Genetic Characterization of Streptococcus pyogenes emm89 Strains Isolated in Japan From 2011 to 2019

Invasive infection caused by Streptococcus pyogenes emm89 strains has been increasing in several countries linked to a recently emergent clade of emm89 strains,designated clade 3.In Japan,the features of emm89 S.pyogenes strains,such as clade classification,remains unknown.In this study,we collected emm89 strains isolated from both streptococcal toxic shock syndrome(STSS)(89 STSS isolates)and noninvasive infections(72 non-STSS isolates)in Japan from 2011 to 2019,and conducted wholegenome sequencing and comparative analysis,which resulted in classification of a large majority into clade 3 regardless of disease severity.In addition,invasive disease-associated factors were found among emm89 strains,including mutations of control of virulence sensor,and absence of the hylP1 gene encoding hyaluronidase.These findings provide new insights into genetic features of emm89 strains.

成人酿脓链球菌导致中毒休克综合征临床分析

目的探讨酿脓链球菌导致毒素休克综合征的致病机制及患者死亡原因。方法研究2例侵袭性酿脓链球菌致坏死性筋膜炎并发毒素休克综合征患者临床资料,对其中1例患者的分离株进行emm基因分型及其超抗原毒素基因的测定。结果患者2感染酿脓链球菌(GAS)产生的emm89型M蛋白,并且同时产生多种超抗原毒素(speG、speI、speK/L、smeZ、ssa、spd1、spd3、spd4、sdn、prtF-15);病例1患者因昏迷、休克,而放弃治疗,病例2患者因多器官功能脏器衰竭死亡。结论我国首例报道由emm89型酿脓链球菌所致严重的侵袭性感染,坏死性筋膜炎伴毒素休克综合征,emm89型酿脓链球菌引起的重症感染应引起有关部门的足够重视,避免形成暴发流行,早期的手术清创以及有效的抗感染、IVIG的使用,是挽救患者的有效手段。