Mycoplasma gallisepticum in a commercial laryngotracheitis vaccine.

Abstract

The vertical transmission of Mycoplasma gallisepticum has been well documented. The possibility egg-propagated vaccines could become contaminated with this organism has been recognized for some time (6). The finding by Conrad (2) in 1958, a portion of the avian Mycoplasma population in egg yolk survives lyophilization tended to substantiate the possibility of vaccine contamination. In 1962 and again in 1965, study groups (8,9) on avian Mycoplasma infections recommended that all eggs used in the production of poultry biologics . . . be obtained from flocks free of M. gallisepticum. While bacterial contamination of poultry vaccines has been demonstrated (3,12), Oshel and Gourlay (7) did not detect antibodies against Mycoplasma gallisepticum using 55 serial lots of Newcastle disease, infectious bronchitis, or combination Newcastlebronchitis vaccines inoculated into the posterior thoracic air sac of two-week-old chicks.