Diagnosis of neonatal sepsis by broad-range 16S real-time polymerase chain reaction.
BACKGROUND
The standard diagnostic test (blood culture) for suspected neonatal sepsis has limitations in sensitivity and specificity, and 16S polymerase chain reaction (PCR) has been suggested as a new diagnostic tool for neonatal sepsis.


OBJECTIVE
To develop and evaluate a new real-time PCR method for detection of bacterial DNA in blood samples collected from infants with suspected neonatal sepsis.


METHODS
Immediately after blood culture, a study sample of 0.5-1.0 ml whole blood was collected and used for a novel 16S real-time PCR assay. All positive samples were sequenced. Detailed case studies were performed in all cases with conflicting results, to verify if PCR could detect pathogens in culture negative sepsis.


RESULTS
368 samples from 317 infants were included. When compared with blood culture, the assay yielded a sensitivity of 79%, a specificity of 90%, a positive predictive value of 59%, and a negative predictive value of 96%. Seven of the 31 samples with a positive PCR result and a negative blood culture had definite or suspected bacterial sepsis. In five samples, PCR (but not blood culture) could detect a pathogen that was present in a blood culture collected more than 24 h prior to the PCR sample.


CONCLUSIONS
This study presents an evaluation of a new real-time PCR technique that can detect culture-positive sepsis, and suggests that PCR has the potential to detect bacteria in culture-negative samples even after the initiation of intravenous antibiotics.
Department of Pediatrics, Örebro University Hospital, Örebro, Sweden. andreas.ohlin@orebroll.se
Andreas
A
Ohlin
Anders
A
Bäckman
Uwe
U
Ewald
Jens
J
Schollin
Maria
M
Björkqvist
D001769:Blood / Q000382:microbiology; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000097:blood / Q000175:diagnosis* / Q000235:genetics; D008297:Male; D008828:Microbiological Techniques; D015997:Neonatal Screening / Q000379:methods*; D012336:RNA, Ribosomal, 16S / Q000032:analysis / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000097:blood / Q000175:diagnosis* / Q000235:genetics
D012336:RNA, Ribosomal, 16S