Objectives: The empirical treatment with trimethoprim or ciprofloxacin of urinary tract infections (UTIs) is now questioned, partly due to the global expansion of a few resistant clonal groups of Escherichia coli.
Methods: In this study we investigated the clonal structure of 34 strains of E. coli (collected from non-pregnant women aged 18-65 years with uncomplicated UTIs in Europe and Canada) resistant to either of two other common treatment alternatives for uncomplicated UTIs, mecillinam or nitrofurantoin, using multilocus sequence typing (MLST).
Result: The 34 isolates were, despite high levels of multiresistance, distributed all over the E. coli genetic diversity spectrum with little association of antibiotic resistance to specific clonal groups.
Conclusions: The results of this study indicate a low probability of a future clonal spread of resistance to mecillinam and nitrofurantoin.
Keywords: antimicrobial resistance; successful clones; uncomplicated urinary tract infections.