Immunomodulatory effects of staphylococcal lipoteichoic acid in early Listeria monocytogenes infection in Balb/c-mice.

Balb/c-mice were intravenously infected with 5 X 10(4) viable cells of Listeria monocytogenes SLCC 4013. Liver, lung and spleen of the animals showed heavy organ colonization 48 h after infection. Pretreatment of experimental animals with staphylococcal lipoteichoic acid (LTA; 2 mg i.p. 7 and 3 days before challenge) significantly reduced the bacterial count in these organs. In vitro, peritoneal macrophages from LTA-treated mice significantly reduced listerial viability as compared to control cells (p less than 0.0025). In vitro, exposure of macrophages from non-treated animals to LTA did not influence their bacterial killing ability.