Submitted to: Avian Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/9/2012
Publication Date: 9/15/2012
Citation: Leigh, S.A., Branton, S.L., Evans, J.D., Collier, S.D. 2012. Effect of infection route and concurrent infectious bronchitis virus vaccination on Mycoplasma gallisepticum disease pathology in an experimental model. Avian Pathology. 41(5):497-503.
Interpretive Summary: Mycoplasma gallisepticum causes chronic respiratory disease in chickens and infectious sinusitis in turkeys. In order to facilitate study of the disease process, a simple, rapid, consistent infection model is needed. Two routes of infection for M. gallisepticum along with the presence or absence of infectious bronchitis virus vaccine were tested. The results demonstrated that simple intratracheal infection caused consistent disease, and vaccination against M. gallisepticum prevented disease symptoms in subsequently infected chickens. This model system will enable large scale studies of M. gallisepticum-caused disease and further research toward understanding current vaccines and developing improved vaccines.
Technical Abstract: The study of Mycoplasma gallisepticum infections is needed, not only to understand the disease process, but also to understand the mechanisms by which M. gallisepticum vaccines protect the host. Many model systems have been used to study the M. gallisepticum disease process. This work compared two different routes of infection, looking for differences in the pathology and the humoral immune response of the host. The impact of concurrent infectious bronchitis virus (IBV) vaccination on disease outcomes was also determined. Results showed that intratracheal infection provided consistent pathology (airsacculitis, tracheal lesion score, and tracheal thickness) at one week post infection, whereas ocular infection produced negligible pathology. IBV vaccination had a negligible outcome on disease pathology, except that it resulted in an apparent decrease in the severity of airsacculitis. Vaccination with an F-strain derivative of M. gallisepticum provided complete protection against airsacculitis.