The chromosomal SezAT toxin–antitoxin system promotes the maintenance of the SsPI-1 pathogenicity island in epidemic Streptococcus suis
Xinyue Yao, Tian Chen, Xiaodong Shen, Yan Zhao, Min Wang, Xiancai Rao, Supeng Yin, Jing Wang, Yali Gong, Shuguang Lu, Shuai Le, Yinling Tan, Jiaqi Tang, Hu Fuquan and Ming Li
Article first published online: 30 JUL 2015 | DOI: 10.1111/mmi.13116
Streptococcus suis is a re-emerging pathogen capable of causing human meningitis and streptococcal toxic shock syndrome, which may be due to a laterally acquired pathogenicity island (renamed SsPI-1). SsPI-1 can spontaneously excise to form an extrachromosomal circular product, however, attempts to cure SsPI-1 have been unsuccessful. Here, we report that a functional Epsilon/Zeta toxin-antitoxin system promotes SsPI-1 stability in bacterial populations, which may explain the persistence of epidemic S. suis.