Molecular detection of late-onset neonatal sepsis in premature infants using small blood volumes: proof-of-concept

Neonatology. 2013;103(4):268-73. doi: 10.1159/000346365. Epub 2013 Mar 12.


Background: Conventional blood culture is still the gold standard for sepsis diagnosis but results are not immediately available and pathogens are only detected in approximately 25% of cases. New molecular assays for the detection of blood stream pathogens are promising diagnostic tools.

Objectives: The aim of the study was to adapt and evaluate a multiplex PCR system using 100 µl blood. -

Methods: 46 blood specimens of very low birth weight infants (818 ± 242 g) with suspected sepsis were analyzed using the Roche SeptiFast MGRADE PCR with a modified DNA extraction protocol and software handling tool for decreased blood volume requirements.

Results: In the non-infected group, 5/21 infants had a positive PCR result with coagulase-negative staphylococci. All pathogens detected in the blood culture positive group (n = 15) were also detected by PCR. In addition, 4/6 patients had a positive PCR result in the clinical sepsis group (clinical and laboratory signs of sepsis but negative blood culture). Overall, the PCR was demonstrated to have a higher sensitivity (90.5%; 95%CI 68.2-98.3%) in comparison to blood culture (71.4%; 95%CI 47.7-87.8%) including clinical sepsis cases, even though it had a lower specificity (80.0%; 95%CI 58.7-92.4% versus 100.0%; 95%CI 83.4-100.0%).

Conclusions: These first data demonstrate the usability and potential benefit of this multiplex PCR using a modified DNA extraction for the rapid detection of nosocomial sepsis in preterm infants in addition to blood culture.

Publication types

  • Comparative Study
  • Evaluation Study

MeSH terms

  • Automation, Laboratory
  • Bacteriological Techniques*
  • Biomarkers / blood
  • Blood Specimen Collection*
  • Cross Infection / blood
  • Cross Infection / diagnosis*
  • Cross Infection / microbiology
  • DNA, Bacterial / blood*
  • DNA, Fungal / blood*
  • Gestational Age
  • Humans
  • Infant, Newborn
  • Infant, Premature / blood*
  • Infant, Premature, Diseases / blood
  • Infant, Premature, Diseases / diagnosis*
  • Infant, Premature, Diseases / microbiology
  • Infant, Very Low Birth Weight / blood
  • Multiplex Polymerase Chain Reaction*
  • Predictive Value of Tests
  • Real-Time Polymerase Chain Reaction
  • Sepsis / blood
  • Sepsis / diagnosis*
  • Sepsis / microbiology
  • Software


  • Biomarkers
  • DNA, Bacterial
  • DNA, Fungal