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[Study of experimental lung lesions caused by extracellular enzyme of Streptomyces thermohygroscopicus]
Abstract:
Rabbits and rats were infected intratracheally with extracellular enzyme of streptomyces thermohygroscopicus (H9-4) for only one exposure and lesions of lung developed which included mononuclear macrophage infiltration as well as bronchitis and vasculitis. The obvious damages in type I pneumocytes, endothelial cells of capillaries and arterioles in the lung were observed by electron microscopy. Immunofluorecent histochemistry examination revealed exudation of plasma fibronectin which might be important to play certein role during the process of wound repairing in lung. The experiment also confirmed that extracellular enzyme of streptomyces thermohygroscopicus might directly damage the lung tissue, and these experimental data may serve valuable reference for studying the etiology and pathogenesis of farmer's lung diseases.
Insights
Extracellular enzymes from Streptomyces thermohygroscopicus (H9-4) caused lung damage in rabbits and rats, including inflammation and cell injury. This research offers insights into the causes of farmer's lung diseases.
Area of Science:
- Microbiology
- Pathology
- Immunology
Context:
- Farmer's lung disease is a hypersensitivity pneumonitis often linked to microbial exposures.
- Extracellular enzymes produced by microorganisms are implicated in lung tissue damage.
Purpose:
- To investigate the direct pathogenic effects of Streptomyces thermohygroscopicus (H9-4) extracellular enzyme on lung tissue.
- To characterize the histological and ultrastructural changes induced by the enzyme in a rabbit and rat model.
Summary:
- Intratracheal instillation of Streptomyces thermohygroscopicus (H9-4) extracellular enzyme in rabbits and rats led to significant lung lesions, including mononuclear macrophage infiltration, bronchitis, and vasculitis.
- Electron microscopy revealed damage to type I pneumocytes and endothelial cells of lung capillaries and arterioles.
- Immunofluorescent histochemistry demonstrated plasma fibronectin exudation, suggesting a role in lung wound repair.
Impact:
- The study provides direct evidence that Streptomyces thermohygroscopicus extracellular enzyme can directly damage lung tissue.
- These findings contribute valuable data for understanding the etiology and pathogenesis of farmer's lung diseases.
- The results may inform future diagnostic and therapeutic strategies for hypersensitivity pneumonitis.
