Increasing resistance to fluoroquinolones in Escherichia coli from urinarytract infections in The Netherlands

In continuous surveillance of routine samples from five Dutch laboratories, we studied resistance to the antibiotics most commonly prescribed for urin ary tract infections (UTI) in The Netherlands, namely norfloxacin, amoxycil lin, trimethoprim and nitrofurantoin, from 1989 to 1998 in >90 000 Escheric hia coli isolates. Resistance to norfloxacin increased from 1.3% in 1989 to 5.8% in 1998. Multiresistance, defined as resistance to norfloxacin and at least two of the other three antibiotics, increased from 0.5% in 1989 to 4 .0% in 1998. Multivariate analysis of the norfloxacin resistance demonstrat ed that this yearly increase (the odds ratio was 1.0 in 1989, 1.6 in 1992, 2.9 in 1995 and 6.1 in 1998) was independent of other determinants of resis tance to norfloxacin, such as age, gender and origin of the isolate. Analys is of strata, classified by year, age and gender, demonstrated an associati on between prescription of fluoroquinolones (defined daily doses per case o f UTI) and resistance to norfloxacin in E. coli (P < 0.001). There was no s ignificant association with the prescription of nitrofuran derivatives (nit rofurantoin) and trimethoprim with or without sulphamethoxazole. The yearly increase of resistance to fluoroquinolones in E. coli from UTI may stem fr om increased prescription of fluoroquinolones for UTI. Resistance of E. col i to these agents is likely to increase further as fluoroquinolone use incr eases in future.