Use of an automated DNA analysis system (DARAS®) for sequence-specific recognition of Neisseria meningitidis DNA

Abstract

Objective. To combine use of the polymerase chain reaction (PCR) for rapid diagnosis of meningococcal meningitis with a novel automated detection system for sequence-specific recognition of PCR products. Methods. DNA was extracted from cerebrospinal fluid (CSF) by a quick boil-lysis method, followed by PCR with primers specific for Neisseria meningitidis. Sequence-specific recognition of N. meningitidis DNA was performed with an automated DNA analysis system (DARAS®) and the data were compared with results following agarose gel electrophoresis or conventional microbiological culture. Results. The DARAS® system had a sensitive detection limit of 102 meningococci/mL with spiked samples, compared with a detection limit of 104 meningococci/mL following agarose gel electrophoresis. When the system was used to examine 74 CSF samples, the 19 CSF samples positive for N. meningitidis by conventional microbiological methods were also all positive in the DARAS® system and the 55 samples negative by DARAS® for meningococci were also negative by conventional microbiological methods. Conclusion. The sensitivity and specificity of the DARAS® system makes it a useful tool for the diagnosis of meningococcal meningitis. The system is user-friendly, requires minimal hands-on time and generates data in an informative numerical format.