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Updated: Aug 8, 2026
A Non-invasive and Technically Non-intensive Method for Induction and Phenotyping of Experimental Bacterial Pneumonia in Mice
Published on: September 28, 2016
Virological and pathomorphological aspects in experimental infections with some triassociated pneumotropic viruses in
1Stefan S. Nicolau Institute of Virology, Bucharest.
Abstract:
Experimental infections were induced in white mice by intranasal administration of parainfluenza virus type 3, 739-2D strain, to which influenza virus A/Beijing, 353/89 (H3N2) strain, and respiratory syncytial virus, Long strain, were associated. The model was organized so as to obtain a triassociated infection, parainfluenza virus type 3 being inoculated the first and the other two viruses, in the following stages-II and III-, alternately. The infections were revealed by the presence of positive immunofluorescence reactions in the pulmonary tissue, of histological, histochemical and histoenzymatic lesions at the level of the respiratory apparatus, as well as of pathomorphological changes in other organs. At the pulmonary parenchyma level the inflammatory lesion had a 100% frequency. The severest pathomorphological picture was the diffuse, lymphohistiocytic and macrophagic bronchopneumonia. The cytoinfiltrate was characterized by a proportionality between lymphocytes and histiocytes and the lower but not insignificant presence of macrophages. The prevalent lesion was the thickening of interparietoalveolar septa, as a consequence of stasis hyperemia, oedema and lymphohistiomacrophagocytic infiltrate, to which dystrophic lesions, especially of biocytes, are often added. Different lesions are present in other organs, such as: in the liver-inflammatory, dystrophico-inflammatory and dystrophic lesions; in the kidney, pancreas, cerebellum and thymus--vascular changes, stasis hyperemia; in the spleen--hyperplasia of megakaryocytes. Generally, the type and severity of lesions vary from one viral-association-induced infection to another.
Insights
This study details a mouse model of tri-associated viral respiratory infection, revealing significant pulmonary inflammation and varied organ damage. The findings highlight how different viral combinations impact disease severity and pathology.
Area of Science:
- Virology
- Pathology
- Immunology
Background:
- Viral respiratory infections pose significant public health challenges.
- Understanding complex viral interactions is crucial for developing effective treatments.
- Previous research has explored single and dual viral infections, but tri-associated infections require further investigation.
Purpose of the Study:
- To establish and characterize a mouse model of tri-associated viral infection.
- To investigate the pathological changes induced by the co-infection of parainfluenza virus type 3, influenza virus A/Beijing (H3N2), and respiratory syncytial virus.
- To analyze the varying severity and type of lesions in different organs based on viral associations.
Main Methods:
- Experimental induction of tri-associated viral infections in white mice via intranasal administration.
- Sequential inoculation of parainfluenza virus type 3, followed by influenza virus A/Beijing (H3N2) and respiratory syncytial virus.
- Assessment of infections through immunofluorescence, histological, histochemical, and histoenzymatic analyses of pulmonary and other organ tissues.
Main Results:
- Pulmonary parenchyma exhibited 100% inflammatory lesion frequency, with diffuse lymphohistiocytic and macrophagic bronchopneumonia as the most severe form.
- Interalveolar septa thickening due to edema and inflammatory infiltrate was a prevalent pulmonary lesion.
- Varied pathological changes, including inflammatory, dystrophic, and vascular lesions, were observed in organs such as the liver, kidney, pancreas, cerebellum, thymus, and spleen.
Conclusions:
- The developed mouse model effectively simulates tri-associated viral respiratory infections.
- Co-infection with multiple respiratory viruses leads to significant pulmonary pathology and systemic organ damage.
- The type and severity of lesions are dependent on the specific viral combination and inoculation sequence.
