Evaluation of the Applied Biosystems automated Taqman polymerase chain reaction system for the detection of meningococcal DNA

In a period where the proportion of culture confirmed cases in the UK has b een steadily declining, diagnosis by PCR has been used to increase the numb er of confirmed cases and provide additional epidemiological data. This rep ort presents a comparative evaluation of the fluorogenic probe-based 5' exo nuclease assay (Taqman) using the Perkin-Elmer Applied Biosystems automated sequence detection system 7700 with previously reported polymerase chain r eaction enzyme-linked immunosorbent (PCR ELISA) assays for the detection of meningococcal DNA ill CSF, plasma and serum samples. Taqman assays develop ed were based on the detection of a meningococcal capsular transfer gene (c trA), the insertion sequence IS1106 and the sialytransferase gene (siaD) fo r serogroup B and C determination and compared with similar assays in a PCR ELISA format. The Taqman ctrA assay was specific for Neisseria meningitidi s, however the IS1106 assay gave false positive reactions with a number of non-meningococcal isolates. Sensitivity of the Taqman ctrA, IS1106 and siaD assays testing samples from culture-confirmed cases were 64, 69 and 50%, r espectively, compared with 26, 67 and 43% for the corresponding PCR ELISA a ssays. Improvements to the DNA extraction procedure has increased the sensi tivity to 93 and 91% for the Taqman(TM) ctrA and siaD assays, respectively, compared to culture confirmed cases. Since the introduction of Taqman PCR a 56% increase in laboratory confirmed cases of meningococcal disease has b een observed compared to culture only confirmed cases. The developed Taqman assays for the diagnosis of meningococcal disease enables a high throughpu t, rapid turnaround of samples with considerable reduced risk of contaminat ion. (C) 2000 Federation of European Microbiological Societies. Published b y Elsevier Science B.V. Ail rights reserved.