Identification of factors enabling Group A Streptococcus reside without virulence

本项目的目的是确定使A群链球菌（GAS）在健康人体内无毒生存的因素。结果，大约80%的健康成年人携带这种细菌，但没有任何疾病。通过对GAS分离培养方法的改进，从13个人中分离出32株GAS。此外，通过基因芯片转录组分析，我们可以鉴定出3个与人类细胞内GAS相关的基因。从系统发育分析来看，这些基因可以与广泛的共生细菌共享，并通过噬菌体转移。这表明这些基因可能揭示了共生细菌如何与人类共存的新机制。

Purpose of this project is to identify factors enabling Group A Streptococcus (GAS) reside without virulence in healthy person. As results, about 80 percent of healthy adult carry this bacteria without any disease. And improvement of culture methods for GAS isolation enabled the 32 GAS isolates from 13 persons. In addition, from the transcriptome analysis using microarray, we could identify 3 genes related to GAS residence inside human cells. From phylogenetic analysis, these genes can be shared with wide range of commensal bacteria and be transferred via bacteriophage. This indicates the genes may shed light on the new mechanisms to how commensal bacteria reside with human.