Streptococcus pneumoniae DNA load in blood as a marker of infection in patients with community-acquired pneumonia.
Direct detection of Streptococcus pneumoniae DNA in blood adds to culture results in the etiological diagnosis of patients with community-acquired pneumonia (CAP). Quantification of the amount of DNA, the bacterial DNA load (BDL), provides a measurement of DNAemia that may increase the understanding of the clinical relevance of S. pneumoniae DNA in blood. We evaluated the S. pneumoniae BDL as a diagnostic tool in adult patients with CAP. The BDL was determined in whole-blood samples collected simultaneously with blood for culture from 45 adult patients with CAP. After DNA extraction, S. pneumoniae DNA was detected with specific real-time PCR amplification, and the BDL was calculated with a standard curve. PCR and microbiological results were compared, and the BDL was related to clinical and laboratory parameters. S. pneumoniae DNA was detected in 10/13 patients with positive blood cultures and in 67% of patients with microbiologically confirmed pneumococcal pneumonia. The positive predictive values of the receiver operating characteristic curves for the BDLs for pneumococcal infection (100%) and pneumococcal bacteremia (69%) were higher than those for the level of C-reactive protein (CRP; 43% and 23%, respectively) and the white blood cell count (WBC; 42% and 35%, respectively); the negative predictive values of these three parameters were in the same range (+/-90 and +/-97%, respectively). The BDL was higher in patients presenting with systemic inflammatory response syndrome and in patients with bacteremia. Positive correlations were observed for the BDL with WBC, CRP level, and length of stay. We conclude that the BDL supports the diagnosis of S. pneumoniae infection in patients with CAP and provides a putative marker of the severity of disease.
Peters
Remco P H
RP
Department of Medical Microbiology & Infection Control, VU University Medical Center, Amsterdam, The Netherlands.
de Boer
Richard F
RF
Schuurman
Tim
T
Gierveld
Sonja
S
Kooistra-Smid
Mirjam
M
van Agtmael
Michiel A
MA
Vandenbroucke-Grauls
Christina M J E
CM
Persoons
Maike C J
MC
Savelkoul
Paul H M
PH
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers; D002097:C-Reactive Protein / Q000032:analysis; D017714:Community-Acquired Infections / Q000382:microbiology*; D004269:DNA, Bacterial / Q000097:blood* / Q000235:genetics; D005260:Female; D006801:Humans; D007902:Length of Stay; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D011018:Pneumonia, Pneumococcal / Q000175:diagnosis*; D016133:Polymerase Chain Reaction / Q000379:methods; D011237:Predictive Value of Tests; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*; D055815:Young Adult
D015415:Biomarkers; D004269:DNA, Bacterial; D002097:C-Reactive Protein
BMC Infect Dis. 2007 Mar 02;7:10
17335562
Chest. 1995 Oct;108(4):932-6
7555163
J Med Microbiol. 2004 Mar;53(Pt 3):189-195
14970243
Thorax. 1995 May;50(5):543-7
7597669
Pediatrics. 1985 Dec;76(6):901-4
3877910
Chest. 2001 Jan;119(1):181-4
11157602
J Clin Microbiol. 2007 Nov;45(11):3641-6
17881553
J Clin Microbiol. 2000 Oct;38(10):3907
11184177
Chest. 2002 Dec;122(6):2212-6
12475865
J Clin Microbiol. 2001 Apr;39(4):1553-8
11283086
Ned Tijdschr Geneeskd. 2005 Nov 5;149(45):2501-7
16304887
Respir Med. 2001 Jan;95(1):78-82
11207022
J Clin Microbiol. 2003 Feb;41(2):576-80
12574249
Clin Infect Dis. 2005 Aug 1;41(3):345-51
16007532
N Engl J Med. 1997 Jan 23;336(4):243-50
8995086
Diagn Microbiol Infect Dis. 2003 Oct;47(2):407-14
14522514
Clin Infect Dis. 2001 Jun 1;32(11):1651-5
11340541
BMC Infect Dis. 2006 Apr 27;6:79
16643662
Thorax. 2000 Feb;55(2):133-7
10639531
Pediatrics. 1982 Jun;69(6):699-702
6804923
Thorax. 2003 May;58(5):377-82
12728155
Diagn Microbiol Infect Dis. 2008 Mar;60(3):255-61
18036762
JAMA. 1996 Jan 10;275(2):134-41
8531309
Chest. 1992 Jun;101(6):1644-55
1303622
J Clin Microbiol. 1993 Oct;31(10):2661-6
8253962
Int J Antimicrob Agents. 2008 Jan;31(1):3-11
17920819
Arch Dis Child. 2002 Jan;86(1):44-6
11806883
Pediatr Infect Dis J. 2007 May;26(5):416-22
17468652
Clin Infect Dis. 2005 Jun 15;40(12):1855-7
15909277
Diagn Microbiol Infect Dis. 2008 May;61(1):72-5
18221851
Clin Infect Dis. 2006 May 1;42(9):1266-73
16586386