Application Of Diagnosing Neonatal Septicemia In 16S RRNA Gram-Specific Probe-Based Quantitative Polymerase Chain Reaction

Objective To find the senstive,rapid and accurate etiology testing method by comparing the usefulness of the Gram-specific probe-based quantitative polymerase chain reaction test and bacterial culture in neonatal septicemia.Methods Based on the 16 S rRNA gene of bacteria,a pair of universal primers and a set of Gram stain-specific-probes(including Gram-positive probe and Gram-negative probe)were designed.Collecting the two copies of sterile body fluids from suspected of infants with clinical features suggestive of bacterial blood-stream infection who were admitted to the neonatology department of Fujian province maternity and child carefrom February 2016 to January 2017.One of the Copy was cultured immediately,and another was extracted DNA then was tected by Gram-specific probe-based quantitative polymerase chain reaction.The results were analyzed using SPSS software.Results1.A total of 304 suspected infection episodes were investigated,of which 254 episodes were blood samples,of which 45 episodes were cerebrospinal fluid,of which 5 episodes were peritoneal fluid.There were 59 positive results 19.41%(59/304)with Gram-specific probe-based quantitative polymerase chain reaction and 44 positive results 14.47%(44/304)with blood culture.The positive rate of Gram-specific probe-based quantitative polymerase chain reaction was significantly higher than that of blood culture(P<0.05).2.Gram-specific probe-based quantitative polymerase chain reaction showed a sensitivity of 81.8%,a specificity of 91.2%,a positive predictive value of 61.0%,and a negative predictive value of 96.7%.3.Gram-specific probe-based quantitative polymerase chain reaction relatively was more sensitive in detecting Gram-negative organisms(90.5%)than Gram-positive organisms(73.9%).There were no difference of specificity,positive predictive value and negative predictive value in detecting Gram-negative organisms and Gram-positive organisms.Conclusions Gram-specific probe-based quantitative polymerase chain reaction has a positive clinical application value in the early identification of bacterial infection,the identification of Gram-specific classification and ruling out the diagnosis of bacterial sepsis in noninfected term neonates.