title: Evaluation of non-culture diagnosis of invasive meningococcal disease by polymerase chain reaction (PCR).
abstract: Antibiotic treatment prior to transport or admission to hospital has reduced the proportion of cases of invasive meningococcal disease (IMD) from which Neisseria meningitidis can be isolated by standard microbiological techniques. Identification of meningococci by polymerase chain reaction (PCR) was assessed in relation to microbiological diagnosis for cases over a 4-year period between 1998 and 2001. A screening assay for the IS1106 gene was used to detect meningococcal DNA and five additional assays for siaD and orf-2 genes were performed to determine the serogroup. PCR results were compared with results of bacteriological culture, other laboratory test results and clinical data. The sensitivity of the PCR assay for culture-confirmed cases was 98.5%. The specificity of the assay was 96% based on test results for patients from whom other bacteria were isolated, children with viral meningitis and afebrile negative controls. The siaD B/C/W-135 and Y as well as the orf-2 gene for serogroup A PCR assays were able to determine the serogroup for 75.2% of cases that were positive by PCR screening assay. When isolates from patients with IMD were tested by both agglutination and PCR, the results agreed in all cases. PCR is a useful tool for diagnosis of IMD when Gram stain and culture tests are negative due to antibiotic treatment prior to collection of samples for microbiological analyses.
authors.affiliation: National Meningococcal Reference Laboratory, National School of Public Health, 196 Alexandras Avenue, Athens, Greece. gtzanak@hotmail.com
authors.forename: Georgina
authors.initials: G
authors.lastname: Tzanakaki
authors.forename: Maria
authors.initials: M
authors.lastname: Tsolia
authors.forename: Vasiliki
authors.initials: V
authors.lastname: Vlachou
authors.forename: Maria
authors.initials: M
authors.lastname: Theodoridou
authors.forename: Anastasia
authors.initials: A
authors.lastname: Pangalis
authors.forename: Maria
authors.initials: M
authors.lastname: Foustoukou
authors.forename: Themistocles
authors.initials: T
authors.lastname: Karpathios
authors.forename: C Caroline
authors.initials: CC
authors.lastname: Blackwell
authors.forename: Jenny
authors.initials: J
authors.lastname: Kremastinou
mesh_terms: D001431:Bacteriological Techniques / Q000706:statistics & numerical data; D001483:Base Sequence; D016022:Case-Control Studies; D002648:Child; D004269:DNA, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D006801:Humans; D008589:Meningococcal Infections / Q000175:diagnosis* / Q000382:microbiology*; D009345:Neisseria meningitidis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction / Q000379:methods* / Q000706:statistics & numerical data; D012680:Sensitivity and Specificity
chemical_list: D004269:DNA, Bacterial