SYSTEMIC DISSEMINATION BY INTRARECTAL INFECTION WITH LISTERIA-MONOCYTOGENES IN MICE

Orally ingested Listeria monocytogenes is known to penetrate into Peye r's patches (PP) and translocate to the spleen and liver. Herein, extr aintestinal dissemination of the bacterium independent of PP was inves tigated. Dissemination of Listeriae to the spleen and liver was observ ed in intrarectally infected mice as well as in intragastrically infec ted animals in spite that no Listeriae were detected in the small inte stines of mice infected intrarectally, Decreased numbers of intestinal intraepithelial lymphocytes (iIEL) and increased numbers of lymphocyt es in the contents of the small and large intestines were observed aft er intragastric infection and in the large intestine after intrarectal infection, giving the assumption that the leakage of iIEL caused by i njury of epithelial layers in intestines might occur during infection. These results suggest that L. monocytogenes might be able to dissemin ate through small and large intestines in part by a PP-independent mec hanism.