Development of a Screening Test for Detection of Streptococcus suis Serotype 2

Abstract

Streptococcus suis (S. suis) is typically a swine pathogen that can cause death in human. Routine diagnosis of this swine pathogen in infected patient is complicated and time consuming. The purpose of this study was to develop an easy, convenient and quick screening test for detecting S. suis. Firstly, Rabbits were immunized with capsular polysaccharide (cps) antigen of S. suis serotype 2. Serum was collected for detecting anti-cps by indirect ELISA. Nonspecific antibodies were removed by adsorption method. Then, the adsorbed anti-cps antibodies were used to develop a screening test using latex agglutination test. Finally, the screening test was evaluated using cps of S. suis and cps or extracted cell membrane of other organisms. The results showed that serum contained nonspecific and specific anti-cps antibodies. The non-specific antibodies could not be adsorbed completely. The screening test made from the adsorbed anti-cps antibodies was able to detect the lower limit of cps of S. suis 125 µg/mL and cross-react to cps of S. pyogenes. In conclusion, this study is able to develop a screening test for detecting S. suis by choosing an alpha hemolysis and gram-positive bacteria for performing with this kit.