Role of polymerase chain reaction as an early diagnostic tool for neonatal bacterial sepsis

Neonatal bacterial sepsis is a challenging disease that needs to be detected early. As it is a life-threatening condition, the use of an approach that could be more rapid than standard culture and identification techniques for detection of neonatal sepsis would be highly desirable.

The aim of this work was to assess the effectiveness of the PCR technique compared with blood culture for the early detection of bacterial sepsis.

This study included 50 neonates with suspected sepsis. A blood sample was collected and divided into two parts: one part was subjected to broad-range 16S rDNA detection by PCR (runtime 6 h) and the other part was inoculated onto blood culture bottles (monitored for 6 days). In addition, some risk factors associated with clinical sepsis were explored.

Twenty-four neonates (48%) were positive for bacterial DNA by PCR and 17 cases (34%) had a positive blood culture. Seventeen neonates were positive for both blood culture and bacterial DNA. There was no statistical significance between both methods and the risk factors studied, except for sex and blood culture. The results of PCR in the detection of bacterial sepsis when compared with blood culture showed 100% sensitivity, 78.79% specificity, 70.83% positive predictive value, and 100% negative predictive value. An excellent agreement was found between the two methods (κ=0.716, P<0.001).

The PCR detected a higher rate of sepsis in neonates than blood culture. Therefore, PCR is useful for the rapid and accurate diagnosis of bacterial infection, with a significant impact on the current inappropriate and unnecessary use of antibiotics in the treatment of newborns. We recommend using broad-range PCR to rapidly diagnose infants with sepsis.