Listeria strains were investigated as regard: the production of PI-PLC and lecytinase, haemolytic and CAMP activity survival in mouse tissues. Although all the examined L. monocytogenes strains produced PI-PLC, they showed a very different activity of this enzyme. It was surprising that one of the four L. innocua strains demonstrated a weak activity of PI-PLC. L. monocytogenes bacteria with strong PI-PLC activity survived in mouse spleens for a much longer period of time than L. monocytogenes microbes with only a weak production of this enzyme. However, L. innocua bacteria producing some PI-PLC were quickly eliminated by infected mice.