本文旨在探讨2016—2018年上海市儿童医院患儿血流感染病原菌的种类分布及耐药状况，为临床预防和治疗血流感染提供合理的用药依据。采用全自动微生物分析系统对血培养分离出的病原菌进行菌鉴定和药敏试验，分析细菌种类分布特点及耐药情况。期间共送检标本24 687份，分离出病原菌2 092株，阳性检出率为8.5%。其中革兰阳性菌占84.4%，革兰阴性菌占15.6%；检出率居前5位的分别为凝固酶阴性葡萄球菌(coagulase-negative Staphylococcus，CoNS)、肠球菌、肺炎克雷伯菌、链球菌、大肠埃希菌。新生儿科患儿血培养阳性检出率最高，为34.5%，其中CoNS的分离率明显高于其他科室，其平均报阳时间为(32.53±12.36)h。未发现对万古霉素和利奈唑胺耐药的葡萄球菌和肠球菌。亚胺培南、美洛培南、阿米卡星、头孢哌酮-舒巴坦和哌拉西林-他唑巴坦对大肠埃希菌的抗菌活性较强，耐药率低于10%。肺炎克雷伯菌对第3代头孢菌素的耐药率达80%以上，对碳青霉烯类的耐药率逐年上升，2018年为62.5%。铜绿假单胞菌对碳青霉烯类的耐药率为9.1%。鲍曼不动杆菌对大部分抗菌药物的耐药率在60%以上，对碳青霉烯类的耐药率为66.7%。结果表明，儿童血培养病原菌种类复杂，CoNS占较大比例，导致血流感染的诊断更加复杂。因此，了解儿童血流感染病原菌的种类分布特征和耐药情况将有助于指导临床合理使用抗菌药物。

This study aims to investigate the species distribution and drug resistance of pathogenic bacteria in the children with bloodstream infections in Shanghai Children’s Hospital from 2016 to 2018, and to provide rational drug use basis for clinical prevention and treatment of bloodstream infections. The automatic microbiological analysis system was used to identify the pathogenic bacteria isolated from the blood culture samples and conduct drug sensitivity test to analyze their distribution characteristics and drug resistance. A total of 24 687 samples were sent for examinations, finally 2 092 pathogenic bacteria were isolated with a positive detection rate of 8.5%. Gram-positive bacteria accounted for 84.4%, and Gram-negative bacteria accounted for 15.6%. The top five pathogens were coagulase-negative Staphylococcus (CoNS), Enterococcus, Klebsiella pneumoniae, Streptococcus and Escherichia coli. The positive detection rate of blood culture in Neonatal Department was 34.5%, and the isolation rate of CoNS was significantly higher than that in other departments. The average time to positivity of CoNS was (32.53±12.36) h. No Staphylococcus and Enterococcus resistant to vancomycin and linezolid were found. Imipenem, meropenem, amikacin, cefoperazone-sulbactam and piperacillin-tazobactam had strong antibacterial activity against Escherichia coli, and the drug resistance rate was less than 10%. The drug resistance rate of Klebsiella pneumoniae to third-generation cephalosporins reached more than 80%, and the drug resistance rate to carbapenems increased year by year, reaching 62.5% in 2018. The drug resistance rate of Pseudomonas aeruginosa to carbapenems was 9.1%. The drug resistance rate of Acinetobacter baumannii to most antimicrobial agents was more than 60%, and to carbapenems was 66.7%. It is shown that pathogenic bacteria from blood culture of children with bloodstream infections are complex, and CoNS accounts for a large proportion, which makes the diagnosis of bloodstream infections become more complicated. Therefore, understanding the distribution characteristics and drug resistance of pathogenic bacteria from blood culture of children with bloodstream infections is helpful to guide the rational use of antibiotics in clinical application.