Establishment of a model of penicillin-resistant Streptococcus pneumoniae pneumonia in healthy CBA/J mice.
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. 10(6) cfu of S. pneumoniae, the bacterial counts in the lungs of CBA/J mice increased from 10(5) to 10(7) 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.
Takashima
K
K
Department of Microbiology, Toho University School of Medicine, Tokyo, Japan.
Tateda
K
K
Matsumoto
T
T
Ito
T
T
Iizawa
Y
Y
Nakao
M
M
Yamaguchi
K
K
D000818:Animals; D015169:Colony Count, Microbial; D004195:Disease Models, Animal; D005260:Female; D007121:Immunocompetence; D008168:Lung / Q000382:microbiology / Q000473:pathology; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D008813:Mice, Inbred ICR; D010403:Penicillin Resistance; D018410:Pneumonia, Bacterial / Q000382:microbiology*; D013290:Streptococcal Infections / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000187:drug effects* / Q000254:growth & development