Abstract：Non-coding RNA plays an important role in diverse cellular processes. In this study， the non-coding RNA AsrC in Salmonella enterica serovar Typhi (S. Typhi) was preliminarily studied for its transcriptional and degradation characteristics and its functions. Northern blot and quantitative real time PCR were used to detect the effects of sigma factor rpoE and rpoS on AsrC transcription. The effects of RNase E and RNase III on AsrC degradation were analyzed when rifampin was used to inhibit the synthesis of bacterial RNA. The growth of bacteria under normal or acidic， oxidative and high osmolarity stress conditions were analyzed in AsrC mutant or overexpression strains. Whole-genome microarray was used to study the changes of gene expression in AsrC overexpression strain. The roles of AsrC on S. Typhi epithelial cells invasive capacity and survival within macrophages were studied further. The results showed that the transcription of AsrC was regulated by rpoE under acidic stress and by rpoS under high osmolarity stress. RNase E is mainly involved in the degradation of AsrC in S. Typhi. The gene expression profiles showed 40 genes were up-regulated and 23 genes were down-regulated in AsrC overexpression strain compared with control strain. Overexpression of AsrC increased the invasive capacity of S. Typhi and resulted in reducing bacterial survival within macrophages.
2018, Vol. 52 
