Bacteriophages in health and disease
Bacteriophages in health and disease
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噬菌体在健康和疾病中的作用
DOI：
10.1079/9781845939847.0033
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Christie G
中科院分区：
文献类型：
--
作者：
Christie G
溶原性转化最近已被定义为“与宿主细胞的基因型和表型的噬菌体相关的可遗传变化，其独立于预期的来自阻遏和整合的效应。换句话说，与溶原性直接相关的现象，例如对重复感染的免疫力（原噬菌体阻遏物的功能）和由插入宿主基因引起的功能丧失（整合酶的功能）是溶原性的预期结果，并且不应被定义为溶原性转化（Los et al.，2010年）。我们现在意识到该定义是不充分的，因为转录组学分析已经揭示溶原化的分子影响可以是相当大的（Su et al.，2010年），甚至有毒噬菌体也可能诱导细胞表型的短暂变化（Busch等人，2011年）。因此，我们建议术语“溶原性转化”或“噬菌体转化”总是与所观察到的表型变化的明确描述结合使用，如“血清型的噬菌体转化”或“溶原性转化为双原性”。我们将在本章中讨论的是非必需的温和噬菌体基因的影响，这些基因被各种各样地描述为白痴（Juhala et al.，2000）或货物基因（Brüssow等人，2004），对导致毒力或表面化学的表型变化的宿主表达。具体的重点将是棒状杆菌，梭菌，埃希氏菌，葡萄球菌，链球菌和弧菌分泌毒素的生产，膜蛋白的合成，以及沙门氏菌和假单胞菌中脂多糖（LPS）结构的改变。最后，我们将简要讨论噬菌体介导的细菌基因转移或转导的概念。
Lysogenic conversion has been recently defined as a ‘phage-associated heritable change in the host cell’s genotype and phenotype that is independent of the effects expected from repression and integration. In other words, phenomena that are directly associated with lysogenization such as immunity to superinfection (a function of the prophage repressor) and loss of function resulting from insertion into a host gene (a function of the integrase) are expected consequences of lysogenization and should not be defined as lysogenic conversion’(Los et al., 2010). We now realize that this definition is inadequate, as transcriptomic analysis has revealed that the molecular impact of lysogenization can be considerable (Su et al., 2010) and that even virulent phages may induce transient changes in the cell’s phenotype (Busch et al., 2011). Therefore, we suggest that the term ‘lysogenic conversion’or ‘phage conversion’always be used in conjunction with an explicit description of the phenotypic change observed, as in ‘phage conversion of serotype’or ‘lysogenic conversion to toxigenicity’. What we will discuss in this chapter is the impact of nonessential temperate phage genes, variously described as morons (Juhala et al., 2000) or cargo genes (Brüssow et al., 2004), on host expression that leads to a phenotypic change in virulence or in surface chemistry. The specific emphases will be on the production of secreted toxins by Corynebacterium, Clostridium, Escherichia, Staphylococcus, Streptococcus and Vibrio, the synthesis of membrane proteins, and alterations in lipopolysaccharide (LPS) structure in Salmonella and Pseudomonas. We will conclude with a brief discussion of the concept of phage-mediated transfer of bacterial genes, or transduction.