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United States Department of Agriculture

Agricultural Research Service

Research Project: COUNTERMEASURES TO PREVENT AND CONTROL AVIAN MYCOPLASMOSIS

Location: Poultry Research

Title: Effect of Dosage and Vaccination Route on Transmission of a Live Attenuated Mycoplasma gallesepticum Vaccine: A Broiler Model

Authors
item Evans, Jeff
item Branton, Scott
item Leigh, Spencer

Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 28, 2009
Publication Date: September 1, 2009
Citation: Evans, J.D., Branton, S.L. 2009. Effect of Dosage and Vaccination Route on Transmission of a Live Attenuated Mycoplasma gallesepticum Vaccine. Avian Diseases. 53(3):416-420.

Interpretive Summary: Mycoplasma gallisepticum (MG) is a major respiratory pathogen to poultry species (chickens and turkeys) worldwide. In the United States alone, economic losses associated with MG infections are significant and have exceeded $150 million annually. Current strategies to control against MG infections include the use of three attenuated strains of MG which are approved for use as vaccines in the commercial table egg layer industry. While the vaccines can reduce the impact of MG infections within this sector of the industry, use of the vaccines may be problematic to broiler- and turkey-related industries due to associated virulence. Therefore, understanding the transmissibility of the live MG vaccines is of particular importance. In the current study, a broiler model addresses the effect of vaccine application route and dosage on the transmission of the MG vaccine. Vaccine was applied via eye-drop or spray and dosage varied from that recommended by the manufacturer (1X) or dilutions thereof (10-3X or 10-6X). Following vaccination, vaccinated subjects were commingled with unvaccinated susceptible subjects for 7 wks. Transmission of the vaccine to the commingled birds was determined via serology and DNA-based detection of the vaccine. Results indicated that transmission of the vaccine only corresponded with the 1X treatment applied via eye-drop. In conclusion, the results of the current study demonstrate that the dosage and vaccination route have direct implications on subsequent transmission of the MG vaccine.

Technical Abstract: Mycoplasma gallisepticum (MG) is an economically significant pathogen of poultry species and among the table egg sector of the poultry industry, live attenuated strains of MG are commonly utilized to limit production losses associated with MG-induced disease. The vaccine, however, may be problematic to broiler- and turkey-related industries due to associated virulence and therefore, understanding the transmissibility of the live MG vaccines is of particular importance. In the current study, a broiler model addresses the effect of vaccine application route and dosage on the transmission of the MG vaccine, FVAX-MG® to commingled unvaccinated subjects for 7 wks post-vaccination. Vaccinations occurred via eye-drop or spray application at 1X (4x106 cfu), 10-3X (4x103 cfu), and or 10-6X (4 cfu) of the manufacturer’s recommended dosage and transmission to unvaccinated subjects was measured. Serological response and presence of MG DNA indicate FVAX-MG® transmission only within the 1X FVAX-MG® eye-drop treatment and among no other treatment was transmission of FVAX-MG® detected. The results of the current study demonstrate that the dosage and vaccination route have direct implications on subsequent transmission of FVAX-MG®.

Last Modified: 4/24/2014
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