Objective To evaluate the diagnostic yield of the multiplex polymerase chain reaction (PCR) method in cerebrospinal fluid (CSF) for the diagnosis of purulent meningitis (PM) in children.

Methods PM was diagnosed according to the European Society for Clinical Microbiology and Infectious Diseases guideline (2016). Patients with PM between May 2015 and October 2018 were included. The multiplex PCR method was used to detect eight common identified bacteria in PM. Its sensitivity and specificity were compared with bacteria culture.

Results A total of 106 cases were enrolled. Pathogenic bacteria were identified in 27 (25.5%) cases by culture and in 37 (34.9%) cases by multiplex PCR assay. The top three bacteria were Streptococcus pneumoniae, Escherichia coli K1, and Streptococcus agalactiae. When using culture as the gold standard, the multiplex PCR assay showed a sensitivity of 100, 88.9, and 75.0% for S. agalactiae, S. pneumoniae, and E. coli K1, respectively, and a specificity of more than 91.3% for all three bacteria. For detectable bacteria, the positive rate of the multiplex PCR assay (36.6%, 37/101) was significantly higher than that of the bacteria culture (21.8%, 22/101). When combining the two methods, etiology was identified in 42.5% (45/106) of the patients.

Conclusion Streptococcus pneumoniae, E. coli K1, and S. agalactiae were the predominant pathogens causing pediatric PM. As a rapid method with high sensitivity and specificity, the multiplex PCR assay in CSF could be used as an adjunctive approach with bacteria culture for the pathogen identification of PM.

目的 评估脑脊液（CSF）中多重聚合酶链反应（PCR）方法诊断儿童化脓性脑膜炎（PM）的诊断率。

方法 根据欧洲临床微生物学和传染病指南（2016）诊断PM。纳入2015年5月至2018年10月之间的PM患者。多重PCR方法用于检测PM中八种常见的细菌。将其敏感性和特异性与细菌培养进行比较。

结果 共纳入106例。通过培养鉴定出致病菌27例（占25.5％），通过多重PCR检测鉴定出37例（34.9％）。排名前三位的细菌是肺炎链球菌，大肠杆菌K1和无乳链球菌。当使用培养物作为金标准品时，多重PCR分析显示无乳链球菌，肺炎链球菌和大肠杆菌的敏感性分别为100％，88.9％和75.0％。所有三种细菌的K1特异性分别超过91.3％。对于可检测的细菌，多重PCR分析的阳性率（36.6％，37/101）显着高于细菌培养物的阳性率（21.8％，22/101）。两种方法结合使用时，在42.5％（45/106）的患者中发现了病因。

结论 肺炎链球菌，大肠杆菌K1和无乳链球菌是引起小儿PM的主要病原体。作为一种具有高灵敏度和特异性的快速方法，脑脊液中的多重PCR检测可以作为细菌培养的辅助方法，用于鉴定PM的病原体。