Clinical and molecular epidemiology of hospital Enterococcus faecalis isolates in eastern France

ObjectiveTo report on the occurrence of Enterococcus faecalis hospital isolates obtained during 1 year in hospitals in the Franche-Comté region of France.MethodsClinical isolates of E. faecalis of different antibiotic susceptibility phenotypes from hospitalized patients were characterized by pulsed-field gel electrophoresis. Patients with positive cultures were investigated by three case-control studies to identify risk factors for colonization/infection.ResultsThe crude incidence of colonization/infection was 2.37%, and 4-day and 7-day colonization rates after admission were 10.0% and 6.36%, respectively. The rates of high-level resistance to kanamycin (HLKR) and to gentamicin (HLGR) were 47.1% and 7.1%, respectively. No isolate was resistant to glycopeptides or produced β-lactamase. The 209 hospital isolates obtained during the study yielded 98 major DNA patterns, of which two were major epidemic patterns including HLKR isolates. No single factor was significantly associated with colonization/infection by HLKR isolates. The length of hospitalization before isolation was associated with colonization by HLGR isolates.ConclusionsThe isolation frequency of E. faecalis strains with acquired resistance to aminoglycoside antibiotics, and the wide dissemination of resistant strains with characteristics that allow them to persist and spread, argue for further large prospective surveys of clinical isolates of E. faecalis in hospitals

The role of water fittings in intensive care rooms as reservoirs for the colonization of patients with Pseudomonas aeruginosa

International audienceOBJECTIVE: To assess the role of the water environment in the Pseudomonas aeruginosa colonization of patients in intensive care units in the absence of a recognized outbreak. DESIGN AND SETTING: Prospective, single-centre study over an 8-week period in two adult ICUs at a university hospital. Environmental samples were taken from the water fittings of rooms once per week, during a 8-week period. Patients were screened weekly for P. aeruginosa carriage. Environmental and humans isolates were genotyped by using pulsed-field gel electrophoresis. RESULTS: P. aeruginosa was detected in 193 (86.2%) of the 224 U-bend samples and 10 of the 224 samples taken from the tap (4.5%). Seventeen of the 123 patients admitted were colonized with P. aeruginosa. Only one of the 14 patients we were able to evaluate was colonized by a clone present in the water environment of his room before the patient's first positive sample was obtained. CONCLUSION: The role of the water environment in the acquisition of P. aeruginosa by intensive care patients remains unclear, but water fittings seem to play a smaller role in non-epidemic situations than expected by many operational hospital hygiene teams

Evidence for Induction of Integron-Based Antibiotic Resistance by the SOS Response in a Clinical Setting

Bacterial resistance to β-lactams may rely on acquired β-lactamases encoded by class 1 integron-borne genes. Rearrangement of integron cassette arrays is mediated by the integrase IntI1. It has been previously established that integrase expression can be activated by the SOS response in vitro, leading to speculation that this is an important clinical mechanism of acquiring resistance. Here we report the first in vivo evidence of the impact of SOS response activated by the antibiotic treatment given to a patient and its output in terms of resistance development. We identified a new mechanism of modulation of antibiotic resistance in integrons, based on the insertion of a genetic element, the gcuF1 cassette, upstream of the integron-borne cassette blaOXA-28 encoding an extended spectrum β-lactamase. This insertion creates the fused protein GCUF1-OXA-28 and modulates the transcription, the translation, and the secretion of the β-lactamase in a Pseudomonas aeruginosa isolate (S-Pae) susceptible to the third generation cephalosporin ceftazidime. We found that the metronidazole, not an anti-pseudomonal antibiotic given to the first patient infected with S-Pae, triggered the SOS response that subsequently activated the integrase IntI1 expression. This resulted in the rearrangement of the integron gene cassette array, through excision of the gcuF1 cassette, and the full expression the β-lactamase in an isolate (R-Pae) highly resistant to ceftazidime, which further spread to other patients within our hospital. Our results demonstrate that in human hosts, the antibiotic-induced SOS response in pathogens could play a pivotal role in adaptation process of the bacteria

Usefulness of weekly methicillin-resistant Staphylococcus aureus screening.

International audienceWe evaluated the usefulness of adding weekly methicillin-resistant Staphylococcus aureus (MRSA) screening to our established admission screening and clinical sampling in 4 acute care units of a university hospital. Our results suggest that weekly MRSA screening allows the detection of 56.1% of all cases of hospital-acquired MRSA carriage. These cases would have remained undetected had admission screening and clinical sampling been the only types of surveillance in place

Consecutive human bifidobacteria isolates and acquired tet genes.

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Ecological Study of the Effectiveness of Isolation Precautions in the Management of Hospitalized Patients Colonized or Infected With Acinetobacter baumannii *.

International audienceObjective. @nbsp; To assess the impact of isolation precautions on the incidence of patients colonized or infected with Acinetobacter baumannii (case patients) in a university hospital during the period from 1999 to 2006. Design. @nbsp; Ecological study. Setting. @nbsp; The Besan? University Hospital in France, a 1,200-bed acute care hospital with approximately 50,000 admissions per year. Methods. @nbsp; Using Poisson regression analysis, we evaluated a total of 350,000 patient-days to determine the annual incidence of case patients. This annual incidence was used as the outcome variable, and infection control practices, antibiotic use, and other aggregated data regarding patients' age, sex, McCabe score, and immune status were used as covariates. Results. @nbsp; The implementation of isolation precautions was independently and negatively associated with the incidence of patients colonized or infected with A. baumannii (relative risk, 0.50 [95% confidence interval, 0.40-0.64]; [Formula: see text]). Conclusions. @nbsp; Our study suggests that the implementation of isolation precautions, in addition to standard precautions, effectively prevents the spread of A. baumannii in a hospital setting

Application des méthodes de typage génomique au laboratoire d'hygiène

International audienceL'étude de l'épidémiologie des infections doit permettre d'identifier le mode d'acquisition du micro-organisme responsable, les modes de transmission, la dynamique de la colonisation, et les facteurs de risque d'infection. Ce type d'étude suppose que la comparaison des souches isolées des malades et de leur environnement permette d'établir leur degré de similitude génétique. C'est dans ce cadre que se placent le développement et l'évaluation des marqueurs phénotypiques et génotypiques et la validation des stratégies de typage adaptées aux différents micro-organismes impliqués dans les infections nosocomiales et communautaires

Impact of barrier precautions and antibiotic consumption on the incidence rate of acquired cases of infection or colonization with Acinetobacter baumannii: A 10-year multi-department study.

International audienceFollowing a previous investigation, this ecological study assessed the impact of barrier precautions and various factors on the annual incidence rate of acquired Acinetobacter baumannii cases in each of the 32 departments of the University Hospital of Besançon from 2000 to 2009. Ultimately, our study confirms the effectiveness of barrier precautions in addition to standard precautions for controlling A baumannii within our hospital departments. In comparison with the previous research, it emphasizes the significant role of fluoroquinolones in the emergence and the spread of this microorganism