One-step heminested PCR for amplification of Neisseria meningitidis DNA incerebrospinal fluid

A one-step polymerase chain reaction (Heminested-PCR) was designed to targe t the 16S rRNA fragment simultaneously using a set of primers for the unive rsal bacterial group and a Neisseria meningitidis species-specific sequence for diagnostic purposes. The diagnostic features of the Heminested-PCR wer e evaluated in the study of 168 cerebrospinal fluid (CSF) specimens from 84 patients with a N. meningitidis infection, meningitis caused by unrelated bacteria and other etiologies (57 patients), or suspicious cases (27 patien ts) with clinical symptoms of bacterial meningitis but with negative result s from bacteriological procedures. About 90% of patients with bacterial men ingitis, including those suspicious cases, had prior antibiotic therapy. Th e sensitivity, specificity, positive, and negative predictive values found in relation to culture and/or microscopy were 91.7, 100, 100, 100, and 90.5 %, respectively. In patients suspected of having bacterial meningitis, the Heminested-PCR revealed 51.9% (14 patients) positive for N. meningitidis in fection and 40.7% (11 patients) positive for unrelated bacterial infections . The agreement of the Heminested-PCR with culture and/or microscopy was hi gh and ranked as almost perfect (kappa indices > 0.856), in contrast to its agreement with other techniques. These findings speak in favor of the mole cular diagnosis of meningococcal meningitis in patients who are culture- an d/or microscopy-negative, due to their prior antibiotic treatment. (C) 2000 Wiley-Liss, Inc.