Effects of rokitamycin and other macrolide antibiotics on Mycoplasma pneumoniae in L cells

Fifty strains of Mycoplasma pneumoniae in L cells were tested for susceptibility to macrolide antibiotics. Rokitamycin, a new macrolide antibiotic, was most active against these organisms, with an MIC for 90% of strains of 0.007 microgram/ml. The MICs of erythromycin, josamycin, and kitasamycin for 90% of strains were 0.03, 0.03, and greater than or equal to 0.06 microgram/ml, respectively. Based on these results, rokitamycin is a promising antibiotic for the treatment of mycoplasmal infections, and further clinical investigations are needed.