[Evaluation of levofloxacin antitubercular activity in vitro and in lung tissue culture].
Levofloxacin in vitro demonstrated bactericidal effect against susceptible and multi-drug resistant Mycobacterium tuberculosis: range of MICs was 0.25-0.5 mcg/mL, MBC-0.5-1.0 mcg/mL. Postantibiotic effect after 24-hour exposition to bactericidal concentrations was 35-39 days. Levofloxacin possesed low toxicity when tested in mice lungs tissue culture--maximum safety concentration was 50 mcg/mL. Bactericidal effect of levofloxacin started three days after exposition and was maximal by 7 days of incubation: by this time mycobacterial microcolonies destruction started with detritus formation. It is emphasized that lung cells kept their viability completely. Combination of levofloxacin with isoniazide or pirazinamide resulted in strong synergistic effect obvious after 5 days of incubation, mycobacterial colonies destruction was registered by 7th day. Combination of levofloxacin with rifampicin resulted in antagonistic effect obvious by 7th day of the contact: the resulting effect was statistically significant and was manifested as microcolonies number and size enlargement when compared to data for single levofloxacin.
Research Institute of Phtisiopulmonology, I. M. Sechenov Moscow Medical Academy, Moscow.
G B
GB
Sokolova
A D
AD
Kunichan
K V
KV
Litovchenko
A A
AA
Tsybanev
D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000995:Antitubercular Agents / Q000008:administration & dosage / Q000494:pharmacology*; D004359:Drug Therapy, Combination; D007538:Isoniazid / Q000008:administration & dosage / Q000627:therapeutic use; D064704:Levofloxacin; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D015242:Ofloxacin / Q000494:pharmacology*; D011718:Pyrazinamide / Q000008:administration & dosage / Q000627:therapeutic use
D000890:Anti-Infective Agents; D000995:Antitubercular Agents; D011718:Pyrazinamide; D064704:Levofloxacin; D015242:Ofloxacin; D007538:Isoniazid