AMPLIFICATION OF THE MENINGOCOCCAL PORB GENE FOR NONCULTURE SEROTYPE CHARACTERIZATION

Since 1992, the proportion of culture-confirmed meningococcal infectio ns compared with numbers of notified cases of meningococcal disease ha s decreased in England and Wales. As most meningococcal strain charact erization methods depend on a clinical isolate, this has resulted in a loss of epidemiological information. To address this problem, and to aid nonculture diagnosis, a semi-nested PCR protocol for the amplifica tion of the meningococcal porB gene from clinical specimens was develo ped. This gene encodes the meningococcal serotyping antigen; strain ty ping data was provided by hybridization of allele-specific oligonucleo tide probes to the digoxigenin-labelled porB amplicon in a 'PCR ELISA' . This assay was specific for meningococcal DNA and sensitivities of 0 .81 for cerebrospinal fluid (CSF), 0.57 for serum, and 0.62 for whole blood taken from patients with proven meningococcal infection were obt ained.