Desroches Marine, Clermont Olivier, Lafeuillade Bruno, Rodriguez Christophe, Darty Mélanie, Royer Guilhem, Bouvet Odile, Ounnoughene Nadra, Noizat-Pirenne France, Denamur Erick, Decousser Jean-Winoc
INSERM UMR1137, IAME, Paris Diderot University, Faculty of Medicine Xavier Bichat, Paris, France.
Department of Bacteriology and Infection Control, University Hospital Henri Mondor, Assistance Publique-Hôpitaux de Paris, Créteil, France.
Transfusion. 2018 Aug;58(8):1940-1950. doi: 10.1111/trf.14812.
Transfusion-transmitted bacterial infections (TTBIs) are the main residual infectious complications of transfusions. Escherichia coli and platelet (PLT) concentrates may be epidemiologically associated, leading to severe, if not lethal, TTBIs. We investigated the genotypic and phenotypic reasons for this clinically deleterious combination.
We investigated a French national E. coli strain collection related to six independent episodes of TTBIs. Their phenotypic characterizations included antibiotic susceptibility testing, growth testing under different culture conditions, serum survival assays, and virulence in a sepsis mouse model. Their genotypic characterizations included polymerase chain reaction phylotyping, whole genome sequencing, and a subsequent in silico analysis.
We highlighted a selection process of highly extraintestinal virulent strains, mainly belonging to the B2 phylogroup, adapted to the hostile environment (high citrate concentration and a bactericidal serum effect) of apheresis-collected platelet concentrates (PCs). Compared to controls, the E. coli TTBI strains grew faster in the PCs due to a superior ability to capture iron. The in vitro growth performances were highly compatible with blood-derived product real-life conditions, including storage conditions and delays. The consistent serum resistance of TTBI strains promotes their survival in both the donor's and the receiver's blood and in the PCs.
This study pointed out that E. coli strains responsible for TTBI exhibit very specific traits. They belong to the extraintestinal pathogenic phylogroups and have a high intrinsic virulence. They can be resistant to complement, capture iron, and grow in the apheresis-collected PCs. These findings therefore support the reinforcement of the postdonation information.
输血传播的细菌感染（TTBIs）是输血主要的残留感染并发症。大肠杆菌与血小板浓缩物在流行病学上可能存在关联，会导致严重的（即便不是致命的）TTBIs。我们调查了这种临床有害组合的基因型和表型原因。
我们调查了与6起独立的TTBIs事件相关的法国全国大肠杆菌菌株收集样本。它们的表型特征包括抗生素敏感性测试、不同培养条件下的生长测试、血清存活试验以及在败血症小鼠模型中的毒力测试。它们的基因型特征包括聚合酶链反应系统发育分型、全基因组测序以及随后的计算机分析。
我们强调了一个高度肠外致病菌株的选择过程，这些菌株主要属于B2系统发育群，适应了单采血小板浓缩物（PCs）的恶劣环境（高柠檬酸盐浓度和杀菌血清效应）。与对照相比，由于捕获铁的能力更强，大肠杆菌TTBI菌株在PCs中生长更快。体外生长性能与血液制品的实际情况高度相符，包括储存条件和时间延迟。TTBI菌株一致的血清抗性促进了它们在供体和受体血液以及PCs中的存活。
本研究指出，导致TTBI的大肠杆菌菌株表现出非常特殊的特征。它们属于肠外致病系统发育群，具有很高的固有毒力。它们能够抵抗补体、捕获铁并在单采的PCs中生长。因此，这些发现支持加强献血后信息告知。
