An approach to the identification of the pathogens of bacterial meningitis by the polymerase chain reaction

A combination of universal and species-specific primers was used to detect and differentiate by nested polymerase chain reaction (PCR) the four species most commonly causing bacterial meningitis. Primers recognising conserved sequences in the 16S and 23S ribosomal RNA genes were employed to amplify the 16S-23S spacer region from Neisseria meningitidis, Haemophilus influenzae (type b), Streptococcus pneumoniae, and Streptococcus agalactiae (group B streptococcus). The sequence of the most abundant spacer product was determined in each case and used to deduce species-specific primers. A nested PCR using universal primers in the first round and a species-specific primer in the second were able to detect and distinguish between the four common pathogens, in the presence of human DNA. Streptococcus pneumoniae DNA was detected in the cerebrospinal fluid of a meningitis patient with negative culture and Gram-stain results.