Antibody response to an autogenous vaccine against Streptococcus suis in weaning piglets in Tien Giang province

Abstract

The objective of this study aimed at evaluating the antibody response to an autogenous vaccine against Streptococcus suis in the weaning piglets in Tien Giang province. A total of 54 throat swab samples were collected from 3 farms with a history of S. suis infection in the weaning piglets and growers as the materials for this study. Three strains, including sly+mrp+sspA+ssnA+ S. suis serotype 2, mrp+sspA+ssnA+ S. suis serotype 1/2 and sspA+ ssnA+ S. suis serotype 31 isolated from farm 1, 2 and 3 were used for producing autogenous S. suis bacterins, respectively. In each farm, 30 piglets at 4 weeks old (farm 1 or 2) and 30 piglets at 6 weeks old (farm 3) were allotted to three treatment groups. Group 1, 2 and 3 were injected with physiological saline solution, adjuvants and autogenous S. suis bacterins, respectively. As a result, the antibody response of the piglets was increased significantly (P<0.05) at the 6th and 8th weeks (farm 1 and 2) and the 10th week (farm 3) after vaccination with the autogenous vaccines and the high antibody level was remained until the end of the experiments. In the control groups (group 1 and 2), the antibody level of the piglets was slightly increased, this might be the antibody response to a natural infection. It is concluded that, the weaning piglets produced specific antibody response after vaccinating autogenous vaccines with the virulent S. suis strains, expecting that this vaccine can be used to prevent S. suis infection in pigs.