<b>A small RNA from </b><b><i>Streptococcus suis</i></b><b> epidemic ST7 strain promotes bacterial</b><b> </b><b>survival in host blood and brain by enhancing oxidative stress resistance</b>

In this study, we found a sRNA rss03 widely present in<i> </i><i>S. suis</i> pathogenic strains that are responsible for pig and human infections. Using three methods to identify rss03 targets, we found that rss03 binds to the coding sequence of <i>glpF</i> mRNA (encoding an aquaporin), unexpectedly protecting it from RNase J1-mediated degradation. Additionally, both rss03 and GlpF enhance <i>S. suis</i> oxidative stress resistance and bacterial survival in murine macrophages, sustaining an elevated bacterial load within the blood and brain. These findings enhance our understanding of <i>S. suis</i> pathogenesis and provide the first sRNA targetome and valuable insights into the regulatory mechanisms of sRNAs in <i>Streptococcus</i> species.

本研究发现，一种名为rss03的小RNA（small RNA, sRNA）广泛存在于引发猪与人类感染的猪链球菌（*Streptococcus suis*, 缩写S. suis）致病菌株中。我们通过三种方法鉴定rss03的靶标，发现其可结合glpF mRNA的编码序列——该mRNA编码水通道蛋白，并意外地保护该mRNA免受RNase J1介导的降解。此外，rss03与GlpF均可增强猪链球菌的抗氧化应激能力，提升细菌在小鼠巨噬细胞中的存活能力，维持血液与脑组织内的细菌载量处于较高水平。本研究结果加深了我们对猪链球菌致病机制的理解，首次提供了猪链球菌的小RNA靶标组，并为链球菌属物种中小RNA的调控机制研究提供了极具价值的新思路。