[Preliminary observation on specific antibody level and reduction of ovulation induced by recombinant Schistosoma japonicum 26 kDa GST antigen in water buffaloes].

ABSTRACT

OBJECTIVE: To observe the specific antibody level and reduction of egg-laying induced by a recombinant Schistosoma japonicum 26 kDa GST antigen (rSjc26 GST) in water buffaloes. METHODS: 20 water buffaloes were randomly divided into two groups, the vaccination group and control group, with 10 buffaloes each. The subjects in vaccination group were immunized with rSjc26 GST antigen while the control received adjuvant only. After challenged with S. japonicum cercariae, the anti-rSjc26 GST antibody level and the numbers of eggs and miracidia in stool were detected. RESULTS: The anti-rSjc26 GST antibody appeared 1 month after immunization with rSjc26 GST antigen and maintained a high level for 12 months. Numbers of eggs (EPG) and miracidia (MPG) in vaccination group were significantly lower than those in control group during the period of day 50 to day 90 post-challenge. However, EPG and MPG tended to decrease starting from day 100 post challenge in both groups. The difference of EPG and MPG between the two groups diminished progressively, and both groups showed zero egg count from day 330 on post challenge. CONCLUSION: The specific anti-rSjc26 GST antibody was detected in vaccinated water buffaloes and maintained a high level for 12 months. The vaccination showed a significant effect to the reduction of ovulation in the first three months after S. japonicum cercariae challenge.