LOCALIZATION OF VIBRIO-CHOLERAE O1 IN THE INTESTINAL TISSUE

Colonization of V. cholerae O1 in vivo is known to be a non-invasive t ype which the vibrios are confined only to the intestinal tissues. The pathway by which the vibrio antigens reach the lymphoid cells and sub sequently give rise to the immune responses is not entirely clear. Thu s, experiments were performed in experimental rats by inoculating live V. cholerae O1 into the ligated ileal loops. The fate of the vibrios in the intestinal tissues was then studied by transmission electron mi croscopy at different times after the inoculation. It was concluded th at live V. cholerae O1 were initially taken up by the M cells which ov erlay Peyer's patches and which subsequently delivered the intact vibr ios to phagocytic cells in the Peyer's patches. These phagocytic cells processed (digested) the vibrios while the lymphocytes and plasma cel ls infiltrated around them. During the late period of infection (12-15 hours after inoculation of the vibrios), vibrios were also found pass ing through the loose intercellular spaces between the absorptive epit helial cells into the underlying intestinal tissues.