Laboratory diagnosis of late-onset sepsis in newborns by multiplex real-time PCR.

Late-onset sepsis is often suspected in the neonatal population, but blood cultures (BC) are rarely positive. This study was aimed at the assessment of the clinical usefulness of a newly commercially available real-time PCR test (LightCycler® SeptiFast) in newborns older than 3 days with clinical suspicion of sepsis. Peripheral blood samples were obtained from preterm and term newborns with clinical signs of sepsis (n = 34) and from healthy neonates (n = 8). The specimens were evaluated for complete blood count, C-reactive protein level, and bloodstream infections (by BC and SeptiFast assays). Sepsis was detected in 7/34 (20.6%) patients by BC and/or SeptiFast. In 3 patients the results of BC and SeptiFast were concordant. However, in 4 cases, only SeptiFast identified the presence of pathogens in blood samples. In the remaining 26 cases (76.5%), both methods were negative. All of the healthy infants tested negative by both BC and SeptiFast. SeptiFast is a clinically usefull method for the laboratory diagnosis of late-onset sepsis in newborns. The major advantage of SeptiFast is the rapid identification of microbes in the blood. Faster availability of results may reduce the inappropriate use of antimicrobial therapy, the risk of antibiotic-resistance and reduce the hospitalization period.