Aptamer-based fluorometric assay for direct identification of methicillin-resistant Staphylococcus aureus from clinical samples.

Accurate and rapid identification of methicillin-resistant Staphylococcus aureus (MRSA) is of important clinical significance. In this study, a novel aptamer-based fluorometric assay was developed for detection of MRSA in clinical samples by coupling with immunomagnetic separation. The S. aureus cells in clinical specimens were enriched by magnetic separation. Following lysis by staphylococcal lysin, the PBP2a proteins were released from S. aureus cells and detected by the aptamer-based fluorometric assay. Without lengthy period of bacteria cultivation in the traditional susceptibility testing, this test has an overall testing time of only 2 h with the detection limit of 2.63 × 10 and 1.38 × 10 CFU/mL in PBS and spiked nasal swab, respectively. Since it is simple, rapid and sensitive, this method could be used for the detection of MRSA in various clinical samples.