Molecular and antigenetic characterization ofStreptococcus suis serotype2 isolates in Central Vietnam

Streptococcus suisis a Gram-positive bacterium with clinical relevance in pigs and is emerging in human. There are 35S. suisserotypes have been distinguished to date, of which serotype 2 is most commonly associated with disease in human and pigs, worldwide. Recently,S. suisemerged as a zoonotic agent in human in contact with infected pigs or with their products. More recently, several studies from Southeast Asia demonstrated thatS. suiscan cause adult endocarditis, septicemia, arthritis and especially meningitis with high fatality rate and severe neurological sequelae. Multilocus enzyme electrophoresis, restriction endonuclease analysis with HaeIII, ribotyping, and pulsed-field gel electrophoresis have been used to determineS. suisstrains epidemiological relationships. Characterization of the 16S-23S ribosomal (r) DNA intergenic spacer region (ITS) has also been used to compare bacterial strains and to identify species within the genus Streptococcus, includingS. suis.In this study, a specific and sensitive PCR assay for fast detection of S. suis serotype 2 is crucial to meningitis treatment based on the S. suis serotype 2 cps2J gene was developed and evaluated for diagnosis in meningitis patients hospitalized in central Viet Nam. The intergenic spacer region was amplified by traditional PCR from strains obtained in this study and sequenced. ITS - based phylogenetic analysis is also presented and discussed. We also identified and characterized the main immunodominant antigens ofStreptococcus suis serotype2 based on the immunoproteomics approach.