[Development of specific technics for the prevention of mycoplasma infections in swine]

Four experimental series were run in 2 experiments with 44 unweaned piglets to test non-inactivated vaccine from ts-mutant M-60 of Mycoplasma (M.) arginini and from attenuated strains of CH-2 M. hyorhinis, EP-29 M. hyosynoviae, M. suipneumoniae, and B-1 Acholeplasma laidlawii. Similar deviations of clinical and immunological parameters were recorded from piglets inoculated with the above vaccine and infected with pathogenic mycoplasma cultures. These deviations, however, were less strongly pronounced in animals which had been inoculated. Mycoplasma species were re-isolated from bronchial lymph nodes and lungs of 62.5% of inoculated piglets. Lasting residual virulence was recorded from the attenuated mycoplasma strains. That residual virulence had no substantial impact upon growth and development of the piglets under laboratory conditions, throughout the period of observation. The above results are likely to suggest the advisability of further studies for the development of a vaccine from ts-mutants and attenuated strains of pathogens of mycoplasmosis in swine.