Evaluation of the protective efficacy of a newly identified immunogenic protein, HP0272, of Streptococcus suis.

Streptococcus suis serotype 2 (SS2) infection is a major cause of sudden death in pigs and is of concern for humans as it has strong zoonotic capabilities. Developing novel effective vaccines would be beneficial to control SS2 infection. HP0272 is a novel immunogenic surface protein; its protective efficacy remains to be evaluated. The present mouse model found that the purified recombinant HP0272 could elicit a significant humoral antibody response, and to confer complete protection against a lethal dose of SS2 infection. In addition, real-time PCR confirmed that in vivo-induced antigen existed in most SS2 field pathogenic strains, and in half of all reference strains of different serotypes of S. suis. The results indicate that HP0272 has the potential as an effective component of a new vaccine.