The present invention provides live, attenuated Mycoplasma bacteria that exhibit reduced expression of one or more proteins selected from the group consisting of pyruvate dehydrogenase, phosphopyruvate hydratase, 2-deoxyribose-5-phosphate aldolase, and ribosomal protein L35, relative to a wild-type Mycoplasma bacterium of the same species. Also provided are vaccines and vaccination methods involving the use of the live, attenuated Mycoplasma bacteria, and methods for making live attenuated Mycoplasma bacteria.
