Abstract: This invention describes quick diagnostic methods to distinguish CA-MRSA MW2 or CA-MRSA USA300 strains in clinical samples from various sources. Fluorescent labeled primers which amplify 1) two unique agr sequences from each strain, 2) a partial spa gene and 3) a partial pvl gene are packaged into a multiplex PCR kit. A real-time instrumentation to amplify and quantify the PCR amplification products, measured by the change of each of the labeled fluorescent reporter and their thermal melting curve, provides a simple and rapid identification of the most virulent and invasive MRSA strains in the United States.

Abstract: The present invention relates to unique agr gene sequences and primer sets for identifying CA-MRSA MW2 or CA-MRSA USA300 strains in clinical samples from various sources. More specifically, this invention provides fluorescent labeled primers which are designed to amplify 1) two unique agr gene sequences from each strain, 2) a partial spa gene and 3) a partial pvl gene. These primer sets can be packaged into one multiplex PCR kit for identifying MRSA strains that are most virulent and pathogenic.