In Vitro and In Vivo Validation of ligA and tarI as Essential Targets in Staphylococcus aureus

Abstract
A conditional expression system has been developed using the isopropyl-β- d -thiogalactopyranoside (IPTG)-inducible P spac promoter to validate essential genes of Staphylococcus aureus in vivo. The system has been applied to prove the essentiality of ligA and to evaluate the function of tarI , which was found to be essential in vitro but not in vivo.