Translator Disclaimer
1 September 2004 Safety of Mycoplasma gallisepticum Vaccine Strain 6/85 After Backpassage in Turkeys
Author Affiliations +

The objective of this research was to evaluate the safety of the 6/85 strain vaccine strain of Mycoplasma gallisepticum in turkeys by backpassing the vaccine strain up to 10 times by contact infection in turkeys and challenging turkeys with the resulting backpassaged strain. The vaccine strain, however, did not spread to in-contact turkeys, and it was necessary to reisolate the organism before challenging turkeys for the next passage. The challenge strain, therefore, was one that had been backpassaged four times in turkeys, with a total in vivo time in turkeys of 66 days. The backpassaged 6/85 vaccine strain was no different in pathogenicity than the original vaccine strain, except that at 10 days postchallenge, it was isolated in higher numbers from air sacs. Both the original 6/85 vaccine strain and the backpassaged strain were apathogenic in turkeys, except for a slightly increased diameter of the tracheal mucosa at 10 days postchallenge; at 20 days postchallenge the tracheal mucosal thickness was no different from that of controls.

M. M. Zaki, N. Ferguson, V. Leiting, and S. H. Kleven "Safety of Mycoplasma gallisepticum Vaccine Strain 6/85 After Backpassage in Turkeys," Avian Diseases 48(3), 642-646, (1 September 2004).
Received: 15 March 2004; Accepted: 1 April 2004; Published: 1 September 2004

Get copyright permission
Back to Top