Use of oligoprobes on amplified DNA in the diagnosis of bacterial meningitis

An approach based on the 16 S rDNA polymerase chain reaction (16S PCR) and oligoprobe hybridization was applied to 77 cerebrospinal fluid samples submitted to the clinical microbiology laboratory for culture. Broad-range 16S rDNA primers were selected in conserved regions of the gene. Oligoprobes specific for Neisseria meningitidis, Haemophilus influenzae, Streptococcus spp., and Mycobacterium tuberculosis were selected in specific variable regions of the amplified 600 base pairs (bp) in the 16S rDNA. None of the oligoprobes cross hybridized with DNA from the other bacteria or from common contaminants. There were no false-negative results in culture-positive cerebrospinal fluid samples. Ten cases of meningitis caused by bacteria other than the four probes were not identified by any of the four probes. In culture-negative cerebrospinal fluid samples with some abnormal chemical parameters, there were 14 amplicons -- one of Haemophilus influenzae, three of Streptococcus spp., six of Mycobacterium tuberculosis, and four not identified -- while in normal cerebrospinal fluid samples there were no amplicons.