Adaptation to zinc restriction in <i>Streptococcus agalactiae</i> : role of the ribosomal protein and zinc-importers regulated by AdcR

<i>Streptococcus agalactiae</i> is a bacterial human pathobiont causing invasive diseases in neonates. Upon infection, <i>S. agalactiae</i> is presented with Zn limitation and excess but the genetic systems that allow bacterial adaptation to these conditions remain largely undefined. A comprehensive analysis of <i>S. agalactiae</i> global transcriptional response to Zn availability shows that this pathogen manages Zn limitation mainly through upregulation of the AdcR regulon. We demonstrate that several AdcR-regulated genes are important for bacterial growth during Zn deficiency, including human biological fluids. Taken together, these findings reveal new mechanisms of <i>S. agalactiae</i> adaptation under conditions of metal deprivation.