Neonatal Sepsis Diagnosis: ; PCR Commercial Technique and Blood Culture

Although advances in neonatal care have improved survival and reduced complications in preterm infants, sepsis still contributes significantly to mortality and in Neonatal Intensive Care Units (NICUs), in particular for very-low-birth-weight (VLBW, \<1500 g) and extremely-low-birth-weight (ELBW, \<1000g). Based on the timing of the infection neonatal sepsis has been classified into early-onset sepsis (EOS) and late-onset sepsis (LOS), with differences in the mode of transmission and predominant organisms. EOS is defined as onset in the first 3 days of life generally due to vertical transmission of bacteria from mothers to infants during the intrapartum period. LOS occurs after 3 days of life and it is attributed to pathogens acquired postnatally (horizontal transmission). Considering generally neonatal sepsis in Europe, 90% of the responsible bacteria resulted to be: Streptococcus agalactiae, Escherichia coli, Klebsiella pneumoniae, e Listeria monocytogenes. The diagnosis is difficult because clinical signs, particularly early in the course of disease, are subtle and nonspecific, and laboratory tests and blood culture are not always reliable. Moreover. blood culture (considered the 'gold standard) takes 48-72 hours for result. In fact the cultural method requires the presence of living and vital germs, depends on the volume of the sample - serious problem in neonatal population -, several hours are needed to process the sample, possibly resulting falsely negative in subjects undergoing concomitant antibiotic treatment or a false positive result can be found by contamination. The method based on molecular biology does not require living germs and, therefore, is not characterised by the sensitivity limitations. Such method can result to be extremely effective in patients receiving antibiotic therapy. In the present study, when an infant has to undergone blood sample for bacteria culture to verify a possible sepsis, a residual blood (200µl) is processed in the same ti