Protective effects of sparfloxacin in experimental pneumonia caused by Chlamydia pneumoniae in leukopenic mice.
The in vivo antichlamydial activities of sparfloxacin and reference drugs were examined in a experimental model of pneumonia caused by Chlamydia pneumoniae in leukopenic mice; their in vitro activities were also examined. The most potent agents in vitro were sparfloxacin (MICs for C. pneumoniae Kajaani and IOL 207, (0.031 and 0.031 micrograms/ml, respectively), clarithromycin (0.031 and 0.031 micrograms/ml, respectively), and minocycline (0.031 and 0.031 micrograms/ml, respectively); these were followed by tosufloxacin (0.063 and 0.125 micrograms/ml, respectively) and ofloxacin (0.5 and 0.5 micrograms/ml, respectively). The MBCs of sparfloxacin, tosufloxacin, ofloxacin, clarithromycin, and minocycline for these two strains were 0.063 and 0.063 micrograms/ml, 0.125 and 0.25 micrograms/ml, 1.0 and 1.0 micrograms/ml, 0.125 and 0.125 micrograms/ml, and 0.25 and 0.25 micrograms/ml, respectively. Fatal pneumonia was induced by intranasal inoculation of cyclophosphamide-treated leukopenic mice with C. pneumoniae IOL 207; infiltration of neutrophils and lymphocytes was observed in the lungs of these mice by histopathological examination. The 50% effective dose of sparfloxacin (oral dose of 0.97 mg/kg of body weight) against the pneumonia was the lowest among the drugs tested; this was followed by those of minocycline (2.22 mg/kg), tosufloxacin (3.47 mg/kg), clarithromycin (4.66 mg/kg), and ofloxacin (16.6 mg/kg). The results indicate that it may be worthwhile to use sparfloxacin against C. pneumoniae infections in humans.
Nakata
K
K
Bioscience Research Laboratories, Dainippon Pharmaceutical Co., Ltd., Osaka, Japan.
Okazaki
Y
Y
Hattori
H
H
Nakamura
S
S
D000818:Animals; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D002690:Chlamydia Infections / Q000517:prevention & control*; D016993:Chlamydophila pneumoniae / Q000187:drug effects; D005260:Female; D024841:Fluoroquinolones; D007970:Leukopenia / Q000150:complications*; D008168:Lung / Q000473:pathology; D051379:Mice; D008813:Mice, Inbred ICR; D008826:Microbial Sensitivity Tests; D018410:Pneumonia, Bacterial / Q000517:prevention & control*; D015363:Quinolones / Q000494:pharmacology / Q000627:therapeutic use*
D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D015363:Quinolones; C061363:sparfloxacin