In-vitro activity of grepafloxacin, a new fluoroquinolone, against mycoplasmas.

The in-vitro activity of grepafloxacin, a new oral fluoroquinolone antibiotic, was compared with those of three other fluoroquinolones and two unrelated antimicrobials, doxycycline and erythromycin, against various Mycoplasma spp. For 65 mycoplasma and 42 ureaplasma strains, grepafloxacin (MIC range 0.03-2 mg/L) was some two to 16 times more active than ofloxacin and ciprofloxacin, showing similar activity to that of sparfloxacin. MBCs of grepafloxacin increased two- to 16-fold when compared with MICs and were comparable to those of sparfloxacin, and lower than those of ofloxacin and ciprofloxacin.