Tatsuno Ichiro, Isaka Masanori, Hasegawa Tadao
Department of Bacteriology, Nagoya City University Graduate School of Medical Sciences, Japan.
Jpn J Infect Dis. 2024 Sep 19;77(5):247-252. doi: 10.7883/yoken.JJID.2023.451. Epub 2024 Mar 29.
Administration of high-dose clindamycin (CLI) and penicillin is recommended for the treatment of streptococcal toxic shock syndrome (STSS). However, CLI-resistant strains have been identified worldwide. In this study, some CLI-resistant strains demonstrated increased extracellular activity of the NAD-glycohydrolase (NADase) exotoxin following CLI treatment. These results support our previous conclusion that CLI-susceptible and CLI-resistant Streptococcus pyogenes strains exhibit CLI-dependent NADase induction. Furthermore, we investigated the mechanism of this phenomenon using 13 types of two-component sensor knockout strains derived from the CLI-susceptible strain 1529 that has a CLI-dependent NADase induction phenotype. Among the knockout strains, only 1529ΔcovS lost the phenotype. Additionally, 1529ΔspeB, 1529Δmga, and 1529Δrgg retained the CLI-dependent NADase induction phenotype. These findings indicate that CovS is related to this phenotype in a SpeB-independent manner.
推荐使用大剂量克林霉素（CLI）和青霉素治疗链球菌中毒性休克综合征（STSS）。然而，全球已鉴定出耐CLI菌株。在本研究中，一些耐CLI菌株在CLI治疗后表现出NAD-糖水解酶（NADase）外毒素的细胞外活性增加。这些结果支持了我们之前的结论，即CLI敏感和耐CLI的化脓性链球菌菌株表现出CLI依赖性NADase诱导。此外，我们使用来自具有CLI依赖性NADase诱导表型的CLI敏感菌株1529的13种双组分传感器敲除菌株研究了这种现象的机制。在敲除菌株中，只有1529ΔcovS失去了该表型。此外，1529ΔspeB、1529Δmga和1529Δrgg保留了CLI依赖性NADase诱导表型。这些发现表明CovS以不依赖SpeB的方式与该表型相关。
