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Airsacculitis in turkeys exposed to Mycoplasma synoviae membranes
1USDA, National Animal Disease Center, Ames, Iowa 50010.
Abstract:
In studies to investigate the pathogenesis of mycoplasmal airsacculitis, exudative lesions were produced in turkeys by intra-air-sac inoculation with Mycoplasma synoviae cell membranes and viable organisms. Membrane inocula containing 5 mg of protein produced more severe lesions than inocula containing either 2.5 mg or 1 mg protein. Turkeys exposed to 5 mg of membrane protein developed moderately severe airsacculitis; those exposed to viable organisms developed markedly severe airsacculitis. Microscopic examinations revealed that membrane-induced lesions were generally similar to those resulting from infection but were less severe. At the termination of the study, 8 days after exposure, M. synoviae was isolated from respiratory tract tissues of all turkeys exposed to live organisms, but it was not isolated from any of those exposed to membranes or from unexposed control turkeys. Antibody against M. synoviae was demonstrated with the tube agglutination test in sera from turkeys exposed to membranes and those exposed to live organisms, but it was not demonstrated in sera from unexposed control turkeys.
Insights
Mycoplasma synoviae cell membranes induced airsacculitis in turkeys, with higher protein doses causing more severe lesions. While membranes caused disease, live organisms led to more severe airsacculitis and systemic infection.
Area of Science:
- Veterinary Pathology
- Avian Diseases
- Microbiology
Background:
- Mycoplasmal airsacculitis is a significant concern in poultry production.
- Understanding the pathogenesis of Mycoplasma synoviae is crucial for disease control.
Purpose of the Study:
- To investigate the role of Mycoplasma synoviae cell membranes in inducing airsacculitis.
- To compare the pathogenicity of cell membranes versus viable organisms.
Main Methods:
- Intra-air-sac inoculation of turkeys with Mycoplasma synoviae cell membranes or viable organisms.
- Dose-response evaluation using varying protein concentrations of membrane inocula.
- Macroscopic and microscopic examination of lesions.
- Bacteriological isolation of M. synoviae.
- Serological testing (tube agglutination) for antibodies.
Main Results:
- Cell membrane inocula induced exudative airsacculitis, with severity correlated to protein dose (5 mg > 2.5 mg > 1 mg).
- Viable organisms caused more severe airsacculitis than membrane inocula.
- Microscopic lesions from membranes resembled infection but were less severe.
- M. synoviae was isolated from respiratory tissues only in turkeys exposed to viable organisms.
- Antibodies against M. synoviae were detected in turkeys exposed to both membranes and viable organisms.
Conclusions:
- Mycoplasma synoviae cell membranes possess pathogenic potential, capable of inducing airsacculitis and an antibody response.
- Viable M. synoviae organisms are more virulent, leading to more severe disease and systemic infection.
- These findings contribute to understanding the pathogenesis of mycoplasmal airsacculitis.