this was performed for l. monocytogenes sipx (-), sipy (-), sipz (-) single mutants, as well as for δsipxy and δsipyz double mutants, and then compared to that of the wild type strain.
The amounts of listeriolysin O (LLO), phosphatidylcholine phospholipase C (PlcB) and zinc metalloproteinase Mpl in the extracellular milieu was significantly decreased upon inactivation of SipZ.