Evidence of pediatric sepsis caused by a drug resistant <i>Lactococcus garvieae</i> contaminated platelet concentrate

Owing to an increasing number of infections in adults, <i>Lactococcus (L.) garvieae</i> has gained recognition as an emerging human pathogen, causing bacteraemia and septicaemia. In September 2020, four paediatric onco-hematologic patients received a platelet concentrate from the same adult donor at Bambino Gesù Children’s Hospital IRCCS, Rome. Three of four patients experienced <i>L. garvieae</i> sepsis one day after transfusion. The <i>L. garvieae</i> pediatric isolates and the donor’s platelet concentrates were retrospectively collected for whole-genome sequencing and shot-gun metagenomics, respectively (Illumina HiSeq). By de novo assembly of the <i>L. garvieae</i> genomes, we found that all three pediatric isolates shared a 99.9% identity and were characterized by 440 common SNPs. Plasmid pUC11C (conferring virulence properties) and the temperate prophage Plg-Tb25 were detected in all three strains. Core SNP genome-based maximum likelihood and Bayesian trees confirmed their phylogenetic common origin and revealed their relationship with <i>L. garvieae</i> strains affecting cows and humans (bootstrap values &gt;100 and posterior probabilities = 1.00). Bacterial reads obtained by the donor’s platelet concentrate have been profiled with MetaPhlAn2 (v.2.7.5); among these, 29.9% belonged to Firmicutes, and 5.16% to Streptococcaceae (&gt;97% identity with <i>L. garvieae</i>), confirming the presence of <i>L. garvieae</i> in the platelet concentrate transfusion. These data showed three episodes of sepsis for the first time due to a transfusion-associated transmission of <i>L. garvieae</i> in three pediatric hospitalized hematology patients. This highlights the importance to implement the screening of platelet components with new human-defined pathogens for ensuring the safety of blood supply, and more broadly, for the surveillance of emerging pathogens.随着成人感染病例的持续增多，加维氏乳球菌（Lactococcus (L.) garvieae）已被认定为一种新兴人类致病菌，可引发菌血症（bacteraemia）与败血症（septicaemia）。2020年9月，罗马邦比诺盖苏儿童医院IRCCS的4名儿科肿瘤血液疾病患者，接受了同一名成年供血者的浓缩血小板输注。4名患者中有3名在输注后1天出现了加维氏乳球菌败血症。 研究人员回顾性收集了患儿体内分离的加维氏乳球菌菌株与该供血者的浓缩血小板样本，分别开展全基因组测序（whole-genome sequencing）与鸟枪宏基因组测序（shot-gun metagenomics），测序平台为Illumina HiSeq。通过对加维氏乳球菌基因组进行从头组装（de novo assembly），我们发现3株患儿分离菌株的同源性高达99.9%，且共存在440个相同的单核苷酸多态性（single nucleotide polymorphism, SNP）位点。3株菌株中均检测到了携带毒力特性的pUC11C质粒，以及温和噬菌体（temperate prophage）Plg-Tb25。 基于核心SNP基因组构建的最大似然系统发育树与贝叶斯系统发育树，证实了3株菌株的系统发育同源性，并揭示了其与感染牛类及人类的加维氏乳球菌菌株的进化关联（自举支持值＞100，后验概率=1.00）。研究人员采用MetaPhlAn2（v.2.7.5）对供血者浓缩血小板样本中的细菌测序读段进行了物种分类注释；结果显示，29.9%的读段隶属于厚壁菌门（Firmicutes），5.16%隶属于链球菌科（Streptococcaceae），且与加维氏乳球菌的同源性＞97%，证实了该浓缩血小板输注样本中存在加维氏乳球菌。 本研究首次报道了3名住院儿科血液疾病患者因输注携带加维氏乳球菌的血小板而发生输血相关性传播引发败血症的3起病例。该研究凸显了针对新型人类致病菌开展血小板成分筛查的重要性，这不仅可为血液供应安全提供保障，更可推广应用于新兴病原体的监测工作。

搜集汇总

背景与挑战

背景概述

该数据集记录了2020年9月在意大利罗马Bambino Gesù儿童医院发生的一起由耐药性乳球菌污染的浓缩血小板引起的儿科败血症事件，涉及三名肿瘤血液病患者。研究通过基因组分析证实了病原体在患者和供体血小板中的共同起源，首次报道了乳球菌通过输血传播导致败血症的案例，突出了加强血液成分筛查以应对新兴病原体的必要性。