Development of an internal amplification control system for a real-time PCR assay for detection of Neisseria meningitidis in CSF and EDTA blood
| Autor: | Sydney M. Bell, Christopher J. McIver, Noel Er |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Meningitides
Detection limit DNA Bacterial Serial dilution Neisseria meningitidis Reference range Context (language use) Biology Meningitis Meningococcal medicine.disease_cause Real-Time Polymerase Chain Reaction Molecular biology Sensitivity and Specificity Pathology and Forensic Medicine law.invention Real-time polymerase chain reaction law Reference Values medicine Humans Polymerase chain reaction |
| Zdroj: | Pathology. 46(4) |
| ISSN: | 1465-3931 |
| Popis: | Summary The aim of this study was to assemble and assess a noncompetitive internal amplification control (IAC) system targeting the Escherichia coli alanine racemase (alr) gene to include in a real-time polymerase chain reaction (PCR) assay for Neisseria meningitidis. Primers and hybridisation probes specific for the IAC were designed and assessed for specificity. Amplification efficiency and limit of detection for the assembled assay was extrapolated using standard curves constructed with serial dilutions of N. meningitidis in saline, pooled cerebrospinal fluid (CSF) and EDTA blood. The 95% confidence limits (CI) were calculated for IAC crossing-points recorded for assays for N. meningitidis ctr A in saline (negative blank), and N. meningitides -negative samples of CSF and EDTA blood. These limits served as a reference range against which the IAC crossing-points recorded for prospective assays are compared to detect sample inhibition. This system was used in testing consecutive EDTA blood samples from two cases of meningococcal disease. The IAC system is specific for Escherichia coli and Shigella species. The amplification efficiency of the assembled assay for N. meningitidis and ability to detect low target DNA levels was not compromised with the inclusion of the IAC system. The IAC crossingpoints varied in clinical samples of CSF and EDTA blood. The elucidated reference range for EDTA blood was used to detect sample inhibition in one of the two clinical cases investigated. The IAC system monitors the performance of all processes in the assembled assay for N. meningitidis . Measuring IAC crossing-points serves as an indicator of sample stability and inhibitory properties when testing single or multiple samples from the same patient. Specificity for E. coli and Shigella species enables inclusion in assays of different targets within the same laboratory. Reporting PCR assay results in the context of the IAC crossing-points and reference ranges validates against sample inhibition and suitability for detection of low levels of target DNA in random and multiple samples. |
| Databáze: | OpenAIRE |
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