Table_1_Diagnostic performance and clinical impact of blood metagenomic next-generation sequencing in ICU patients suspected monomicrobial and polymicrobial bloodstream infections.xlsx

IntroductionEarly and effective application of antimicrobial medication has been evidenced to improve outcomes of patients with bloodstream infection (BSI). However, conventional microbiological tests (CMTs) have a number of limitations that hamper a rapid diagnosis.
MethodsWe retrospectively collected 162 cases suspected BSI from intensive care unit with blood metagenomics next-generation sequencing (mNGS) results, to comparatively evaluate the diagnostic performance and the clinical impact on antibiotics usage of mNGS.
Results and discussionResults showed that compared with blood culture, mNGS detected a greater number of pathogens, especially for Aspergillus spp, and yielded a significantly higher positive rate. With the final clinical diagnosis as the standard, the sensitivity of mNGS (excluding viruses) was 58.06%, significantly higher than that of blood culture (34.68%, P<0.001). Combing blood mNGS and culture results, the sensitivity improved to 72.58%. Forty-six patients had infected by mixed pathogens, among which Klebsiella pneumoniae and Acinetobacter baumannii contributed most. Compared to monomicrobial, cases with polymicrobial BSI exhibited dramatically higher level of SOFA, AST, hospitalized mortality and 90-day mortality (P<0.05). A total of 101 patients underwent antibiotics adjustment, among which 85 were adjusted according to microbiological results, including 45 cases based on the mNGS results (40 cases escalation and 5 cases de-escalation) and 32 cases on blood culture. Collectively, for patients suspected BSI in critical condition, mNGS results can provide valuable diagnostic information and contribute to the optimizing of antibiotic treatment. Combining conventional tests with mNGS may significantly improve the detection rate for pathogens and optimize antibiotic treatment in critically ill patients with BSI.

引言：早期合理应用抗菌药物已被证实可改善血流感染（bloodstream infection, BSI）患者的预后。然而，传统微生物检测（conventional microbiological tests, CMTs）存在诸多局限，阻碍了快速诊断的开展。
方法：本研究回顾性收集了162例来自重症监护室的疑似血流感染患者的血液宏基因组二代测序（metagenomics next-generation sequencing, mNGS）检测结果，旨在对比评估mNGS的诊断效能及其对抗菌药物使用的临床影响。
结果与讨论：结果显示，与血培养相比，mNGS可检出更多病原体，尤其是曲霉属（Aspergillus spp），且阳性率显著更高。以最终临床诊断为金标准，mNGS（不含病毒检测）的敏感度为58.06%，显著高于血培养的34.68%（P<0.001）。联合血液mNGS与血培养结果后，敏感度提升至72.58%。共46例患者为混合病原体感染，其中以肺炎克雷伯菌（Klebsiella pneumoniae）和鲍曼不动杆菌（Acinetobacter baumannii）最为常见。与单菌感染患者相比，多菌血流感染患者的序贯器官衰竭评分（SOFA）、天冬氨酸氨基转移酶（AST）水平、住院病死率及90天病死率均显著升高（P<0.05）。共计101例患者接受了抗菌药物调整，其中85例依据微生物检测结果进行调整：包括45例基于mNGS结果调整（40例升级治疗、5例降阶梯治疗），以及32例基于血培养结果调整。综上，对于重症监护室疑似血流感染的危重患者，mNGS可提供有价值的诊断信息，助力抗菌药物治疗方案的优化。联合传统检测与mNGS，可显著提高危重血流感染患者的病原体检出率，并优化其抗菌治疗方案。