摘要目的:本研究旨在评估杀白细胞素（Panton-Valentine leukocidin，PVL）基因与临床特征之间的关系，描述侵袭性金黄色葡萄球菌（简称金葡菌）感染临床分离株的分子生物学特征。方法:收集自2016年1月至2019年12月间首都医科大学附属北京儿童医院引起侵袭性感染的金葡菌分离株，并使用电子病历回顾性收集对应患儿临床资料；对分离株进行多基因座序列分型和葡萄球菌蛋白A分型，并检测pvl基因携带情况。此外，使用微量肉汤稀释法检测所有分离株的抗生素最低抑菌浓度，根据金葡菌分离株是否携带pvl分为pvl+和pvl-两组，使用成组 t检验及Mann-Whitney U检验比较两组临床资料；使用 χ2检验比较两组分离株药物敏感性。 结果:研究期间共收集到127例侵袭性金葡菌感染病例，pvl+组患儿的白细胞计数、中性粒细胞计数、CRP高于pvl-组（ P=0.001、 P=0.001、 P=0.005）。pvl携带率为44.9%，在57例pvl+致病株中，64.9%（37/57）为MRSA感染。pvl-分离株的多重耐药率高于pvl+分离株（70% vs. 49.12%， P=0.02）。 结论:在侵袭性金葡菌感染中，pvl与患儿炎症指标升高有关；临床分离株中pvl阳性率较高，且pvl-金葡菌多重耐药率较高。

abstractsObjective:To evaluate the relationship between the Panton-Valentine leukocidin (pvl) strain and clinical characteristics, and to describe the molecular biological characteristics of invasive Staphylococcus aureus ( S. aureus) infected clinical isolates. Methods:The isolates of S. aureus caused by invasive infection were collected in Beijing Children's Hospital Affiliated to Capital Medical University from January 2016 to December 2019, and the clinical data of the corresponding children were collected retrospectively using electronic medical records. Multilocus sequence typing, spa typing and pvl gene were analyzed using the PCR. In addition, the minimum inhibitory concentrations (MIC) of antibiotics of all isolates were detected by the micro-broth dilution method, and the isolates were divided into the pvl+ and pvl- groups according to whether or not the S. aureus isolates carried pvl. The t test and the Mann-Whitney U test were used to compare the clinical symptoms between the pvl+ and pvl- groups. Chi-square test was used to compare the drug susceptibility between the two isolates. Results:A total of 127 cases of invasive S. aureus infection were collected during the study period. The white blood cell count, neutrophil count, and C-reaction protein level in the pvl+ group were significantly higher than those in the pvl- group ( P=0.001, P=0.001, P=0.005). The rate of pvl carrier was 44.9%. Among 57 pvl+ pathogenic strains, 64.9% (37/57) were MRSA. The multidrug resistance rate of pvl- isolates was higher than that of pvl+ isolates (70% vs. 49.12%, P=0.02). Conclusions:In invasive S. aureus infection, pvl+ strain is associated with elevated inflammatory markers in children. the positive rate of pvl is higher in clinical isolates, and the multidrug resistance rate of pvl- S. aureus is higher.