%0 Journal Article %A Takashima, K. %A Tateda, K. %A Matsumoto, T. %A Ito, T. %A Iizawa, Y. %A Nakao, M. %A Yamaguchi, K. %T Establishment of a model of penicillin-resistant Streptococcus pneumoniae pneumonia in healthy CBA/J mice %D 1996 %J Journal of Medical Microbiology, %V 45 %N 5 %P 319-322 %@ 1473-5644 %R https://doi.org/10.1099/00222615-45-5-319 %I Microbiology Society, %X Examination of strain differences in the susceptibility of mice to experimental respiratory tract infection with penicillin-resistant Streptococcus pneumoniae TUM19 revealed that a fatal infection model could be induced in immunocompetent CBA/J mice, but not in C3H/HeN, C57BL/6 or ICR mice. After intranasal instillation of c. 106 cfu of S. pneumoniae, the bacterial counts in the lungs of CBA/J mice increased from 105 to 107 cfu after 3-5 days, and gradually increased thereafter. The challenge organisms localised mainly in the lungs until 14 days after infection. Mice began to die c. 7 days after infection, and by 3 weeks most of the mice had died. Histopathologically, infiltration of neutrophils and lymphocytes around bronchi was observed from 1 day after infection, and fibrin deposition was seen in alveolar and bronchial spaces from 5 days. This model may be useful for investigating therapy of respiratory tract infection caused by penicillin-resistant S. pneumoniae because its pathological features resemble those observed in the human disease. %U https://www.microbiologyresearch.org/content/journal/jmm/10.1099/00222615-45-5-319