Ikeda T, Otake S, Hirasawa M, Williams K, Kiyoyono H, McGhee J R, Shiota T
Infect Immun. 1980 Jan;27(1):25-31. doi: 10.1128/iai.27.1.25-31.1980.
Mutant C4, a poor plaque-forming mutant of Streptococcus mutans 6715-HSR, was employed to obtain isolates resembling the parent strain (a plaque former). Seventeen presumptive revertants, as identified by colonial morphology, were isolated from mutant C4 after enrichment cycles in a sucrose-glass beads medium. These isolates displayed properties which resembled the parent in ability to produce plaque, patterns of fermentation, and resistance to streptomycin. In a detailed study, five selected isolates were found to be similar to the parent type 6715-HSR with respect to content of the serotype antigen, sucrose- or dextran-induced cell aggregation, glucosyltransferase and adherence activities, and cariogenicity. Thus, in selection for revertants to parental colonial morphology, the pleiotropic changes in plaque formation, adherence, glycosyltransferase activity, and virulence demonstrated by C4 all concomitantly reverted to their parental phenotypes.
变异体C4是变形链球菌6715-HSR的一种形成菌斑能力较差的突变体，被用于获得类似于亲本菌株（一种能形成菌斑的菌株）的分离株。在蔗糖-玻璃珠培养基中经过富集培养后，从变异体C4中分离出了17株根据菌落形态鉴定的推定回复突变体。这些分离株在形成菌斑的能力、发酵模式和对链霉素的抗性方面表现出与亲本相似的特性。在一项详细研究中，发现5株选定的分离株在血清型抗原含量、蔗糖或葡聚糖诱导的细胞聚集、葡糖基转移酶和黏附活性以及致龋性方面与亲本6715-HSR型相似。因此，在选择回复到亲本菌落形态的回复突变体时，C4所表现出的在菌斑形成、黏附、糖基转移酶活性和毒力方面的多效性变化都同时回复到了它们的亲本表型。
