Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock, multi-organ failure, and puerperal sepsis and shows high mortality. Its primary cause is group A streptococcus (GAS, Streptococcus pyogenes). In this study, we genotyped the cell-surface M virulence protein gene (emm) from 621 GAS isolates obtained from patients with STSS in Japan in 2013–2018 and performed antimicrobial susceptibility testing using the broth microdilution method. The predominant emm type was found to be 1, followed by 89, 12, and 3, which were identified in more than 70 % of STSS isolates. The proportions of emm3 and emm89 increased from 2.4 % and 12.0 %, respectively, during 2010–2012 to 5.6 % and 23.3 % during 2013–2018. In contrast, the proportion of emm1 decreased from 60.6 % to 39.3 % during the same two periods. Some emm types showed increasing proportions and were not isolated from patients with STSS in 2010–2012. Among these, an emm76 type increased in prevalence and was not included in the 30-valent M protein-based vaccine. Continual investigation of changes in the epidemiology of GAS which causes STSS can provide useful monitoring information such as future vaccination strategies and the emergence status of antimicrobial-resistant bacteria.

链球菌中毒性休克综合征（STSS）是一种严重的侵袭性感染，其特征是休克突然发作，多器官衰竭和产后败血症，并显示出高死亡率。其主要原因是A组链球菌（GAS，化脓性链球菌）。在这项研究中，我们对2013-2018年日本STSS患者获得的621株GAS分离株的细胞表面M毒力蛋白基因（emm）进行了基因分型，并使用肉汤微量稀释法进行了药敏试验。主要的EMM类型被发现是1，接着89，12，和3，这是在STSS的70％以上的鉴定菌株。的比例emm3和emm89分别从2010-2012年的2.4％和12.0％增至2013-2018年的5.6％和23.3％。相反，在相同的两个时期内，emm1的比例从60.6％降至39.3％。在2010–2012年间，某些emm类型所占比例不断增加，并非从STSS患者中分离出来。其中，一种emm76型患病率增加，并且不包含在30价基于M蛋白的疫苗中。持续调查导致STSS的GAS流行病学变化可以提供有用的监测信息，例如未来的疫苗接种策略和抗药性细菌的出现状况。