The Lysis of Pathogenic Escherichia coli by Bacteriophages Releases Less Endotoxin Than by β-Lactams.
The Lysis of Pathogenic Escherichia coli by Bacteriophages Releases Less Endotoxin Than by β-Lactams.
复制标题
DOI：
10.1093/cid/cix184
复制
发表时间：
2017-06-01
期刊：
影响因子：
--
通讯作者：
Debarbieux L
中科院分区：
文献类型：
--
作者：
Dufour N;Delattre R;Ricard JD;Debarbieux L
噬菌体能迅速杀死细菌。噬菌体诱导的内毒素释放可能是噬菌体治疗过程中的一个问题。我们发现噬菌体比β-内酰胺更快地阻止细胞生长，导致内毒素释放更低。除了评估噬菌体治疗效果的大量实验数据外，有关该方法安全性的问题尚未得到充分解决。特别是，由于噬菌体可以在10分钟内杀死细菌细胞，因此由革兰氏阴性菌引起的严重感染中相关的内毒素释放（ER）可能是值得关注的问题。研究了两种治疗性强毒噬菌体和4种参比抗生素在体外杀灭2株致病性大肠杆菌和产生内质网的能力。通过在光镜下观察瞬时细胞活力、菌落形成单位计数、释放的游离内毒素浓度和细胞形态，评估这些参与者之间的早期相互作用（前3小时）。虽然β-内酰胺的作用相对缓慢，但两种被测试的噬菌体以及阿米卡星都能够迅速消除细菌的生长。即使考虑到最快的噬菌体（细胞在9分钟内裂解），噬菌体诱导的ER浓度也从未达到抗生素治疗所记录的最高值。在噬菌体处理的条件下，内毒素随时间的累积浓度低于β-内酰胺组，接近阿米卡星组。β-内酰胺类导致细胞形态发生强烈变化（亚胺培南作用下的球质体，头孢西丁和头孢曲松作用下的丝状细胞），而阿米卡星和噬菌体不会改变细胞形状，而是产生细胞内包涵体。这项工作为噬菌体治疗的安全性提供了重要和令人欣慰的数据。与治疗相关的噬菌体具有低内毒素释放谱和快速杀菌作用，并不逊于β-内酰胺。
Bacteriophages kill bacteria very rapidly. Bacteriophage-induced endotoxin release could be an issue during phage therapy. We show that bacteriophages stop cell growth more rapidly than do β-lactams, resulting in a lower endotoxin release. Other than numerous experimental data assessing phage therapy efficacy, questions regarding safety of this approach are not sufficiently addressed. In particular, as phages can kill bacterial cells within <10 minutes, the associated endotoxin release (ER) in severe infections caused by gram-negative bacteria could be a matter of concern. Two therapeutic virulent phages and 4 reference antibiotics were studied in vitro for their ability to kill 2 pathogenic strains of Escherichia coli and generate an ER. The early interaction (first 3 hours) between these actors was assessed over time by studying the instantaneous cell viability, the colony-forming unit count, the concentration of free endotoxin released, and the cell morphology under light microscope. While β-lactams have a relatively slow effect, both tested phages, as well as amikacin, were able to rapidly abolish the bacterial growth. Even when considering the fastest phage (cell lysis in 9 minutes), the concentrations of phage-induced ER never reached the highest values, which were recorded with antibiotic treatments. Cumulative concentrations of endotoxin over time in phage-treated conditions were lower than those observed with β-lactams and close to those observed with amikacin. Whereas β-lactams were responsible for strong cell morphology changes (spheroplast with imipenem, filamentous cells with cefoxitin and ceftriaxone), amikacin and phages did not modify cell shape but produced intracellular inclusion bodies. This work provides important and comforting data regarding the safety of phage therapy. Therapeutically relevant phages, with their low endotoxin release profile and fast bactericidal effect, are not inferior to β-lactams.