Reduced turnaround time and improved diagnosis of invasive serogroup B Neisseria meningitidis and Streptococcus pneumoniae infections using a lyophilized quadruplex quantitative PCR

J Med Microbiol. 2015 Nov;64(11):1321-1328. doi: 10.1099/jmm.0.000154. Epub 2015 Aug 5.

Abstract

Since 1996 the Meningococcal Reference Unit (MRU) in Manchester has provided a national service for PCR confirmation of meningococcal and pneumococcal disease. Neisseria meningitidis serogroup B is predominant in the UK, accounting for >60% of cases. In response to this, the MRU has developed a quadruplex quantitative PCR that detects N. meningitidis capsule transporter (ctrA), serogroup B sialyltransferase (siaDB), Streptococcus pneumoniae pneumolysin (ply) and an internal control. The assay was prepared in a ready-to-use lyophilized format by Applied Biosystems. Laboratory validation showed excellent performance in a specificity panel of 52 isolates and improved detection in comparison with the routine assay. Testing of 244 patient samples showed sensitivity of 93% [95% confidence interval (CI): 88-98%] for the ctrA assay, 95% (95% CI: 91-100%) for the siaDB assay and 100% (95% CI: 95-100%) for the ply assay. Specificity was 100% (95% CI: 98-100%) for both meningococcal targets and 95% (95% CI: 92-98%) for ply. The quadruplex also retained high performance in mixed samples and had acceptable reproducibility. After introduction of the quadruplex into routine use the turnaround time for N. meningitidis group B PCR confirmation reduced from 37 to 29 h and the internal control has proved useful for detecting inhibitory samples. The quadruplex assay provides rapid group B confirmation of meningococcal positive samples, enabling timely public health interventions for the most common disease-causing meningococcal serogroup in the UK.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Humans
  • Meningitis, Meningococcal / diagnosis*
  • Meningitis, Meningococcal / microbiology
  • Neisseria meningitidis, Serogroup B / classification
  • Neisseria meningitidis, Serogroup B / genetics
  • Neisseria meningitidis, Serogroup B / isolation & purification*
  • Pneumococcal Infections / diagnosis*
  • Pneumococcal Infections / microbiology
  • Real-Time Polymerase Chain Reaction / methods*
  • Streptococcus pneumoniae / classification
  • Streptococcus pneumoniae / genetics
  • Streptococcus pneumoniae / isolation & purification*

Substances

  • Bacterial Proteins