Denou Emmanuel, Bruttin Anne, Barretto Caroline, Ngom-Bru Catherine, Brüssow Harald, Zuber Sophie
Nestlé Research Center, Nestec Ltd, Lausanne 26, Switzerland.
Virology. 2009 May 25;388(1):21-30. doi: 10.1016/j.virol.2009.03.009. Epub 2009 Apr 1.
A combination of in vitro and in vivo experiments with comparative phage genomics was used for the rational design of a phage cocktail against E. coli diarrhea. Orally applied T4 coliphages representing three different subgroups (T4-, RB49- and JS98-like phages) had no negative impact on the murine gut microbiota. T4 phages were found with high titers in the cecum and colon and lower titers in the small intestine, but were not detected in the blood, liver or spleen. No adverse effects were observed after one-month exposure to phage nor were serum anti-T4 antibodies detected. T4 phages belonging to the same subgroup showed closely related genomes that differed by 12 (phage JS10 vs. JS98 reference) to 17 (phage JSE vs. RB49 reference) insertion/deletions mostly representing single small ORFs. Bioinformatic analysis did not reveal undesired genes in the T4 genomes. Sequence variability was seen over the tail fibre genes, but the variability did not correlate with phage host range. The investigated T4 phages were not only species- but also strain-specific, necessitating the use of phage cocktails consisting of 10 and 16 T4 phage isolates to cover half to two thirds of E. coli strains representing the five main pathotypes isolated from diarrhea patients.
结合体外和体内实验以及比较噬菌体基因组学，对针对大肠杆菌腹泻的噬菌体鸡尾酒进行了合理设计。口服的代表三种不同亚组（T4样、RB49样和JS98样噬菌体）的T4大肠杆菌噬菌体对小鼠肠道微生物群没有负面影响。在盲肠和结肠中发现T4噬菌体的滴度较高，在小肠中滴度较低，但在血液、肝脏或脾脏中未检测到。暴露于噬菌体一个月后未观察到不良反应，也未检测到血清抗T4抗体。属于同一亚组的T4噬菌体显示出密切相关的基因组，它们之间存在12个（噬菌体JS10与JS98参考株相比）到17个（噬菌体JSE与RB49参考株相比）插入/缺失，大多代表单个小开放阅读框。生物信息学分析未在T4基因组中发现不良基因。在尾丝基因上观察到序列变异性，但这种变异性与噬菌体宿主范围无关。所研究的T4噬菌体不仅具有种特异性，还具有菌株特异性，因此需要使用由10种和16种T4噬菌体分离株组成的噬菌体鸡尾酒，以覆盖代表从腹泻患者中分离出的五种主要致病型的一半至三分之二的大肠杆菌菌株。
