Method for the detection and identification of methicillin-resistant staphylococcus aureus

A method to detect the presence of an MREJ type ix methicillin-resistant Staphylococcus aureus (MRSA) strain nucleic acid in a sample, comprising:

• a) performing an amplification reaction comprising contacting a sample to be analyzed for the presence of said MREJ type ix MRSA strain nucleic acid with a first amplification primer and a second amplification primer to generate a first amplicon if said MREJ type ix MRSA strain nucleic acid is present in said sample, said MREJ type ix MRSA strain nucleic acid including a staphylococcal cassette chromosome mec (SCCmec) element containing a mecA gene inserted into chromosomal DNA, said chromosomal DNA being orfX, thereby generating a polymorphic right extremity junction (MREJ) type ix nucleic acid sequence that comprises nucleic acid sequences from both the SCCmec element right extremity and orfX adjoining said right extremity;
• wherein said first primer is at least 10 nucleotides in length and specifically hybridizes at least under conditions of 50 mM KCl, 10 mM Tris-HCl (pH 9.0), 0.1% Triton X-100, 2.5 mM MgCl2 at 55° C. with an SCCmec element right extremity of an MREJ type ix nucleic acid sequence selected from the group consisting of:
• SEQ ID NO:
• 168 and the complement thereof,
• wherein said second primer is at least 10 nucleotides in length and specifically hybridizes at least under conditions of 50 mM KCl, 10 mM Tris-HCl (pH 9.0), 0.1% Triton X-100, 2.5 mM MgCl2 at 55° C. with orfX,
• wherein said first amplicon generated if said MREJ type ix MRSA strain nucleic acid is present in said sample comprises polymorphic right extremity junction (MREJ) type ix sequence and orfX sequence, including the junction of the two, and is indicative of the presence of MREJ type ix MRSA strain nucleic acid in said sample;
• and
• b) detecting said first amplicon if present.