Listeriolysin O (LLO) is a hemolysin produced by the bacterium Listeria monocytogenes, the pathogen responsible for causing listeriosis.
Furthermore, LLO permits L. monocytogenes to escape from phagosomes into the cytosol without damaging the plasma membrane of the infected cell.
The alterations of the histones cause the down regulation of genes encoding proteins involved in the inflammatory response.
[7] Transcription of hly, as well as other virulence factors of L. monocytogenes within LIPI-1, is activated by the protein encoded by prfA gene.
Urease produces ammonia and creates a basic environment which inhibits listeriolysin activity, so it is knocked out to provide the optimal pH.