Related Experiment Videos
Histopathological changes in the lungs of influenza-infected mice superinfected with Staphylococcus aureus
Abstract:
Histopathological changes in the lung were assessed in a model infection of mice using swine influenza virus and Staphylococcus aureus. Virus preinfection markedly enhanced both the persistence of S. aureus and the extent and duration of the inflammatory response. Lymphocytic infiltration was increased and regeneration and squamous metaplasia were delayed, suggesting an enhancement of an immunopathological response to the virus. Mice with the dual infection showed a decrease in phagocytic cell infiltration of the lung compared to that observed in those with the bacterial infection only, and this may reflect a decline in alveolar macrophage function after influenza infection.
Insights
Swine influenza virus preinfection significantly worsened Staphylococcus aureus lung infections in mice. This dual infection model revealed enhanced inflammation and delayed lung tissue repair, indicating a heightened immunopathological response.
Area of Science:
- Veterinary Pathology
- Immunology
- Microbiology
Background:
- Bacterial coinfections can complicate viral respiratory illnesses.
- Staphylococcus aureus is an opportunistic pathogen that can cause secondary lung infections.
- Swine influenza virus (SIV) is a significant respiratory pathogen in swine and can infect humans.
Purpose of the Study:
- To investigate the histopathological changes in the lungs of mice coinfected with SIV and S. aureus.
- To assess the impact of SIV preinfection on the severity and duration of S. aureus lung infection.
- To evaluate the immunopathological responses and cellular infiltration in a dual infection model.
Main Methods:
- A mouse model was used to establish coinfections with SIV and S. aureus.
- Histopathological examination of lung tissues was performed to assess inflammatory responses and tissue damage.
- Quantitative analysis of cellular infiltration, including phagocytic cells, was conducted.
Main Results:
- SIV preinfection markedly enhanced the persistence of S. aureus in the lungs.
- Dual infection led to an increased extent and duration of the inflammatory response compared to bacterial infection alone.
- Lymphocytic infiltration was increased, while tissue regeneration and squamous metaplasia were delayed in dual-infected mice.
- Phagocytic cell infiltration in the lungs was decreased in dual-infected mice, suggesting impaired alveolar macrophage function.
Conclusions:
- SIV preinfection exacerbates S. aureus lung infections by enhancing immunopathology and delaying tissue repair.
- Impaired alveolar macrophage function may contribute to the increased susceptibility to S. aureus following influenza infection.
- This study highlights the complex interplay between viral and bacterial pathogens in the respiratory tract.