Abstract：
Approximately 90 % of infants born before 28 full weeks(extremely-preterm-infants) receive erythrocyte transfusions in early life. Umbilical cord blood(UCB) has been investigated as an alternative source for erythrocyte transfusions to preterm neonates. This retrospective study aimed to compile/evaluate spectrum of bacteria groups/species intermittently detected in processed UCB at National-Swedish-Cord blood bank, (NS-CBB) during the years 2008-2020. Consecutive data from the years 2008-2020 were investigated. UCB from healthy newborns born after 37 full weeks of gestation was collected following clamping of cord (1 min) through cannulation of umbilical vein(vaginal-and C-section-deliveries). In total, 5194 cord blood units (UCBUs) that met NS-CBB-guidelines for total nucleated-cell-content(TNC) were manufactured from 8875 collections. Of 5194 UCBUs,77,6 % were from vaginal-and 22,4 % from C-section deliveries.Samples(10 mL) were collected from surplus eryhtrocyte fraction post-processing(n = 5194), transferred into BACT/ALERT® aerobic/anaerobic culture flasks and monitored 10 days using BACT/ALERT®-3D-Microbial-Detection-Systems. Positive samples were subcultured and typed for bacterial groups and/or species. Out of 5194 processed sampled UCB units,186 (3,6 %) were discarded due to positive sterility tests, 92 % were detected in samples from vaginal-deliveries and 8 % from C-section-deliveries. In all,16 different groups of bacteria and 27 species were identified. Common bacterial/groups and species were anaerobe gram-negative rods(n = 28),coagulase-negative-staphylococci(n = 21),gram-positive rods(n = 21),anaerobe-gram-positive cocci(n = 20) and viridans-streptococci(n = 13). Extracted from these results,in positive samples(n = 13) from C-section deliveries, bacteria were found:viridans-streptococci(n = 7),Aerococcus-urinae(n = 1), Staphylococcus lugdunensis(n = 1),other coagulase-negative staphylococci(n = 1) or a mix of aerobic/anaerobic bacteria(n = 3). Our results are in alignment with previously published contamination rates in processed UCBUs. Still, results point towards importance of strict microbial monitoring when manufacturing UCBUs to achieve patient-safe- products for stem-cell transplantation/transfusion.
摘要：
大约90%在28周前出生的婴儿(极早产儿)在生命早期接受红细胞输血。已经研究了脐带血（UCB）作为早产儿红细胞输血的替代来源。这项回顾性研究旨在汇编/评估在瑞典国家脐带血库中处理过的UCB中间歇性检测到的细菌群/物种的频谱，（NS-CBB）在2008-2020年期间。对2008-2020年的连续数据进行了调查。通过脐静脉插管（阴道和剖腹产）夹住脐带（1分钟）后，从妊娠37周后出生的健康新生儿中收集UCB。总的来说,从8875个集合中制造了符合NS-CBB总有核细胞含量（TNC）指南的5194个脐带血单位（UCBU）。在5194个UCBU中，77,6％来自阴道分娩，22,4％来自剖腹产。从处理后的剩余红细胞级分收集样品(10mL)(n=5194),转移到BACT/ALERT®需氧/厌氧培养瓶中，并使用BACT/ALERT®-3D-微生物检测系统监测10天。对阳性样品进行传代培养，并对细菌群和/或物种进行分型。在5194个经过处理的采样UCB单元中，186(3.6%)因无菌试验阳性而被丢弃，在阴道分娩的样本中检测到92％，在剖腹产的样本中检测到8％。总之,鉴定了16种不同的细菌和27种。常见的细菌/群体和物种是厌氧菌革兰氏阴性棒(n=28)，凝固酶阴性葡萄球菌（n=21），革兰氏阳性棒（n=21），厌氧菌革兰氏阳性球菌（n=20）和绿柱菌链球菌（n=13）。从这些结果中提取，在剖腹产的阳性样本(n=13)中，发现细菌:绿柱石链球菌(n=7)，尿球菌（n=1），罗氏葡萄球菌(n=1),其他凝固酶阴性葡萄球菌（n=1）或需氧/厌氧菌混合物（n=3）。我们的结果与以前发表的处理过的UCBUs中的污染率一致。尽管如此，研究结果指出,在生产UCBUs时,必须进行严格的微生物监测,以实现干细胞移植/输血的患者安全产品.
