Rapid detection of methicillin-resistant Staphylococcus aureus in screening samples by relative quantification between the mecA gene and the SA442 gene.

Rapid detection of methicillin-resistant Staphylococcus aureus (MRSA) is important to identify patients colonized with this pathogen and implement infection control precautions. We aimed to improve the combined use of the mecA gene polymerase chain reaction (PCR) and the SA442 PCR to detect MRSA in clinical screening samples. In a true MRSA the mecA copy number will be equal to the SA442 copy number, whereas in samples with a methicillin-sensitive Staphylococcus aureus (MSSA) combined with a methicillin-resistant coagulase-negative Staphylococcus (MRCNS) the copy numbers will usually differ.