Data for the manuscript.

Sepsis is the leading postnatal cause of neonatal mortality worldwide. Globally Klebsiella pneumoniae is the leading cause of sepsis in hospitalized neonates. This study reports the development and evaluation of an ELISA for anti-Klebsiella IgG using dried blood spot (DBS) samples and evaluates the association of anti-Klebsiella IgG (anti-Kleb IgG) antibodies in maternal and neonatal samples with the risk of neonatal sepsis. Neonates and their mothers were enrolled at 0–96 hours of life in the neonatal unit of a tertiary referral hospital in Gaborone, Botswana and followed until death or discharge to assess for episodes of blood culture-confirmed neonatal sepsis. Neonates with sepsis had significantly lower levels of Kleb-IgG compared to neonates who did not develop sepsis (Mann-Whitney U, p = 0.012). Similarly, samples from mothers of neonates who developed sepsis tended to have less Kleb-IgG compared to mothers of controls. The inverse correlation between Kleb-IgG levels and all-cause bacteremia suggests that maternal Kleb-IgG may be protective through cross-reactivity with common bacterial epitopes. These data support the continued use of immunoglobulin assays using DBS samples to explore the role of passive immunity on neonatal sepsis risk and reaffirm the critical need for research supporting the development of maternal vaccines for neonatal sepsis.脓毒症是全球范围内新生儿产后死亡的首要致死原因。全球范围内，肺炎克雷伯菌（Klebsiella pneumoniae）是住院新生儿脓毒症的首要致病菌。本研究报道了一种基于干血斑（dried blood spot, DBS）样本检测抗克雷伯菌IgG（anti-Klebsiella IgG）的酶联免疫吸附试验（Enzyme-Linked Immunosorbent Assay, ELISA）的开发与评估，并分析了孕产妇及新生儿样本中的抗克雷伯菌IgG（简称anti-Kleb IgG）抗体水平与新生儿脓毒症发病风险的关联。本研究纳入博茨瓦纳哈博罗内某三级转诊医院新生儿科中出生后0~96小时内的新生儿及其母亲，对所有受试者随访至死亡或出院，以评估血培养确诊的新生儿脓毒症发作情况。罹患脓毒症的新生儿，其体内Kleb-IgG水平显著低于未发生脓毒症的新生儿（曼-惠特尼U检验，Mann-Whitney U，p=0.012）。与之类似，发生脓毒症的新生儿的母亲样本中，Kleb-IgG水平也较对照组新生儿的母亲更低。Kleb-IgG水平与全因菌血症呈负相关，这提示孕产妇体内的Kleb-IgG可能通过与常见细菌表位发生交叉反应而发挥保护作用。本研究数据支持继续采用干血斑样本开展免疫球蛋白检测，以探究被动免疫在新生儿脓毒症发病风险中的作用，并再次证实开发针对新生儿脓毒症的孕产妇疫苗的研究需求极为迫切。