Sensibilité aux antibiotiques de souches d' Escherichia coli isolées en 1998 et 1999: résultats d'une enquête multicentrique française
Seven hospital lab departments were enrolled in this study in order to update and analyse data on E. coli susceptibility to antibiotics in 1998 and 1999.
Material and methods
1,114 strains were randomly selected for analysis, a large number of which had been obtained from female (65,7%) and elderly patients, and essentially from urinary samples (56%) and blood cultures (23%).
It was observed that resistance rates (R+I) were elevated for amoxicillin (44%), ticarcillin (42%), co-amoxiclav (31%) and cephalothin (36%), moderate for nalidixic acid (8%), ciprofloxacin (5%) and gentamicin (2%), and very low for ceftazidime (1%) and ceftriaxone (0.8%); 2 strains only (0.2%) were ESBL producers. Finally, it was noteworthy that pediatry units were providers of strains significantly more resistant to amoxicillin, co-amoxiclav, ticarcillin and cephalothin than strains from other units; no other risk-factor of resistance was detected. While the previous 1114 randomised strains presented MIC50 and 90 of 0.125 and 0.25 μg/mL for ceftazidime and 0,03 and 0,06 μg/mL for ceftriaxone, a complementary analysis carried out on a pool of 76 ESBL producers and 137 strains resistant (R+I) to ceftazidime and/or to cefotaxime/cetriaxone (but ESBL−) revealed that these value were increased of 7 to 9 dilutions for the 76 ESBL+ strains and of 5 to 6 for the 137 ESBL− strains in comparison with susceptible strains. Moreover these strains were observed to present elevated rates of co-resistance (R+I) to nalidixic acid, ciprofloxacin and gentamicin: 52%, 37% and 41% respectively for ESBL+ strains and 43%, 21% and 16% respectively for ESBL− strains.
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ABSTRACT: The authors had for aim to assess, the incidence of symptomatic bacteriuria and the level of antibiotic resistance in bacteria identified in long-term care facilities (LTC). Symptomatic bacteriuria cases were prospectively collected, during 9 months in the two LTC of the Strasbourg French Teaching Hospital (196 beds). One hundred and eleven bacteriuria cases were included. They concerned 67 of the 274 residents (cumulative incidence: 2.07/1,000 patients-day). A gram-negative bacillus was identified in 85% of the symptomatic bacteriuria cases, and Escherichia coli in 40%. Sixty percent of the identified bacterial strain was resistant to amoxicillin (Amx-R) and 42% to the clavulanic acid combination (AmC-R). Third generation cephalosporins (3GC) were effective in 90% of Urinary tract infections (UTIs) and fluoroquinolones in 65% (Fq). Four bacterias with broad beta-lactamase spectrum were identified (0.04%) including 3 Enterobacter aerogenes. No yeast infection was diagnosed. E. coli strains were 65% Amx-R and 50% AmC-R. Concerning the Fq-R strains (15%), 50% were cotrimoxazole resistant (Stx-R) and 70% Amx-R; 3GC remained effective (82%). In LTC, multi-drug resistance bacteria are rare and 3GCs seem to be the best first line treatment. Nevertheless, Fq-R is increasing (15 vs 8%), and attention must be paid to the antibiotic therapy used.MÃ©decine et Maladies Infectieuses 06/2006; 36(5):280-4. · 0.75 Impact Factor
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ABSTRACT: Objective The authors had for aim to evaluate the frequency of isolation and the antibiotic susceptibility of bacteria responsible for urinary infections among in and out-patients.Medecine Et Maladies Infectieuses - MED MAL INFEC. 01/2008; 38(6):324-327.
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ABSTRACT: Objectives The increasing implication of resistant Escherichia coli in severe infections required updating of bactericidal power of β-lactams used alone or in antibiotic combinations. Methods Four clinical E. coli isolates have been selected, having different resistance mechanisms to β-lactams. Bactericidal effect of amoxicillin, piperacillin and ticarcillin have been tested by means of bactericidal kinetics, with concentrations 2 × MIC and combinations with β-lactamase inhibitors and gentamicin (at its MICs 1 or 2 mg/L). A pharmacodynamic approach used in vitro for bactericidal kinetics residual antibiotic concentrations as established previously for piperacillin, ticarcillin and their inhibitors in patients’ serum collected during treatments including these antibiotics. Results In all bactericidal tests, the addition of gentamicin to penicillins (amoxicillin, piperacillin, ticarcillin) enforced bactericidal power of penicillins. Bactericidal effects of piperacillin and ticarcillin varied when tested with or without β-lactamase inhibitors against a penicillinase producer. Against a high-level cephalosporinase producer, high amoxicillin concentration (256 mg/L) resulted in a short bactericidal effect only in the presence of gentamicin. In contrast, piperacillin presented a persistent bactericidal activity in the presence of tazobactam and gentamicin 2 mg/L, but regrowth occurred with gentamicin 1 mg/L. Ticarcillin showed the most rapid and persistent (> 24 h) bactericidal effect when associated with clavulanic acid and gentamicin 2 mg/L. The tests carried out in simulation of in vivo conditions provided similar bactericidal effects as in vitro. Synergistic effects of combination of a β-lactam plus gentamicin is confirmed all along the study.Antibiotiques 01/2008; 10(1):50-58.