The effect of oil-emulsion vaccines on the occurrence of nonspecific plate agglutination reactions for Mycoplasma gallisepticum and M. synoviae.

Six groups of ten 18-week-old mycoplasma-free white leghorn pullets were vaccinated with one of the following: Mycoplasma gallisepticum (MG) bacterin. Haemophilus gallinarum bacterin, Pasteurella multocida bacterin, combined infectious bursal disease (IBD)-Newcastle (NDV) chicken-embryo-origin (CEO) vaccine. IBD-NDV tissue-culture-origin (TC) vaccine, or saline emulsified in oil; one group received no vaccine. Plate agglutination tests for M. synoviae (MS) and MG were done for 10 weeks after vaccination using three different test antigens. Pullets vaccinated with H. gallinarum bacterin and IBD-NDV TC vaccine showed the greatest incidence of nonspecific plate agglutination reactions. The incidence of positive plate agglutination reactions varied with test antigens. Five groups of fifty 18-week-old mycoplasma-free heavy-breed pullets were vaccinated with one of the following: saline emulsified in oil, chicken embryo fibroblasts emulsified in oil, allantoic fluid emulsified in oil, chicken embryos emulsified in oil, or MS-contaminated chicken embryos emulsified in oil. Plate agglutination tests for MS and MG were done for 8 weeks after vaccination. Chickens vaccinated with chicken embryo fibroblasts emulsified in oil had the greatest incidence of nonspecific plate agglutination reactions. Pullets vaccinated with MS-contaminated chicken embryo vaccine had only a small increase in MS-positive plate agglutination reactions compared with pullets vaccinated with uncontaminated chicken embryo vaccine.