The 94th Annual Meeting of Japanese Society for Bacteriology

Presentation information

On-demand Presentation

6 Virulence Factors and Biophylaxis

[ODP6E] e. Basic Studies using Infection Model

[ODP-170] Establishment of a new Streptococcal toxic shock syndrome model using immunocompromised mice

○Takahiro Tsuji1, Fumiko Obata1, Ryo Ozuru1, Satoshi Miyahara2, Mitsumasa Saito2, Jun Fujii1 (1Div. Bacteriol., Dept. Microbiol. Immunol., Faculty of Med., Tottori Univ., 2Dept. Microbiol., Sch. Med., Univ. of Occupational and Environmental Health)

Background:  Streptococcal toxic shock syndrome (STSS) is caused by the S. pyogenes infection. It starts with necrotic fasciitis, which rapidly progresses sepsis leading to become acute respiratory distress syndrome (ARDS), multiorgan failure (MOF) and death. The mechanism of STSS has not yet been clear due to a lack of precise animal model.
Methods and results: We previously reported an STSS-like mouse model using ddY with intramuscularinjection of S. pyogenes SP2 strain that caused delayed death after about 20 days along with a rapid weight loss (Saito M. et al., Microbiol Immunol, 2001). In this study, we improved our STSS model using immunocompromised NOD-SCID mice with our method. The NOD-SCID STSS model showed shorter survival period and fasciitis development than ddY model. Histopathological features from multiple tissues will be presented.
Discussion: NOD-SCID mouse lacks T and B cells, thus representing immunocompromised humans. Also, some immunocompromised patients are known to develop STSS that the NOD-SCID STSS model serves as a good model to study the mechanism of STSSdevelopment. The pathogenic factor of SP2 strain involves two-transcription factor component system covR/covS gene mutations (Otsuji K et al., Microb Pathog, 2020). We are now planning covR/covS knockout SP2 infection using NOD-SCID, that may clarify the mechanism of STSS onset.