Abstract
Staphylocoagulase, an extracellular protein produced by staphylococci, specifically forms a complex with prothrombin. The staphylocoagulases are classified into eight serotypes based on the ability of antisera to cross-neutralize plasma clotting activity. We have developed a test based on the polymerase chain reaction (PCR) to detect the Staphylococcus aureus coagulase (coa) gene. The sequences of the oligonucleotide primers used in this assay were 5'-TAGGCGCATTAGCAGTTG-3' and 3'-CTCTGGTTCTAAGTTGTT-5'. We describe the coagulase typing of S. aureus based on the amplification and subsequent Dra I digestion of the PCR products of the coagulase gene. We ditermin'ed the coagulase types of 200 clinical isolates of S. aureus by antisera and PCR methods. The results suggest that the PCR method of coagulase typing was useful for the untypable strains by antisera methods. We also found variants of coagulase types II, V and VII. The variants were isolated at high frequency among 12 of 14 untypable strains by antisera methods.
