPE) 10 times to calculate an intraclass correlation coefficient (ICC of 0.98), showing the excellent repeatability of the method. Second, 43 strains (25 CPE and 18 non-CPE) different from the 223 strains used to calculate the ratio cutoff were used as external controls and blind tested. They yielded sensitivity and specificity of 100%. The total cost per test is <0.10 U.S. dollars (USD). This easy-to-perform assay is time-saving, cost-efficient, and highly reliable and might be used in any routine laboratory, given the availability of mass spectrometry, to detect CPE. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
Aumeran C.,Service dHygiene Hospitaliere |
Thibert E.,Service dHygiene Hospitaliere |
Chapelle F.A.,Service dHygiene Hospitaliere |
Hennequin C.,Laboratoire Of Bacteriologie |
And 2 more authors.
Journal of Clinical Microbiology | Year: 2012
Opinions differ on the value of microbiological testing of endoscopes, which varies according to the technique used. We compared the efficacy on bacterial biofilms of sampling solutions used for the surveillance of the contamination of endoscope channels. To compare efficacy, we used an experimental model of a 48-h Pseudomonas biofilm grown on endoscope internal tubing. Sampling of this experimental biofilm was performed with a Tween 80-lecithin-based solution, saline, and sterile water. We also performed a randomized prospective study during routine clinical practice in our hospital sampling randomly with two different solutions the endoscopes after reprocessing. Biofilm recovery expressed as a logarithmic ratio of bacteria recovered on bacteria initially present in biofilm was significantly more effective with the Tween 80-lecithin-based solution than with saline solution (P = 0.002) and sterile water (P = 0.002). There was no significant difference between saline and sterile water. In the randomized clinical study, the rates of endoscopes that were contaminated with the Tween 80-lecithin-based sampling solution and the saline were 8/25 and 1/25, respectively (P = 0.02), and the mean numbers of bacteria recovered were 281 and 19 CFU/100 ml (P = 0.001), respectively. In conclusion, the efficiency and therefore the value of the monitoring of endoscope reprocessing by microbiological cultures is dependent on the sampling solutions used. A sampling solution with a tensioactive action is more efficient than saline in detecting biofilm contamination of endoscopes. Copyright © 2012, American Society for Microbiology. All Rights Reserved.
Barbier F.,Center Hospitalier Regional dOrle ans |
Barbier F.,University Paris Diderot |
Andremont A.,University Paris Diderot |
Andremont A.,Laboratoire Of Bacteriologie |
And 2 more authors.
Current Opinion in Pulmonary Medicine | Year: 2013
Purpose of review: The recent evidence is reviewed on clinical epidemiology, trends in bacterial resistance, diagnostic tools and therapeutic options in hospital-acquired pneumonia (HAP), with a special focus on ventilator-associated pneumonia (VAP). Recent findings: The current incidence of VAP ranges from two to 16 episodes for 1000 ventilator-days, with an attributable mortality of 3-17%. Staphylococcus aureus (with 50-80% of methicillin-resistant strains), Pseudomonas aeruginosa and Enterobacteriaceae represent the most frequent pathogens in HAP/VAP. The prevalence of carbapenemase-producing Gram-negative bacilli (GNB) and the emergence of colistin resistance are alarming. Procalcitonin seems to have a good value to monitor the response to treatment. Rapid molecular tests for the optimization of empirical therapy will be available soon. Recent studies support the use of a high-dosing regimen of colistin in HAP/VAP caused by extensively drug-resistant GNB. Linezolid may probably be preferred to vancomycin for a subset of methicillin-resistant S. aureus HAP/VAP. Given the scarcity of novel antimicrobial drugs, different approaches such as bacteriophage therapy or immunotherapy warrant further clinical evaluations. Summary: HAP/VAP is a major cause of deaths, morbidity and resources utilization, notably in patients with severe underlying conditions. The development of new diagnostic tools and therapeutic weapons is urgently needed to face the epidemic of multidrug-resistant pathogens. Copyright © 2013 Lippincott Williams & Wilkins.
Brisse S.,Institute Pasteur Paris |
Brisse S.,French National Center for Scientific Research |
Passet V.,Institute Pasteur Paris |
Passet V.,French National Center for Scientific Research |
And 5 more authors.
Journal of Clinical Microbiology | Year: 2013
Pathogens of the genus Klebsiella have been classified into distinct capsular (K) types for nearly a century. K typing of Klebsiella species still has important applications in epidemiology and clinical microbiology, but the serological method has strong practical limitations. Our objective was to evaluate the sequencing of wzi, a gene conserved in all capsular types of Klebsiella pneumoniae that codes for an outer membrane protein involved in capsule attachment to the cell surface, as a simple and rapid method for the prediction of K type. The sequencing of a 447-nucleotide region of wzi distinguished the K-type reference strains with only nine exceptions. A reference wzi sequence database was created by the inclusion of multiple strains representing K types associated with high virulence and multidrug resistance. A collection of 119 prospective clinical isolates of K. pneumoniae were then analyzed in parallel by wzi sequencing and classical K typing. Whereas K typing achieved typeability for 81% and discrimination for 94.4% of the isolates, these figures were 98.1% and 98.3%, respectively, for wzi sequencing. The prediction of K type once the wzi allele was known was 94%. wzi sequencing is a rapid and simple method for the determination of the K types of most K. pneumoniae clinical isolates. © 2013, American Society for Microbiology. All Rights Reserved.
Gisbert J.P.,Hospital Universitario Of La Princesa |
Calvet X.,Hospital Of Sabadell |
O'Connor A.,Trinity College Dublin |
Megraud F.,Laboratoire Of Bacteriologie |
O'Morain C.A.,Trinity College Dublin
Journal of Clinical Gastroenterology | Year: 2010
Background: Alternative treatment regimens for standard triple therapy are urgently needed. Aim: To critically review the evidence on the role of "sequential" regimen for the treatment of Helicobacter pylori infection. Methods: Bibliographical searches were performed in MEDLINE and international congresses. Results: Several pooled-data analyses and meta-analyses have demonstrated that sequential regimen is more effective than standard triple therapy. Sequential therapy is not affected by bacterial (CagA status, infection density) and host factors (underlying disease, smoking). Clarithromycin resistance seems to be the only factor reducing their efficacy. However, even in these patients, an acceptable >75% eradication rate can be achieved. Unfortunately, almost all the studies have been performed in Italy. Whether it is necessary to provide the drugs sequentially or if the 4 components of sequential therapy can be given concurrently is unclear. Nonbismuth quadruple therapy seems to be an effective and safe alternative to triple therapy and is less complex than sequential therapy. Conclusions: Sequential therapy is a novel promising treatment approach that deserves consideration as a treatment strategy for H. pylori infection. However, further robust assessment across a much broader range of patients is required before sequential therapy could supplant existing treatment regimens and be generally recommended in clinical practice. © 2010 by Lippincott Williams & Wilkins.
Berger S.,Nancy University Hospital Center |
Alauzet C.,Nancy University Hospital Center |
Aissa N.,Nancy University Hospital Center |
Henard S.,Nancy University Hospital Center |
And 3 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2013
In this work, we characterized a new, 160-kb, blaOXA-48-harboring IncL/M-type plasmid isolated from a Klebsiella pneumoniae strain from France. Moreover, we report the transfer of a 60-kb OXA-48-encoding plasmid from Klebsiella pneumoniae to other Enterobacteriaceae in two patients. Copyright © 2013, American Society for Microbiology. All Rights Reserved.
Bessede E.,Laboratoire Of Bacteriologie |
Bessede E.,University of Bordeaux Segalen |
Bessede E.,French Institute of Health and Medical Research |
Delcamp A.,University of Bordeaux Segalen |
And 5 more authors.
Journal of Clinical Microbiology | Year: 2011
Campylobacter species, especially Campylobacter jejuni and Campylobacter coli, are a major cause of human bacterial enteritis. Current detection in stools is done essentially by culture on selective and nonselective media with filtration. These methods were compared to 2 molecular biology methods, an in-house real-time PCR and a multiplex PCR named Seeplex Diarrhea ACE Detection, and 3 immunoenzymatic methods, Premier Campy, RidaScreen Campylobacter, and ImmunoCard Stat!Campy. Out of 242 stool specimens tested, 23 (9.5%) fulfilled the positivity criteria, i.e., they were positive by one or both culture methods or, in case of a negative culture, by a positive molecular method and a positive immunoenzymatic method. The striking feature of this study is the low sensitivity of culture, in the range of 60%, in contrast to immunoenzymatic and molecular tests. Copyright © 2011, American Society for Microbiology. All Rights Reserved.
De Bentzmann S.,Aix - Marseille University |
Plesiat P.,Laboratoire Of Bacteriologie
Environmental Microbiology | Year: 2011
Pseudomonas aeruginosa, a Gram-negative environmental species and an opportunistic microorganism, establishes itself in vulnerable patients, such as those with cystic fibrosis or hospitalized in intensive care units. It has become a major cause of nosocomial infections worldwide (about 10% of all such infections in most European Union hospitals) and a serious threat to Public Health. The overuse and misuse of antibiotics have also led to the selection of resistant strains against which very few therapeutic options exist. How an environmental species can cause human infections remains a key question that still needs elucidation despite the incredibly high progress that has been made in the P. aeruginosa biology over the past decades. The workshop belonging to Current trends in Biomedicine series, which was held under the sponsorship of the Universidad International de Andalucia between the 8th and the 10th November 2010 brought in the most recent advances in the environmental life of P. aeruginosa, the human P. aeruginosa infections, the new animal models to study Pseudomonas infections, the new genetic aspects including metabolomics, genomics and bioinformatics and the community lifestyle named biofilm that accounts for P. aeruginosa persistence in humans. This workshop organized by Soeren Molin (Danemark), Juan-Luis Ramos (Spain) and Sophie de Bentzmann (France) gathered 46 researchers coming from 11 European and American countries in a small format and was hosted in the 'Sede Antonio Machado' in Baeza. It was organized in seven sessions covering animal models for P. aeruginosa pathogenesis, resistance to drugs, regulatory potency including small RNA, two component systems, extracytoplasmic function sigma factors and trancriptional regulators, new therapies emerging from dissection of molecular mechanisms, and evolutionary mechanisms of P. aeruginosa strains in patients. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.
Ruppe E.,Laboratoire Of Bacteriologie |
Andremont A.,Laboratoire Of Bacteriologie
Frontiers in Microbiology | Year: 2013
The intestinal microbiota is a complex environment that hosts 1013 to 1014 bacteria. Among these bacteria stand multidrug-resistant enterobacteria (MDRE), which intestinal densities can substantially vary, especially according to antibiotic exposure. The intestinal density of MDRE and their relative abundance (i.e., the proportion between the density of MDRE and the density of total enterobacteria) could play a major role in the infection process or patient-to-patient transmission. This review discusses the recent advances in understanding (i) what causes variations in the density or relative abundance of intestinal colonization, (ii) what are the clinical consequences of these variations, and (iii) what are the perspectives for maintaining these markers at low levels. © 2013 Ruppé and Andremont.
Gatin L.,EA 3647 |
Saleh-Mghir A.,EA 3647 |
Tasse J.,Laboratoire Of Bacteriologie |
Ghout I.,Urc Paris Ouest Laboratoire Of Biostatistiques |
And 2 more authors.
Antimicrobial Agents and Chemotherapy | Year: 2014
Ceftaroline (CPT), the active metabolite of the prodrug ceftaroline-fosamil (CPT-F), demonstrates in vitro bactericidal activity against methicillin-resistant Staphylococcus aureus (MRSA) and is effective in rabbit models of difficult-to-treat MRSA endocarditis and acute osteomyelitis. However, its in vivo efficacy in a prosthetic joint infection (PJI) model is unknown. Using a MRSAinfected knee PJI model in rabbits, the efficacies of CPT-F or vancomycin (VAN) alone and combined with rifampin (RIF) were compared. After each partial knee replacement with a silicone implant that fit into the tibial intramedullary canal was performed, 5×107 MRSA CFU (MICs of 0.38, 0.006, and 1 mg/liter for CPT, RIF, and VAN, respectively) was injected into the knee. Infected animals were randomly assigned to receive no treatment (controls) or CPT-F (60 mg/kg of body weight intramuscularly [i.m.]), VAN (60 mg/kg i.m.), CPT-F plus RIF (10 mg/kg i.m.), or VAN plus RIF starting 7 days postinoculation and lasting for 7 days. Surviving bacteria in crushed tibias were counted 3 days after ending treatment. Although the in vivo mean log10 CFU/g of CPT-treated (3.0±0.9, n=12) and VAN-treated (3.5±1.1, n=12) crushed bones was significantly lower than those of controls (5.6±1.1, n=14) (P<0.001), neither treatment fully sterilized the bones (3/12 were sterile with each treatment). The mean log10 CFU/g values for the antibiotics in combination with RIF were 1.9±0.5 (12/14 were sterile) for CPT-F and 1.9±0.5 (12/14 were sterile) for VAN. In this MRSA PJI model, the efficacies of CPT-F and VAN did not differ; thus, CPT appears to be a promising antimicrobial agent for the treatment of MRSA PJIs. © 2014, American Society for Microbiology. All Rights Reserved.