Scientists at the Japanese National Institute of Animal Health in the city of Tsukuba, Ibaraki, have successfully reduced mycoplasmal pneumonia in swine using a new strain for oral vaccination.
In a pre-publication on PubMed, the scientists, Y. Ogawa, E. Oishi, Y. Muneta, A. Sano, H. Hikono, T. Shibahara, Y. Yagi and Y. Shimoji, announced to have successfully used a live Erysipelothrix rhusiopathiae vaccine strain as a vector.
They used the Erysipelothrix rhusiopathiae Koganei 65-0.15 strain, which is the live swine erysipelas vaccine for subcutaneous injection, as it has been shown to colonise the tonsils of pigs after oral inoculation.
For this reason, the scientists evaluated the possible use of the strain as a vector for oral vaccination against mycoplasmal pneumonia of swine.
Mice and pigs
Recombinant E. rhusiopathiae strains were examined for vaccine efficacy in mice and pigs. Mice subcutaneously inoculated with the recombinant strains were protected from challenge exposure to a virulent E. rhusiopathiae.
Administration of milk replacer containing recombinant E. rhusiopathiae expressing the M. hyo protein protected pigs from death after exposure to E. rhusiopathiae and significantly reduced the severity of pneumonic lung lesions caused by infection with M. hyo.