Toward rational control of Escherichia coli O157:H7 by a phage cocktail
Toward rational control of Escherichia coli O157:H7 by a phage cocktail
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DOI：
10.1007/s00253-003-1438-9
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发表时间：
2004-04-01
影响因子：
5
通讯作者：
Unno, H
中科院分区：
文献类型：
--
作者：
Tanji, Y;Shimada, T;Unno, H
从不同来源筛选出26个感染大肠杆菌O157：H7的噬菌体。其中9株能使O157：H7细胞在LB型液体培养基中明显裂解。然而，大肠杆菌细胞和噬菌体的长时间孵育允许出现抗噬菌体细胞。噬菌体抗性细胞对9种噬菌体的敏感性不同。从噬菌体抗性细胞转化的机理出发，探讨了一种合理的筛选有效的噬菌体鸡尾酒的方法。从大肠杆菌细胞中删除OMPC有助于产生对SP21噬菌体具有抗性的细胞。孵育8h后出现SP21耐药细胞。相反，脂多糖(LPS)谱的改变促进了细胞对SP22噬菌体的抵抗力，这在孵育6小时后观察到。用SP21和SP22混合噬菌体感染大肠杆菌O157：H7细胞，需要30h才能产生对这两个噬菌体具有抗性的细胞(R-C)。R-C细胞携带的外膜和内毒素成分与野生型细胞几乎相同。然而，这两种噬菌体对R-C细胞的结合能力降低，表明噬菌体对R-C表面的吸附受到干扰。尽管出现了对两种噬菌体都有抗性的R-C细胞，但这项工作表明，合理选择噬菌体至少有可能延缓噬菌体抵抗的出现。
Twenty six phages infected with Escherichia coli O157:H7 were screened from various sources. Among them, nine caused visible lysis of E. coli O157:H7 cells in LB liquid medium. However, prolonged incubation of E. coli cells and phage allowed the emergence of phage-resistant cells. The susceptibility of the phage-resistant cells to the nine phages was diverse. A rational procedure for selecting an effective cocktail of phage for controlling bacteria was investigated based on the mechanism of phage-resistant cell conversion. Deletion of OmpC from the E. coli cells facilitated the emergence of cells resistant to SP21 phage. After 8 h of incubation, SP21-resistant cells appeared. By contrast, alteration of the lipopolysaccharide (LPS) profile facilitated cell resistance to SP22 phage, which was observed following a 6-h incubation. When a cocktail of phages SP21 and SP22 was used to infect E. coli O157:H7 cells, 30 h was required for the emergence of cells (R-C) resistant to both phages. The R-C cells carried almost the same outer membrane and LPS components as the wild-type cells. However, the reduced binding ability of both phages to R-C cells suggested disturbance of phage adsorption to the R-C surface. Even though R-C cells resistant to both phages appeared, this work shows that rational selection of phages has the potential to at least delay the emergence of phage resistance.