title: Effect of levofloxacin on the viability of intracellular Chlamydia pneumoniae and modulation of proinflammatory cytokine production by human monocytes.
abstract: 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 microg/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-alpha (TNF-alpha), interleukin (IL)-1beta, 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.
authors.affiliation: Stratton Veterans Affairs Medical Center, Albany, NY 12208, USA. aldona.baltch@med.va.gov
authors.forename: Aldona L
authors.initials: AL
authors.lastname: Baltch
authors.forename: Raymond P
authors.initials: RP
authors.lastname: Smith
authors.forename: William J
authors.initials: WJ
authors.lastname: Ritz
authors.forename: Andrea N
authors.initials: AN
authors.lastname: Carpenter
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Bopp
authors.forename: Phyllis B
authors.initials: PB
authors.lastname: Michelsen
authors.forename: Cynthia J
authors.initials: CJ
authors.lastname: Carlyn
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Hibbs
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002460:Cell Line; D016993:Chlamydophila pneumoniae / Q000187:drug effects*; D016207:Cytokines / Q000096:biosynthesis*; D022781:Hepatocytes / Q000382:microbiology; D006801:Humans; D064704:Levofloxacin; D009000:Monocytes / Q000187:drug effects* / Q000276:immunology / Q000382:microbiology; D015242:Ofloxacin / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D016207:Cytokines; D064704:Levofloxacin; D015242:Ofloxacin