ABSTRACT

The studies discussed herein were conducted to develop a vaccine for use in alleviating Mycoplasma hyorhinis associated disease in swine. This goal necessitated the development of a consistent and robust challenge model. We exploited M. hyorhinis’ affinity to infect tissue culture and have generated a cell-associated challenge material. This material was then administered in a consecutive-day, variable route model resulting in a high degree of lameness, arthritis and polyserositis in caesarian derived, colostrum deprived pigs. We further demonstrated an age limitation of the pigs for susceptibility to M. hyorhinis infection in this model. An inactivated whole-cell vaccine was developed and efficacy was evaluated in the challenge model. Vaccination provided significant reductions of pericarditis, arthritis and lameness as well as a significant increase in weight gain compared to a placebo control group. Lastly, a comparative proteomic analysis was performed between a broth-derived culture and two cell-associated cultures of a single isolate of M. hyorhinis. Differential expression of several membrane-associated proteins was observed in the cell-associated cultures. The identified proteins provide insight into the infection process and are targets for future vaccine trials.