Rapid detection of mecA in methicillin resistant Staphylococcus aureus using cycling probe technology

A novel method has been developed for the detection of the mecA gene, that confers the principle mechanism of methicillin resistance in staphylococci. Cycling Probe Technology (CPT) is a rapid, simple, isothermal method for the detection of specific target sequences. CPT utilizes a unique chimeric DNA-RNA-DNA probe sequence that provides an RNase H sensitive scissile link when hybridized to a complementary target DNA sequence. In the presence of target DNA, the cycling reaction converts full-length chimeric probe into cleaved probe fragments, which accumulate and are quantified. A cycling probe designed for detection of a specific sequence within the mecA gene was used to develop a culture confirmation assay for methicillin resistant Staphylococcus aureus. The CPT assay was used to screen 238 S. aureus isolates and the results were in complete agreement with detection of the mecA gene by polymerase chain reaction (PCR). Detection of mecA should be considered the gold standard for determining methicillin resistance in S. aureus. This study demonstrates the feasibility of using CPT to meet this need.