In
agar diffusion tests 2603 bacterial strains of species known to cause
urinary tract infections were tested routinely in regard to their sensitivity towards
Terizidon, a derivative of
cycloserine. In order to relate the results which were obtained in terms of the diameter of the inhibiton zone, to the minimal inhibitory concentrations (MIC), 304 of these strains were tested additionally in
agar dilution tests. The MICs of the other strains were estimated from the results of these tests. Since it is known that after the
oral administration of 500 mg
Terizidon the urine contains, on average, more than 128 mug/ml
Terizidon for 12 hours and longer, it may be concluded from the results of this investigation that 75% of the strains of E. coli and Citrobacter, 45% of enterobacter, 40% of Proteus mirabilis and enterococci, 35% of the
indole-positive Proteus strains and 30% of Pseudomonas aeruginosa would have been successfully attacked by
Terizidon in the case or
urinary tract infections. By contrast, Klebsiella must be reagarded as being completely resistant to this
antibiotic. It follows that the administration of
Terizidon is mainly indicated in the treatment of acute
urinary tract infections with E. coli as the predominant causative agent.