RESUMO
The objective of this study was to assess the in vitro activity of levofloxacin compared to other antibiotics against Escherichia coli strains isolated from female patients with acute pyelonephritis in 23 French hospitals in 2005. Minimal inhibitory concentrations (MICs) were determined in a central laboratory, by agar dilution method in compliance with the recommendations of the Comité de l'antibiogramme de la Société française de Microbiologie (CA-SFM). The percentages of susceptible strains were calculated according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints approved by the CA-SFM (2005) for ciprofloxacin, levofloxacin, and ofloxacin and according to the CA-SFM breakpoints for the other antibiotics. Amongst the 231 strains collected, 46.3% of strains were isolated from urinary samples, 10.8% from blood culture, and 42.9% from both. Concerning fluoroquinolones, the percentages of susceptibility were 93.1%, 90.5%, and 92.7% for levofloxacin, ofloxacin, and ciprofloxacin, respectively. For the other antibiotics, a higher percentage of susceptibility was observed with ceftriaxone (99.6%) and amikacin (94.8%), whereas a lower percentage of susceptibility was observed with amoxiclav (68.8%), and cotrimoxazole (65.4%). Levofloxacin exhibited a good in vitro activity against E. coli strains isolated from acute pyelonephritis with 93.1% of susceptible strains.