[In vitro bactericidal effects of ofloxacin on S. aureus]

Two Staphylococcus aureus (S. aureus) strains with differing susceptibility to penicillin G as expressed by the minimum inhibitory concentration were exposed in vitro over a period of 8 h to the continuously changing concentrations of ofloxacin achieved in human serum and cantharides blister fluid (CBF) after the single oral application of 600 mg. In both strains bacterial density was rapidly, but not totally reduced: a reduction by 99 percent took no longer than about 1 and 1.5 h resp. facing the serum level profile and about 1.5 h facing the tissue level profile. The maximum reduction of staphylococcal density in percent (kn) amounted to 0.0007 and 0.0034 and to 0.0038 and 0.0047 resp. Thus not only the serum level profiles but also the skin tissue level profiles obtainable in man proved highly effective in vitro against S. aureus irrespective of the bacterial suspectibility against penicillin G. Therefore oral ofloxacin should prove useful in staphylococcal diseases especially in so far as cutaneous tissue is involved.