EXPERIMENTAL RABBIT MODELS OF CHLAMYDIA-PNEUMONIAE INFECTION

Chlamydia pneumoniae (TWAR), a common cause of acute respiratory disea se in humans, has recently been associated with coronary and aortic at herosclerosis. In this study, we evaluated rabbit models of chlamydial infection to investigate the pathogenesis of C. pneumoniae infection. New Zealand White rabbits were inoculated intranasally and intratrach eally with C. pneumoniae, strain AR-39, and primary and repeated infec tion were assessed. After a single inoculation, lung pathology was cha racterized by a moderate self-resolving interstitial pneumonia with br onchiolitis of 21 days in duration. Chlamydial DNA was detected by pol ymerase chain reaction (PCR) intermittently in the upper respiratory t ract and lung tissue at day 14, and peripheral blood mononuclear cells at days 3 and 21. After repeated inoculations, chlamydial DNA was det ected by PCR in the upper respiratory tract and lung tissue through da y 42. Lung lesions consisted of multifocal interstitial mononuclear ce ll aggregates that persisted up to day 42. Watanabe heritable hyperlip idemic rabbits were less susceptible to C. pneumoniae infection. After multiple inoculations of Watanabe rabbits, C. pneumoniae was detected by PCR and/or immunocytochemistry until day 21. In conclusion, C. pne umoniae induced a moderate respiratory infection in these rabbit model s.