Glucose Level Affects the Regulation of MgaSpn on Virulence and Adaptability of Streptococcus pneumoniae

<em>Streptococcus pneumoniae</em> can regulate virulence gene expression by sensing environmental changes, which is the key to pathogenicity. Carbohydrate is a significant environmental factor affecting the growth and virulence of bacteria. Here, we found that glucose level could affect the content of phosphocholine, which was mediated by Mga<em>Spn</em>. Mga<em>Spn</em> belongs to a virulence regulator (PCVR) family containing phosphotransferase system (PTS) regulatory domains (PRDs). PTS can phosphorylate Mga<em>Spn</em> to varying degrees according to the availability of glucose, thereby altering its virulence regulation. In addition, Transcriptome analysis of wild-type D39s between low and high sugar concentrations revealed that Mga<em>Spn</em> was also involved in the regulation of carbon metabolism inhibition (CCR) and translation process, which made <em>S.pneumoniae</em> still have strong competitiveness in fluctuating environments. In contrast, Mga<em>Spn</em> is closely related to virulence, carbohydrate metabolism, and environmental adaptability of <em>Streptococcus pneumoniae</em>.