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Updated: Jun 19, 2026
Characterization of Inflammatory Responses During Intranasal Colonization with Streptococcus pneumoniae
Published on: January 17, 2014
PATHOLOGY OF PNEUMOCOCCUS INFECTION IN MICE FOLLOWING INTRANASAL INSTILLATION
1Laboratories of The Rockefeller Institute for Medical Research.
Abstract:
Pneumonia can be produced in mice, which have not been previously prepared, by intranasal inoculation of broth cultures of certain strains of pneumococci. Lesions which are quantitatively different can be produced in different breeds of mice by inoculation of the same type of pneumococcus. Similar inoculation of different types of pneumococci into one breed of mice results in lesions which are qualitatively different. In general, these lesions are as follows: a diffuse pneumonia and an acute glomerular nephritis in unselected mice receiving Type I strains; a confluent pneumonia and a tubular nephritis in the case of Type II strains; and as result of Type III strains, an interstitial pneumonia with extensive gelatinous pleurisy, together with necrosis and abscess formation in the spleen and cervical lymph nodes. Resistant strains of mice with Type III pneumococci show slight changes in the lungs, but marked lesions in the spleen and cervical nodes, while susceptible mice with the same type of pneumococcus show marked changes in the lung and moderate lesions in the spleen and cervical nodes. The method of development of Type III pneumonia, studied by means of serial sections of nasally infected mice, appears to proceed in the stages of vascular engorgement, interalveolar interstitial exudate, albuminous fluid exudate into the alveoli and the perivascular lymphatics draining the affected site, and finally, a frank pneumonia with a cellular exudate in the alveoli but without much fibrin.
Insights
Pneumonia research in mice shows that different pneumococcus strains and mouse breeds cause distinct lung and kidney lesions. Type III pneumococci induce pneumonia, pleurisy, and organ damage, varying with mouse susceptibility.
Area of Science:
- Microbiology
- Pathology
- Immunology
Background:
- Pneumonia is a significant respiratory infection.
- Understanding pathogen-host interactions is crucial for disease management.
- Streptococcus pneumoniae strains exhibit varying virulence.
Purpose of the Study:
- To investigate the pathological effects of different pneumococcus strains in mice.
- To determine how mouse breed influences pneumonia development.
- To characterize the lesions caused by specific pneumococcus types.
Main Methods:
- Intranasal inoculation of mice with pneumococcus broth cultures.
- Utilizing different mouse breeds and pneumococcus serotypes (Type I, II, III).
- Histopathological examination of lung, kidney, spleen, and lymph nodes.
Main Results:
- Mouse breed and pneumococcus type significantly altered lesion severity and type.
- Type I strains caused diffuse pneumonia and glomerular nephritis.
- Type II strains led to confluent pneumonia and tubular nephritis.
- Type III strains resulted in interstitial pneumonia, pleurisy, and systemic organ damage (spleen, lymph nodes).
- Susceptibility influenced lesion distribution, with Type III pneumococci affecting lungs more in susceptible mice.
Conclusions:
- Pneumococcus strains and host genetics dictate pneumonia pathology.
- Type III pneumococci exhibit unique pathogenic mechanisms involving systemic spread.
- The study provides a model for dissecting pneumococcal pneumonia pathogenesis.
