Immunokinetics in Severe Pneumonia Reveals Bacterial-Influenza Coinfection Mechanisms

According to recent research from Japan, coinfections of bacteria and influenza are a major cause of excessive mortality during influenza epidemics. In a study published in the European Respiratory Journal, scientists found that mice infected with influenza virus and then with Streptococcus pneumoniae developed severe bronchopneumonia with massive hemorrhage, leading to death within 2 days. The researchers also identified immune mediators, including cytokines and chemokines, as playing a crucial role in the pathology of coinfection.

Key Takeaways:

Coinfections of bacteria and influenza virus are a major cause of excessive mortality during influenza epidemics.
Mice inoculated with influenza virus followed by Streptococcus pneumoniae developed severe bronchopneumonia with massive hemorrhage, leading to death within 2 days.
Short-term survival correlated with pathological changes in the lungs of infected mice.
Intrapulmonary levels of inflammatory cytokines/chemokines, type-1 T-helper cell cytokines, and Toll-like receptors were increased in coinfected mice.
Immune mediators, including cytokines and chemokines, through Toll-like receptors/mitogen-activated protein kinase pathways, play important roles in the pathology of coinfection.
The study suggests that understanding the synergy between influenza virus and bacteria is crucial for developing effective treatments.
The research was conducted by M. Seki and colleagues from Nagasaki University, School of Medicine.

Statistics:

2 days: The time it took for mice to develop severe bronchopneumonia and die after inoculation with Streptococcus pneumoniae.
24(1):143-149: The volume and page numbers of the European Respiratory Journal issue where the study was published.
2 days: The time period during which pathological changes in the lungs and massive hemorrhage occurred in coinfected mice.

Sources:

Seki, M. et al. (2004). Immunokinetics in severe pneumonia due to influenza virus and bacteria coinfection in mice. Eur Resp J, 24(1), 143-149.
European Respiratory Society Journals Ltd. (Publisher)