Cleary P, Johnson D, Wannamaker L
J Infect Dis. 1979 Nov;140(5):747-57. doi: 10.1093/infdis/140.5.747.
The phylogenetic relationships of 73 strains of group A Streptococcus isolated over a six-year period from a population with a high prevalence of streptococcal infections were analyzed with use of four serotype-specific markers: the serum opacity factor (OF), the T antigen, the determinant of the M antigen that precipitates with antibody, and the M antiphagocytic determinant. OF inhibition tests divided the strains into five subtypes: a, b, c, d, and e. Strains within subtypes a, b, and c shared a previously unidentified M precipitin. The identification of this new common M precipitin was based on absorption studies, double agar immunodiffusion, and immunoelectrophoresis analysis. Antisera directed against representative strains from subtypes a, b, and c contained cross-reactive bactericidal antibody, and absorption studies indicated that determinants of the M precipitins were identical, whereas determinants of resistance to phagocytosis were closely related but not identical. The association of a common M precipitin with three different OF antigens, two different T antigens, and three different, yet similar, antiphagocytic determinants is discussed in light of the possibility that the genes that code for these antigens have reassorted or recombined. Moreover, the possibility that differences in the antiphagocytic determinants of these strains have resulted from antigenic drift in a common gene is considered.
利用四种血清型特异性标志物，即血清混浊因子（OF）、T抗原、与抗体沉淀的M抗原决定簇以及M抗吞噬决定簇，分析了在六年期间从链球菌感染高发人群中分离出的73株A群链球菌的系统发育关系。OF抑制试验将这些菌株分为五个亚型：a、b、c、d和e。a、b和c亚型内的菌株共有一种先前未鉴定的M沉淀素。这种新的常见M沉淀素的鉴定基于吸收研究、双琼脂免疫扩散和免疫电泳分析。针对a、b和c亚型代表性菌株的抗血清含有交叉反应性杀菌抗体，吸收研究表明M沉淀素的决定簇相同，而抗吞噬决定簇密切相关但不相同。鉴于编码这些抗原的基因可能发生了重排或重组，讨论了一种常见的M沉淀素与三种不同的OF抗原、两种不同的T抗原以及三种不同但相似的抗吞噬决定簇之间的关联。此外，还考虑了这些菌株抗吞噬决定簇的差异可能是由一个共同基因中的抗原漂移导致的可能性。
