Diagnostic accuracy of the ROCHE Septifast PCR system for the rapid detection of blood pathogens in neonatal sepsis-A prospective clinical trial

PLoS One. 2017 Nov 8;12(11):e0187688. doi: 10.1371/journal.pone.0187688. eCollection 2017.

Abstract

Introduction: Diagnosis of neonatal sepsis remains a major challenge in neonatology. Most molecular-based methods are not customized for neonatal requirements. The aim of the present study was to assess the diagnostic accuracy of a modified multiplex PCR protocol for the detection of neonatal sepsis using small blood volumes.

Methods: 212 episodes of suspected neonatal late onset sepsis were analyzed prospectively using the Roche SeptiFast® MGRADE PCR with a modified DNA extraction protocol and software-handling tool. Results were compared to blood culture, laboratory biomarkers and clinical signs of sepsis.

Results: Of 212 episodes, 85 (40.1%) were categorized as "not infected". Among these episodes, 1 was false positive by blood culture (1.2%) and 23 were false positive by PCR (27.1%). Of 51 (24.1%) episodes diagnosed as "culture proven sepsis", the same pathogen was detected by blood culture and PCR in 39 episodes (76.5%). In 8 episodes, more pathogens were detected by PCR compared to blood culture, and in 4 episodes the pathogen detected by blood culture was not found by PCR. One of these episodes was caused by Bacillus cereus, a pathogen not included in the PCR panel. In 76/212 (35.8%) episodes, clinical sepsis was diagnosed. Among these, PCR yielded positive results in 39.5% of episodes (30/76 episodes). For culture-positive sepsis, PCR showed a sensitivity of 90.2% (95%CI 86.2-94.2%) and a specificity of 72.9% (95%CI 67.0-79.0%).

Conclusion: The Roche SeptiFast® MGRADE PCR using a modified DNA extraction protocol showed acceptable results for rapid detection of neonatal sepsis in addition to conventional blood culture. The benefit of rapid pathogen detection has to be balanced against the considerable risk of contamination, loss of information on antibiotic sensitivity pattern and increased costs.

MeSH terms

  • Blood Culture
  • False Positive Reactions
  • Female
  • Fungi / genetics*
  • Fungi / isolation & purification
  • Gram-Negative Bacteria / genetics*
  • Gram-Negative Bacteria / isolation & purification
  • Gram-Negative Bacterial Infections / diagnosis*
  • Gram-Negative Bacterial Infections / microbiology
  • Gram-Positive Bacteria / genetics*
  • Gram-Positive Bacteria / isolation & purification
  • Gram-Positive Bacterial Infections / diagnosis*
  • Gram-Positive Bacterial Infections / microbiology
  • Humans
  • Infant, Newborn
  • Male
  • Multiplex Polymerase Chain Reaction
  • Mycoses / diagnosis*
  • Mycoses / microbiology
  • Neonatal Sepsis / diagnosis*
  • Neonatal Sepsis / microbiology
  • Sensitivity and Specificity

Grants and funding

AB received a Grant of the Oesterreichische Nationalbank (OeNB, www.oenb.at) Anniversary Fund (Nr. 14277). Roche Diagnostics Vienna, Austria, provided equipment and reagents for PCR analyses. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.