Comparative in vitro activity of fleroxacin (RO 23-6240) againstUreaplasma urealyticum andMycoplasma hominis

The susceptibility of 67 isolatedUreaplasma urealyticum, 25Mycoplasma hominis and fiveMycoplasma spp. reference strains to fleroxacin, ofloxacin, josamycin and doxycycline was determined by agar dilution. Josamycin had the best activity againstUreaplasma urealyticum, followed in order by doxycycline, ofloxacin and fleroxacin. All the strains were inhibited by josamycin at 0.4 mg/l, while only 38.8 % of the strains were inhibited by doxycycline at this concentration.Mycoplasma hominis strains were more susceptible to doxycycline, ofloxacin and fleroxacin than wereUreaplasma urealyticum strains. Here, doxycycline had the best activity followed by ofloxacin, josamycin and fleroxacin. Notably, threeUreaplasma urealyticum strains and oneMycoplasma hominis strain were not inhibited by 6.4 mg/l doxycycline.