Activity of nalidixic acid and fluoroquinolones on Escherichia coli strains isolated from non-complicated urinary infections (reseau TSN - France, 1999 - 2001)

OBJECTIVE: The authors studied the susceptibility of 1,647 non-repeat isolates of Escherichia coli to quinolones and fluoroquinolones. METHOD: The strains were isolated from non-complicated urinary infections in women 18-64 years of age. Data was provided by the TSN Database France, a real time electronic database which collects antibiotic susceptibility results and patient demographic data. The data was collected from 1999 to 2001 in 63 French hospital laboratories, each using their own routine test methods. Quantitative data was interpreted (S, I, R) according to CA-SFM breakpoint guidelines. RESULTS: Ninety-eight and 94,6 % of the strains were susceptible to ciprofloxacin and nalidixic acid respectively. Cross resistance was assessed as well as intrinsic difference in activity within the fluoroquinolone class. Current fluoroquinolones are still highly efficient, and ciprofloxacin is the most active. CONCLUSION: Since 1996, little change in resistance to fluoroquinolones has been observed. These results confirm the choice of fluoroquinolones as first intention therapy as recommended by consensus conferences.