一、前言:早在本世纪30年代,已经充分证明了肺炎球菌的型的特异抗原性是同细菌的脱氧核糖核酸有关,从而奠定了抗原遗传变异的分子生物学基础。以后又在大肠杆菌、流感杆菌、奈氏球菌及枯草杆菌等中证 First, the preamble: As early as the 1930s, it has been fully proved that the type of pneumococcal antigenicity is specific with the bacterial DNA, which laid the molecular basis of genetic variation in antigens. Later in Escherichia coli, influenza bacilli, Neisseria and Bacillus subtilis card