Use of robotized DNA isolation and real-time PCR to quantify and identify close correlation between levels of Neisseria meningitidis DNA and lipopolysaccharides in plasma and cerebrospinal fluid from patients with systemic meningococcal disease.
The present study, using robotized DNA isolation and quantitative PCR based on the Neisseria meningitidis-specific capsular transport A gene, demonstrates the ease, rapidity, specificity, and sensitivity of quantifying neisserial DNA in plasma (n = 65) and cerebrospinal fluid (CSF) (n = 12) from patients with systemic meningococcal disease. We found a close correlation between the levels of neisserial DNA and lipopolysaccharides in plasma (r = 0.905) and in CSF (r = 0.964). The median concentration of neisserial DNA in plasma in 23 patients with persistent shock was 2 x 10(7) copies/ml, versus <10(3) copies/ml in 42 nonshock patients. Furthermore, quantitative PCR made possible estimates of the total number of meningococci in plasma, as opposed to conventional blood cultures, suggesting about 1,000 dead meningococci for every viable bacterium. Finally, with logistic regression analyses, neisserial DNA may predict a patient's disease severity and outcome at hospital admission. The number of meningococci in plasma and CSF appears to be the main determinant of the lipopolysaccharide levels, clinical presentation, and outcome.
Øvstebø
Reidun
R
The Research and Development Group, Department of Clinical Chemistry, Ullevål University Hospital, NO-0407 Oslo, Norway. reidun.ovstebo@medisin.uio.no
Brandtzaeg
Petter
P
Brusletto
Berit
B
Haug
Kari Bente Foss
KB
Lande
Knut
K
Høiby
Ernst Arne
EA
Kierulf
Peter
P
D004269:DNA, Bacterial / Q000097:blood*; D006801:Humans; D008070:Lipopolysaccharides / Q000097:blood* / Q000134:cerebrospinal fluid; D016015:Logistic Models; D008589:Meningococcal Infections / Q000175:diagnosis* / Q000401:mortality; D009345:Neisseria meningitidis / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D012772:Shock, Septic / Q000401:mortality
D004269:DNA, Bacterial; D008070:Lipopolysaccharides