Treatment of acute Chlamydia pneumoniae infection with telithromycin in C57BL/6J mice

Objectives: The efficacy of telithromycin, a new ketolide antibiotic, was investigated in the treatment of acute Chlamydia pneumoniae infection in a mouse model. Methods: C57BL/6J mice were inoculated intranasally, and the effects of three different doses of telithro-mycin (25, 50 and 100 mg/kg) were assessed after 5 and 10 days of treatment. Lungs for culture, PCR, histo-pathology, and blood for serum samples were collected immediately after each treatment period and at 3 weeks post-inoculation. C. pneumoniae-specific antibodies were analysed, and the effect of treatment was assessed by culture, detection of C. pneumoniae DNA and determination of histopathological inflammatory changes in mouse lungs. Results: Culture negativity in the lungs was achieved with the higher doses, 50 and 100 mg/kg, after 10 days of treatment. C. pneumoniae DNA was not totally eradicated with the treatments, but the groups treated with 50 and 100 mg/kg doses for 10 days had the lowest DNA positivity rates (10%) 3 weeks after the inoculation. In lung histopathology, the efficacy of telithromycin on inflammatory changes was also dose-dependent