The cps genes of Streptococcus suis serotypes 1, 2, and 9: Development of rapid serotype-specific PCR assays

We developed three type-specific PCR assays for the rapid and sensitive det ection of Streptococcus suis serotype 1 (plus 14), serotype 2 (plus 1/2), a nd serotype 9 strains in tonsillar specimens from pigs, The PCR primers wer e based on the sequences of type-specific capsular genes of S. suis serotyp e 1, 2, and 9 strains. We recently characterized a major part of the capsul ar biosynthesis (cps) locus of S, suis serotype 2, Were we extended these s tudies and characterized major parts of the cps loci of S. suis serotypes 1 and 9, Type-specific genes were identified by cross-hybridization experime nts between the individual cps genes and chromosomal DNAs from the 35 diffe rent serotypes, Four genes of S, suis serotype 1 specifically hybridized wi th serotype 1 and 14 strains only, Five genes of S. suis serotype 2 specifi cally hybridized with serotype 2 and 1/2 strains only, and two genes of S. suis serotype 9 specifically hybridized with serotype 9 strains, Until now rapid and sensitive diagnostic tests were available only for pathogenic str ains of serotype 2 and highly pathogenic strains of serotype 1, The serotyp e-specific PCR assays can therefore be useful tools for the identification of serotype 1, 14, 2, 1/2, and 9 strains both for diagnostic purposes and i n epidemiological and transmission studies. Therefore, these tests may faci litate control and eradication programs.