Bloodstream infections (BSIs) are common in hospitals, often life-threatening and increasing in prevalence. Microorganisms in the blood are usually rapidly cleared by the immune system and filtering organs but, in some cases, they can cause an acute infection and trigger sepsis, a systemic response to infection that leads to circulatory collapse, multiorgan dysfunction and death. Most BSIs are caused by bacteria, although fungi also contribute to a substantial portion of cases. Escherichia coli, Staphylococcus aureus, coagulase-negative Staphylococcus, Klebsiella pneumoniae and Candida albicans are leading causes of BSIs, although their prevalence depends on patient demographics and geographical region. Each species is equipped with unique factors that aid in the colonization of initial sites and dissemination and survival in the blood, and these factors represent potential opportunities for interventions. As many pathogens become increasingly resistant to antimicrobials, new approaches to diagnose and treat BSIs at all stages of infection are urgently needed. In this Review, we explore the prevalence of major BSI pathogens, prominent mechanisms of BSI pathogenesis, opportunities for prevention and diagnosis, and treatment options.

血流感染 （BSI） 在医院很常见，通常危及生命并且患病率不断增加。血液中的微生物通常会被免疫系统和过滤器官迅速清除，但在某些情况下，它们会引起急性感染并引发败血症，败血症是对感染的全身反应，导致循环衰竭、多器官功能障碍和死亡。大多数 BSI 是由细菌引起的，尽管真菌也导致了很大一部分病例。大肠埃希菌、金黄色葡萄球菌、凝固酶阴性葡萄球菌、肺炎克雷伯菌和白色念珠菌是 BSI 的主要原因，尽管它们的患病率取决于患者人口统计学和地理区域。每个物种都配备了独特的因子，有助于初始位点的定植以及在血液中的传播和存活，这些因子代表了干预的潜在机会。随着许多病原体对抗菌素的耐药性越来越强，迫切需要新的方法来诊断和治疗感染各个阶段的 BSI。在本综述中，我们探讨了主要 BSI 病原体的流行率、BSI 发病机制的主要机制、预防和诊断的机会以及治疗选择。