Rôle du phénotype hypermutateur chez Staphylococcus aureus dans l'adaptation et la résistance aux antibiotiques dans un modéle d'osteite du rat

CAEN-BU Médecine pharmacie (141182102) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

High mortality in peritonitis due to Mycobacterium avium complex: retrospective study and systematic literature review

International audienc

Differences in Potential for Selection of Clindamycin-Resistant Mutants Between Inducible erm(A) and erm(C) Staphylococcus aureus Genes▿

In staphylococci, inducible macrolide-lincosamide-streptogramin B (MLSB) resistance is conferred by the erm(C) or erm(A) gene. This phenotype is characterized by the erythromycin-clindamycin “D-zone” test. Although clindamycin appears active in vitro, exposure of MLSB-inducible Staphylococcus aureus to this antibiotic may result in the selection of clindamycin-resistant mutants, either in vitro or in vivo. We have compared the frequencies of mutation to clindamycin resistance for 28 isolates of S. aureus inducibly resistant to erythromycin and bearing the erm(C) (n = 18) or erm(A) (n = 10) gene. Seven isolates susceptible to erythromycin or bearing the msr(A) gene (efflux) were used as controls. The frequencies of mutation to clindamycin resistance for the erm(A) isolates (mean ± standard deviation, 3.4 × 10−8 ± 2.4 × 10−8) were only slightly higher than those for the controls (1.1 × 10−8 ± 6.4 × 10−9). By contrast, erm(C) isolates displayed a mean frequency of mutation to clindamycin resistance (4.7 × 10−7 ± 5.5 × 10−7) 14-fold higher than that of the S. aureus isolates with erm(A). The difference was also observed, although to a lower extent, when erm(C) and erm(A) were cloned into S. aureus RN4220. We conclude that erm(C) and erm(A) have different genetic potentials for selection of clindamycin-resistant mutants. By the disk diffusion method, erm(C) and erm(A) isolates could be distinguished on the basis of high- and low-level resistance to oleandomycin, respectively

Femoral vs jugular venous catheterization and risk of nosocomial events in adults requiring acute renal replacement therapy: a randomized controlled trial.

CONTEXT: Based on concerns about the risk of infection, the jugular site is often preferred over the femoral site for short-term dialysis vascular access. OBJECTIVE: To determine whether jugular catheterization decreases the risk of nosocomial complications compared with femoral catheterization. DESIGN, SETTING, AND PATIENTS: A concealed, randomized, multicenter, evaluator-blinded, parallel-group trial (the Cathedia Study) of 750 patients from a network of 9 tertiary care university medical centers and 3 general hospitals in France conducted between May 2004 and May 2007. The severely ill, bed-bound adults had a body mass index (BMI) of less than 45 and required a first catheter insertion for renal replacement therapy. INTERVENTION: Patients were randomized to receive jugular or femoral vein catheterization by operators experienced in placement at both sites. MAIN OUTCOME MEASURES: Rates of infectious complications, defined as catheter colonization on removal (primary end point), and catheter-related bloodstream infection. RESULTS: Patient and catheter characteristics, including duration of catheterization, were similar in both groups. More hematomas occurred in the jugular group than in the femoral group (13/366 patients [3.6%] vs 4/370 patients [1.1%], respectively; P = .03). The risk of catheter colonization at removal did not differ significantly between the femoral and jugular groups (incidence of 40.8 vs 35.7 per 1000 catheter-days; hazard ratio [HR], 0.85; 95% confidence interval [CI], 0.62-1.16; P = .31). A prespecified subgroup analysis demonstrated significant qualitative heterogeneity by BMI (P for the interaction term 28.4). The rate of catheter-related bloodstream infection was similar in both groups (2.3 vs 1.5 per 1000 catheter-days, respectively; P = .42). CONCLUSION: Jugular venous catheterization access does not appear to reduce the risk of infection compared with femoral access, except among adults with a high BMI, and may have a higher risk of hematoma. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00277888

Distribution of Achromobacter species in 12 French cystic fibrosis centers in 2020 by a retrospective MALDI-TOF MS spectrum analysis

International audienceAchromobacter spp. are nonfermenting Gram-negative bacilli mainly studied among cystic fibrosis (CF) patients. The identification of the 19 species within the genus is time-consuming (nrdA-sequencing), thus data concerning the distribution of the species are limited to specific studies. Recently, we built a database using MALDI-TOF mass spectrometry (MS) (Bruker) that allows rapid and accurate species identification and detection of the multiresistant epidemic clones: A xylosoxidans ST137 spreading among CF patients in various French and Belgium centers, and A. ruhlandii DES in Denmark. Here, we first assessed whether species identification could be achieved with our database solely by analysis of MS spectra without availability of isolates. Then, we conducted a multicentric study describing the distribution of Achromobacter species and of the clone ST137 among French CF centers. We collected and analyzed with our local database the spectra of Achromobacter isolates from 193 patients (528 samples) from 12 centers during 2020. In total, our approach enabled to conclude for 502/528 samples (95.1%), corresponding to 181 patients. Eleven species were detected, only five being involved in chronic colonization, A. xylosoxidans (86.4%), A. insuavis (9.1%), A. mucicolens (2.3%), A. marplatensis (1.1%) and A. genogroup 3 (1.1%). This study confirmed the high prevalence of A. xylosoxidans in chronic colonizations and the circulation of the clone A. xylosoxidans ST137 in France: four patients in two centers. The present study is the first to report the distribution of Achromobacter species from CF patients samples using retrospective MALDI-TOF/MS data. This easy approach could enable future large-scale epidemiological studies