Treatment of acute Chlamydia pneumoniae infection with telithromycin in C57BL/6J mice.
OBJECTIVE
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 telithromycin (25, 50 and 100 mg/kg) were assessed after 5 and 10 days of treatment. Lungs for culture, PCR, histopathology, 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: higher doses were more effective in reducing the inflammatory reaction. Overall, the 25 mg/kg dose had a weaker effect compared with the others.


CONCLUSIONS
Telithromycin had both time- and dose-dependent effects on the eradication of chlamydia and on reducing infection-induced inflammatory changes in mouse lungs.
Törmäkangas
L
L
National Public Health Institute, P.O. Box 310, FIN-90101 Oulu, Finland. liisa.tormakangas@ktl.fi
Saario
E
E
Bem David
D
D
Bryskier
A
A
Leinonen
M
M
Saikku
P
P
D000208:Acute Disease; D000818:Animals; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D000907:Antibodies, Bacterial / Q000032:analysis; D002690:Chlamydia Infections / Q000188:drug therapy* / Q000382:microbiology; D016993:Chlamydophila pneumoniae / Q000187:drug effects / Q000235:genetics; D004269:DNA, Bacterial / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D005260:Female; D007074:Immunoglobulin G / Q000032:analysis; D007249:Inflammation / Q000473:pathology; D048628:Ketolides; D008168:Lung / Q000382:microbiology / Q000473:pathology; D018942:Macrolides / Q000627:therapeutic use*; D051379:Mice; D008810:Mice, Inbred C57BL; D018410:Pneumonia, Bacterial / Q000188:drug therapy* / Q000382:microbiology; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000900:Anti-Bacterial Agents; D000907:Antibodies, Bacterial; D004269:DNA, Bacterial; D007074:Immunoglobulin G; D048628:Ketolides; D018942:Macrolides; C106791:telithromycin