病毒学基础

第一章病毒学基础

第一章病毒学基础（Viruse）
　

Virus: A submicroscopic, (obligate, intracellular) parasitic, filterable agent consisting of a nucleic acid surrounded by a protein coat.

简介（Introduction）

病毒是超显微结构的非细胞型生物。每一种病毒只含有一种核酸，专性活细胞内寄生，依靠寄主进行增殖。病毒在寄主体外以大分子颗粒形式存在并保持侵染活力。

　病毒寄生于几乎所有的生物；是现代生命科学的重要研究对象；

Viruses are very different from other organisms. They are not composed of cells and cannot be seen with a light microscope. A virus particle contains a single type of nucleic acid, either DNA or RNA. The nucleic acid is contained in a protein coat, and the coat sometimes enclosed in an envelope of lipids, proteins, and carbohydrates. Viruses must reproduce inside living cells, by using the synthesizing machinery of the cells.

Virus is a submicroscopic, parasitic, filterable agent consisting of a nucleic acid surrounded by a protein coat. (Tortora G)

Viruses are simple, acellular entities consisting of one or more molecules of DNA or RNA enclosed in a coat of protein (and sometimes, in addition, substances such as lipids and carbohydrates). They can reproduce only within living cells and are obligately intracellular parasites. (Prescott 5/E, 2002, 362 )

病毒的主要特征是：

     ①超显微非细胞型生物；
     ②每一种病毒只含有一种核酸，DNA或RNA；
     ③缺乏独立代谢能力，专性活细胞内寄生，依靠宿主进行增殖；
     ④在细胞外以大分子颗粒存在并保持侵染活性；
     ⑤对一般抗生素不敏感，而对干扰素敏感。

在历史上，由于人类视觉和研究工具的限制，体形越小的生物就越不易被发现。因而在微生物中，病毒的发现比细菌等更迟。