The influence of long-term treatment with mecillinam on fecal Escherichia coli.

The influence of long-term treatment with a low dose of pivmecillinam on the fecal flora was investigated. Before treatment Escherichia coli was detected in about 88% of 30 outpatients with chronic recurrent urinary tract infections, but after 1-2 months only about 55% had detectable E. coli in the intestinal flora. E. coli resistant to mecillinam were not selected during the therapy. A similar group of patients treated with nitrofurantoin showed neither changes in the E. coli flora nor in the resistance pattern.