Rapid detection of mecA and spa by the loop-mediated isothermal amplification (LAMP) method

Aim: To develop a detection assay for staphylococcal mecA and spa by using loop-mediated isothermal amplification (LAMP) method. Methods and Results: Staphylococcus aureus and other related species were subjected to the detection of mecA and spa by both PCR and LAMP methods. The LAMP successfully amplified the genes under isothermal conditions at 64 degrees C within 60 min, and demonstrated identical results with the conventional PCR methods. The detection limits of the LAMP for mecA and spa, by gel electrophoresis, were 102 and 10 cells per tube, respectively. The naked-eye inspections were possible with 103 and 10 cells for detection of mecA and spa, respectively. The LAMP method was then applied to sputum and dental plaque samples. The LAMP and PCR demonstrated identical results for the plaque samples, although frequency in detection of mecA and spa by the LAMP was relatively lower for the sputum samples when compared to the PCR methods. Conclusion: Application of the LAMP enabled a rapid detection assay for mecA and spa. The assay may be applicable to clinical plaque samples. Significance and Impact of the Study: The LAMP offers an alternative detection assay for mecA and spa with a great advantage of the rapidity.