A method for Porphyromonas gingivalis based on recombinase polymerase amplification and lateral flow strip technology.

OBJECTIVE: A practical visual detection method was established to detect Porphyromonas gingivalis (P. gingivalis) by employing a combination of recombinase polymerase amplification and lateral flow strips (RPA-LF) assay, designed for conducting point-of-care testing in clinical settings. METHODS: Primers and probes targeting the P. gingivalis pepO gene were designed. The RPA-LF assay was established by optimising reaction temperature and time, determining the limit of detection (LOD). The specificity of the method was determined by assessing its cross-reactivity with deoxyribonucleic acid from 23 pathogenic bacteria. Finally, the clinical samples from healthy controls (n = 30) and individuals with periodontitis (n = 31) were analysed. The results were compared with those obtained using real-time polymerase chain reaction (PCR). RESULTS: The optimal reaction temperature and time were 39 °C and 12 min. The method exhibited a LOD at 6.40 × 10-4 µg/mL and demonstrated high specificity and sensitivity during cross-reactivity assessment. The RPA-LF assay achieved a P. gingivalis detection rate of 84 % in individuals with periodontitis and 3 % in healthy controls. The results were consistent with those obtained through real-time PCR. CONCLUSION: An RPA-LF assay was developed for detecting P. gingivalis, characterised by its high sensitivity, high specificity, simple operational procedure, and rapid reaction time.