Comparative in vitro activity of azithromycin, clarithromycin, erythromycin and lomefloxacin against Mycoplasma pneumoniae, Mycoplasma hominis and Ureaplasma urealyticum.

The in vitro activity of three macrolides, azithromycin, clarithromycin and erythromycin and a new fluoroquinolone, lomefloxacin, against pathogenic mycoplasma (16 to 18 strains of Mycoplasma pneumoniae, 41 to 77 strains of Mycoplasma hominis, 65 to 104 strains of Ureaplasma urealyticum) was compared. The three macrolides were highly active against Mycoplasma pneumoniae. Clarithromycin was the most active macrolide against Ureaplasma urealyticum whereas azithromycin was somewhat more active than erythromycin against Mycoplasma hominis. Lomefloxacin was moderately active against all three mycoplasma species.