Identification of factors enabling Group A Streptococcus reside without virulence

本研究的目的是找出A群链球菌（GAS）在健康人体内无毒力的因素。结果，大约80%的健康成年人携带这种细菌而没有任何疾病。改进GAS分离培养方法，从13人中分离出32株GAS。此外，从使用微阵列的转录组分析中，我们可以鉴定3个与GAS在人体细胞内驻留相关的基因。系统发育分析表明，这些基因在多种细菌中具有同源性，并可通过噬菌体进行转移。这表明这些基因可能揭示了肠道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.