Histopathological and Immunohistochemical Findings in the Lungs of Pigs Infected Experimentally with Mycoplasma hyopneumoniae

• Published in: Journal of comparative pathology Vol. 140; no. 4; pp. 260 - 270
• Main Authors: Redondo, E., Masot, A.J., Fernández, A., Gázquez, A.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.05.2009
• Subjects: Animals; Bronchi - immunology; Bronchi - microbiology; cytokines; Enzyme-Linked Immunosorbent Assay - veterinary; experimental infection; histopathology; immunohistochemistry; Immunohistochemistry - veterinary; intranasal administration; Lung - immunology; Lung - pathology; lungs; lymphoid markers; Lymphoid Tissue - immunology; Lymphoid Tissue - microbiology; Mycoplasma hyopneumoniae; Mycoplasma hyopneumoniae - immunology; mycoplasmosis; pig; pneumonia; Pneumonia of Swine, Mycoplasmal - immunology; Pneumonia of Swine, Mycoplasmal - microbiology; porcine enzootic pneumonia; Sus scrofa; swine; Swine Diseases - metabolism; Swine Diseases - pathology; Mycoplasma hyopneumoniae; porcine enzootic pneumonia; pig
• ISSN: 0021-9975; 1532-3129
• DOI: 10.1016/j.jcpa.2008.12.008

Pigs were infected intranasally with Mycoplasma hyopneumoniae and killed at intervals ranging from 7 to 35 days post-infection (dpi). Histopathological changes consisted of (1) exudates in airways and alveolar lumina, (2) peribronchial and peribronchiolar lymphoid hyperplasia, and (3) enlargement of alveolar septa. These changes were particularly marked from 7 to 28 dpi, coinciding with significant increases in the expression, detected immunohistochemically, of cytokines (IL-1α, IL-1β, IL-8, TNF-α and INF-γ) and lymphoid markers (CD4+, CD8+, muramidase, IgG+, IgA+). Both the lesions and immunohistochemical signals declined in intensity beyond 35 days.