Multiplex PCR method for detection of variability in genes encoding the alpha proteins of Streptococcus agalactiae

The majority of Streptococcus agalactiae strains express one or more surface-anchored proteins that vary by strain. These proteins, which are characteristic for S. agalactiae, and are able to induce protective antibodies, include the alpha C, Rib proteins, alpha-like protein 2, and alpha-like protein 3. In this study was developed multiplex PCR method for detection of genes encoding these proteins, and its occurrence within a various S. agalactiae isolates of bovine origin. Also are reported two new genes from bovine isolates of S. agalactiae amplified by PCR, encoding other putative members of the family, alphalike protein 6, and alpha-like protein 7. They contain an overall genetic organization highly similar to that of the alpha C and Rib proteins.