Effect of levofloxacin on the viability of intracellular Chlamydia pneumoniae and modulation of proinflammatory cytokine production by human monocytes

• Published in: Diagnostic microbiology and infectious disease Vol. 50; no. 3; pp. 205 - 212
• Main Authors: Baltch, Aldona L., Smith, Raymond P., Ritz, William J., Carpenter, Andrea N., Bopp, Lawrence H., Michelsen, Phyllis B., Carlyn, Cynthia J., Hibbs, Jonathan R.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.11.2004; Elsevier
• Subjects: Anti-Bacterial Agents - pharmacology; Bacteriology; Biological and medical sciences; Cell Line; Chlamydophila pneumoniae; Chlamydophila pneumoniae - drug effects; Cytokines - biosynthesis; Fundamental and applied biological sciences. Psychology; Hepatocytes - microbiology; Humans; Infectious diseases; Levofloxacin; Medical sciences; Microbiology; Miscellaneous; Monocytes - drug effects; Monocytes - immunology; Monocytes - microbiology; Ofloxacin - pharmacology; Human; Infection; Levofloxacin; Chlamydia pneumoniae; Chlamydiaceae; Microbiology; Monocyte; Cytokine; Chlamydiales; Bacteria; Intracellular; Antibacterial agent
• ISSN: 0732-8893; 1879-0070
• DOI: 10.1016/j.diagmicrobio.2004.07.009

Although antibiotics are known to affect the intracellular growth of Chlamydia pneumoniae in acute infections, their efficacy in therapy for chronic infections, including atherosclerosis, remains debatable. Human monocyte-derived macrophages (MDM) obtained from monocytes of healthy donors were infected with C. pneumoniae AR-39 and treated with levofloxacin (8 μg/mL) immediately after infection (0 hours) or 24 hours after infection. Levofloxacin treatment at 24 hours, but not at 0 hours, resulted in a significant decrease in the number of C. pneumoniae inclusions within the MDM ( p < 0.05). Also decreased were concentrations of proinflammatory cytokines tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and IL-8 in the extracellular medium ( p < 0.01). Viable counts in titrations remained similar to those in untreated controls. In summary, levofloxacin administered to MDM at serum-attainable levels 24 hours after C. pneumoniae infection significantly decreased inclusion counts and proinflammatory cytokine production, but did not eliminate the C. pneumoniae infection.