ABSTRACT
<p><b>OBJECTIVE</b>To evaluate mice as experimental animals for Chlamydia pneumoniae (C. pneumoniae) infection and investigate the pathogenesis of C. pneumoniae derived pneumonitis.</p><p><b>METHODS</b>Icr mice were inoculated with the C. pneumoniae strain, CWL-029, either intranasally or intravenously. After a single dose inoculation, mice were killed on the 1st, 3rd, 7th, 14th, 21st, 28th and 60th days. The pathological changes in lung tissue were analyzed.</p><p><b>RESULTS</b>The Icr mice were shown to be susceptible to C. pneumoniae. Inoculation into mice with C. pneumoniae induced a prolonged course of lung infection, as demonstrated by persistence of lung pathology (up to 60 days). Via intranasal inoculation of mice, lung pathology was characterized by patchy interstitial pneumonitis with predominantly neutrophil leukocyte infiltration early (within the first 7 days) and lymphocyte infiltration in the later stages (14 days later) of infection. After intravenous inoculation, a similarly developed interstitial pneumonitis was observed, but it was milder and patchier, especially in early stages. C. pneumoniae DNA was detected by polymerase chain reaction (PCR) intermittently in the lung tissue. Inoculated mice developed serum IgG antibody responses.</p><p><b>CONCLUSION</b>The Icr mice were susceptible to C. pneumoniae, resulting in a pulmonary infection characterized by interstitial pneumonitis, occurring most strongly via intranasal inoculation.</p>
Subject(s)
Animals , Male , Mice , Chlamydia Infections , Pathology , Chlamydophila pneumoniae , DNA, Bacterial , Lung , Pathology , Mice, Inbred ICR , Pneumonia, Bacterial , Pathology , Polymerase Chain ReactionABSTRACT
Objective To investigate the histopathology of liver,spleen and heart in mice model with Chlamydia pneumoniae ( C pneumoniae ) pneumonia Methods The Icr mice were inoculated with C pneumoniae ,strain CWL 029,by the intranasal or intravenous routes After a single inoculation,mice were killed on the 1st,3rd,7th,14th,21st,28th and 60th day separately Specimens of spleen,liver and heart were obtained from the acute stage of C pneumoniae pneumonitis and stained with hematoxylin eosin Results After inoculation of C pneumoniae ,there were infiltration of neutrophils and macrophages in the spleen and necrosis of hepatocytes The histopathology of iv inoculation group was more serious than that of intranasal inoculation group No pathology changes were observed in heart Conclusions After iv inoculation of C pneumoniae ,the histopathologic changes appeared in the tissue of liver and spleen correspondingly,and the changes were more serious than that of iv inoculation group This study demonstrated that C pneumoniae was mainly limited to lungs and dissemination of C pneumoniae was seldom
ABSTRACT
Objectives: To evaluate mice as experimental animal for Chlamydia pneumoniae, a common cause of acute respiratory infections in human. Methods: Intranasal inoculation of Icr mice with C. Pneumoniae induced a prolonged course of lung infection, as demonstrated by persistence of lung pathology(60 days). Results: Icr mice were susceptible to C. pneumoniae. Lung pathology was characterized by patchy interstitial pneumonitis with predominately neutrophil leukocyte infiltration in the early(7 days) and lymphocytes infiltration in the later stages(14 days later) of infection. Conclusions:Icr mice were susceptible to C. pneumoniae and the mouse model is useful for the investigation of the pathogenesis of C. pneumoniae infection.