Application Of Targeted Macrogenome Sequencing Technology Based On Nanopore Platform In The Detection Of Pathogens In Blood Of Children With Sepsis

Objective: Nanopore-based Targeted Macrogenomic Sequencing(nTMS)based on nanopore platform detects pathogens in blood samples of children with sepsis,and compares it with routine blood culture(BC),to explore its application value in pathogen detection in blood samples of children with sepsis.Methods: This study is a prospective observational study that included 56 children diagnosed with sepsis related organ dysfunction in the pediatric intensive care unit of Shengjing Hospital affiliated with China Medical University from October 2020 to February 2022.The detection rates of nTMS and blood culture were compared,and the consistency was analyzed;Then the detection rates of blood culture,nTMS and their combination were compared among different subgroups;Finally,nTMS is combined with traditional blood culture.Positive nTMS or blood culture is the pathogen detection group,and both are negative for the undetected group.Relevant clinical indicators of the pathogen detection group and the undetected group are analyzed and compared.Results: 1.In this study,the detection rate of nTMS in blood samples of children with sepsis was significantly higher than that of blood culture(46.4% vs 17.8%),but it did not achieve good consistency(Kappa value was 0.102,P>0.05).Among the 10 patients with positive blood culture,the detection results of nTMS were consistent with those of blood culture,while in the other 5 cases,4 cases were negative,and 1 case produced inconsistent results.2.In subgroup analysis,the detection rate of blood culture combined with nTMS in septic shock group was significantly higher than that in non-shock group(72.0% vs38.7%,P<0.05),and the difference was statistically significant.The detection rate of nTMS in shock group was higher than that in non-shock group,but the difference was not statistically significant(P>0.05);nTMS or the combination of the two methods had no statistical difference between the single organ dysfunction group and the multiple organ dysfunction group(P>0.05),but compared with the single organ dysfunction group,the nTMS detection rate and the combined detection rate of the two methods in the multiple organ dysfunction group had an upward trend;There was no statistical difference between blood culture test,nTMS or combination of the two methods in different primary infection sites(P>0.05).3.Combining nTMS with blood culture,positive nTMS or blood culture is the pathogen detection group,and both are negative for the undetected group,with 30 cases in the detection group(53.6%)and 26 cases in the undetected group(46.4%).The levels of PCT,IL-6,D-D and the proportion of septic shock in the pathogen detection group are significantly higher than those in the undetected group,with a statistically significant difference(P<0.05).There is no statistically significant difference in other clinical indicators(P>0.05),but the detected group has higher CRP compared with the undetected group PELOD-2 score,p SOFA score,hospital days and mortality,lower platelet count.Conclusions: nTMS can improve the detection rate and coverage of pathogens in blood samples of children with sepsis.The detection rate is relatively high in children with septic shock and multiple organ dysfunction,but it is not consistent with blood culture.nTMS should be regarded as an auxiliary method of blood culture,not an alternative method.This technology still has some limitations and needs to further optimize the sequencing process.At the same time,the interpretation of sequencing data is also crucial for clinical diagnosis and treatment.