Establishment of the molecular beacon-loop-mediated isothermal amplification method for the rapid detection of Porphyromonas gingivalis

Porphyromonas gingivalis, a clinically important oral pathogen causing periodontal disease, is difficult to culture in routine conditions. Hence, it is necessary to establish a reliable technique to detect this pathogen. Previously, our laboratory developed a new isothermal detection method, called MB-LAMP (molecular beacon-Loop mediated isothermal amplification), which combines the advantages of LAMP and qPCR through the accurate and quantitative detection of LAMP products. This approach offers significant potential for the point-of-care detection of P. gingivalis. Here, MB-LAMP was used to detect P. gingivalis targeting a specific fragment, and the sensitivity was as high as 1.4 x 10(-1) pg mu L-1. The method showed no cross-reaction with 14 other bacterial pathogens. For clinical samples, this assay showed a high diagnostic sensitivity (100%) and specificity (100%), equivalent to that of real-time quantitative polymerase chain reaction (real-time qPCR). Moreover, detection with MB-LAMP was significantly faster than that with real-time qPCR, reducing the time required for clinical diagnosis. Finally, we established an absolute quantification method with MB-LAMP for P. gingivalis using pilot samples. Thus, the highly specific, sensitive, and rapid assay developed in this study makes it feasible to diagnose P. gingivalis.