Objective: To establish TaqMan Real-Time PCR method for detection and identification of Neisseria meningitidis.
Methods: Seven sets of primers and FAM-labeled probes targeting different genes of Neisseria meningitidis were designed and synthesized. ctrA gene was used for identification of N. meningitidis species. Six serogruops (A, B, C, X, Y, W135) of N. meningitidis were detected with following genes: sacB (A), siaD (B), siaD (C), xcbB (X), synF (Y) and synG (W135) respectively. Sensitivity and specificity of Real-Time PCR were assessed for different primers and probes. 121 cerebrospinal fluid (CSF) specimens from suspected N. meningitidis invasive meningitis cases were detected by latex agglutination test and Real-Time PCR assay simultaneously.
Results: 79 N. meningitidis isolates of different serogroups could be detected and identified by seven sets of primers and probes in this study. Real-Time PCR seemed more sensitive than standard PCR by 10(1)-10(3) times. The respective sensitivities for ctrA, sacB, siaD (B), siaD (C), xcbB, synF and synG were 8, 8, 80, 8, 8, 80, 8 genome DNA copies in each reaction. Of the 121 CSF specimens, 11 were positive for Real-Time PCR and 6 for latex agglutination test.
Conclusion: Real-Time PCR could rapidly detect and identify N. meningitidis of different serogroups and seemed more sensitive. It could be widely used for diagnose of invasive meningitis caused by N. meningitidis.