Myhal M L, Cohen P S, Laux D C
J Gen Microbiol. 1983 May;129(5):1549-58. doi: 10.1099/00221287-129-5-1549.
Escherichia coli F-17 Sr a human faecal isolate, is resistant to the T-series of bacteriophages (i.e. T2 to T7). A T2-sensitive mutant of E. coli F-17 Sr was isolated following acriflavin treatment. This mutant, E. coli F-17 Sr Ts was found to be sensitive to the entire T-series of phages. E. coli F-17 Sr and E. coli F-17 Sr Ts did not differ quantitatively in total LPS content. However, analysis of LPS revealed that a large fraction of E. coli F-17 Sr Ts was devoid of O-side-chains. This accounted for the sensitivity of this strain to bacteriophages T3, T4, and T7. In addition, E. coli F-17 Sr Ts contained only about half the amount of capsular material contained by E. coli F-17 Sr accounting for the sensitivity of the mutant to bacteriophages T2, T5, and T6. Although the two strains colonized equally well when fed individually to streptomycin-treated mice, when fed simultaneously to streptomycin-treated mice, E. coli F-17 Sr Ts colonized at a level of about 1 x 10(8) cells (g faeces)-1, whereas E. coli F-17 Sr colonized at only 1 x 10(4) cells (g faeces)-1. These studies suggest that bacterial cell surface components modulate the large intestine colonizing ability of E. coli F-17 Sr in the mouse large intestine.
大肠杆菌F-17 Sr是从人类粪便中分离出来的，对T系列噬菌体（即T2至T7）具有抗性。经吖啶黄素处理后，分离出了大肠杆菌F-17 Sr的T2敏感突变体。发现该突变体大肠杆菌F-17 Sr Ts对整个噬菌体T系列敏感。大肠杆菌F-17 Sr和大肠杆菌F-17 Sr Ts的总脂多糖含量在数量上没有差异。然而，对脂多糖的分析表明，大肠杆菌F-17 Sr Ts的很大一部分没有O侧链。这解释了该菌株对噬菌体T3、T4和T7的敏感性。此外，大肠杆菌F-17 Sr Ts所含的荚膜物质仅约为大肠杆菌F-17 Sr的一半，这解释了该突变体对噬菌体T2、T5和T6的敏感性。虽然将这两种菌株单独投喂给经链霉素处理的小鼠时，它们的定殖情况相同，但当同时投喂给经链霉素处理的小鼠时，大肠杆菌F-17 Sr Ts的定殖水平约为1×10⁸个细胞/（克粪便）⁻¹，而大肠杆菌F-17 Sr的定殖水平仅为1×10⁴个细胞/（克粪便）⁻¹。这些研究表明，细菌细胞表面成分调节了大肠杆菌F-17 Sr在小鼠大肠中的定殖能力。
